The Halo JC 2

[REOFan]

Gentlemen,

I've had my Halo JC 2 since early July, and I have to say that it has exceeded my expectations. It replaced a Parasound P/LD 2000, which I used for ten years. So my experience with preamps in my home is limited.

Once I decided to upgrade the preamp, my list of preamps in my price range became a short one: Aesthetix Calypso, Modwright LS 36.5, and the Halo JC 2. I saw and heard the Modwright preamp (as much as one can hear a preamp in an unfamiliar system) at HES 2007 in NYC. It impressed me (as did Dan Wright, who I've met a couple of times). Ultimately, however, I opted for the JC 2 for two reasons: (1) I believe in John Curl designs and (2) I like the notion of system synergy by pairing the JC 2 with a pair of JC 1s.

A Chicagoland dealer delivered the new preamp to my house (now that's service!). After the preamp settled in (the manual suggests 72 hours; I put 200 or more on it), I now enjoy an enriched soundstage, more detail, more solid images, better bass, and a quieter background. I guess the improved detail is what impresses me most. Well-recorded live CDs are fantastic. Guitars sound great. I play rock, blues, country, and jazz, but the mainstay is rock, old and new. My reference CD is "You Get What You Play For" by REO Speedwagon (no surprise, right; it's one album I've played more times than I care to admit), and it's never sounded so rich.

My system is rather modest: Esoteric X-03 SE (which I purchased last year), Halo JC 2, Parasound T/DQ 1600 Tuner, Halo JC 1s, Shunyata Hydra (8 and 2s), Tara Labs Air 1 cabling, Shunyata Anaconda power cables, Element Cable power cables, and Legacy Whisper loudspeakers (with processor).

All in all, I am very pleased with the JC 2. I have one minor quibble, and it has to do with the remote: the Mute button is between the volume Up and Down buttons. I sometimes press the Mute button instead of the intended volume button--and having the music inadvertently cut off is quite startling. (If you see the Modwright remote, for example, the Mute button is nowhere near the volume buttons. A good thing for occassionally clumsy handlers like me.)

I hope my downloading of pictures works (thanks for the help, Chris). They are not even close to the quality of photos one finds at 6Moons. Sorry, guys.

--Mark--

[Chris D]

Who is REO Speedwagon? (just kidding... I saw their farewell concert back in... like 1990 or something?) :tomato:

Cool stuff, Mark! I wouldn't exactly describe your setup as "modest" if you've got a JC-2, *TWO* JC-1's, and Hydras. All that's definitely banana-worthy. :banana:

That's interesting to me that the JC-2 is continuing what we've found with Parasound Halo gear to get much better after a break-in. Also, I'm curious--are you using balanced cables for all of your connections?

It looks like you've got the JC-1's on the floor right next to each speaker. Is that right?

[Chris D]

And Mark's pictures blown up for all to see:

[REOFan]

Amps

Chris,

The amps, in my present configuration, flank the the Bell'O equipment rack. The rack is to the right of the listening chair. The amps are not near the Whispers. Perhaps one day, in a different room.

You saw REO either right before or right after their implosion. I saw them right about that same time--or shortly thereafter--when only about a 1,000 fans showed up at the Dane County Coliseum (now Alliant Energy Center) in Madison, WI. Five years earlier the same arena was sold out. But they had just replaced their long-time drummer (retired) and long-time lead-guitarist. I walked up to the stage and stood ten feet away. Now, when I go to shows (they tour a lot around here; Summerfest in Milwaukee, as one example), they draw 5,000 - 10,000 fans, depending on venue. They're a good, fun Midwestern band. New album this year, too.

Wish I could compare the JC 2 to other preamps to give visitors here a better sense of its performance, but my experience with preamps is limited. I bet we see some reviews by mainstream audio media soon, plus other users will post comments. I am satisified with the build-quality (the Halo look is cool). Overall, the JC 2 represents--no surprise--a major improvement over the P/LD 2000. One other factor in my purchase decision was to stick with a solid-state design.

Funny you should ask about the cabling. I am switching from RCA to balanced cables. I have one more RCA cable to swap out (preamp to Whisper processor). I've read and heard that Halo equipment (particularly the JC 1s) benefits from balanced cabling, so I am going to find out.

Thanks again for the tips with the pictures . . .

[Vince Helm]

Maybe a review by Stereophile is lurking in the near future for the JC2!?

#1.In the September 07 issue, John Atkinson reviewed the GS10 speakers from Monitor Audio and as part of that review he used the JC1 monoblocks and gave kodos to the John Curl design amps. He (JA) has not used or at least not mentioned the JC1 monoblocks in quite a few reviews. Not mentioned in the review, but listed on his "associated equipment" was the Parasound Halo JC2.
#2.In the October 07 issue, Sam Tellig said this... "Finally-in what turned out to be hifi bedlam-Richard Schram, of Parasound, arrived bearing John Curl's new halo JC-2 line-stage preamp for use with my reference Halo JC-1 monoblocks. I'd been waiting for this piece for more than four years. How could I say no?"... Sam went on a bit about the JC'1s, the set up and that was it. Not one hint about his experience with the JC-2.

What do you think will happen next???


Vince

[Chris D]

Yes... methinks you're right, Vince. I've been getting some hints that might happen!

[Aubi]

The Norwegian magasin "Fidelety" have anounced that they will review the JC-2 in their next issue.

[Chris D]

Aubi, you MUST let us know the results! (sadly, we don't seem to get Norwegian magazines over here)

[Aubi]

Another sad thing though, is that the reviewer and the magazine in general is known to hear eksactly what the price tag tells.
On second thought, that should be a better review than if it was done over by you .

[Chris D]

Whoa... ouch! 8O

[hamtor]

Another sad thing though, is that the reviewer and the magazine in general is known to hear eksactly what the price tag tells.
On second thought, that should be a better review than if it was done over by you .

I don`t agree with your description of "Fidelity" magasine. The editor is one
of the most respected and high rated Hi-Fi journalists in scandinavia.

Parasound Halo has always been given nice critics in "Fidelity".

Here are some links:

http://www.ncms.no/Parasound/HALO_Tester/JC1_fidelity_6-2006.pdf

http://www.ncms.no/Parasound/HALO_Tester/A51_fidelity_12-2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A21_Fidelity_09-2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A23_fidelity_feb_2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A23_fidelity_feb_2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/C2_fidelity%2006-2003.pdf

Peter Nielsen is the man for the translation

I agree on those test`s, and I think most of you will too.

Remember that the prices are very much higher in Norway than in the US.
A pair of JC1 cost over $13000.

[Zoran]

I don`t agree with your description of "Fidelity" magasine. The editor is one
of the most respected and high rated Hi-Fi journalists in scandinavia.

Parasound Halo has always been given nice critics in "Fidelity".

Here are some links:

http://www.ncms.no/Parasound/HALO_Tester/JC1_fidelity_6-2006.pdf

http://www.ncms.no/Parasound/HALO_Tester/A51_fidelity_12-2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A21_Fidelity_09-2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A23_fidelity_feb_2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/A23_fidelity_feb_2004.pdf

http://www.ncms.no/Parasound/HALO_Tester/C2_fidelity%2006-2003.pdf

Peter Nielsen is the man for the translation

I agree on those test`s, and I think most of you will too.

Remember that the prices are very much higher in Norway than in the US.
A pair of JC1 cost over $13000.

@Hamtor,

As I can see from links above both Halo JC-1 and A21 were tested in some form of group-tests...

I am very curious which other amplifiers were included in those group tests? As an owner of A21, I am particularly interested on the Halo A21 test - list of competing amplifiers and verdict, of course!

Thank you.

[hamtor]

Thats right, it was group tests.

The A21 was tested with:

Dynamic Presision A1
Rotel RB 1090
Tact SDA 2175
Embla Coenia
Hegel HP-4A
EAR 509 Silver Jubilee Limited Edition
McIntosh 275

This test is from 2004.

[hamtor]

The JC1 was tested with:

Midgard Oberon 6.1
Electrocompaniet AW 600 Nemo
Classe` CAM 400
Audio Research Refrence 210

This test is from 2006

[Zoran]

Hamtor,

Hoping not bother you, but could you somehow report the verdicts of both tests? I am pretty frenzied about the Halo A21 vs Rotel RB-1090 showdown, since I own both!!! Also, Halo JC-1 vs Classe CA-M400 vs EC Nemo is very interesting for me...

Any link available, even non-English...?

Thank you once more!!!

[Chris D]

Sweet, yes, we English speakers want to know the results!

[REOFan]

You've Hit the Mark

Maybe a review by Stereophile is lurking in the near future for the JC2!?

What do you think will happen next???


Vince

Vince - I think there is sufficienct evidence to suggest a forthcoming review in Stereophile. It will most likely be the first by a mainstream American audio publication (print or web). I anticipate a positive review. I especially look forward to reading comments by users--writers included--who have experience with other preamps. I am curious to read how the JC 2 compares to other brands. All I can add is that I am thoroughly enjoying mine. Just love listening to music these days (often with the volume at 10 o'clock) . . .

[mattburk]

Hamtor,

Hoping not bother you, but could you somehow report the verdicts of both tests? I am pretty frenzied about the Halo A21 vs Rotel RB-1090 showdown, since I own both!!! Also, Halo JC-1 vs Classe CA-M400 vs EC Nemo is very interesting for me...

Any link available, even non-English...?

Thank you once more!!!

Did you ever get an answer to your questions?

[Peter Nielsen]

Halo JC-1 vs Classe CA-M400

That one I have some info on.

The Classe CA-M400 has some interesting technical data. For instance, they promise a very high outout in "Class A", yet the amps do not run extremely hot as you would expect.

What Classe is doing is some trickery with upping the voltage on demand. As expected, this may come with a time lag penalty.

My friend Jesse who is running current demanding Magnepan 20.1 speakers used to have a pair of M400s. When he switched over to JC-1s, he noticed more controlled bass. (This goes hand in hand with my suspicions about the M400 trickery not doing its job without audible side effects).

Just FWIW...

Peter

[RebelMan]

Peter,

The CA-M400 perform admirably and the trickery you think they employ makes no compromise to bass output and attack. Krell uses the same techniques in their amplifiers and they are considered to have set the standard in bass performance. The CA-M400 are every bit the caliber of the JC1 if not better.

Our friend Jesse has audiophilia nervosa like tendencies. I respect him and his opinions but I prudently exercise caution when accepting the advice of transient pacesetters. Jesse sold his JC1's... months ago!

Your suspicions regarding the CA-M400 are not based on credible evidence and are without merit. I've seen numerous Maggies driven by Classe' with superb results.

[RebelMan]

Uncanny timing at Club Classe'! This was just posted... Maggies and Classe'

[Peter Nielsen]

Jesse sold his JC1's... months ago!

Yes, because he always liked the specific nuance of his MacIntosh amps the best. I think he was considering keeping the JC-1s for the bass, but in the end he decided to spend a lot more $$$ to get four identical Mac amps... (Makes sense since he spent $5000 on the crossover alone - a Pass Labs XR-1)

The fact remains that he could tell a clear improvment in bass control when going from the M-400 to the JC-1.

You can't change the laws of physics. The Classe M-400 specification makes it obvious that there is something wrong with the Class A rating of the amp. It should run burning hot and require multiple fans to cool it. Yet passive cooling is enough. Trickery is what makes it possible.

I miss the JC-1s. Best amps I've ever owned! My new amps are also cool running "amps of trickery" and the wonderful bass control of the JC-1 is not there...

Peter

[Peter Nielsen]

Uncanny timing at Club Classe'! This was just posted... Maggies and Classe'

How is that relevant? Did the guy switch from JC-1s to the M-400?

I know that there are quite a few people with MG20.1 and M400. If I had listened to the seller at Audio Advice, that would include me too. (Audio Advice is the only authorized seller of Magnepan in North Carolina, so to get Maggies I have to go there. Audio Advice does not carry the Parasound brand. Obviously they recommend that you buy one of their brands, Bryston or Classe, for your MG20.1s).

If I recall correctly, Jesse got his Magnepan MG20.1/Classe M400 combo from Audio Advice...

Find me a post from someone that has owned both amps. That's more relevant.

Peter

[RebelMan]

Yes, because he always liked the specific nuance of his MacIntosh amps the best. I think he was considering keeping the JC-1s for the bass, but in the end he decided to spend a lot more $$$ to get four identical Mac amps... (Makes sense since he spent $5000 on the crossover alone - a Pass Labs XR-1)

The fact remains that he could tell a clear improvment in bass control when going from the M-400 to the JC-1.

You can't change the laws of physics. The Classe M-400 specification makes it obvious that there is something wrong with the Class A rating of the amp. It should run burning hot and require multiple fans to cool it. Yet passive cooling is enough. Trickery is what makes it possible.

I miss the JC-1s. Best amps I've ever owned! My new amps are also cool running "amps of trickery" and the wonderful bass control of the JC-1 is not there...

Peter

You conveniently neglected to mention that about Jesse.

He says that about McIntosh but he like most honest people are really drawn to their classic look and those blue memorizing meters. That plus he probably wanted them to match the rest of his gear which is also McIntosh. I am certain it was primarily an aesthetics decision. He used all McIntosh equipment with his 800D too when he had them! Read between the lines Peter.

I gave you more credit than I should have. More dollars spent does not automatically translate to more performance gained when it comes to power amplifiers driven within their design specifications. I thought you knew that. If I recall you've mentioned something about that once before. Besides, how often do you listen to reference volumes?

The fact is you haven't heard the CA-M400. The biggest difference besides price is they (JC1's) unnecessarily waste energy for nothing. Your bias towards Jesse is quite obvious, he has the Maggies which coincidentally you do too. A conflict of interest if you are going to offer an objective opinion.

I like the JC1's and the CA-M400's for what they are each capable of doing. I don't favor one over the other just because I belong to a speaker club and I won't use science to cover up my motives.

[RebelMan]

How is that relevant? Did the guy switch from JC-1s to the M-400?

It's relevant in that the CA-M400 have what it takes to satisfy the requirements for Maggie owners. You gave one example of someone who felt they weren't all that and I offered another that showed they are. Tit for tat you might say. LOL

Find me a post from someone that has owned both amps. That's more relevant.

I agree that it has more potential.

[Zoran]

Did you ever get an answer to your questions?

I haven't get any answer yet, unfortunately. I am still very curious, but...

[Peter Nielsen]

I am certain it was primarily an aesthetics decision. He used all McIntosh equipment with his 800D too when he had them! Read between the lines Peter..

Yes, he did say that going with 4 Macs was an aesthetics decision. He was 100% happy with the bass control of the JC-1s, but he thought the Mac had an advantage in the upper frequencies. (If I recall correctly, Macs are known to have an slightly empasized warmer sound by design. Something to make them sound more tube like. I may be wrong, so a Mac expert can correct this comment if needed.)

So, he did consider keeping the JC-1s for the bass and going with Macs for the highs. Since he was completely happy with the JC-1s for the bass end, it obviously was an aesthetics decision to go with 4 Macs...

More dollars spent does not automatically translate to more performance gained when it comes to power amplifiers driven within their design specifications.

Right. That's why I think the Parasound JC-1 is a bargain compared to the Classe M-400. To most people the amps sound more or less the same, and the specifiations are for most practical use the same. FWIW: I paid $1,800/each for my brand new JC-1s. If I recall correcly, the M-400 would have cost me around $4,000/each+tax since Audio Advice doesn't offer any discount.

I thought you knew that.

I know that. That's why I commented on Jesse getting the Pass Labs crossover. If he's prepared to pay that for a crossover, then spending money for aesthetics on an all McIntosh setup makes sense.

IMHO a Pass Labs crossover is waste of money for people with Maggies (and I told Jesse that). What you pay for is a very very low noise floor. This is important with highly efficient speakers like horns. People with Accapellas will probably want a Pass Labs crossover. However, superinefficient speakers like Maggies cannot reproduce the noise of cheaper crossovers.

Besides, how often do you listen to reference volumes?.

In my current TacT/Boz setup I often listen at maximum volume level, and usually watch movies at 95-98%. (That's because of acoustic problems with my room and the room correction eating up more than 12dB. My next home will have a room designed for good acoustics, so that I don't have to deal with this problem).

The fact is you haven't heard the CA-M400.

Not with MG20.1s, no. Have YOU heard the M-400 and JC1 with the MG20.1?

I have heard the M-400 with B&W 802s. However, that tells me nothing as I don't like the sound of the 802s. Also, the 802s present a much different load to the M400s than a Maggie will.

I'm sure we can find speakers that sound better with the M-400 than with the JC-1s. Classe sure knows what they're doing. Anyway, my point is that I don't think the M-400 is ideal for the MG20.1.

The biggest difference besides price is they (JC1's) unnecessarily waste energy for nothing.

The JC-1 uses a traditional well-proven AB amplifier design. It is very lean without any trickery or unproven circuits. What makes the JC-1 so great is the proven design combined with carefully selected components and well designed circuit board and enclosure.

Classe is trying to solve the heat problem in the M-400. It's innovative, like my TacT amplifiers, but the innovation comes with a price.

My current amp (the $34,000 TacT Boz 216/2200) doesn't waste any energy. It is cool running. However, it cannot control the bass in the Maggies like the JC-1s could.

I won't use science to cover up my motives.

That's a weird statement. If anything is objective, science is!

If there's anything to cover up, something's wrong...

Anyway, don't you find it amazing that I keep rambling about amplifiers that I don't even own anymore? I do that, because they offer an exceptional value. Low cost, great performance, and if you don't like them any more be happy, because the trade value is also exceptional. I sold all of my nine JC-1s for $100-$200/each more than I originally paid for them. They were obviously an exceptional investment. How often does that happen in high-end audio? (If I wanted to sell my current TacT amps, I would lose about $10,000! I refuse to accept this loss, so I'm now staying with what I have).

Peter

[RebelMan]

Yes, he did say that going with 4 Macs was an aesthetics decision. He was 100% happy with the bass control of the JC-1s, but he thought the Mac had an advantage in the upper frequencies. (If I recall correctly, Macs are known to have an slightly empasized warmer sound by design. Something to make them sound more tube like. I may be wrong, so a Mac expert can correct this comment if needed.)

Contrary to popular belief McIntosh is less tube like than Classe’.

So, he did consider keeping the JC-1s for the bass and going with Macs for the highs. Since he was completely happy with the JC-1s for the bass end, it obviously was an aesthetics decision to go with 4 Macs...

I can’t consolidate the rational for form over function. Does that sound like sound advice as it pertains to audio performance? I think not. Either way you look at it, it doesn’t favor the JC1s.

Not with MG20.1s, no. Have YOU heard the M-400 and JC1 with the MG20.1?

I have not but like you I have based my position on the experience of others that have.

I have heard the M-400 with B&W 802s. However, that tells me nothing as I don't like the sound of the 802s. Also, the 802s present a much different load to the M400s than a Maggie will.

The 802’s present an equally challenging load.

Anyway, my point is that I don't think the M-400 is ideal for the 20.1.

Your opinion is based on hearsay not measurements and are acceptable only when prefaced as such. That didn’t occur.

The JC-1 uses a traditional well-proven AB amplifier design. It is very lean without any trickery or unproven circuits. What makes the JC-1 so great is the proven design combined with carefully selected components and well designed circuit board and enclosure.

Since when is Parasound the authority over well proven traditions? Krell has been using similar amplifier techniques that the Classe’ Delta series has exploited for years. Why is that so hard for you to accept?

Classe is trying to solve the heat problem in the M-400. It's innovative, like my TacT amplifiers, but the innovation comes with a price.

TacT are employing digital amplifiers Classe' Class A/B which is a fundamental difference in designs. The CA-M400's amplifiers are much smarter than the JC1's which exacts a proportional measure of efficiency. It's not trickery but superior engineering to deliver more Class A output across the power band while simultaneously controlling waste when demands do not require it. Clearly you have never greeted an CA-M400 after a solid hour of duty.

That's a weird statement. If anything is objective, science is!

Not when the motives and the arguments are influenced by personal bias.

Anyway, don't you find it amazing that I keep rambling about amplifiers that I don't even own anymore?

I can relate and I don't own them. The only advantage the JC1s have over the CA-M400's is price and that makes them alluring. However, overtime that upfront advantage is lost. Your circumstances make the perfect example of this!

[Peter Nielsen]

Rebelman,

I'm sorry, but many of your comments appear absurd (to me). I see no point in continuing the discussion since the communication cannot be kept at a scientific/professional/university level.

Thanks,
Peter

[RebelMan]

Ditto

[Peter Nielsen]

Of course, I didn't realize that the Parasound forum is all about promoting Cassé...

My bad!

Peter

[RebelMan]

Taking a position based strictly on someone else's opinion that amplifier A is better than amplifier B is naive. You made a weak case for the JC1's by making assumptions that they are better than another brand because a friend thought so. Yet that same individual no longer prefers the brand and you are unwilling to accept the contrary opinons of others in similar cases. That was illogical reasoning and should never have been stated to prove the real point that you don't like Classe', not that they don't perform. It seems to me you have some vendetta against Classe'. Maybe the dealer turned you off, who knows. But as one that has audition both brands and likes both (me) I can see no other conclusions.

If you want to discuss the science then let's have at it. But get real with the intentions.

[Peter Nielsen]

Taking a position based strictly on someone else's opinion that amplifier A is better than amplifier B is naive.

I've gone through quite a few amplifiers. Parasound A51 is for instance a champ at burning Maggie fuses. (This is a horrible amp for the bigger Maggies because of the low per-channel power supply capacitance. Thanks to tighter coupling and higher power supply capacitance A21 on the other hand works much better although the power specification is the same on paper).

Magnepans are a bit peculiar to drive, and I have a lot of experience in this area. They put completely different demands on the amp compared to a pair of traditional speakers. For good and for bad.

You made a weak case for the JC1's by making assumptions that they are better than another brand because a friend thought so.

I never pretended that I owned the Classé M-400. However, my friend's conlusion is all in line with my own experiences with amps of other manufacture.

Maggies need simple brute force, and there is no substitute for it. Big trafos, huge PS capacitance, and a bunch of power transistors in pure AB configuration. The power supply capacitance is extremely important for driving the power hungry Maggies.

[QUOTE=RebelMan]Yet that same individual no longer prefers the brand/QUOTE]

That's your assumption. His business is going well and he has the money to spend. Why not spend it?

that you don't like Classe'

Obviously you haven't listened to me at all (referring to earlier posts not in this thread). The Classé Omega monoblocks is one of my all time favorite amps. This is the ultimate amp for the MG20.1s if you don't bi-amp and can swing the cost. (They are arguably unnecessarily powerful for the maggies, but if you want a pair of really cool looking monos with a pure design, these are my #1 choice for the MG20.1. All the power you'll ever need).

Just because a company does (maybe) one of the best amplifiers in the world, does not make all their amplifiers great!

It seems to me you have some vendetta against Classe'.

Purely your speculation.

If you want to discuss the science then let's have at it. But get real with the intentions.

I guess manufacturer trickery (to twist specifications) combined with Forum FUD and dealer nonsense/incompetence has turned me down. I want clean proven solutions that work. I do NOT want to purchase expensive equiment at MSRP and be a "beta tester". There you go! Classe has not turned me down (since I don't own any of their equipment), but other high end companes have. That's why I rant when I see "trickery" in expensive pieces...

The JC-1 has all it takes to drive the Maggies to the point that they bottom out and beyond. The key is the power supply capacitance of 132,000uF. (This is also why the A51 is so horrible with the big Maggies. It only has 32,000uF/channel)

The CA-M400 appears to have 80,000uF power supply capacitance. I have not bee able to verify this, but if it's true, it's a notable difference compared to the JC-1s 132,000uF and it will definitely have effect on bass performance to some degree when used with the Magnepan MG20.1. This could possibly explain the difference our friend heard. (This is actually a much more plausible explanation than my previous guess that it's the Class A heat limitation trickery that causes the issue).

My point: Why spend so much more on the M-400 when the JC-1 does the job? (Again, remember that I'm only speaking about Magnepan speakers here. With a pair of B&Ws or Martin Logans, the situation may be different). Of course, if you have an all-Classé system, it makes a lot of sense to pay more for the M-400 (since it has a ton of integration features). But Magnepan owners that don't own Classé equipment and just need an amp - is it worth the added cost? (rhetoric question)

And yet another twist on this: In my opinion it's the Classé Omega (or the less expensive Omega Omicron) that should be compared to the JC-1. Both are the top-of-the amps from respective manufacturer and follow a pure design philosophy and are equipped with massive power supplies with huge capacitance. (Classé of course wins this battle hands down if you can disregard the cost... :B )

Peter

[mattburk]

Peter you bring up some great points. I appreciate your point of view and your friendly approach.

[REOFan]

Second That

Peter,

Mattburk beat me to it: I, too, enjoyed your views and guesses. I am surprised this thread generated such a lively discussion about amps.

I still can't imagine owning and operating nine JC 1s, though the heat they generated would've come in handy around here in January and February (unseasonably c-c-c-cold). Of course, I can't imagine what that would've done to my energy bills (which are challenging enough in this area these days).

Best wishes for a revitalizing spring to you, RebelMan, and all club members.

[Chris D]

watching this thread with a smile.

[RebelMan]

I've gone through quite a few amplifiers. Parasound A51 is for instance a champ at burning Maggie fuses. (This is a horrible amp for the bigger Maggies because of the low per-channel power supply capacitance. Thanks to tighter coupling and higher power supply capacitance A21 on the other hand works much better although the power specification is the same on paper).

Magnepans are a bit peculiar to drive, and I have a lot of experience in this area. They put completely different demands on the amp compared to a pair of traditional speakers. For good and for bad.

Do you have the impedance and phase curves to back this up?

I never pretended that I owned the Classé M-400. However, my friend's conlusion is all in line with my own experiences with amps of other manufacture.

Maggies need simple brute force, and there is no substitute for it. Big trafos, huge PS capacitance, and a bunch of power transistors in pure AB configuration. The power supply capacitance is extremely important for driving the power hungry Maggies.

How do you explain the articles published by stereophile and SoundStage!? The review posted by stereophile examines the MG3.6R with the CAM-350 which is not an exact comparison but the MG20.1's driven by the lessor brute Lamm 1.2's illustrates that the Maggies favor agility over raw power in both cases. This is in direct contrast to your theoretical position.

Although I'm a big believer in the axiom that more power is always better, the VAC Renaissance 70/70, the lowest-powered amp I had on hand, came closest to matching the CAM 350's dynamics. With a lot of speakers, in fact, it was a tossup. With Meadowlark Kestrels and Castle Severns, for example, the VAC's speed, precision, impact, and gradients equaled those of the heavyweight Classé. The Maggies, however, are a far hungrier load, and with them the CAM 350 had a clear advantage.

Another area where the Classé was superb—and again, one that contributed to its fast, open sound—was in its performance at the frequency extremes. It seemed to take the MG3.6/R about half an octave lower than other amps. A quick set of measurements suggested that this wasn't really true; I think the impression arose from the CAM 350's ability to better maintain its speed and precision to the very bottom of the frequency range. The VTL, for example, went every bit as low as the Classé, and with excellent power and lovely pitch definition; but it didn't have quite as much air, and didn't define the leading and trailing edges of bass notes as well.

The MG201s can go from no sound to full orchestral clamor with remarkable speed and agility. Again, "spooky," especially outside the concert hall. Of course, this presumes an amplifier that is equal to the task -- in terms of sonic ability, not sheer power. While some will tell you that 200 watts are minimum for the MG20.1 and even more power is preferable, the Lamm M1.2 Reference monoblocks were the only amps I used and the ones with which I formed all of my listening impressions. These amps are rated to deliver 110 watts each into 8 ohms, but, as our measurements of them show, their actual output is 157 watts (300 watts into 4 ohms). I never reached their limit, never even pushed them hard, and the results were thrilling with all kinds of music, at all volume levels.

Yet that same individual no longer prefers the brand

That's your assumption. His business is going well and he has the money to spend. Why not spend it?

It is fact that he sold the JC1's for the McIntosh. That is his preference, and that is indisputable. McIntosh amplifiers are notorious for lacking the necessary sustaining power to drive demanding loads and generally must be significant oversized for the job. If the MG20.1 are as demanding as you say then the McIntosh are probably the worse choice one could make. Alas, they are not according to him, another contradiction.

Obviously you haven't listened to me at all (referring to earlier posts not in this thread). The Classé Omega monoblocks is one of my all time favorite amps. This is the ultimate amp for the MG20.1s if you don't bi-amp and can swing the cost. (They are arguably unnecessarily powerful for the maggies, but if you want a pair of really cool looking monos with a pure design, these are my #1 choice for the MG20.1. All the power you'll ever need).

I have listened but I don't recall.

Just because a company does (maybe) one of the best amplifiers in the world, does not make all their amplifiers great!

Agreed but it doesn't make them not so great either.

I guess manufacturer trickery (to twist specifications) combined with Forum FUD and dealer nonsense/incompetence has turned me down. I want clean proven solutions that work. I do NOT want to purchase expensive equiment at MSRP and be a "beta tester". There you go! Classe has not turned me down (since I don't own any of their equipment), but other high end companes have. That's why I rant when I see "trickery" in expensive pieces...

You need to understand the historical lessons learned from some of the all time amplifier greats like Nelson Pass and Krell Industries. Classe' has taken those concepts to the next level. I can tell you if you are willing to listen without prejudice.

The JC-1 has all it takes to drive the Maggies to the point that they bottom out and beyond. The key is the power supply capacitance of 132,000uF. (This is also why the A51 is so horrible with the big Maggies. It only has 32,000uF/channel)

The CA-M400 appears to have 80,000uF power supply capacitance. I have not bee able to verify this, but if it's true, it's a notable difference compared to the JC-1s 132,000uF and it will definitely have effect on bass performance to some degree when used with the Magnepan MG20.1.

What is your frame of reference? Quit quoting amplifier specifications. Show me the speaker graphs that correlate with amplifier output. FWIW, my estimates put the CA-M400 closer to 93,600 μF but I can get this verified.

(This is actually a much more plausible explanation than my previous guess that it's the Class A heat limitation trickery that causes the issue).

I can palate this argument.

My point: Why spend so much more on the M-400 when the JC-1 does the job? (Again, remember that I'm only speaking about Magnepan speakers here. With a pair of B&Ws or Martin Logans, the situation may be different). Of course, if you have an all-Classé system, it makes a lot of sense to pay more for the M-400 (since it has a ton of integration features). But Magnepan owners that don't own Classé equipment and just need an amp - is it worth the added cost? (rhetoric question)

Good point. Perhaps because they (Classe') excel on both ends of the spectrum.

And yet another twist on this: In my opinion it's the Classé Omega (or the less expensive Omega Omicron) that should be compared to the JC-1. Both are the top-of-the amps from respective manufacturer and follow a pure design philosophy and are equipped with massive power supplies with huge capacitance. (Classé of course wins this battle hands down if you can disregard the cost... :B )

The CA-M400 is not perfect but it is a proven design with ties to the 1970's.

[Peter Nielsen]

Do you have the impedance and phase curves to back this up?

The impedance curve is close to flat on Magnepans. They are known as an "easy" load, which is true if you don't need much loudness from them.

What makes Maggies so hard to drive is the extremely low efficiency. Magnepan says they are 85dB/1W/1m. However, this is of course in an ideal room. In real life, it's more like 83-84dB...

Remember that each increase in 3dB requires double the amplifier power.

Most speakers never need to use the power of the JC-1/M-400/etc since they play way loud before you even come close to the limits.

How do you explain the articles published by stereophile and SoundStage!?

I did not find any curves that measure the response to bass transients near full power.

What is your frame of reference? Quit quoting amplifier specifications. Show me the speaker graphs that correlate with amplifier output.

My OWN practical experments with burnt fuses as result in the worst cases...

The CA-M400 is not perfect but it is a proven design with ties to the 1970's.

Well, how do you explain their Class A figure? A proven design of the 1970s will run EXTREMELY hot with the Class A numbers that they rate the M-400 with.

The JC-1 uses pure class a up to 10W or 25W depending on the bias selector. In 25W mode, the heat sinks are burning hot. This is the classical implementation used by PassLabs, Lamm, Krell, etc.

Or do you mean that Classe has used its proprietary (patented?) design since the 1970s?

I'm not so sure everybody would agree that a proprietary solution classifies as a proven solution...

Peter

[Peter Nielsen]

Maybe a little out of topic, but...

Now, after this discussion, I have realized that I of course must have a pair of Classé Omegas to match my Lian-Li computer cases. :B

Following the same logic I used for selecting computer cases, I can justify spending $14,000 each on Classé Omegas. Lian-Li cases are $240 each. I could get a regular computer case for $40 or a cheap one for $19...

Why would I pay $240 for a computer case? For the looks of couse. I'm not the one to believe that the case performs 10X the price of the economy case...

All is not what it seems. Why do I only buy American cars, when I could get Japanese cars for less? Without doubt, spending $10k on a pair of M-400s might make sense, even though a used pair of JC-1s can be had for less than $4k. However, it is still very easy to pinpoint the better deal... (Or is it? If the M-400s are more visually pleasing, they may be the better deal although they cost a lot more).



FWIW, I love my Norwegian Håg Balans chair (manufactured by HÅG). This is my 2nd one. I've refurbished my 1st one that I bought back in 1989 and is using it at work... 100% recommended! (Yes, Chris, those are Klipsch speakers. A very good value!)

Peter

[RandyL999]

Peter...

I don't know how you have the patience to continue to respond politely...

You serve as a beacon for us lowly mortals to point towards...

:-)

Randy

[RebelMan]

The impedance curve is close to flat on Magnepans. They are known as an "easy" load, which is true if you don't need much loudness from them.

What makes Maggies so hard to drive is the extremely low efficiency. Magnepan says they are 85dB/1W/1m. However, this is of course in an ideal room. In real life, it's more like 83-84dB...

Remember that each increase in 3dB requires double the amplifier power.

Most speakers never need to use the power of the JC-1/M-400/etc since they play way loud before you even come close to the limits.

Let's assume you sit 4m away. A pair of 83dB speakers with 1w of power will sound like 74dB at the listening position. According to OSHA these are safe SPLs. Now let's drive them with 10w of input power. That puts the pair at 84dB, 1 dB shy of safe levels. Another 90w and you are up to 94dB. Double that input twice, equivalent to a 400wpc amplifier (aka JC1 and CA-M400) not including dynamic headroom, and now you have 100dB SPL. Anyone listening to 100dB sustained levels on a regular basis would be insane. I asked you before if you listened to reference volumes on a regular basis but you didn't meter the mark. I ask again are you and if so at what dB?

I did not find any curves that measure the response to bass transients near full power.

My OWN practical experments with burnt fuses as result in the worst cases...

I've seen a pair of B&W XT4 of similar sensitivity to the MG20.1 render an amplifier of similar caliber to the A51 useless. All it goes to show is that speaker and amplifier pairing should be properly accounted for. It's doesn't prove that the MG20.1 is any more demanding than another speaker and it doesn't preclude the CA-M400 from have the guts to drive them... responsibly. I'm sure if you didn't give a darn about your JC1's or your Maggies you would have driven them to full output power. I seriously doubt you tried to play mad scientist on your system.

Well, how do you explain their Class A figure? A proven design of the 1970s will run EXTREMELY hot with the Class A numbers that they rate the M-400 with.

The JC-1 uses pure class a up to 10W or 25W depending on the bias selector. In 25W mode, the heat sinks are burning hot. This is the classical implementation used by PassLabs, Lamm, Krell, etc.

Or do you mean that Classe has used its proprietary (patented?) design since the 1970s?

I'm not so sure everybody would agree that a proprietary solution classifies as a proven solution...

An amplifier is classified by the design and implementation of its output stage transistors. A Class A amplifier is one where the transistor amplifies both the positive and negative phases of the audio signal. A Class-B amplifier is one that employs a complementary pair of transistors, NPN and PNP, where the first transistor amplifies the positive half of the audio signal and the other the negative half. A Class A/B amplifier is one that combines the linear performance of a Class A amplifier at low input power (low voltage) with the efficiency of the Class B amplifier at high input power (high voltage).

The transition point from Class A to Class B is determined by the amount of bias applied to the base of a NPN/PNP transistor and is usually fixed to a few watts. The bias level governs the linear operating region of the transistor and is dependent on the transistor’s internal design. When the threshold of the transistor’s linear operating region nears the saturation point the amplifier’s transistors engage Class B push-pull mode.

Before Class A/B amplifiers became commonplace a few pioneering engineers were developing new methods to improve the efficiency of Class A amplifiers without altering their native characteristics to amplify the entire audio signal without inducing distortion. One such engineer was Nelson Pass. During the mid 70’s Nelson Pass invented a sliding bias technique called dynamic biasing which allowed the amplifier to run full Class A output on demand yet pull only a fraction of the power when the amplifier was idling. A 200 watt amplifier would only draw 50 watts at idle. Later he conceived of a high current handling device, called stasis, that would shield a low current linear transistor from current variations and thus control the quality of the voltage swing. It was an elegant design that trapped one of the root causes of non-linearity when semiconductor gain was varied from small to large voltage signals.

By the 1990’s, when Class A/B amplifiers gained a stronger foot hold, Krell Industries carried the torch with the introduction of sustained plateau biasing. When an amplifier using this design was standing by, the bias level would be low but strong enough to allow average listening levels and prevent the complementary pair of transistors from toggling on and off. When a signal transient was about to demand more current than that currently supplied by the quiescent current, a very fast acting circuit turns up the bias level. The bias level would remain fixed at that level for a period of time. If subsequent signals did not demand high (or even higher) bias the quiescent current level was restored.

Classe’ has taken this technique one step further for the 21’st century by continuously varying the bias levels to one third input power (voltage) to enable a broader range of linear operation. Rather than sustaining fixed bias plateaus with techniques of previous decades, Classe’ was able to efficiently utilize Class A/B transistors in a more traditional Class A role without impairing their integrity. As a result, Classe’ Delta Series amplifiers are capable of delivering more linearity for given input, albeit for brief intervals of time. Given the dynamic nature of music signals and reasonable listening SPLs, this method not only improves sonic deliver over a much broader range but it also preserves efficiency when operating in Class A mode. This is not some form of audio trickery but an evolution of audio engineering. It maybe proprietary but it’s proven and proficient. Evidence has been shown in benchmark labs and in the listening room.

[RebelMan]

Now, after this discussion, I have realized that I of course must have a pair of Classé Omegas to match my Lian-Li computer cases. :B

Following the same logic I used for selecting computer cases, I can justify spending $14,000 each on Classé Omegas. Lian-Li cases are $240 each. I could get a regular computer case for $40 or a cheap one for $19...

Why would I pay $240 for a computer case? For the looks of couse. I'm not the one to believe that the case performs 10X the price of the economy case...

All is not what it seems. Why do I only buy American cars, when I could get Japanese cars for less? Without doubt, spending $10k on a pair of M-400s might make sense, even though a used pair of JC-1s can be had for less than $4k. However, it is still very easy to pinpoint the better deal... (Or is it? If the M-400s are more visually pleasing, they may be the better deal although they cost a lot more).

As a PC junkie myself I would concur with your process of elimination, or better yet acquisition.

To be honest I do find it difficult to slight the JC1's as I find much to like of them but like our friend I have my preferences too. I will admit cosmetics does play a role in my selection process but I don't allow that to interfere with performance. I am guilty for having an insatiable need to satisfy my ears with musical bliss and my eyes with audio candy. The JC1 and the CA-M400 qualify as having both.

The JC1 is without question the value leader in this debacle but the CA-M400 will mate better with a Classe' front end and I always give that part of the system priority in the decisions I make. I will concede that the JC1's may out muscle the CA-M400 if pushed to the limits but the CA-M400 will sound sweeter (linear) more often. :B

[Peter Nielsen]

The JC1 is without question the value leader in this debacle but the CA-M400 will mate better with a Classe' front end and I always give that part of the system priority in the decisions I make.

No question about that. Honestly, if I had a Classé front end, I would probably not even consider the JC-1. With a Classé front end, it only makes sense to get matching amps that can take use of Classé's system integration...

Peter

[Peter Nielsen]

Let's assume you sit 4m away. A pair of 83dB speakers with 1w of power will sound like 74dB at the listening position. According to OSHA these are safe SPLs. Now let's drive them with 10w of input power. That puts the pair at 84dB, 1 dB shy of safe levels. Another 90w and you are up to 94dB. Double that input twice, equivalent to a 400wpc amplifier (aka JC1 and CA-M400) not including dynamic headroom, and now you have 100dB SPL. Anyone listening to 100dB sustained levels on a regular basis would be insane. I asked you before if you listened to reference volumes on a regular basis but you didn't meter the mark. I ask again are you and if so at what dB?

You are assuming that my speakers and room are flat.

Alas, 25Hz bass at 100dB is not that loud. 1kHz at 100dB is very loud/deafening...

My room has a few severe dips around 55Hz and 110Hz. (~12dB dips at 55Hz and 7dB dips at 110Hz). Those eat up a lot of the headroom when electronically corrected.

So, around 55Hz, my room+speakers are only able to produce ~73dB/1W/1M. With my current Boz amps (400W), this translates to ~96dB (I would need 512W to reach 97dB).

To answer your question: Normally I listen to music at a level bewteen -20dB to -10dB of full output. I do occationaly crank it upp to full volume for a song or two. However, for movies I usually need to run close to full volume to get a decent level. Usually I run 2-3dB below max level. In movies it is of course only the loudest part (crashes, explosions, etc. that get the full output and it is not even particuarily loud in my setup).

I'm eagerly waiting for TacTs upgrade that let me upgrade the Boz 2200s from 400W to 1000W per channel. That will give me a few more dBs of headroom that I really need.

Now, of course, if I run the TCS in bypass without room correction I will gain 12dB and have plenty of loudness, but no compensation for the frequency dips in my room... (I know that I should spend money on room treatment, so don't lecture me on that. My next home will have an acustically engineered room).

I'm sure if you didn't give a darn about your JC1's or your Maggies you would have driven them to full output power. I seriously doubt you tried to play mad scientist on your system.

With the JC-1s, I've had the speaker (bass panel) bottom out. So, yes, I've driven my MG20.1s to the limit with the JC-1s. (The JC-1s never even came close to clipping, so I can't say I have tried its limit).

The A51 started clipping so severly (before the bass panel bottomed out) that it output garbage signals that blew the midrange and tweeter fuses on my MG3.6 (I'm glad that I didn't try the A51 on my MG20.1s).

The nice thing about TacT digital amps is that you cannot overdrive them like you can with an analog amp. The TacT amps will produce full output when the digital signal is at full level (all bits set to 1). Consequently there is no way to exceed the amp specification.

With my TacT setup anyone is welcome to dial up the volume to max. Nothing will break. That's the way it should be in all systems!

Oh, and who said I'm not a mad scientist? :B :rofl:

Peter

[RebelMan]

You are assuming that my speakers and room are flat.

I took your word that the MG20.1 are flat but I did make some assumptions about your room.

Alas, 25Hz bass at 100dB is not that loud. 1kHz at 100dB is very loud/deafening...

Agreed but the vast majority of music rarely approaches anything close to 25Hz.

My room has a few severe dips around 55Hz and 110Hz. (~12dB dips at 55Hz and 7dB dips at 110Hz). Those eat up a lot of the headroom when electronically corrected.

So, around 55Hz, my room+speakers are only able to produce ~73dB/1W/1M. With my current Boz amps (400W), this translates to ~96dB (I would need 512W to reach 97dB).

By my calculations its closer to 102dB. 85dB (each speaker) -12dB (loss at 55Hz) + 3dB (two speakers) + 26 dB (400W) = ~102dB. Not trying to split hairs but it seems to be a bigger difference than one is led to believe.

To answer your question: Normally I listen to music at a level bewteen -20dB to -10dB of full output. I do occationaly crank it upp to full volume for a song or two. However, for movies I usually need to run close to full volume to get a decent level. Usually I run 2-3dB below max level. In movies it is of course only the loudest part (crashes, explosions, etc. that get the full output and it is not even particuarily loud in my setup).

Is max level with respect to the speakers or the amplifiers or unity gain of the pre-amplifier?

With the JC-1s, I've had the speaker (bass panel) bottom out. So, yes, I've driven my MG20.1s to the limit with the JC-1s. (The JC-1s never even came close to clipping, so I can't say I have tried its limit).

I suspect the CA-M400 would too but I wouldn't recommend anyone play Russian Roulette with their speakers and the CAM's just to find out.

Oh, and who said I'm not a mad scientist? :B :rofl:

My bad. :B

Peter, now that the JC2 is out why haven't you gone back to running the MG20.1 with a pair of JC1 for two channel stereo?