A21 Balanced Vs RCA

[milpai]

I have been using the A21 power amp with my romitheus Reference C-Core TVC. Though the TVC has a Balanced IN/OUT, I have been using the RCA to A21. I do not have a Balanced source to TVC.
My question is, with this setup, will it make sense to connect the TVC to A21 with Balanced cable? Some of the reviews I had read years ago mentioned that, to get the best out of A21, one has to use the Balance inputs on the A21. Has anyone tried the Balanced Vs RCA on the A21, with an unbalanced "source" (CDP) to the preamp?

[Chris D]

Hey, milpai--I don't think I've given you a welcome banana before, so welcome to the Guide and Club Parasound! :banana:

Although I'm not familiar with your specific pre/pro, using balanced pre-outs usually has no bearing on whether the source also uses balanced or unbalanced. They're two separate connections, so unless there's something special in the pre-pro like a balanced-to-balanced straight pass-through without any processing or volume control, whether one is balanced or not has no bearing on the other one being balanced or not.

There's a section in the Club FAQ here that talks about balanced vs. unbalanced, but I'd say as a summary that it would depend on three things--what kind of speakers you are using, the length of your cables from your pre/pro to the A21 (typically rather short for home A/V users) what kind of EMI your setup produces in the area of those cables.

[milpai]

Thanks for the banana

Hi Chris,
Thanks for the banana.....

I am strictly using the A21 in stereo configuration and it is nothing short of stellar performance for my requirements. The preamplifier that I use is completely balanced, per it's manufacturer. It is a Transformer Volume Control and a passive one at that.

The cable lengths that I user are pretty short - especially since I use passive preamp. The RCA from CDP to TVC is 3 feet. The RCA from TVC to a21 is 2 feet. But, will it make a difference if I keep the cable lengths as-is and use a XLR between the TVC and the A21? The question is - does A21 perform better with a XLR connection compared to a RCA connection, everything else being the same in a audio system?

Thanks,
Milind

[Chris D]

Do please check out the FAQ here in Club Parasound. I put a discussion on balanced cables in there for just this sort of thing. http://www.htguide.com/forum/showthread.php4?t=6995

I don't think there's any difference in amplification in the actual amp for Parasound on balanced vs. non-balanced inputs. (vs the pre-outs on Parasound pre-amps, which actually have a small gain increase) So I guess it wouldn't matter what kind of speakers you have, unless your pre-amp also does have some sort of different output between the two types, like Parasound does.

Sooo.... like most home users, your connecting cables are relatively short. I don't know what kind of EMI you have in your racks where the cables run, but also like most home users, I'm guessing it's low. So are you going to get any benefit from using balanced cables? Probably not much. But would using balanced cables make the sound any WORSE? Not unless there's some sort of problem with the balanced design of any of the jacks, circuitry, or you're using cheap balanced cables. You're not going to find that on the Parasound end.

Bottom line, if all else is equal including the quality of the cables you're considering, are you going to get better performance from using balanced or unbalanced? The answer should be balanced, but there's not much reason to expect a big difference.

I'm still getting around to switching over to balanced myself, but since I'm also not expecting a big difference, I'm not in any hurry.

[milpai]

Chris,
I think this is the review that made me feel that XLR was much better than RCA with the A21. But that may not be:

http://www.audioholics.com/reviews/amplifiers/parasound-halo-a-21/halo-a-21-amplifier-listening-tests

[Chris D]

wow, milpai, good find. I've never seen that review before. That makes me want even more to jump over to balanced connections on my own Halo gear.

If you're buying new cables to start with, and have to decide between balanced and unbalanced, might as well go with balanced. You might not be able to do an A-B comparison with what the unbalanced connections would have sounded like, but I'm going to bet you that either way, they'll sound great!

[milpai]

Then you should also read this....

....pdf file from a Norwegian magazine, where they compared the A21 to amps costing 3-4 times and the A21 came in as a winner:

http://www.audiofidelity.no/comlete_mags/10.pdf

This review alone will make u very proud to own this amp. I don't go by reviews...but hey, in this case they gave me an ego boost 8)

Yes, I agree that the A21 is good as is through RCA. But if the reviewer in the previous review gave additional brownies to XLR connections, then I feel that this amp is untouchable for 5X times it's price range. I have a new dedicated room to 2-channel audio and obviously the "upgrade" bug (only fuses, connectors, footers, etc) bit me. Of course room treatments and getting the audio stand off of the middle were the BIGGEST improvements.

[Glen B]

Deleted.

[Glen B]

Here are links to posts by Ralph Karsten, well respected amp designer and founder of Atma-Sphere Music Systems. He explains the benefits of balanced vs unbalanced operation, even with short cables, when the equipment is of true balanced/differential design. Atma-Sphere products, which are all balanced differential designs, have won many reviewer awards, so Ralph must be doing something right.

http://www.audioasylum.com/forums/amp/messages/17/177312.html

http://www.audioasylum.com/forums/amp/messages/17/177317.html

http://www.audioasylum.com/forums/amp/messages/17/177344.html

http://www.audioasylum.com/forums/amp/messages/17/177348.html

http://www.audioasylum.com/forums/amp/messages/17/177354.html

[milpai]

I have posted this on audiogon.com as well:
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ALRIGHT - received the XLRs, installed in the system and finally got the answer I was looking for. Without keeping you guy waiting, here it is - JUST GO for XLR.

Did not take more than 15-20 seconds to realize this with 2 CDs I used - Famous Blue Raincoat and Hobo (Sara K).

FBR is well recorded and I have used it on multiple occasions to test various components. Listening to "Bird On A Wire" it was immediately apparent that the stage depth and height had increased. Hobo is also very well recorded. But my constant complaint was that the recording sounded thin. With the XLRs in place this is no more an issue.

Here are the changes that I noted with XLR compared to RCA:
1. Superb dynamics (big, bold, lifelike presentation)
2. Excellent depth
3. Subtleties became so apparent
4. Increased stage height
5. Pinpoint imaging (separation of individual sound?)
6. Center vocals do not move to sides if you move your head
7. More muscle to music
8. Increased gain

That last point above is what I don't understand. I had to go down 2 notches on the volume control. Why did this happen? My CDP remains the same. Only the connection from preamp to amp changed. If someone could care to explain, it will be very helpful. Thanks in advance.

I can say this confidently - if you are not utilizing the XLRs on the A21, then you are only listening to $1000 amp. Use the XLRs on the A21 and now you are listening to the $2300 amp that you really paid. You really don't know what you are missing on the A21, unless you listen to it using XLRs. I am not going back to RCA on the A21 for sure.

For people who are using passive preamps or TVCs - XLRs is THE way to go if your amp is A21. You will be surprised by the "gain" that you gain (no pun intended). I am pretty happy with the positive change in my system, that the XLRs have bought. Though the CDP is the weakest link in the chain now, I am in no hurry to replace it - since all my old CDs are NEW again and I need to listen to them again - at least once!!

[r100gs]

I've ran a P3/A21 combo for some time and never got a sonic difference running xlr's. I think your preamp may be fully balanced. The P3 and A21 are not fully balanced.

[milpai]

Yes r100gs, my preamp is a dual mono TVC from Promitheus and is fully balanced. The difference in sound between XLR and RCA is staggering for me.

[Chris D]

Very interesting, milpai. I really appreciate you posting this stuff. You are absolutely right about the gain. Parasound designed the XLR jacks to have an additional gan over the RCA. I think it's +3dba, if I remember right.

I just want to make sure, though, that the additional clarity and sonic benefits you are noticing are more than just the gain itself, that you're making direct apple-to-apple comparisons at the same gains. (i.e. slightly turn down the volume after switching over to XLR)

Quite curious.

[r100gs]

Yes r100gs, my preamp is a dual mono TVC from Promitheus and is fully balanced. The difference in sound between XLR and RCA is staggering for me.

Sorry I did read your post more clearly. Fully balanced pre is nice. I recently replace my P3 with a MF a5cr pre and got a huge sonic increase. Soundstage has increased, speakers are quiet at full volume, detail seperation is great. This all with unbalanced connections. The A21 is fantastic amp when given the right source and preamp. I only wish the JC2 was in my budget.

[r100gs]

Very interesting, milpai. I really appreciate you posting this stuff. You are absolutely right about the gain. Parasound designed the XLR jacks to have an additional gan over the RCA. I think it's +3dba, if I remember right.

I just want to make sure, though, that the additional clarity and sonic benefits you are noticing are more than just the gain itself, that you're making direct apple-to-apple comparisons at the same gains. (i.e. slightly turn down the volume after switching over to XLR)

Quite curious.

Chris, I know what you are talking about. The attenuater on the P3 ramps up very slowly. I generally listen to at the 12 o clock position, 40 vs. 80 full on. The MF A5cr pre, I listen to at the 9 o clock position for the same listening volume. The sonic difference between the two pre amps is day and night. The MF was a good step forward for my system. The A21 really shines now.

[Chris D]

Well, there you go! Makes me even more looking forward to switching over to XLR myself. After like 9 years of owning my Halo gear, and 5 years after moving on from my previous speakers that were better on RCA, you'd think I'd have done the XLR switch by now.

[milpai]

Chris,
I understand the apples-to-apples comparison you mentioned.
I used to listen with volume control at position 13. With XLRs in place I had to go down to position 8 (from 0). Even after doing this, I am having the benefits that I have mentioned before. With my passive preamp, the difference is like - thin string Vs thick rope. In a reviewer's word, it is like adding meat on bones. It is a staggering difference in my system.
Honestly I did not know what I was missing until I switched to XLRs on the A21. I do not understand why this should happen, cause my CDP is still connected to the preamp via RCA and outputs 2.2V as it has been doing all these years.
I think you SHOULD switch to XLRs and see if it makes any difference in your system. I am not switching back!!

[milpai]

Chris,
I should have updated this earlier. I found the reason for gain. Looks like with XLR, you get "2x" volts to the amp, rather than "x" volts, that the RCA would have sent. This is because each leg (+ve and -ve) sends "x" volts to the amp.
With the XLRS in my system, the A21 is a potent amp. Have you tried XLRs in your system yet?