P3 bi-amping

[braamman]

First off if any spelling is incorrect it's becouse i'm Dutch ;-)

Guys and gals I need your help.

I now own a P3 + A21 and really soon to have B&W 802 ;-) Should be absolutely no problem to power these beauties at all, but not strange to audiolovers...
I can purchase a secondhand A51 (probably trade and pay extra), I was hoping to use both my outputs (xlr and cinch) on my P3 to to adress 4 inputs on the A51 and so to bi-amp my soon to have 802's.

Apart from the esthetics and or probable advise to get a C1/C2, I don't have any money for these two and am just wondering if at all it is possible. And (i think it's possible) if so what's the advise on connecting? XLR on the lows and cinch on the mid/high or vv.

thx for the advise.

ps I don't want or need surround, been there don't want it anymore, glad to be back on stereo, so no upgrade path needed (c1/c2)

[Peter Nielsen]

I can purchase a secondhand A51 (probably trade and pay extra), I was hoping to use both my outputs (xlr and cinch) on my P3 to to adress 4 inputs on the A51 and so to bi-amp my soon to have 802's.

That won't work. The A51 has a toggle switch for balanced/unbalanced. It's common for all 5 inputs, so you have to decide on either all-XLR or all-RCA. You can't use both...

Why not get a second A21 instead of trading your A21 for an A51? The A21 is in all respects a better amp than the A51 thanks to the way it is designed. The A51 has 5 small circuit boards with only two big capacitors/board. The A21 has a much better design with all components on one big board and a shared big bank of capacitors. The A21 has a higher idle bias (=more Class A watts) and double per-channel heat sink capacity compared to the A51....

Peter

[braamman]

That won't work. The A51 has a toggle switch for balanced/unbalanced. It's common for all 5 inputs, so you have to decide on either all-XLR or all-RCA. You can't use both...

thx good advise, but that's probably solvable thru an adapter on the xlr cable (xlr to cinch or vv)

Why not get a second A21 instead of trading your A21 for an A51? The A21 is in all respects a "better" amp than the A51 due to the way it is designed. (The A51 has 5 small circuit boards with only two capacitors/board. The A21 has a much better design with all components on one big board and a shared bank of capacitors).

Peter

two answers, 1 my wife will **** me for getting antoher somewhat big box in the livingroom and 2 an extra A21 will set me back another 3000 euro's as with this option it will cost me my A21 + 1000 euro's.

Brainwave: other possibility is to connect the P3 with the XLR (allready own that on) and use an y-adapter (from ie XLO electric) to connect to 4 inputs on the A51 (which then are all XLR offcourse) and so create vertical bi-amping?!

[braamman]

That won't work. The A51 has a toggle switch for balanced/unbalanced. It's common for all 5 inputs, so you have to decide on either all-XLR or all-RCA. You can't use both...

thx good advise, but that's probably solvable thru an adapter on the xlr cable (xlr to cinch or vv)
[/QUOTE]

Why not get a second A21 instead of trading your A21 for an A51? The A21 is in all respects a "better" amp than the A51 due to the way it is designed. (The A51 has 5 small circuit boards with only two capacitors/board. The A21 has a much better design with all components on one big board and a shared bank of capacitors).

Peter

two answers, 1 my wife will **** me for getting antoher somewhat big box in the livingroom and 2 an extra A21 will set me back another 3000 euro's as with this option it will cost me my A21 + 1000 euro's.

Brainwave: other possibility is to connect the P3 with the XLR (allready own that on) and use an y-adapter (from ie XLO electric) to connect to 4 inputs on the A51 (which then are all XLR offcourse) and so create vertical bi-amping?!

[Chris D]

Hi, braaman, welcome to the Guide and Club Parasound! :banana:

[Peter Nielsen]

thx good advise, but that's probably solvable thru an adapter on the xlr cable (xlr to cinch or vv)

Yes, you can do that. XLR to RCA should work fine.

two answers, 1 my wife will **** me for getting antoher somewhat big box in the livingroom and 2 an extra A21 will set me back another 3000 euro's as with this option it will cost me my A21 + 1000 euro's.

Ok. Here in the US the A51 costs $4k and the A21 is $2k, i.e. two A21s cost the very same as the A51...

A warning though: The A51 is not able to pump the same per-channel current as the A21...

Also, when biamping, how balanced are the low versus the high on your speaker? Do they need equal power? If not, maybe you could get a smaller stereo amp like the A23 to drive the highs?

Of course, there's probably nothing you can do about the Wife Acceptance Factor... :B

Brainwave: other possibility is to connect the P3 with the XLR (allready own that on) and use an y-adapter (from ie XLO electric) to connect to 4 inputs on the A51 (which then are all XLR offcourse) and so create vertical bi-amping?!

Yes, an Y-adapter for the XLR will work flawlessly, and it should not cause any impedance problems either! This is actually a lot better than using an XLR/RCA adapter!

Both these attempts to biamp are called "passive biamping". (In contrast to the more fancy "active biamping" when you remove the passive internal speaker crossovers and use an active electronic crossover before your amps).

Peter

[blownrx7]

A warning though: The A51 is not able to pump the same per-channel current as the A21...

Peter,
Is that correct about the A21 putting out more curren/ch than the A51??
The specs on the Parasound website say 60amps/ch for both.

Also, when biamping, how balanced are the low versus the high on your speaker? Do they need equal power? If not, maybe you could get a smaller stereo amp like the A23 to drive the highs?

One caution about passive biamping. The amp(s) must have the same GAIN otherwise you may drive the drivers at different levels.
The simple solution is to use the same amp to drive lows and highs but it does seem like a waste of power to drive the lows with 250 watts and the uppers with 250 watts as well. Using the A23 is a good solution provided it does have the SAME GAIN.
It is implied that it does since the A51, A21 and A23 are THX certified and the A21 and A23 have adjustable GAIN with a THX reference position.

So does the THX reference position of the A21 and A23 correspond to the same GAIN for the A51??

[Peter Nielsen]

Peter,
Is that correct about the A21 putting out more curren/ch than the A51??
The specs on the Parasound website say 60amps/ch for both.

I somehow incorrectly remembered that the A21 has more output transistors/channel, but that's not the case. However, the A21 still has twice the cooling capacity, and a better power supply thanks to the shared bank of capacitors.

One caution about passive biamping. The amp(s) must have the same GAIN otherwise you may drive the drivers at different levels.

That's a very good point, which brings us to the question about how identical the gain of 4 channels in an A51 really is...

Peter

[braamman]

I somehow incorrectly remembered that the A21 has more output transistors/channel, but that's not the case. However, the A21 still has twice the cooling capacity, and a better power supply thanks to the shared bank of capacitors.



That's a very good point, which brings us to the question about how identical the gain of 4 channels in an A51 really is...

Peter

Sorry been away a few days. Spoke with Parasound NL and using a y-adapter indeed is a possibility.

Another one then, will I be able to do bi-amping with a C2 + A51? There are a lot of connections on a C2 so...

And now for something completely different ;-)
Would it be possible to use a Pioneer VSX-AX4AVi (us model would be the VSX-74TXVi) as only the pre-amp. Off-course I can use the pre-out fronts, but can I also use the pre-out surroundrears and thus with selector on a+b use bi-amping thrue the pre-outs (connected 4xcinch to the Parasound A51
inputs)
I know its a "strange" step, but it has some plusses (subjective and personal), integration with all my other Pioneer gear, a few extra connections (mainly ipod), looks good as well.
I recon that the quality the Pioneer gives me only used as a preamp is simular to the Parasound, said differently, not better or worse just different, the Halo P3 isn't a "million dollar" pre as well.

[kfr01]

Braaman:

What do you expect to acheive by passively bi-amping?

It won't provide an increase in available power. Seems like a waste of money to me. Active bi-amping is a different story entirely....

[braamman]

Hi Karl,

(it's BraaMMan :-)) no probs

It's not a questions of hoping I allready know I gain (some) extra power with that solution. Now my A21 needs to drive (and it's doing a good job as well) my B&W N802's. With the A51 (and thus bi-amping) I'll have some extra punch overall and more than that it will most defenately give "rest" and better "easy of listening" overall.

[kfr01]

By achieving less energy loss due to splitting up the passive crossover components? Increasing the damping factor? Just curious as to how you expect passive bi-amping to add any / much audible punch. Please explain or direct me to a link to educate myself.

IMHO, you honestly -do not- stand to gain much audible power stepping up to a passively bi-amped system. You realize that passively bi-amping two 250w amplifier channels still provides, for all practical purposes, the same SPL headroom as one 250w amplifier, right?

If you really want more power you need to either:

a) actively bi-amp or
b) buy a single larger amplifier.

If your A21 is doing a good job driving your speakers, I honestly think you stand to gain next to nothing passively bi-amping; other than a dent in your wallet...

[braamman]

Well, this is where it's getting tricky because my tech English is not as good as my "normal", I'll try though.
The punch is derived by separating the wires to your speakers to the low and the mid/high. Instead of the amp (A21 ie) having to drive the whole speaker (low and mid/high) with the A51 you can separate these wires and (allthough passive) create 2 independent feeds (everybody allready knew this probably ;-). Indeed this doesn't give you extra SPL however it will take away feedback loops from the low end of the speakerunit and thus not "give a dirty signal" to the mid-high which will result in a more clean sound, better separated and more vivid also because the amp (A51 ie) has 4 outputs the dedicated lows will have a better constant feed (A21 needs to devide its power to lows and mid/high) which in return will result in a thighter and more robust deep bass.

I did have had 3 amps (mine was in the shop) so I could do some testing and it seems that these N802's are really powerhungry, which isn't a problem I just want to look for a suitable solution.
I do know i'm on the right track with this bi-amping though everybody is recommending it (apart from me allready having heard it in several various settings), however I can't afford an extra A21 I can however pay a little extra and swap mine for a A51 though.

pls be nice to me, I tried it in my best English it's difficult though with these tech words, so I might have written it in simple English...

[kfr01]

Your english is fine. I think you're getting bad advice-probably from someone who wants to sell you a shiney new A51...

I think the damping factor of these amps is sufficiently high enough for passive bi-amping v.s. not passively bi-amping to make little audible difference with regards to feedback...

I don't think it is clear (by a longshot) that the beefier power supply and construction of the A21 will perform worse than a passively bi-amped system using an A51.

[braamman]

It's a shame I can't test otherwise we'd know for sure, I'll surely be more carefull now, I don't need to spend my money (like to though), if it's not needed or otherwise hardly noticeable then i'll invest my money in other cables or something.

Thx Karl

[kfr01]

Cables? Noooo!! :-)

Save up money for true bi-amping, if it is on your mind::

http://sound.westhost.com/bi-amp.htm

[braamman]

well I found a fairly new vendor in Europe that is, it's called Xindak espec the Gold series. I'm a absolute fan of the Siltech Classic series (can't afford the sig series...) and these Xindak Gold series really outdo Siltech but only for a fraction of the price. I found a new dealer here in NL where I can get almost get it for bottom prices but otherwise it's kinda ok priced. Look @ nysound.com and see for yourself, it's a bargain for the quality you get. I just tried a FA-Gold interlink out of the blue and was really positively suppriesed.

and bi-amping, I almost forgot about it allready, I most defenitely will not be "screwing" around in my brand new Nautilusses ;-) so no active bi-amping for me (for now).

[kfr01]

bluejeanscables.com or diycable.com for me. I'd rather throw money down the toilet than waste it on neat looking cables.

Read this article about cables:

http://sound.westhost.com/cables.htm

[Chris D]

Hey, Karl, have you looked at Cat Cables, the company that operates this forum? They're great cables that will beat any of those in price and performance. All my cables are made by Cat. Worth taking a look.

www.catcables.com

[kfr01]

Hey, Karl, have you looked at Cat Cables, the company that operates this forum? They're great cables that will beat any of those in price and performance. All my cables are made by Cat. Worth taking a look.

www.catcables.com

They sure look nice. However they're easily twice as expensive as the bluejeans cables. Is performance twice as good? I doubt it is measurable. I don't like paying for looks when a cable sits behind my component rack.

But yes, thank you for the link. They do seem like a decent deal for nice looking cables.

[Chris D]

Karl, what I'd recommend is E-mailing Doug the owner for more information on cables, and just try out a set. No cables should ever be bought because they look nice. The key is the quality of construction, leading directly into the degree of performance. For the price, I personally have never found other cables to perform nearly as well as my Cats. You're certainly free to choose what products you use, of course. I'm just passing on a helpful suggestion for the forum, as well as that I hate seeing people make non-optimal purchases because they're not familiar of options available to them.

[kfr01]

Understood. Thank you for the recommendation.