A31 vs. A51

[akopperl]

Is it possible that the A31 sounds different than the A51?

I purchased the A31 and thought it sounded great. I decided to return the A31 to get the A51 figuring I would get the same great sound and simplify my setup.

To my surprise, I didn't like the A51 as it appeared to sound bright in my system and I couldn't listen to music for more than 30 minutes without experiencing listener fatigue. The A31 sounded much warmer and had no listener fatigue.

Does this make any sense? The only change I made to my system was the amp.

Thanks

[Peter Nielsen]

The A21 is very different from the A51 although the specifications are the same. The A21 has all components laid out on one big PCB. The A51, on the other hand, is using one separate PCB for each channel and a lot of internal wiring...

When pushing my old 3.6 maggies with the A51, the fuses in my maggies blew (ouch!). The A51 apparently began outputting DC. When doing the same with the A21, no problem. All was good. Quite a big difference here that could be objectively demonstrated.

Unfortunately I'm not familiar with the internals of the A31. If it's built up like the A21, then it may sound better...

[WAFWARRIOR]

The A21 is very different from the A51 although the specifications are the same. The A21 has all components laid out on one big PCB. The A51, on the other hand, is using one separate PCB for each channel and a lot of internal wiring...

When pushing my old 3.6 maggies with the A51, the fuses in my maggies blew (ouch!). The A51 apparently began outputting DC. When doing the same with the A21, no problem. All was good. Quite a big difference here that could be objectively demonstrated.

Unfortunately I'm not familiar with the internals of the A31. If it's built up like the A21, then it may sound better...

The A31 and the A51 are based off of the same amp modules. They should sound exactly the same.

[Chris D]

Agreed. Even the A21 and A51 should give you the same general sonic characteristics and performance, the A21 will just do it a little cleaner. Don't think there should be a difference between A51 and A31. Would be interesting to hear what the Parasound guys would say, though.

[Edit: changed second reference to A51 as intended]

[akopperl]

Thank you for the replies.

I'm not sure why the A31 sounded better to me. It just appeared to have better balance and was non-fatiguing over extended periods. When I switched to the A51, I couldn't listen to music for an extended period of time without experiencing listening fatigue.

Maybe the A51 that I got had an issue. Would like to try the A31 again, but it is a hassle dealing with the size and weight of these amps.

[Peter Nielsen]

Agreed. Even the A21 and A51 should give you the same general sonic characteristics and performance, the A21 will just do it a little cleaner. Don't think there should be a difference between A21 and A31. Would be interesting to hear what the Parasound guys would say, though.

Chris, that's not my experience. The A51 seemed to lack some of the ability to drive the low range that the A21 has. The A51 ran out of juice before the A21. Also, doesn't the A21 power supply have 50,000uF/channel whereas the A51 is 32,800uF/channel. That could explain some of the difference.

No doubt, the A21 is superior to the A51.

As for the A31, I can't tell, but it sure looks like it possibly may be using the A51 modules considering the 98,400uF (=3 x 32,800uF) specification.

[Peter Nielsen]

Thank you for the replies.

I'm not sure why the A31 sounded better to me. It just appeared to have better balance and was non-fatiguing over extended periods. When I switched to the A51, I couldn't listen to music for an extended period of time without experiencing listening fatigue.

Maybe the A51 that I got had an issue. Would like to try the A31 again, but it is a hassle dealing with the size and weight of these amps.

Hmm, is there a possiblility that your A31 has been burnt in (used for 100 hours or more) whereas the A51 is brand new out of the box? This certainly can make a difference!

[Chris D]

Whoops, thanks Peter, I meant to say that I don't think there would be a difference in performance between the A31 and A51. Fixed. Agreed that the A21 is a cleaner amp than A51. interesting that you found it to be stronger as well.

[WAFWARRIOR]

A31 and A51 use the same modules

Chris, that's not my experience. The A51 seemed to lack some of the ability to drive the low range that the A21 has. The A51 ran out of juice before the A21. Also, doesn't the A21 power supply have 50,000uF/channel whereas the A51 is 32,800uF/channel. That could explain some of the difference.

No doubt, the A21 is superior to the A51.

As for the A31, I can't tell, but it sure looks like it possibly may be using the A51 modules considering the 98,400uF (=3 x 32,800uF) specification.

You got it. As stated previously, the A31 and the A51 use the same modules.

[JimP]

Hey guys,

Thanks for the comments comparing the A21 to the A51.
I've been thinking of replacing my Rotel RMB 1090 and RB 990 with an A51 plus a A21. I've heard/read elsewhere where others prefer the A21 over the A51. I'll probably start with a couple of A21s for center channel and left right fronts....and continue using (at least for the time being) the Rotel RMB 1090 for the side and back surrounds. I'm got a 7.1 system.

[Orcrone]

I'm considering an A21 for my front speakers. Just wondering how the A23 compares with the A21. I understand it's half the power, but is it closer to the A21 or A51 sonically?

[Chris D]

Hey, Orcrone, welcome to the Guide and Club Parasound! :banana: You'll find that the A21 and A51 are in a different class than the A23. But if you have to compare the three, the A51 is going to be closer to the A23 than the A21 is to the A23.

[Orcrone]

Hey, Orcrone, welcome to the Guide and Club Parasound! :banana: You'll find that the A21 and A51 are in a different class than the A23. But if you have to compare the three, the A51 is going to be closer to the A23 than the A21 is to the A23.

Thanks Chris,l

I don't have a lot of extra room in my entertainment center so I decided I'd rather stay with a single amp and purchased a Sunfire TGA7401.