Emotiva xpa-1 - Page 4

Originally Posted by Jrunr

I wonder if these would be well suited to PSB Synchrony One towers... Any thoughts?

Originally Posted by Jrunr

I understand that as far as volume is concerned, but are there any other differences in sound quality? This is a predominately a home theater set-up so i will need more than two channels...

Originally Posted by Jrunr

Anyone???

Originally Posted by Jrunr

Actually I was wondering if there are any real sonic or sound quality differences between the XPA-1, 2, and 5 when used in a HT 5.2 configuration. I know that if I am listening to two channel stereo, the XPA-5 will put out more than its 350 stated whats with my PSB Synchrony speakers. So, how does that translate to SQ or performance vs the stereo or mono Emotiva amps?

I have included a link to the PSB Synchrony site:

http://www.psbspeakers.com/products/Synchrony

and the Synchrony One towers:

http://www.psbspeakers.com/products/.../Synchrony-One

lastly, my CC speaker:

http://www.psbspeakers.com/products/...ynchrony-One-C

Thanks

Originally Posted by strindl

There are differences in sound and capability between the XPA amps. The XPA-1, XPA-2, and XPA-5 were each designed with a specific purpose and they perform best when used for their designed purpose. That would mean that it would be better to use an XPA-2 or a pair of XPA-1's if you are driving a two channel system. While the XPA-5 uses the same 1200 VA toroidal transformer as the other two amps mentioned, that power is designed to be split between all 5 channels. If you use it in two channel mode and really push it to it's limit, you will be pushing more power through the power output stages of those two channels than the designers intended for long term durability.

The XPA-2 for example uses a 1200 VA toroidal transformer and 45,000uF of effective storage capacitence , along with 12 output devices per channel. The XPA-5 uses that same transformer with 60,000uF of storage capacitence and 6 output devices per channel. The XPA-1 again uses the same transformer but backs that up with 120,000uF of storage capacitence and 24 output devices per channel.

Originally Posted by MichaelJHuman

I should suggest that protection circuits and voltage supply rail limitations mean there should not be a real problem running two channels from the XPA-5 amp. What do you think happens when people are playing a stereo source with the XPA-5? I can't agree 100% with your assessment.

I am a bit lost of exactly what Jrunr whats. He's posting to multiple threads asking a lot of questions, so I sense some confusion maybe.

The XPA-5 should work fine for his needs, IF I understand his needs.

As for sonic differences between XPA amps, who knows. You would expect nearly identical circuit topologies with differences due to output devices, and power supply. Without careful listening tests, I would assume XPA amps sound a bit much the same.

Originally Posted by strindl

For the normal user, an XPA-5 is fine being used in two channel mode ...HOWEVER...if you are someone who really pushes your amp in two channel mode to the limit on a regular basis, an XPA-5 is really not the right choice . While the power supply is capable of providing plenty of juice to those two channels...it does have more storage capacitence than an XPA-2 after all....you are pushing all of that power through 6 output devices per channel instead of the 12 per side in the XPA-2. That's probably not what the designers intended.

Originally Posted by MichaelJHuman

Well, I certainly hope the XPA-5 does not have the flaws you imply. I would not suggest it to anyone if it did.

While it's never good to drive you amp to the limit, it's the job of the amp maker to prevent over current conditions.

While I can't prove the XPA-5 is perfectly adequate for his uses, I don't think you can prove it's not, unless you have the service manual and have figured out how the protection circuits work, what the supply voltage is, what the limits are on the output devices, etc.

You would have to prove the supply voltage will not be limited, and is at it's limits dangerous to the output devices. A horrible design if true.

The short answer to the question is yes, you can use the amp with fewer channels running than what it was designed to do. As long as you stay within the power specs we state and give the amp plenty of air to cool, this won’t be an issue.

However………..

This is a question where the answer is both easy and complicated at the same time. You see when you use less than all five channels. All the energy of the power supply (well in excess of 1K watt) is directed at however many channels that are being used (which are designed to dissipate 300 watts RMS). This means the rail voltage on a specific channel goes up significantly which causes that channel to produce more heat (because it is dissipating more energy). Thus it is going to need adequate cooling to keep from stressing the channel(s). With the increased rail voltages you get more power and as long as you stay within the rated spec, no problem. But how do you know if you are within the rated spec? Honestly there isn’t any way for the average Joe to know without a lot of sophisticated gear to measure the output. So if you plan on driving the amp hard, you could over drive the module which isn’t good. But if you listen at a reasonable level, say something short of your ears bleeding then no problem. Honestly there are a lot of other things that should be considered, like the impedance curves of the speakers (how low do they dip), what other equipment is in the system (are they using an EQ with a lot of boost), etc. but we won’t go down those roads (not enough time). So there are a lot of factors involved in what we recommend and since we never seem to have all the information, I always tell everyone to err on the side safety. Stick with what the equipment was designed to do and everyone wins. I have told a lot of people that we don’t recommend using the multi-channel amps for strictly stereo or mono-block use. If you want a high power stereo or mono-block amp, then that is what you should buy. Using anything in a manner other than what it was designed for is never a good idea. ;D

Originally Posted by MichaelJHuman

That implies they run their rail voltage high to compensate for voltage drop under load, and have no limiter. I can understand the high rail voltage, but why does their limiter not compensate for the situation.

After all, even if you normally use the XPA-5 for movies, you certainly would use if for music too, and why should you worry about it?

I wonder if he considered the implications of his answer to buyers. I think it's just CYA myself for the majority of users, who will not have any issues using the XPA-5 for two channel music.

Originally Posted by MichaelJHuman

One thing to note, tbe XPA-5 can do 20x5 watts continuous power. Which means the output devices should be able to handle 200 watts continuous. If I read that post right, they can handle 300 watts continuous (multiple output devices spitting the load maybe.)

I think I understand what rep ( I think Lonnie is a rep?) is saying. But you have to deaf to sit in a room with more than 200 watts continuous being sent to your speakers.

If you have no concern for your hearing and have speakers that won't blow up under a continuous 200 watt load, with 90 dB of efficiency, if my numbers are right, the average SPL level would be over 110 dB (at one meter) with 200 watts. Peaks could be much higher.

So ok, while I think I understand what Lonnie is saying, I still think it's CYA and there is not much to be concerned about.

Originally Posted by Jrunr

Is there a sonic difference between using the rca or xlr inputs?

Originally Posted by Jrunr

Is there a sonic difference between using the rca or xlr inputs?

Originally Posted by Votinh

They still have the ratings for the XPA5 in 1-5 channel listed at their online store http://emotiva.com/shop/cart.php?m=product_detail&p=4

Originally Posted by WilsonL

how would the XPA-1 behaves as a sub amp?

Good tight bass liked what the krell amps do with the speakers?

Originally Posted by WilsonL

how would the XPA-1 behaves as a sub amp?

Good tight bass liked what the krell amps do with the speakers?

Originally Posted by Hammie

What would be a better option? A single XPA-1 per speaker or a single XPA-2 per speaker and bi-amp?