PA-1 Amp for Center Channel, Auto-On and mechanical issue

[blaze]

I recently purchased a PA-1 to connect with my XMC-1, via balanced XLR connection, and drive a Martin Logan ESL center channel. I’ve had (3) issues and would be curious to know if these are representative of the product and support:


1. The XLR cable retention mechanism is apparently cosmetic only. It does not actually function to retain the cable (or at least not the Emotiva XLR cable that I’m using).
Certainly not a deal-breaker for my app, but does beg the question why.
2. The auto-on feature requires significant input level before activating. By “significant”, my reference my sub input (which also has “auto-on”) and turns-on at a volume level setting typically less than 14 steps (db’s on the front display of the XMC-1) than does the PA-1. This means sometimes needing to increase the volume to active the PA-1 and then turning down for listening.

3. Response from Emotiva’s service, for both the above features, has been: “don’t use those features”. Actually, to be fair, in the case of #1, they did offer the apology of “sorry about the mechanics”.


I have read other comments about auto-on, but wondering if the sensitivity issue has been quantified (or just based on relative performance of other components … as in my case). And if these issues are typical of other’s buying, use and service experience?


Other than these initial problems, the amp seems to be excellent for the price. 

Thanks,

Dave

[davidl81]

Jul 16, 2020 19:41:25 GMT -5 blaze said:

I recently purchased a PA-1 to connect with my XMC-1, via balanced XLR connection, and drive a Martin Logan ESL center channel. I’ve had (3) issues and would be curious to know if these are representative of the product and support:


1. The XLR cable retention mechanism is apparently cosmetic only. It does not actually function to retain the cable (or at least not the Emotiva XLR cable that I’m using).
Certainly not a deal-breaker for my app, but does beg the question why.
2. The auto-on feature requires significant input level before activating. By “significant”, my reference my sub input (which also has “auto-on”) and turns-on at a volume level setting typically less than 14 steps (db’s on the front display of the XMC-1) than does the PA-1. This means sometimes needing to increase the volume to active the PA-1 and then turning down for listening.

3. Response from Emotiva’s service, for both the above features, has been: “don’t use those features”. Actually, to be fair, in the case of #1, they did offer the apology of “sorry about the mechanics”.


I have read other comments about auto-on, but wondering if the sensitivity issue has been quantified (or just based on relative performance of other components … as in my case). And if these issues are typical of other’s buying, use and service experience?


Other than these initial problems, the amp seems to be excellent for the price. 

Thanks,

Dave

I just keep my PA-1s on in my living room with my Martin Logan’s. They run super cool and burn very little energy anyway. But yeah it’s been reported by others here that the auto on needs a decent amount of gain.

[daveczski65]

Same here .just leave them on all the time..i have same issue.

[leonski]

First? ONCE the amp is triggered on, can you lower the level and it STAYS on? My Parasounds with the same feature tends to shut off if the level gets TOO low. And this is with very low sensitivity speakers,
so I'd presume the output was on the high side for any given level.

And secondly? Due to the extremelly LOW housekeeping power, the ONLY reason to turn 'em off would be some kind of annoying 'THUMP' or 'POP" when other stuff is turned on or off. Such nasties probably will
not be effected by VC level. Again? My Parasound PRE will put a nasty thump into the HEADPHONEs at power off. So I'm careful to unplug the cans prior to power-off. NO SUCH problem when connected to speakers.

If you live in an area with Thunderstorms and such? (I lived in Florida, so I KNOW) my opinion would be that when a storm blows thru, UNPLUG ALL POWER.    Even the cable from the wall if you have small dish or
central cable.....

[vcautokid]

Yep if the PA-1 is on all the time, you don't need to worry about auto or trigger anything. Makes life real simple. Isn't time we got easy in our life? The PA-1 should not be bothered by staying on 24/7 either. It is one very efficient amplifier and a very cool runner. I am starting a new project soon and the PA-1 may figure into that equation.

[leonski]

Jul 18, 2020 23:31:35 GMT -5 vcautokid said:

Yep if the PA-1 is on all the time, you don't need to worry about auto or trigger anything. Makes life real simple. Isn't time we got easy in our life? The PA-1 should not be bothered by staying on 24/7 either. It is one very efficient amplifier and a very cool runner. I am starting a new project soon and the PA-1 may figure into that equation.

'D' amp high efficiency claims are at or nearly at Full Power.    Efficiency drops at lower and more reasonable and useful levels.
At ZERO out put, the efficiency is ZERO, as well.     But since the housekeeping power is only a few watts, that isn't a problem, usually.

[vcautokid]

Nope not really. Many D amps in the pro world for instance do very well. As a matter fact much less self heat than and weight of linear designs. Note I didn't say better. From a packaging standpoint and efficiency when pushed a class D has its plusses like you said. At less work yeah you are right there, but in practice not a big deal. Theory sometimes isn't real life for many. That is including me. Everyone is different on how this all applies to them. Makes the hobby fun and interesting.

[leonski]

Pleasee show me some data. I want measurements of some sort.

Also? I may still be able to find the B&O datasheets which show efficiency which they take at full power and is typically in the 80s or 90s.

By the laws of physics, I suspect it is immutable that efficiency drops as power does. The possible exception would be lowering bias which would

result in an Class 'B' amp bias at the lower power range. Not good for sound, methinks.

icepower.dk/products/other/asp-series/#comparison-chart

Scroll down to 'Key Performance Parameters' and see that the ASP modules ran 83% efficient which given the on board SMPS I must assume is 'plug to speaker'.....

The power / efficiency curve for 'D' amps IS very steep.   But at useful or more common power levels?    No where near the advertised claims.

And STILL and all?   At some point you need to be connected to a speaker which rarely exceeds maybe just OVER 2% efficiency.    So your entire system is LESS than that.......