FYI for anyone looking into these sorts of install amps, there are similar amps from Extron that come in 1, 2 and 4 channels and up to 400W per channel. Do an Ebay search like this:
extron (xpa-2002,xpa-2001,xpa-4002)
Make sure the amp is not 70V or 100V only and can power 4/8 Ohm loads. These come up all the time, so if you do not find one repeat your search periodically or do a saved search and get sent a notification via email.
You want to look for:
AMP-2210xx
AMP-3210xx
where xx can be T,S, or HT. All of those are 4/8 Ohm compatible and are 1U full rack width size.
OOOoops! Boy did I ever blow that one - paid too much attention to the manual and not the part numbers in detail.
That could have been and "electrifying" purchase for someone . . . Good catch 6thPlanet & Charlie - I stand corrected.
On another note Creston is a billion dollar company. And what’s installed in true “high-end” residences for automated lighting, shades, drapes, security, audio and video and theatres. all controllable from wall mounted touchscreens.
One only has to look at what one glorious JBL are launching to see that the Golden Era in hifi was long ago.
Two 2210T amps arrived in one box and BOY, was I surprised when I went to pick it up off of the porch floor!
Yeow! I thought Class-D was light . . . . more later . . .
@tktran The AMP-2210xx and AMP-3210xx have universal AC input.
One really nice feature I like in these amps is auto-on with detection via the audio inputs. In standby they use like 1W or something. You just leave them on all the time and they take care of powering up and down as needed.
The Crestron amp is definitely cleaner (lower distortion) than the old Pioneer SX-205 receiver that it replaced here in the shop - been listening to it a lot while working on a set of cabinets.
The speakers sound cleaner and not as loud but the SPL is definitely there - gotta be careful as I can feel the floor vibrating 30 feet away from the speakers and it doesn't "sound" as loud as it did with the Pioneer unit - I even dewaxed my ears last night to be sure . . .
I would hazard a guess that Crestron did not make a class-D "chip amp" but designed their own circuit in house. But I never opened up the case on any of the several that I own, so I can't say for sure. The line has been around for several years, so it might even predate IcePower. Could be Pascal I suppose.
I do have one with only 2 out of 3 channels working and I could pop the lid and take a look inside if that would be of interest.
Sorry for not getting around to taking apart a Crestron 2 channel amp this weekend, tktran - got side tracked by the new drum pads and just jammed in the basement and readjusted kit today. (They are awesome, BTW).
One thing I have noticed is that the Output of the Focusrite 2i2 Gen1 isn't hot enough to push the Crestron to max volume (SPL). Not exactly an issue.
@Steve_Lee said:
Sorry for not getting around to taking apart a Crestron 2 channel amp this weekend, tktran - got side tracked by the new drum pads and just jammed in the basement and readjusted kit today. (They are awesome, BTW).
One thing I have noticed is that the Output of the Focusrite 2i2 Gen1 isn't hot enough to push the Crestron to max volume (SPL). Not exactly an issue.
The Crestron AMPs have input stage gain controls on the rear that span -10 to +10dB. Just turn up the gain. When gain is 0dB you need 2.22Vrms to drive the amp to full power.
Anyway I looked up the specs for the Focusrite 2i2 and it supposedly has 10dBu max output on the line outs. That translates to 2.45Vrms, so you should have enough gain on tap. You can increase the gain somewhere upstream in your signal chain, e.g. in the DSP part or whatever app is generating and sending audio data to the Focusrite interface.
Well thanks to this thread I finally wired the Focusrite audio interface (balanced outputs via 1/4" socket) to the LM3886-based test amplifier (Thoman PM40c with balanced input via Neutrik TRS/XLR combo input) with the CORRECT cabling (instead of using whatever cabling I had found laying around)
I put that USB-C Multifunction hub back in. And guess what?
With the HDMI monitors, the USB to coaxial/optical bridge, the miniDSP, the Woofer Tester 3,the USB receiver for wireless keyboard and mouse...
It's dead quiet. Even quieter than when I wasn't using the hub. I really had to check if the amp was on.
So now the air conditioning in the lab is the biggest source of noise...
@tktran The amplifier part is probably where the two toroidal transformers connect. Can you take a pic of that area only? There might be devices underneath the PCB that contact the bottom of the chassis for heatsinking. But you probably should not disassemble that.
@ugly_woofer said:
Looks like a chip amp to me. No discreet output devices and heat sinks
It's a class-D amplifier. No real heatsinking is needed except the chassis itself. I have some Hypex nCORE amps and they are just screwed onto the bottom of the aluminum chassis for heatsinking. I used these in my Cones a Flapping project at the SDC. The chassis gets pretty hot just with the idle dissipation (about 20W) from the nCORE modules. Supposedly Hypex has a somewhat high quiescent current flowing through the output transistors or something. When I had it sitting on a shelf but not playing audio after 1 hour the temp was over 120F. So I changed to the wire rack shelf and this allowed air to circulate past the bottom of the amp and case temps dropped to a more reasonable level.
I use a couple of the Crestron amps here and they barely get warm.
@ugly_woofer said:
You are correct Charlie, but would you consider something like a tpa3255 to be a chip amp?
This is a question that seems to be up for some debate. ICs like the TPA3255 do contain most of the amplifier parts except the output filter. This IS like the LM3886 and other class-AB "chip amps" but that label isn't typically assigned to class-D ICs. Not sure why. But I wouldn't fault you at all for using it in that way.
I think at this point that different models of PC's produce more or less noise injected into the digital and analog signal chains when using USB audio even into a TOSLink [optical] converter.
The Dell Latitude 5520 I am using is noisy as can be - especially when the video screen changes.
The Dell Inspiron e5500 is quieter.
The Dell XPS [now 10 years old with integrated sound card] is dead quiet except for a very low frequency hum sent to a subwoofer when the screen loads an image.
But once the music starts everything is fine because I cannot hear the chattering/hum.
But it makes taking measurements annoying as the screen refreshes and the noise is quite audible.
I should probably burn a CD to contain the test sweeps and try using a dedicated CD player as the signal source and see if that clears any of this up.
I have a Crestron 120 W/ch amp connected [RCA > Balanced-in/shield grounded] to some commercial speakers and USB out to a Focusrite 2i2 and the PC chatter is there, albeit just at very low volume.
Comments
FYI for anyone looking into these sorts of install amps, there are similar amps from Extron that come in 1, 2 and 4 channels and up to 400W per channel. Do an Ebay search like this:
extron (xpa-2002,xpa-2001,xpa-4002)
Make sure the amp is not 70V or 100V only and can power 4/8 Ohm loads. These come up all the time, so if you do not find one repeat your search periodically or do a saved search and get sent a notification via email.
OOOoops! Boy did I ever blow that one - paid too much attention to the manual and not the part numbers in detail.
That could have been and "electrifying" purchase for someone . . . Good catch 6thPlanet & Charlie - I stand corrected.
Haha, hope I didn't cause anyone some headache.
Ok here’s another brain buster.
What’s modules/chips are these amps using (I know that may not matter, as much as the implementation)
Does it accept universal voltage input?
Eg. 240VAC/50Hz?
Looking on the Creston website which shows current models eg.
https://www.crestron.com/Products/Audio/Amplifiers/Commercial-Amplifiers/AMP-8075
there’s I prefix for 240VAC models
https://www.crestron.com/Products/Audio/Amplifiers/Commercial-Amplifiers/AMPI-8075
On another note Creston is a billion dollar company. And what’s installed in true “high-end” residences for automated lighting, shades, drapes, security, audio and video and theatres. all controllable from wall mounted touchscreens.
One only has to look at what one glorious JBL are launching to see that the Golden Era in hifi was long ago.
What? A 8” paper cone to a waveguide?
This was done a decade ago by Mark K
https://www.erinsaudiocorner.com/loudspeakers/jbl_4329p/
Two 2210T amps arrived in one box and BOY, was I surprised when I went to pick it up off of the porch floor!
Yeow! I thought Class-D was light . . . . more later . . .
@tktran The AMP-2210xx and AMP-3210xx have universal AC input.
One really nice feature I like in these amps is auto-on with detection via the audio inputs. In standby they use like 1W or something. You just leave them on all the time and they take care of powering up and down as needed.
OK, both units tested and check-out as fully operational.
Quiet, clean and I adjusted the input pots to have matching voltage output at the speakers using the same cable lengths.
So far, I am quite pleased with this purchase.
The Crestron amp is definitely cleaner (lower distortion) than the old Pioneer SX-205 receiver that it replaced here in the shop - been listening to it a lot while working on a set of cabinets.
The speakers sound cleaner and not as loud but the SPL is definitely there - gotta be careful as I can feel the floor vibrating 30 feet away from the speakers and it doesn't "sound" as loud as it did with the Pioneer unit - I even dewaxed my ears last night to be sure . . .
What class D chip are they using Steve?
Any chance you can pop the hood and have a peek?
I did take one apart and take pics yesterday because I KNEW **you **would be asking but I didn't think to focus upon the chipset. (Dammit!)
I'll try to get to it this weekend . . .
I would hazard a guess that Crestron did not make a class-D "chip amp" but designed their own circuit in house. But I never opened up the case on any of the several that I own, so I can't say for sure. The line has been around for several years, so it might even predate IcePower. Could be Pascal I suppose.
I do have one with only 2 out of 3 channels working and I could pop the lid and take a look inside if that would be of interest.
I picked up an Aiyima A07 amplifier some time ago. Not bad, as an amp for the workshop but only 2 channels.
https://www.audiosciencereview.com/forum/index.php?threads/aiyima-a07-tpa3255-review-amplifier.18984/
Here's a another TI TPA3255 based chip amp for $100:
https://www.audiosciencereview.com/forum/index.php?threads/fosi-audio-v3-amplifier-review.45757/
Be nice to have a (couple of) 4 channel amps use for prototyping, without all the heat/size of class A/B, and with the low cost of LM3886 done right.
Wonder if these Creston amps are based on similar things...
Sorry for not getting around to taking apart a Crestron 2 channel amp this weekend, tktran - got side tracked by the new drum pads and just jammed in the basement and readjusted kit today. (They are awesome, BTW).
One thing I have noticed is that the Output of the Focusrite 2i2 Gen1 isn't hot enough to push the Crestron to max volume (SPL). Not exactly an issue.
The Crestron AMPs have input stage gain controls on the rear that span -10 to +10dB. Just turn up the gain. When gain is 0dB you need 2.22Vrms to drive the amp to full power.
Anyway I looked up the specs for the Focusrite 2i2 and it supposedly has 10dBu max output on the line outs. That translates to 2.45Vrms, so you should have enough gain on tap. You can increase the gain somewhere upstream in your signal chain, e.g. in the DSP part or whatever app is generating and sending audio data to the Focusrite interface.
dBu info here:
https://www.sowter.co.uk/decibels.php
Thanks, Charlie - very useful info.
The wealth of knowledge on this forum is just 2nd to none. No better SINAD!!
Well thanks to this thread I finally wired the Focusrite audio interface (balanced outputs via 1/4" socket) to the LM3886-based test amplifier (Thoman PM40c with balanced input via Neutrik TRS/XLR combo input) with the CORRECT cabling (instead of using whatever cabling I had found laying around)
I put that USB-C Multifunction hub back in. And guess what?
With the HDMI monitors, the USB to coaxial/optical bridge, the miniDSP, the Woofer Tester 3,the USB receiver for wireless keyboard and mouse...
It's dead quiet. Even quieter than when I wasn't using the hub. I really had to check if the amp was on.
So now the air conditioning in the lab is the biggest source of noise...
Did anyone confirm what’s powering the Creston or Extron amps?
There’s a few in my neck of the woods
XPA 1002 for US$60 and 2210T
Edit: I purchased the XPA 4002. Will report back to let you know how it turns out.
https://dropbox.com/scl/fi/g3ui2n21tz0w1sr90jxm2/Crestron-Output-Section-2.JPG?rlkey=qox1wvtq15hxmnyguao8wdlhi&raw=1
https://dropbox.com/scl/fi/3b4goqu16r3du7b8j1lfa/Crestron-Output-Section.JPG?rlkey=3ggbqqanp3710ph254ntihv1p&raw=1
It doesn't really look like a "chip amp" to me.
Looks like a chip amp to me. No discreet output devices and heat sinks
@tktran The amplifier part is probably where the two toroidal transformers connect. Can you take a pic of that area only? There might be devices underneath the PCB that contact the bottom of the chassis for heatsinking. But you probably should not disassemble that.
It's a class-D amplifier. No real heatsinking is needed except the chassis itself. I have some Hypex nCORE amps and they are just screwed onto the bottom of the aluminum chassis for heatsinking. I used these in my Cones a Flapping project at the SDC. The chassis gets pretty hot just with the idle dissipation (about 20W) from the nCORE modules. Supposedly Hypex has a somewhat high quiescent current flowing through the output transistors or something. When I had it sitting on a shelf but not playing audio after 1 hour the temp was over 120F. So I changed to the wire rack shelf and this allowed air to circulate past the bottom of the amp and case temps dropped to a more reasonable level.
I use a couple of the Crestron amps here and they barely get warm.
You are correct Charlie, but would you consider something like a tpa3255 to be a chip amp?
You took photos of the power supply. Amplifier is off to the right. Big transformers are for 70V output.
This is a question that seems to be up for some debate. ICs like the TPA3255 do contain most of the amplifier parts except the output filter. This IS like the LM3886 and other class-AB "chip amps" but that label isn't typically assigned to class-D ICs. Not sure why. But I wouldn't fault you at all for using it in that way.
Well thanks to this thread I now have a Extron amplifier.
Here are the innards-
Does anyone know the story behind Crestron or Extron? Are they related companies?
Here are the outtards:
Enough to tri-amp a 3 way with just 2U!
Made in Country of Origin.
Ah the olden days-
Sweet!
I think at this point that different models of PC's produce more or less noise injected into the digital and analog signal chains when using USB audio even into a TOSLink [optical] converter.
The Dell Latitude 5520 I am using is noisy as can be - especially when the video screen changes.
The Dell Inspiron e5500 is quieter.
The Dell XPS [now 10 years old with integrated sound card] is dead quiet except for a very low frequency hum sent to a subwoofer when the screen loads an image.
But once the music starts everything is fine because I cannot hear the chattering/hum.
But it makes taking measurements annoying as the screen refreshes and the noise is quite audible.
I should probably burn a CD to contain the test sweeps and try using a dedicated CD player as the signal source and see if that clears any of this up.
I have a Crestron 120 W/ch amp connected [RCA > Balanced-in/shield grounded] to some commercial speakers and USB out to a Focusrite 2i2 and the PC chatter is there, albeit just at very low volume.