Amp Camp Amp - ACA

Bfpca - unfortunately, I don't have an oscilloscope, but my multimeter (Fluke 115) has a frequency measurement. I'm not sure if that will work, but I'll test tomorrow comparing the working and non-working channels.

If you put your DVM on ac volts you should be able to see the input signal. If it is a test tone it will show up as a low ac voltage. If you are using music as a test signal it will show a low varying ac reading. The DVM frequency range is not really suitable for this test.
 
Bfpca - unfortunately, I don't have an oscilloscope, but my multimeter (Fluke 115) has a frequency measurement. I'm not sure if that will work, but I'll test tomorrow comparing the working and non-working channels.
Have you checked there isn't a short between the MOSFETs and the heatsink of the affected channel?

The fact that there IS music should say this isn't the place to look... perhaps something else is shorting against the heatsink?

One last swap test: have you changed the inputs to discard source fault?
 
Did a search and did not find what I needed so apologies if that has already been sorted, please direct me to the right place if that is the case.

Has anyone posted or can post a simplified wiring diagram for an ACA v1.6 for only a balanced mono design i.e. front power switch, rear panel only power in, XLR in and +/- speaker out.

Thanks in advance.
 

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Amp Camp Amp V1.6 Build Guide - diyAudio Guides

Step 34 photo 2

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I have a pair of KEF R900 speakers and a pair of Amp camps. Should I run the Amp camps in bridged mono or parallel mono? Balanced is not currently an option. The speakers are 90db, nominal impedance is 8ohms and minimum is 3.7ohms.

Also, any reason not to bi Amp this speaker with another pair of acas? If I did, would it change the ideal monoblock mode? I plan to use a Schiit preamp to control volume. Their preamps have two sets of single ended outputs, always on and identical.

Thanks!
 
I have a pair of KEF R900 speakers and a pair of Amp camps. Should I run the Amp camps in bridged mono or parallel mono? Balanced is not currently an option. The speakers are 90db, nominal impedance is 8ohms and minimum is 3.7ohms.

Thanks!

The simple solution (and fun too!) is to try it both ways and see which you like best. It’s not really possible to predict 100% what will work best for your speakers. You might also consider the tweak which raises the input impedance of the amp. I have shown one way with the “Premium ACA” mods, and there are others as well. The 24 Volt power supply seems to work best in almost all cases.
 
Another one lives! Just fired it up yesterday and it sounds amazing! A few notes on gain and power from my experience since this was something I was concerned about. I am running FF105WK speakers (88db sensitive) plus a sub and have a cap on the input side to roll off starting around 120Hz. For a pre I am using a Schiit Vali 2, Mani for phono pre and a Modi Multibit for digital inputs. Living room is 16' x 19' and I sit 10' away from the speakers.

I have 2 gain settings, 2 db (1.2) and 14 db (5). On the high gain setting it will drive the amp to clipping, at least this is where I notice distortion, around 90% volume. I find this extremely loud, a volume far higher than I would ever consider using. At low gain the max volume is still higher than what I would ever use, after around the 80% mark to me it's just "lets see what this thing will do" level. As always your mileage may vary but this is my experience.

One more thing. If you are like I was a year ago a bit intimidated and wondering if you can put one of these together do it. I am an accountant by trade and completely unskilled in the world of audio electronics even at an amateur level. You can do it. Thanks all for your efforts making something like this available to the less skilled like me, it is fantastic!
 

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