I mentioned the other day I built an Amp Camp Amp.
Here is the back story:
I bought an Amp Camp kit for my daughter for Christmas hoping that helping her build her own amplifier to use with the Andrew Jones speakers I gave her last year would nudge her away from her iPhone and Bose Bluetooth speaker and into the world of moderately priced real HiFi.
Unfortunately she was not able to make it home for the holidays.
The kit had taunted me for nearly 2 months leading up to and following the holidays.
I wanted to hear it.
I caved and built it the other night. (I'll buy her another).
This little amp along with the PASS B1 I built earlier to give to her with ACA is simply amazing.
Anyone reading this on the fence?
My advice, do it. Maybe two running balanced dual mono. That is my new plan.
Cheers,
-BB
Here is the back story:
I bought an Amp Camp kit for my daughter for Christmas hoping that helping her build her own amplifier to use with the Andrew Jones speakers I gave her last year would nudge her away from her iPhone and Bose Bluetooth speaker and into the world of moderately priced real HiFi.
Unfortunately she was not able to make it home for the holidays.
The kit had taunted me for nearly 2 months leading up to and following the holidays.
I wanted to hear it.
I caved and built it the other night. (I'll buy her another).
This little amp along with the PASS B1 I built earlier to give to her with ACA is simply amazing.
Anyone reading this on the fence?
My advice, do it. Maybe two running balanced dual mono. That is my new plan.
Cheers,
-BB
Attachments
It will sound the same, whatever the measurements.
Duly noted. The layout for the back panel is done and holes are being drilled.
2 ACA's in bridged mono are making just fantastic music for me.
Your plan is sound, go for it.
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I'm a little stumped and could use some assistance. I finished one of my pair of monoblocks, and one channel isn't working - no sound at all. That being said, I do hear the speaker thump when I turn the power on and off.
I've measured all of the voltages from Step 56 (troubleshooting), and everything checks out.
Appreciate any suggestions for the next places to look.
I've measured all of the voltages from Step 56 (troubleshooting), and everything checks out.
Appreciate any suggestions for the next places to look.
Check wiring and hookup wiring, is the switch in the back in the right position... I assume you were testing in stereo and one channel did work?
Here's a picture of the back panel wiring - it's the red/right channel. It's a bit hard to see, but the green wire only goes to the tab on the RCA jack (and to IN G); the red wire (to balanced), white wire (to IN+), and the resistor all go into the middle hole of the RCA jack.
And this is the board; and from the other side.
AFAIK, the input wiring is okay, but appreciate more eyes.
And this is the board; and from the other side.
AFAIK, the input wiring is okay, but appreciate more eyes.
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A few questions.
Is the switch on noise a 'burp' or fizz, or a thump? Is it the same both sides?
Are you using the RCA or XLR inputs?
If it is the RCAs, have you swapped the left and right leads round, is your source OK?
Check the resistance from the RCA outer ring to centre connector. It should be about 45 - 50k ohms. Compare to the good side.
No wires touching the heatsink behind the board, etc.
Let us know. Alan
Here are the details of the test I just ran:
Stereo/Mono switch is down for Stereo.
Connected an RCA cable from my pre-amp to the red/right channel, and connected the speaker to the right outputs.
Sound at power-on: more of a fizz. If I power the unit off and then on quickly, then I get a thump; if I give it ~10 seconds or more, I get the fizz at power-on again.
Sound at power-off: thump
**I was incorrect when I said that there is no sound. If I stick my ear into the speaker, I can very faintly hear the music with my pre-amp at ~30. So it isn't that there isn't any sound - it's that there almost isn't any sound at all. If I turn the pre-amp up to 100 (max), I can hear music, but it's nowhere near as loud as it should be. (This channel at 100 is significantly quieter than my working channel at 30.)
Then, all I did was move the RCA cable from the right/red channel to the left/white channel, and moved the speaker wire from the right to the left outputs. I didn't change the source, RCA cable, speaker wire, or speaker - the only thing that changed was the ACA channel. (Remembered to turn the pre-amp back down to ~30 before powering up!)
Sound at power-on: similar fizz as the right channel, music starts playing at a normal level almost immediately after the fizz. Also same behavior if I power the unit off and then on quickly (thump), but if I give it ~ 10 seconds, then I get the fizz at power-on again. Didn't bother testing more volume - I can hear it just fine at ~30.
Sound at power-off: thump
Red/right works its way up to 50.30k ohms; white/left works its way up to 50.28k ohms.
I need to go to bed - will pull the amp apart on Sunday to verify nothing is touching the heatsinks.
Thanks again.
Stereo/Mono switch is down for Stereo.
Connected an RCA cable from my pre-amp to the red/right channel, and connected the speaker to the right outputs.
Sound at power-on: more of a fizz. If I power the unit off and then on quickly, then I get a thump; if I give it ~10 seconds or more, I get the fizz at power-on again.
Sound at power-off: thump
**I was incorrect when I said that there is no sound. If I stick my ear into the speaker, I can very faintly hear the music with my pre-amp at ~30. So it isn't that there isn't any sound - it's that there almost isn't any sound at all. If I turn the pre-amp up to 100 (max), I can hear music, but it's nowhere near as loud as it should be. (This channel at 100 is significantly quieter than my working channel at 30.)
Then, all I did was move the RCA cable from the right/red channel to the left/white channel, and moved the speaker wire from the right to the left outputs. I didn't change the source, RCA cable, speaker wire, or speaker - the only thing that changed was the ACA channel. (Remembered to turn the pre-amp back down to ~30 before powering up!)
Sound at power-on: similar fizz as the right channel, music starts playing at a normal level almost immediately after the fizz. Also same behavior if I power the unit off and then on quickly (thump), but if I give it ~ 10 seconds, then I get the fizz at power-on again. Didn't bother testing more volume - I can hear it just fine at ~30.
Sound at power-off: thump
Red/right works its way up to 50.30k ohms; white/left works its way up to 50.28k ohms.
I need to go to bed - will pull the amp apart on Sunday to verify nothing is touching the heatsinks.
Thanks again.
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Before taking it apart -If you have an oscilloscope I would look at the audio signal flow to see if the signal is actually getting to the input stage. I have had defective rca jacks in the past that produced a similar problem. You may be able to follow the signal with a DVM If you don’t have a scope.