A turn on thump (assuming thats what it is) will look a lot worse into a high impedance load of a multimeter than what it will look like across 8 Ohms.
Maybe it's not as bad in reality as initially stated.
Tested it tonight for the first time. It's working great! No pops either on or off. I have it hooked up to some Dayton Audio BR-1's that I bought a long time ago, and even for a crappy speaker, sounds pretty good. Once I finish my audio rack, the whole system will get assembled together.
Here she is. BTW, I have two pet rabbits that like to hop around and chew on things, hence the strategically placed fence.
Guys, now that I have this thing going with the TT and my preamp, I noticed that the left channel is significantly louder than the right. To make sure it's not my preamp, I hooked my iPhone up to a second set of inputs and it's the same thing. Is there any way to remedy this?
After unplugging the louder left channel, it actually sounds like the right channel is pretty distorted. I shut the TT off and re-measured DC offset on the outputs and they're holding steady. Is this something that can be tweaked with R3 on the FE, or am I looking at component failure somewhere? Turning the volume up results is absolute garbage on just that right channel.
Have you swapped channels at the inputs yet?
Have you swapped channels at the outputs yet?
Have you measured the ratio of output voltage to input voltage yet?
Have you swapped channels at the outputs yet?
Have you measured the ratio of output voltage to input voltage yet?
Swapping inputs and outputs results in no change. The problem follows the right binding posts. I thought at first maybe it was one of my speakers, so I crossed the cables and it followed the right channel. I have 3 sets of inputs and switching between any of them results in no change.
To measure input vs. output, I need an AC signal generator or something?
To measure input vs. output, I need an AC signal generator or something?
check for bad solder joints , part values , orientation
so , check everything
if that doesn't help , measure, post here, find CRO
so , check everything
if that doesn't help , measure, post here, find CRO
Well I feel stupid, yet again. This morning before work I was racking my brain and I realize that I never tried swapping the cables that I built. I made the second one a few months back, and since I made them, immediately ruled them out as a problem. Sure enough, a continuity check of the new cable shows a short somewhere. That would pretty much exactly explain my problem. The cables are made from hand woven cat5e, with the colors separated at the ends. I must have missed one. Will rebuild the cable tonight.
...... tough bugger , that BA3 ........ 
No,
download the test frequency put up by Pano.
Use that for your measurements.
There are many over downloads you can use for test signals.
Question for the front-end only:
How much bias are you running? Schematic says 45mA (1V/22R), Nelson hints that 100mA is possible with more heatsinking. Anyone tried this and how did it sound? Unfortunately the boards are not really heatsink friendly but I have some 1 inch x 1/2 thick aluminum bar stock I could use. I've noticed at 45mA the mosfets the mosfets are fairly cool. More bias sounds like a good idea.
How much bias are you running? Schematic says 45mA (1V/22R), Nelson hints that 100mA is possible with more heatsinking. Anyone tried this and how did it sound? Unfortunately the boards are not really heatsink friendly but I have some 1 inch x 1/2 thick aluminum bar stock I could use. I've noticed at 45mA the mosfets the mosfets are fairly cool. More bias sounds like a good idea.
I have only biased to just a hair under 1, sounds glorious! I have ordered a bunch of larger heatsink, the ones I have now are not that large and get fairly toasty, on both BA-3 pre and power amps.
Russellc
"Schematic says 45mA (1V/22R)".....you didnt read the post...nor the build guide....call for 1 volt across the resistor. Would be 45 mA
Russellc
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