All my solder connections are solder to the leads on both sides of the boards.
I checked every resistor on the board including the trimmers. Everything is within spec. except the 10K resistors which give a reading that rises. Is this because the they are in circuit with the regs? Also I removed the caps. My DMM only reads capacitance to 200 uF. but charging/discharging test with DMM indicated they are good.
It is not certain that it comes from there but it does not cost anything to test.
With a tester to continue (beep) between the two holes circled in red the measurement must be able to be tested.
Inductor holes show continuity (beep)
With the transistors, and caps off the board are there any tests I can do with my DMM with the board powered?
@BRN
Have you overcome the problems yet?
If not see post 809 above as one elcap is wrong polarity.
[I posted 809 without ref. as to which builder's picture was involved!
Thanks for the catch. The buffer has played fine. I would have thought that a cap would have gone bad.
They should be as I swapped them from ones on the good board, and the ones I removed from the bad board are now working on the good board.
I just reordered most of the BOM from Mouser, so since half of the board has already been stripped of parts, that might be a good idea rather than putting a bunch of new parts on a questionable board. Yeah - please send me a new board, and PM me the bill.
Thanks,
Lacro
Received the new board, but didn't use it. With some new parts I was able to get the problem board up and running. The Kuartlotran is sounding great in my system. Thanks for all the help with solving my issues.
Good to hear Lacro. I wonder what the problem was?
Scaling the buffer up to higher power levels increases thermal distortion, and worsens input impedance. I have experimented with higher current but there always seems to be a large tradeoff. Thermal drift could cause significant offset at the output. Clipping behavior could be very bad for your headphones and your ears. So this kind of design takes some work. I may do some experiments.
Scaling the buffer up to higher power levels increases thermal distortion, and worsens input impedance. I have experimented with higher current but there always seems to be a large tradeoff. Thermal drift could cause significant offset at the output. Clipping behavior could be very bad for your headphones and your ears. So this kind of design takes some work. I may do some experiments.