Yup, did that - lowered the gain. Helps somewhat... thanks.
Still wondering about the sound a bit... not quite there... about 10db between k2/k3. A bit dark and mudded... but I guess it's still running in.
Got some caps thought! Couldn't help myself. 😀 Happened to have a couple Mundorfs around. A pic at:
http://www.diyaudio.com/forums/pass...-your-diy-pass-amplifier-391.html#post5001681
Still wondering about the sound a bit... not quite there... about 10db between k2/k3. A bit dark and mudded... but I guess it's still running in.
Got some caps thought! Couldn't help myself. 😀 Happened to have a couple Mundorfs around. A pic at:
http://www.diyaudio.com/forums/pass...-your-diy-pass-amplifier-391.html#post5001681
Volume control wiring for BA-3 preamp
Hi Guys, I am preparing for BA-3 preamp ... I am still not able to figure out the wiring diagram for Volume control for this setup. I have a spare Alps - 20K stereo pot lying idle, hope I can use it.... From the pics on the first page it is not very clear how the Goldpoint ATTENUATOR has been wired...Guess those are multi-layered cables...any wiring diagram would be really helpful
Hi Guys, I am preparing for BA-3 preamp ... I am still not able to figure out the wiring diagram for Volume control for this setup. I have a spare Alps - 20K stereo pot lying idle, hope I can use it.... From the pics on the first page it is not very clear how the Goldpoint ATTENUATOR has been wired...Guess those are multi-layered cables...any wiring diagram would be really helpful
Or a detailed pic maybe from anyone who has added a pot to BA-3 pre
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🤣 ZM, want to add it at the input level, just like B1...will it be same for BA-3
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exactly the same
signal hot from selector to top of pot
bottom of pot to signal gnd
pot wiper is hot to preamp input
signal hot from selector to top of pot
bottom of pot to signal gnd
pot wiper is hot to preamp input
I have trouble adjusting the bias. I did not get up to 390mV. Use K170 / J74 paired and IRF610 / 9610. P1 and P2 of 500 Ohms. The power supply is +24.20V and -23.90V. In both channels the same thing happens. Should I raise the value of P1 and P2 to 1K Ohm?
I believe you should. IRF610/IRF9610 (like the Fairchilds) have higher Vgs than the Toshiba parts.
Cheers,
Dennis
Good times. I can't wait to get this thing assembled in a box and hear it. I too did the unspeakable and used IRF9610 and IRF610.
I have a second PCB and may just go ahead and order the FQP3P20 and FQP3N30 but let me hear the IRF devices first.
I have a second PCB and may just go ahead and order the FQP3P20 and FQP3N30 but let me hear the IRF devices first.
Can we take out a balanced output from the BA3 preamp board? If yes which connections should I be using as I want to pair with XLR cables to my Aleph J. Also can I give balanced input from my DAC to the BA3.
They're really not as hard to remove as you might think...heat the outside pins from underneath one at a time rocking the trimmer back and forth...then the inside pin...then outsides again...keep this sequence up until it's out.
It's helpful (I would say essential) to have a pcb holder for this.