The filters to select in this case would be -
Film Capacitor
220pF
Radial leads
polypropylene
5mm lead spacing
in stock
FKP2D002201D00HA00 WIMA | Mouser
Film Capacitor
220pF
Radial leads
polypropylene
5mm lead spacing
in stock
FKP2D002201D00HA00 WIMA | Mouser
So I took the chassis with the BA-3 Preamp and removed the gain stage and replaced it with the purple boards.
These have the alternate outputs, in the TO-126 package, and have plenty of drive for my low-impedance headphones. PSU voltage is high enough to drive high-impedance phones as well.
The BA-3 preamp. Taping the switches and attenuator up as work is done on it. Yes, the transformer is enormous, it was intended for a chipamp project that never happened. It's super quiet and was the right voltage. And was on my my shelf...
Installed with the purple boards.
The headphone jack is a switched type, it will pass through the signal if no plug is installed, and send the signal to headphones if installed. So the jack is wired first on the output of the boards, and then output RCAs are further downstream.
I'm going to install the Broskie regulator (and a more reasonable transformer) next and take more photos of the connections.
Very Nice!
Per 6L6...
The only requirement, which is very minor, is you must use a transformer with dual secondaries. Center-tapped won't work.
So I took the chassis with the BA-3 Preamp and removed the gain stage and replaced it with the purple boards.
These have the alternate outputs, in the TO-126 package, and have plenty of drive for my low-impedance headphones. PSU voltage is high enough to drive high-impedance phones as well.
The BA-3 preamp. Taping the switches and attenuator up as work is done on it. Yes, the transformer is enormous, it was intended for a chipamp project that never happened. It's super quiet and was the right voltage. And was on my my shelf...
Wasn't the BA3 a 24 volt power supply? (I think that is what I used ) I just ordered the Glassware power supply in 18 volt...guess it could be 24V with a couple resistor changes?
Russellc
Installed with the purple boards.
The headphone jack is a switched type, it will pass through the signal if no plug is installed, and send the signal to headphones if installed. So the jack is wired first on the output of the boards, and then output RCAs are further downstream.
I'm going to install the Broskie regulator (and a more reasonable transformer
Wasn't the BA3 a 24 volt power supply? (I think that is what I used ) I just ordered the Tubecad power supply in 18 volt...guess it could be 24V with a couple resistor changes?
Russellc
Hmmmmm, somehow I tried to edit Tubecad to glassware and it appeared between some of your pics, and didn't change here! Don't know how I did that....( on my quote, not your original post )
Dual/Bipolar LV-Reg
Russellc
Dual/Bipolar LV-Reg
Russellc
Nutz, I should have got another 3 position selector from TubeCad, (like I used in BA3 preamp) when I ordered the power supply. Oh well, lets see if I can dig something up in my various parts boxes. I have an extra 25K ladder stereo volume pot like I used in BA3 preamp build already, unless another value would be better? I'll check posts and see what others used.
Russellc
Russellc
Phew, all those numbers on the paper are making me dizzy!
That is really great news, maybe some BA3’s for sale...
What is the highest stable gain values?
The reason I ask is I’ve placed them inside my F4 and the SPL is still wimpy.
I’ve always wanted to try and test a circuit for distortion but never really found enough information to be comfortable, what would be the most economical test rig does anyone have a link to send me down the worm hole?
That is really great news, maybe some BA3’s for sale...
What is the highest stable gain values?
The reason I ask is I’ve placed them inside my F4 and the SPL is still wimpy.
I’ve always wanted to try and test a circuit for distortion but never really found enough information to be comfortable, what would be the most economical test rig does anyone have a link to send me down the worm hole?
The BA3? I use 2sk. Well it doesn't mean that this one is better, just different.
I wont be divesting BA3 FE either...I have two. Always needing more preamps. A Couple of tube ones arent used so much, also have a B-1. Building this one as well as finishing DGB3.....also 1/2 finished Pumpkin-Shunty....never too many pre amps! Some systems need no gain, some need a little, some need a lot. Once Iron pumpkin hits store I will build it. That ought to do, but 6L6 hinted at some other secretive pre project in the works. That's fine, 3 more power amps in various stages too! Sissy sit is next, then either M25 or Vfet kit needs built. F7 clone and J2 clone parts collected, going to put F7 clone in F5 box...Absolutely no rest for the wicked.
Russellc
Russellc
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