Tube Amp Archive

Ended up with nos Ge 5751 v1 and 2, Tad 7025 pi and tad 6l6 it sounds amazing.

Hi
Got a kit amp Jtm45 that sounds great recently installed a ppimv with great result. Thinking about going v1 5751 v2 5751 pi 7025 and 6i6 output tubes. Any comments?

The problem is that the amp is in pieces at the moment and its not possible to get in touch with the builder, I've tried. These fotos are from the original layout hope it helps. Any pointers you guys can give me is much appreciated.

The bypass cathode is correct because the leads are reversed. No I don't have any documents or schematic that's whats make it so hard to for me. I will continue to try and figure out the circuit. I know its based on a bassman with some tweaks. Fixed NFB, balanced bias, single channel, bass, middle, ...

Your right there's only 1 channel but why do you add this extra lead from pin 3? Ground wire? The lead to the left is from pin 3, resistor is 2,7K.The other picture is the old board from above. Still learning but making progress.

The builder said (not me) it was a split cathode V1 but as was pointed out it only use one side. Just needed the confirmation.

Can't get my head around this V1 seems like and odd solution. Pin 1 100k 0,022uf, pin 2 68k, pin 3 820 ohm 22uf.

Whats the benefits of a split cathode in V1 on a bassman micro variant?

... I get it just wanted to get a presence control in there but somehow the robrob version of it canceled out all the guitar signal... Detail, both in design (eg schematic) and implementation (layout and actual build) is critical in this game. Making vague references to things you've done as per ab...

Not your question...it looks like you can use some basic help on how to solder. Attached has an excellent tutorial. Some of those solders are fine, others need to be redone. Also, clean off the flux with 90% isopropyl alcohol with a rag or q-tip. Thanks for the tip, im working on it this is my firs...

Its not a 5f6a that's my conclusion but probably based on it. It's impossible to help with the circuit since we have no idea what it should be. Parts of it resemble a 5F6A. Other parts of it do not. And without seeing any interconnecting wires to control panel, tube sockets, power supply, etc., it ...

Ten Over wrote: ↑Sun Mar 10, 2024 4:55 pm

Kee22 wrote: ↑Sun Mar 10, 2024 4:06 pm Its not a 5f6a that's my conclusion but probably based on it. The cap i actually correct because of the original board layout. This is the front and back.

The picture of the bottom is incomplete.

The last wire is connected to NFB resistor 28k and is connected to the 8 ohm tap.

Its not a 5f6a that's my conclusion but probably based on it. The cap i actually correct because of the original board layout. This is the front and back.

Ok Im going to do some reading 470k resistor is a typo it should read 470 just as you mentioned. I really don't know what the 2k7 resistor on the board does but thats how the original layout was wired. Should mention that there's only one input on the amp.

I know the basics of what negative feedback is what I cant figure out is what the leads and resistor to the right of the PI is doing. Shouldn't just the NFB go from 4ohm tap back to the PI? So why the feed from the other side. Regarding the circuit Its not my original build and Im still trying to fi...