The Amp Garage

GAStan wrote: ↑Mon Apr 22, 2024 6:35 pmWould I have won? :wink:

You have a point there :^) To me, one component being in series with another means they have the same current.

GAStan wrote: ↑Mon Apr 22, 2024 5:59 pmDid I get it correct?

Would you have bet money that you did? ;^)

Hi Ryan, it's this. As drawn vs. the red. Your layout shows the red.

Raoul Duke wrote: ↑Mon Apr 22, 2024 12:32 pm I wonder how the layout’s dropping string values would interact with a Bassman spec PT? I realize the PI is different and that plays a part.

By the time you get to the preamp nodes it doesn't mater. If you keep the same dropping string, B+3 to 4, and B+4 to 5, the PI will fall into place.

The swap between the 10k & 2.2M was either a tip I received from someone (likely) or based on observation of other amps. The stability of the reverb was not great with 2m2 in series with the reverb send pot. I also realized that feedback made much more sense with 2m2 and the 10k in series with the ...

Re the voltages, most important is to get the V1 plates into line. As I said, I don't have any direct BM experience, and there aren't any voltages listed on the layout. The TF-130 PT was a Fender Twin replacement, so you should shoot for 440-450V B+1. I think I’m hung up on all the different color r...

Cheap, too!

sluckey wrote: ↑Thu Apr 18, 2024 4:43 pm I just installed a 100K master volume pot in my single channel DR. Lets you control how much signal is sent to the PI. Works fine for me. Take a look...
https://sluckeyamps.com/tdr/tdr.pdf

Gotta say, this is a really nice little amp! Love the look, too.

I have no idea why Fender wanted such high voltage on the reissue Bassman. The original 5F6-A voltage was shown at 450V. That OT look like the solution I think it is? Should be fine. I think you'd be good with the Black Bassman PT, or maybe Hammond 290DX. ...just trying to figure out the V1 resistor...

The Bassman RI would produce a pretty high B+1 voltage, 490V on the '59 Bassman reissue schematic. You could use it and drop the PI and preamp voltages down as you have done before.

Thanks, Erwin. I had to read on from there to find the specific reference: https://ampgarage.com/forum/viewtopic.p ... 42#p427842
Ryan seemed to favor moving the FB (2M2) to the grid side of the 10k, as shown in the latest layout. Do others agree?

None that I can find or recall. Maybe Ryan or Erwin can comment?

The original hand drawn schematic had the 10k between the 2M2 and the grid. Should be a lot more feedback with the 2M2 on the grid, like Ryan's layout.

Mark wrote: ↑Sat Apr 20, 2024 1:09 pmWhat makes you think the problem is exclusive to the Hot Rod series Fender amps?

Something I recall reading about some time ago. May be just internet lore, but maybe Fender did end up with the bulk of the bad product from that era.

Raoul Duke wrote: ↑Fri Apr 19, 2024 11:51 am ]Heyboer makes a Marshall type 50w with 3k9 primary, M6 laminate, Dagnall wind pattern. Says “JMP/JCM800 general replacement” designed to work with both 6l6 and EL34 - which sounds about right.

Got a link to that?