Tube Amp Archive

Thanks everyone for your ideas and input! I will take all of these ideas into consideration!!

Hello, I am looking for suggestions on what I should build next! I have recently come into an old piece-of-shit (broken) Crate amp that I took the chassis out of and am looking for a new circuit to retrofit into the cabinet. I know how to design my own chassis and circuit board for the amp, I just d...

sorry if you think I'm just wasting your time, I promise that's not what I'm trying to do. I'm trying to learn as much as I can about this, and I really appreciate your help. When I get home from school, I will post a marked-up schematic with all of the voltages going to the plates (I think they're ...

maybe I'm using incorrect terminology. Right after the signal goes from the choke to the first signal step-down resistor, I put an extra resistor. Is this not what Martin meant? I again have absolutely no idea what I'm doing, so i could have done something completely wrong. Sorry if I misinterpreted...

Just put in an extra 10k ohm 1 watt screen resistor. The A+ (With all tubes plugged in, no standby switch on because the amp doesn't have a standby switch) now reads at 358vDC, which is well within the tolerance of the 365vDC that it should be at. It sounds incredible now. Thanks everyone for your h...

Oh im sorry. I still don't have the terminology completely down.my new understanding is that the The screen filter cap is the 470 ohm resistor on the tube socket lowering the voltage going into the output tubes. Let me know if this is correct. Im trying to learn all I can about this. Thanks to all o...

You dont have to delete my mistake, I misread his name. I apologize for this accident and will make sure to be more careful in the future.

SOrry again.

OMG I'm so sorry Sluckey. I didn't mean that. I have edited it above. I'm so sorry I legitimately thought that that's what your name was... I guess I should read more carefully. I will trace it whenever I get time. the screen resistors are the ones on the PCB that control how much voltage gets into ...

Hello, sorry for my absence yesterday That 290CX will be fine for a 2 x 6L6 amp. You say your B+ is 500vDC instead of 365vDC. You need to qualify that by telling us what conditions you measured 500V, ie, was the STBY switch in standby mode? Or were the output tubes plugged in? Things like that. Once...

Ok. Will a 35V difference really make this much of a difference? Do you have a recommendation for an output transformer? This is the one Hammond said to use, but they of course could be wrong. I will do some research and let you all know what transformer I plan on getting. Thanks again for all of yo...

Sorry thats what I meant, it wasn't putting out 365VDC it was putting out 365VAC. I mistyped. Sorry!!

Hello All, I have figured out that the amp is running hot, and I think this may be the cause of toe overdriven crackly problem. According to the Schematic, the C+ voltage should be at about 275vDC, but my C+ voltage is significantly higher, coming in at around 375vDC. This is signifigantly higher th...

Stevem wrote: ↑Mon May 01, 2023 10:45 pm Where is that black wire that spans between the two preamp tubes going to and from pin wise on both of those sockets?

This is the cathode capacitor and resistor pair for the two preamp tubes. On the original fender schematic, it has them sharing one.

Took a quick look at your board. It seems that all four of those black bypass caps are installed backwards. This ^^ the dimple is the positive side, that's supposed to be connected to the tube side of the board, you've got the positive all connected to the ground. ~Phil Thanks so much. I just switc...

I just rewired the inputs, now its worse than it was earlier. There is no hum, rather, whenever i play a note, it buzzes really loudly. This is only when I hit a note super hard. When I hit a note softer, it will not play out. Nothing plays when I plug directly into the effects return, meaning that ...