Tube Amp Archive

Absolutely wonderful guys! I knew I could rely on you! I checked the resistors and sure enough, one lead was poking through the solder joint. I simply did a quick test and resoldered the lead securely. It totally fixed the problem as far as I can tell. I'll eventually replace the resistors, but for ...

Hey guys, I just recently got a used 410 Deville. It played great for a few weeks but of course, there is now a problem. The amp has fallen victim to giant volume leaps during playing. This happens whether on the clean, drive, or more drive settings. I can actually hit the amp a couple of times and ...

Best of luck! Dr. Z knows how to design a great amp!

Personally I would put the tone stack between V1a and V1b with the gain coming off of the treble pot output.

Is there a benefit to that?

As of right now, I am down to 3 problems left before this sucker can sing! 1. In order to come anywhere close to the Volume of a 40ish W amp, I have to turn the GAIN and MASTER VOLUME all the way up. 2. In certain positions with the MIDDLE, TREBLE, and GAIN pots, I can dial in a lovely crackling noi...

Guys! You rock! I got the amp making actually pleasing noises. Overall volume seems a little low still, but I am going to try rebiasing the amp now. Hopefully that will get it sounding great!

I think you guys are right, I got the 10R idea from a schematic I saw that ran EL34s and used the 10ohm resistors on top of the bias. I liked the sound clips, so I just wanted to check it out! haha. I am not attached to them, so I think I'll just remove them. I kind of like having some kind of Catho...

I have changed my schematic accordingly! Thanks guys! I am afraid I made an error in the schematic that I unfortunately followed in my wiring. Ill get to that change in the morning! More on that later! On a different note... This next thought won't make much difference but here goes. You've got the ...

I just started a new thread. Here's the link

https://tubeamparchive.com/viewtopic.php?t=9122

Hey guys, you can check out the other thread that has gotten me to this point here.... https://tubeamparchive.com/viewtopic.php?t=9107 But anyways. My amp powers up and makes some pretty bad noises. The Gain and Master Volume appear to be working pretty well, but I am not getting anywhere near full ...

I am having a bit of confusion on biasing with the cathode resistors. I know typically you run a 1 ohm between PIN 8 and GROUND and measure the voltage across and what not. This design used a 10 ohm cathode resistor already, so can I still use that in place of the 1 ohm, and then change my calculati...

Guys! You rock!!! Turns out I am a moron for the whole presence thing and even worse, the OT ground. But I am happy to say... MY AMP MADE NOISE! That's a start. Its pretty low volume and if it gets too loud, it makes a gross farting noise! SO now we are here. The presence had been removed and the 10...

Hey, regarding the fuse in the Primary, it is not labeled correctly in the schematic. It should read 2A. I didn't have the Common grounded, so I will try that! Thanks guys!

I meant 0 ohms of resistance. I can use the two plates to complete a circuit well enough to light a pilot lamp with a 9V battery. I don't think its the speaker. It's working fine.

One more thing, I've been reading up on symptoms of a blown OT, and one is the Power Tubes will overheat due to the excess voltage unable to pass through the OT. I noticed my EL34s heating up a little too much but disregarded it as bad biasing. I think the OT is bad news.