Tube Amp Archive

I loved the look of the leather corners so I put them on the Tweedle-Dee head I built. I wished I had seen that before I did mine. They weren't very hard, but reading that could have saved me some time experimenting. Next time I'll make sure to clean up the unfinished back side of the leather to mak...

Thanks! When I take a break from playing it, and remount the master volume knob in its final location I will try that.

the amount of bass is already enough. That's no kidding. If jumper will give more bass, then I won't be doing it. I keep the tone on the amp pegged and would even like a little more. I like the way my Tele cuts through. I don't want to tame it too much. I've heard people talking about getting rid o...

If you are plugged into the normal-high input can you jumper the normal-low to bright-high input? I read somewhere (even though I can't find it now) that the mods to this amp removed the interaction between the channels. Is that true? I tried jumping the inputs, and amp made a squealing sound simila...

You're not the only one that is aware that MV doesn't totally kill the signal. How important is that? It is not that important. I was just wondering if there was another way that might work better. Even if there was a better way, it would have to wait. Because, right now I am just enjoying playing ...

Not sure if it's just an error on that schematic, but normally 'connected' wires need a dot like in other spots and there's no 'dot' on the joint between the wiper, screen, the NFB on top and the 1M below to the cathode. Just a nit pick. I fixed the dot. Even though it is a nit, nits are important....

Update...I installed the master volume the "Right Way" and I am not completely happy with it, but it works pretty well. Maybe I'm just being a perfectionist but it doesn't turn the amp all the way down. With the channel volume at 75% it turns it down to about the volume of a conversational voice, bu...

No, you did a great job of explaining it. Being a NUBE I just had trouble explaining how I previously thought it was supposed to be done. These pictures explain it way better than I can. I had planned on doing it the wrong way until you told me about the right way. The way I had planned to do it was...

Man, am I glad I read your post. I was going to leave the LNFB connected like it is, rather than attach it to the wiper. But, after reading your post I see that would have been changing the feedback circuit as I adjusted the volume. THANKS!

Are you talking about a Pre-PI MV? I saw this one on Rob Robinette’s website (Thank you Rob! Your site is awesome. It's what made me believe I could actually build one of these). This is what I wanted to try first, but wasn’t sure how it would work with the LNFB. If you’re saying it will work with L...

Do you mean something more like this?

I checked and the pot I have is audio taper so I couldn't understand why all of the control was in the first 25%...Then I did a little math and realized that putting the pot parallel to the 220K resistors linearizes it! I am going to remove it and replace the 2 220K resistors with a dual gang 200K p...

Well I still don't know if the Pre-PI master volume will work...but I know the Post PI works. It sounds good but it seems like all of the adjustment in in the first quarter of the pot. I used an audio taper pot, maybe a linear would have worked better...any thoughts?

I just finished my Tweedle-Dee build. I can't turn it up enough to start breaking up before it is too loud for my house. Will a Pre-PI master volume work on a Tweedle-Dee. I saw one for a 5E3 on Rob Robinette's website, but since the Tweedle -Dee has local negative feedback from plate to grid, I was...

Just finished my first amp build. No one warned that it would be addictive. It's time to start spearfishing and I haven't even touched my boat to get it ready! It's sitting in the yard full of leaves and all I can think about is tweeking the head I built and making plans for the matching cab. Seriou...