The Amp Garage

The Jeff Gerhing-designed Revibe is a hefty build. The harmonic vibrato trem taken from the large Brown Fenders uses 2 and 1/2 tubes That's why Weber's original kit is listed as one of their most complex kits, were as the Bias Mod Tore-Vibe is listed as one of the least complex. And that's why Hoffm...

Fawn, Red, White, etc. weren't uncommon, but they were less common than Black and usually command a higher price (not that it matters anymore).

I would figure an American-bought model probably came stock with 6500's, but if it came down from Canada, it probably had EL34 or maybe even 6CA7 stock.

It's a JMP 2203 (100 watt) or 2204 (50 watt). You're friend should be able to remember at least 50 or 100-watt. He may remember it saying something like said "Master Model 50w Lead" or "Master Model 100w Superlead" on the back. Lots of 2203/2204 schematics and layouts on the web. The amo would event...

The 6G15 doesn't provide unity gain.

When paired with a true-bypass switch you may notice a noticeable drop in signal strength when you turn the reverb on.

Read through these... http://ampgarage.com/forum/viewtopic.php?t=21917 http://ampgarage.com/forum/viewtopic.php?t=24837 Precise? No, I think there is discussions about assumptions made. Layout? Not really. But there are some board pics that you can cross-reference to the schematics. Print out a pic ...

IIRC, the originals just used 5F6a Bassman transformer specs (uncompensated for modern wall voltage...which was by the B+ was always so high in them). So, you can certainly use a Tweed Bassman PT, if it fits the chassis, but if it's been compensated, you might find you B+ voltages lower. You need 6....

I saw the Eagles in Vancouver on the original reunion tour in '95. Don Felder stole the show, I mean absolutely played everyone (including Walsh) under the stage, I joked he played like he needed the money the most. The rest were relatively solid, but Felder made a good show into a GREAT show. I cou...

Before the PI (pins 6,7,8 of V2)?

Or before the 2nd gain stage (pins 1,2,3 of V2)?

What about the Volume/Tone controls?

So, you built a dozen working 5E3's and now two in row that don't work?

Troubleshooting these things is always easier with a scope or at least a probe that can send the signal to another working amp.

Oh, and fuse should always go on the Hot/Line.

Not too familiar with the 1221, but I had a blue 1011 (100w four input with trem and 'verb) for years. When it blew out (spectacularly, I might add...the OT and two tubes ruined), an amp tech ran off with it when he split town. That was decades ago. The best I can describe the 1011 amps is cool look...

Using another gain stage to boost/recover is just fine. But boosting the signal after the tone stack is different than having an active tone stack for the purposes of a technical conversation. Is this getting built into an amp? Or as a separate boost? There is no reason your plan won't work, BUT you...

The James tone stack is PASSIVE, passive tone stacks don't allow any boost of the signal (there is no where from the energy to come from, all they do is cut. That's why's it's so lossy...it builds in the "headroom" from the circuit to mimic the boost....it's not a boost, it's just less cut. http://w...

I've had some correspondence with Joe in the past and from what I gathered, he's somewhat limited in what he can produce. What I wanted was very basic and based on a classic Vox faceplate that he said he couldn't do. I was surprised, but there are so many fish in the sea of finishing companies. I'v...

rdjones wrote:That amp is calling out for Sylvania/ECG/Philips 6CA7s, you know, the "big bottles". ;->

rd

Yep. That's probably what came stock in there.

Plate voltage in the 1A is ~540VDC? What is the screen voltage? 500+? Might limit options for new manufacture.

gui_tarzan wrote:I want to do the opposite (removing the trem circuit instead of the reverb) because I never use it but I'm not sure how to terminate it..

The trem is "wiggles" the power tube bias. You scrap the tremolo circuit and leave a traditional adjustable fixed-bias circuit in its place.