The Amp Garage

Qustion here, is the 18K plate stage considered a Cathode Follower(looking at original schematic)? Is that why it can be DC coupled, in the original schematic? However there is signal coming off the plate too, no? through the small 820pf coupling cap? or is that a function of the varistors? So based...

That's awesome! Yep I'm sure I put a 1M stopper at the concertina, I remember tying different values at some point, and there was no high end loss even at 1M. Thanks for confirming the dc coupled PI. Yea the amp works so well with single coils because of the unbypassed, perhaps dark flavored, cathod...

Smokebreak, Did you stick to the original schematic? Have you measured voltages? I am especially interested in the cathodyne; how balanced or unbalanced it is. For the most part yes, but that was 10 years ago! Certainly I kept the PI and power section the same, as well as the vibrato section....als...

Yea that tone control is neat, it acts as a mixture of cathode bypass on one side, and high frequency dump on the other, or a mix. I think the overall sound of the amp is unique due to the combo of high Rp/Rk values on the unbypassed 1st stage. I put an added stage in front , on my amp, using a seco...

Revisiting this amp I built 10 years ago (!). It has become my shop amp over the past few years with a great sounding Jensen blackbird alnico speaker. I ended up modifying over the years, and built an extra gain staged in front of the posted schematic. It's a thick, kinda dark amp, and sounds great ...

Should be good enough for rock n roll! Someone else may want to confirm, I don't have the DRRI in my possesion anymore

My apologies, I had 4 incorrect measurements. I think everything adds up now...

The length is actually 16 1/4
The height is actually 2 7/16
2 other intraboard measurements were off by 1/8

It looks like you have 2 1/16 written out as 2 1/8 . For the other two 2 3/8 measurements on far right, they both should be 2.375, but then then would add up to 16 1/4 I think. Shit. I'll re-measure tomorrow

I'm working on a board layout for this... Can anyone verify the DRRI board dimensions including the mounting holes? If so, I will post here for general use in a DRRI or similar. This should be everything , center to center. Not to scale haha. The 4 outside mounting holes are 3/16" from board edge o...

Absolutely! I look forward to hearing others' musings and clips

Yea I aped the original vid eq settings. I put a 1M variable resistor pot inline with the 15K to test. When the master was low, it definitely helped to add resistance and take away harshness, but when the master was cranked it dulled it. But that's the place to smooth it out if you want. We're defin...

Ok I took one for the team and made a couple clips with the amp at volume. It's ridiculously loud, but once I got it there I realized it was doing the thing we're all lookin for....at least very close. My sloppy playing reflects the fact that I was completely a deer in headlights, as I was shocked i...

Correct, but the grid leak value(as it applies to the lo gain side) wouldn't be changed by the pot value or rotation bc the switching contact would be open. But yhes, whatever the grid leak is would affect the pot value in OD mode. That is a device used in higher gain amps, a Fortin or maybe Cameron...

For the treble peaking I had settled on only one from the verb side, which acts as a high end dump for the dry signal, but today I took it off. That is certainly a spot that will vary with different speakers Yea that bright cap is way to big to be of use on the MV. Yea that pot, resistor, resistor f...

Here's my observations after playing the amp today and trying different things: -The Clean side is just gorgeous. It has the same qualities as the clean UP amps. I threw every guitar I could at it and they all sounded great. Awesome edge of breakup sounds -The OD takes a minute to dial in , and I fe...