Overdrive Deluxe amp

[Guy77]

One nice thing about it not being bias trem is that we can play with all different size power tubes. 6L6, 6550, EL34.
This one is on my bucket list as soon as I get through the pile of amps I need to finish LOL

Cheers
G

[didit]

Hello Guy —

One nice thing about it not being bias trem is that we can play with all different size power tubes. 6L6, 6550, EL34.
This one is on my bucket list as soon as I get through the pile of amps I need to finish LOL

Fully agree this is one for some near future. Next year perhaps, and by then sharp minds here will have it well sorted.

On bias tremolo, if you inject wobble signal upstream of the output stage it will work well avoiding interference with the power tube bias. An example likely familiar can be seen on the Vibro-Champ.

Best ..

[Aaron]

Slowly making way through the schematic. This is where I'm at so far.
Assume it has errors, a little bit more to go.

Thanks,
Aaron

Couple things:

There’s a cap connected to the treble cap entrance. Is the rock/jazz switch possibly being used as what we usually know as the mid boost function instead of typical rock/jazz configuration? Extra capacitance across the treble cap activated by the switch?

I wonder if there’s something like a 1M grid reference resistor hiding around the low input Jack that we can’t see. Would that low input work well without grid ref?

Bright cap is labeled 180j 1kV

Ah, yes. I forgot to edit the tonestack. I just edited an existing schematic (Ultra-Phonix gain), will update.
Only thing I was unsure of was the reverb, I thought it would have been a little further down in the circuit?

Thanks,
Aaron

[aab0mb]

Slowly making way through the schematic. This is where I'm at so far.
Assume it has errors, a little bit more to go.

Thanks,
Aaron

Couple things:

There’s a cap connected to the treble cap entrance. Is the rock/jazz switch possibly being used as what we usually know as the mid boost function instead of typical rock/jazz configuration? Extra capacitance across the treble cap activated by the switch?

I wonder if there’s something like a 1M grid reference resistor hiding around the low input Jack that we can’t see. Would that low input work well without grid ref?

Bright cap is labeled 180j 1kV

Ah, yes. I forgot to edit the tonestack. I just edited an existing schematic (Ultra-Phonix gain), will update.
Only thing I was unsure of was the reverb, I thought it would have been a little further down in the circuit?

Thanks,
Aaron

Yeah the reverb insertion point was surprising. I wonder if putting it before or after the master would work better? Would it negatively interact with the trem?

[aab0mb]

More pics. Different amp, same model.

Notice the lack of treble peaking capacitors at the resistors preceding the v1b “level” control. One was preceding the “level” control and one was returning from the reverb circuit.

Cathode follower 100k moved off the board to a grounded ring terminal.

Mid boost cap changed to silver mica. Maybe a change in value, hard to tell.

Accent/presence control removed

Power tube grid stoppers more clearly visible in these pics.

Still wondering about v1a and v1b 1meg grid ground ref resistors hiding around the jacks.

[Aaron]

Revised schematic on page 1

[aab0mb]

Looks like .022uf caps for v1a and v1b couplers.

Phase inverter looks like .047uf or .05uf output caps.

Phase inverter input might be .001uf but the cap looks like the same size as the trem caps so this isn’t certain.

Trem caps looks like .02uf

Mid switch has a 4.7m across it for anti-pop purpose. The treble cap is permanently connected and the additional capacitance is laid over the treble cap by a spst with a 4.7m across it.

—————————250pf—————————
^——boost cap——4.7m across spst—^

The bright cap is across the vol control going into v1b, no bright cap on the master that I can see.


Updated version of the amp has no bright caps on the reverb output in-line attenuation resistor or the cap in line with the vol pot feeding v1b. So those seem optional for voicing per player.

Also optional is the accent control seen in the first round of pics.

[aab0mb]

Double

[Aaron]

Maybe more like this?

Thanks,
Aaron

[aab0mb]

Maybe more like this?

Thanks,
Aaron

That’s looking great! I really appreciate the help on this.

The one thing I see now is that the
4.7m should be placed across the mid switch contacts. It’s just there for anti-pop duties.

Cap across PI plates is 47pf

The second set of pics show that trem and reverb each have an rca style foot switch jack. Obvious this is optional.

A helpful soul has suggested to me that 1m pots miiiight be a huge amount of gain and that a person could play with something like 250k for the first and or second pot. This element might take some experimenting to get right. The original YouTube video show the master and the level knobs maxed out and the first drive knob is around 1 o’clock on the dial. We should be able to use that as a general metric for getting the pot values and gain close enough to the original.

Maybe we could look to some of the other Dumble style Marshall mods for clues as far as filter cap/resistor values.

All things considered, we have enough of a mapping to start experimenting with this topology which is very exciting!

[Smokebreak3]

Hell yea!! Good work guys, thank you!
I've certainly been chasing this dragon for quite a while, and still have two different deluxe kits in the amp pile that I used as mules years ago.
I'm sure they're in various states of disassembly, but at least I'll have a good start. I went back and read my first post in this thread and I was close in my guess haha!
However I never woulda guessed that the clean side was basically Mark Huss' 6V6 Plexi, that I'm sure we've all built numerous times , and is indeed a fantastic amp!!! Add some internet hyperbole, a great demo vid , and a large price tag and here we are

Anyways, still so many questions, and some observations

Does anyone currently have this amp in possession? I'm curious about transformers, voltages and speaker. I know the original clones had the Allesandro designed EJ1240, and there's a Sebago on Reverb as we speak with the Allesandro SC59. Those 2 speakers seem to be very similar.
Which production clones are these amps?

-Output couplers are definitely .1uf, you can barely see 104 printed on one of them

- I'm not convinced the resistor coming off the OD pot going to the low input switching jack is 100K. The second amp doesn't even appear to have this resistor.
Given there's the input resistor mystery, I could see that resistor being 470k, and the lo input grid resistor also being 470K, which would make a 470K divider. Otherwise, there would be waaaaay too much gain . That's all just a guess

-Lo input 1st stage Rk appears to be 1uf . OD stage Rk appears to be a mystery.

-I'll start with a 250K pot for the OD and tack on resistors to ground till it sounds right

- I think one of the major contributors to the sound of this amp, and it giving up the goods so well, is where the trem is inserted. That 50K pot has a serious loading effect, as it does in the normal Fender amps

-PI entrance cap is indeed 103, .01uf

- for the 220k divider, a treble peaker really doesn't do that much with that value, which is why it's more effective with the usual 470k. So I'm not surprised they could be omitted , or not.... especially with one peaking, and the other leaking

[dorrisant]

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.

[Smokebreak3]

I've got a DRRI in for repair right now, will be day or 3 b4 I get to it. If you need it sooner or someone else doesn't do it first let me know and I'll pull it

[aab0mb]

Hell yea!! Good work guys, thank you!
I've certainly been chasing this dragon for quite a while, and still have two different deluxe kits in the amp pile that I used as mules years ago.
I'm sure they're in various states of disassembly, but at least I'll have a good start. I went back and read my first post in this thread and I was close in my guess haha!
However I never woulda guessed that the clean side was basically Mark Huss' 6V6 Plexi, that I'm sure we've all built numerous times , and is indeed a fantastic amp!!! Add some internet hyperbole, a great demo vid , and a large price tag and here we are

Anyways, still so many questions, and some observations

Does anyone currently have this amp in possession? I'm curious about transformers, voltages and speaker. I know the original clones had the Allesandro designed EJ1240, and there's a Sebago on Reverb as we speak with the Allesandro SC59. Those 2 speakers seem to be very similar.
Which production clones are these amps?

-Output couplers are definitely .1uf, you can barely see 104 printed on one of them

- I'm not convinced the resistor coming off the OD pot going to the low input switching jack is 100K. The second amp doesn't even appear to have this resistor.
Given there's the input resistor mystery, I could see that resistor being 470k, and the lo input grid resistor also being 470K, which would make a 470K divider. Otherwise, there would be waaaaay too much gain . That's all just a guess

-Lo input 1st stage Rk appears to be 1uf . OD stage Rk appears to be a mystery.

-I'll start with a 250K pot for the OD and tack on resistors to ground till it sounds right

- I think one of the major contributors to the sound of this amp, and it giving up the goods so well, is where the trem is inserted. That 50K pot has a serious loading effect, as it does in the normal Fender amps

-PI entrance cap is indeed 103, .01uf

- for the 220k divider, a treble peaker really doesn't do that much with that value, which is why it's more effective with the usual 470k. So I'm not surprised they could be omitted , or not.... especially with one peaking, and the other leaking

I might be looking for a Deluxe to build if one of those kits needs a home. Feel free to Pm me

Cathode resistors on V1 are both clearly visible in the second round of pics.

40-16519
120V Primary
330V-0-330V @120mA
6.3V @3A
5V @3A
50V Bias Tap

P-TF41318
For Deluxe®, Deluxe Reverb®
125A1A & 041318
25watta
8ohm secondary
6600CT primary
3.125", vertical
1.6lbs

P-cf22707
125C3a
50ma choke
2” vertical
.4lbs

[Smokebreak3]

My bad I meant the cathode caps on v1 . The low input stage looks like 1u

Yea let me see what I've got and get back with you. I pulled the first one In could get to this morning and am just about done with it, I kinda got lucky, it was semi-finished. What it was, who knows haha.
Thanks for the xformer specs, the one I'm working on has the same PT, but multitapped, 40-18028 , and my OT is the same , but multi secondary 40-18087, 6k6 same

Are we sure the filtering is as is on the current schematic? I didn't check earlier, but can we confirm 5 filtering stages, not 4, like a BF deluxe? I've got the CF and gain stages on the same node in mine, as it'd be a PITA to change it with the existing underboard wiring I've got going on.

Also, IIRC the UP amps had a 500K Bass pot?