plotting out deluxe rvb with some dumble bits

[imo1]

Nice! Where did you end up putting the level controls in the circuit?

I put the OD level at the end of the OD circuit. It works perfectly. I have only messed with it for about 30 minutes, but seems like my usage with be with the level pretty high(8-9), which brings relative gain perception slightly hotter than "clean" and then having the drive around 4-5. That slightly altered tone stack works well for this side too.

As I said in the initial discussions, my hope was to have a Deluxe style clean that I could play at break up edge and then use the OD circuit to push that into lead tones. It sure seems like it fits the bill. Obviously, need to play it live and see what it is like over the course of a tour, but pretty damn cool!

Thanks for all the help. Especially you, Martin! That schem of the pre-amp was slightly different than the one I drew up. The OD circuit especially

[imo1]

Ive got some buzz on the reverb. I tried grounding reverb pot at the pre-amp ground point. Hoping moving ground to the B-C spot will clean that up. I don't have shielded wire going to Reverb( I do to dwell on back) as I wasnt that close to anything I thought would cause any buzz, but if the moving of ground doesn't help, ill look at that next

[martin manning]

Can you describe exactly what you have now? Is it the preamp I drew with the level control at the reverb output moved to the OD output? Since this is a unique design, and a reinvention of the ODS, I'd like to capture it.

[imo1]

I added an OD “output level” coming off of the treble wiper. I also used a 4.7uF instead of a 3.3 in the reverb

[imo1]

The layout I am making needs some corrections and to be cleaned up a bit but it will show how to build this using a deluxe reverb form.

[imo1]

I'm getting a decent 120hz buzz on the reverb. It isn't an issue at the reverb level that I'm using, but I would like to figure it out if possible as it doesn't seem right. I know Fender reverb circuits are noisy, but this is too noisy!
Seems to be around the recovery tube and is there whether reverb is hooked up or not. The cathodes of the recovery is shared, and the grounds go to the B-C ground point. I tried moving ground from reverb pot to either B-C, or D with little effect. I replaced lines to high and wiper of reverb pot with shielded cable, ground tied on high impedance side. The only thing I haven't done is insulated jacks for reverb in and out(I don't have them). I'm not seeing anything obvious at this point to chase

[imo1]

I am using a dwell pot though I don't hear any increase in buzz as this is increased. The ground of this is currently going to the ground on the reverb input jack.

[martin manning]

Does the reverb level pot affect the hum?

[imo1]

Yes. I was about to upload a short vid. Directly related to reverb level. At 3, where i would play it, it sounds similar to a typical fender noise wise. At about 5-6, it gets quite a bit louder, and buzz is 120hz

[imo1]

https://vimeo.com/1111471291?fl=pl&fe=sh

[martin manning]

What happens if you ground the grid of the recovery stage (center pin of the reverb return jack)? Does the return level still affect the hum? If it does, the hum is getting in at the recover stage. If not, the hum is getting in at the tank's return transducer.

[imo1]

Grounding the return of reverb doesn't change this. I still get additional hum at reverb level.
A few things I'm thinking about

-I don't have a cap on the 220k from output return to ground. I know that helps with picking up stray oscillations.
-I have a 4.7nF, instead of a 3.3nF from plate 1 of the recovery to the reverb level pot.

Other than that, voltages look good. Values are right. Don't see anything that would be picking up crosstalk. I replaced the two wires to and from reverb with shielded

[imo1]

Here are shots of recovery tube area , middle of board, and reverb pot. You can see the high and wiper coming from board(4.7nF and 470k).
Reverb grounb is currently going to the B/C grounding spot, but I initially had it at the D ground spot. No difference. I also have the 220k to ground V2 and 3 cathode ground, which I think you did on your deluxe. The original ties it to the V4/5 cathode

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IMG_4623.JPG

[imo1]

Incidentally, I found an interesting thing with the input of the amp and the volume pot on my guitar. When I go from 0-10 there is a spot towards the middle that has a little more hum than the top or bottom. What is interesting is that it happens on all of my strats, and it happens on my other Dumble style amps as well. I tried it on 3 amps with the same result. Different cables just to rule that out. Could it be something with the 33k input grid resistor doing some kind of weird impedance thing?

[martin manning]

I don't see anything obvious, except the heater leads are wrapped close to the reverb recover tube socket. Generally not a good idea, but that would be more likely introduce 60 Hz.

When you roll down a volume control with a parasitic capacitance on the output you get a low pass filter where the corner frequency is lowest at 50%. That might account for what you are hearing by making any low frequency hum stand out.