Post-OD 3-tube reverb schematic

[EaNot]

Look for Post-OD 3-tube reverb schematic. ODRS #60 IMO has many errors. I have built it, and many modifications were required to reach a good sound.

Thanks!
Roman

[Synchu]

You can look at mhartman's thread on his SSS take (similar to SSS02 & JM's TwoRock) for a 3 tube reverb ideas.
Niki

[mhartman]

You may also want to consider doing a post-OD fender style reverb (2 tube). While I've built a couple of amps with the 3-tube setup, I actual prefer a modified Fender approach. But, that may just be me...

[EaNot]

You can look at mhartman's thread on his SSS take (similar to SSS02 & JM's TwoRock) for a 3 tube reverb ideas.
Niki

Niki, thanks, but SSS02 & 2Rock JM Sig are PRE-OD reverbs. I need POST-OD.

[mhartman]

You can look at mhartman's thread on his SSS take (similar to SSS02 & JM's TwoRock) for a 3 tube reverb ideas.
Niki

Niki, thanks, but SSS02 & 2Rock JM Sig are PRE-OD reverbs. I need POST-OD.

Actually, the JM Sig is 3-tube reverb period (and SSS02 is 4 tube reverb). There is no OD in those amps. Two Rock put out a Overdrive Signature that was the Sterling Sig/JM 3-tube reverb setup with Overdrive, but I think OD in that amp was preamp tube 5 of 6, which indicates that the reverb likely was pre-OD. You could always implement the 3-tube setup and then tweak the entry point for the reverb to satisfy your needs.

If you look to other Two Rock amps (Custom Sig./Opal/Emmy Pro), the reverb was post OD. Lets face it, Two Rock's specialization was really taking the ODS design and adding reverb while keeping everything in a tidy package. As far as I'm concerned, they did reverb as well or better than Dumble (that only my opinion so no one chime in to tell me how wrong I am). All of that being said, on the TR amps, you are dealing with a two tube fenderish design.

Dumble's later ODSR amps likely were post reverb OD with separate reverb controls for overdrive and clean. No schems around here for those though.

[EaNot]

You can look at mhartman's thread on his SSS take (similar to SSS02 & JM's TwoRock) for a 3 tube reverb ideas.
Niki

Niki, thanks, but SSS02 & 2Rock JM Sig are PRE-OD reverbs. I need POST-OD.

Actually, the JM Sig is 3-tube reverb period (and SSS02 is 4 tube reverb). There is no OD in those amps. Two Rock put out a Overdrive Signature that was the Sterling Sig/JM 3-tube reverb setup with Overdrive, but I think OD in that amp was preamp tube 5 of 6, which indicates that the reverb likely was pre-OD. You could always implement the 3-tube setup and then tweak the entry point for the reverb to satisfy your needs.

If you look to other Two Rock amps (Custom Sig./Opal/Emmy Pro), the reverb was post OD. Lets face it, Two Rock's specialization was really taking the ODS design and adding reverb while keeping everything in a tidy package. As far as I'm concerned, they did reverb as well or better than Dumble (that only my opinion so no one chime in to tell me how wrong I am). All of that being said, on the TR amps, you are dealing with a two tube fenderish design.

Dumble's later ODSR amps likely were post reverb OD with separate reverb controls for overdrive and clean. No schems around here for those though.

Thanks!
By structure (entry point, mixing etc.) 2Rock JM Sig and SSS02 both have pre-OD reverb (like ODRS #13). Unlike ODRS #60 who has post-OD reverb.

[mhartman]

Gotcha. Yeah, SSS02/JM have the entry point that they have because there is no advantage of having it later (i.e., to accomodate the OD). That being said, you're right, I forgot about ODSR 60. See attached (Aaron's great work, not mine).

[glasman]

Gotcha. Yeah, SSS02/JM have the entry point that they have because there is no advantage of having it later (i.e., to accomodate the OD). That being said, you're right, I forgot about ODSR 60. See attached (Aaron's great work, not mine).

The feedback loops in the reverb look suspect. Cant see how they would work effectively, given the phase shifts.

Maybe I am missing something.

[mhartman]

Gotcha. Yeah, SSS02/JM have the entry point that they have because there is no advantage of having it later (i.e., to accomodate the OD). That being said, you're right, I forgot about ODSR 60. See attached (Aaron's great work, not mine).

The feedback loops in the reverb look suspect. Cant see how they would work effectively, given the phase shifts.

Maybe I am missing something.

They do seem a bit strange. Maybe Aaron can chime in and give us his degree of confidence in the schem. I'm not sure if he has built it or not.

[EaNot]

Gotcha. Yeah, SSS02/JM have the entry point that they have because there is no advantage of having it later (i.e., to accomodate the OD). That being said, you're right, I forgot about ODSR 60. See attached (Aaron's great work, not mine).

The feedback loops in the reverb look suspect. Cant see how they would work effectively, given the phase shifts.

Maybe I am missing something.

They do seem a bit strange. Maybe Aaron can chime in and give us his degree of confidence in the schem. I'm not sure if he has built it or not.

I built it. As presented - unusable:
- common sound (both clean & OD ) - compressed and harsh;
- reverb - noisy and overdosed, poorly controlled.
This is because not all details are clearly visible on the available photos of #60:
- feedback resistor in dry\wet mixer V5B;
- grid leak resistor of reverb restore V4A;
- reverb pot values and types;
- resistor between V4 plates;
- all decoupling caps on reverb;
- feedback circuit in reverb driver V3.

IMO need some minor modifications (i did so, and got a good result):
- feedback resistor in dry\wet mixer V5B - 27M;
- grid leak resistor of reverb restore V4A - 56k;
- reverb pot values and types - Send 100k log, Recv 25k log;
- resistor between V4 plates - 1M;
- all decoupling caps on reverb - 2n;
- feedback circuit in reverb driver V3 - 2M-22n-2M.

Also looks suspect Rp & Rk values of V1. With 180k\1k & 130k\1k8 - HUGE, heavy mids. For what guitar\pickup\cabinet\style is it done? I did it as #124.

Sorry for my english.

[Aaron]

Gotcha. Yeah, SSS02/JM have the entry point that they have because there is no advantage of having it later (i.e., to accomodate the OD). That being said, you're right, I forgot about ODSR 60. See attached (Aaron's great work, not mine).

The feedback loops in the reverb look suspect. Cant see how they would work effectively, given the phase shifts.

Maybe I am missing something.

They do seem a bit strange. Maybe Aaron can chime in and give us his degree of confidence in the schem. I'm not sure if he has built it or not.

Hi Mike,
I drew that up from looking at the photos supplied in the original thread. I haven't built it, yet... I did build the pre though and it does sound very nice.
Aaron

[Synchu]

Argh... I seem to completely have missed the post-OD requirement.
You might want to search for Mesa Lonestar special schematic. It is not 3 tube reverb, but this can be "fixed", if you insist From what I remember, can't look for it on the phone now, it is post-OD.
Niki

[EaNot]

Argh... I seem to completely have missed the post-OD requirement.
You might want to search for Mesa Lonestar special schematic. It is not 3 tube reverb, but this can be "fixed", if you insist From what I remember, can't look for it on the phone now, it is post-OD.
Niki

Thanks, Ninki. I know this amp. Around the world there are many "post-all-preamp" reverb schematics. But there is the only one "Dumble post-OD" version .

[Synchu]

Actually not that many But I guess you're right.
Good luck and looking forward to the end result.
Niki

[EaNot]

I finally built the amp with an amazing clean, big-sounding reverb and smooth, deep tremolo. Preamp - clean part from #124 (with test option - from #60 ODRS). Reverb - from #60, with many mods. Tremolo - from...Vibro-Champ . It is beautiful, "velvet" tremolo (with some (very little) low-mid crunch when ON). Transformers - vintage Tesla\JJ from PA (except reverb transformer).

Sound - giant clean with 3D roar when Boost ON.

Sorry for my English.