Steel String Singer question

[talbany]

Wyatt
I have never seen that type of stack anywhere near a Dumble amplifier. Looks like some kind of a cross between a Classic and a Skyliner? There are a couple of typos in the Hand drawn schemo as well the resistor on the bass pot should be a 10k and the slope resistor should be a 100k (/w .047 mid cap) as in the pic/schemo Aaron posted. Generally, if I don't know the actual source and can verify a schematics authenticity I take it with a grain of salt, especially if it says "Prototype"

Tony

[jfs322]

That thread should be corrected. That amp is NOT a prototype of the Two-Rock John Mayer model. If you look at the gutshot in that thread, the amp is dated 2009. The Mayer signature amps were built in 2007. What that amp is is one of a handful of JM circuit amps that Two-Rock built (approx. 2009-2010) as a custom order. Essentially, Two-Rock limited its production of the Mayer Signature amps to 25, which sold out quickly, and thus a LOT of customers were coming to Two-Rock around 2009-2010 saying, "I didn't get a chance to purchase one of the 25, can I pretty pretty order a custom amp with the JM circuit?" To which Two-Rock obliged. As far as I know, there are about 6 or so post-production JM circuit amps built by Two-Rock. The amp in that thread is one of those "post-limited run" amps, as well as the Wonderland itself. Amplified Nation did NOT clone a Two-Rock John Mayer Signature amp that was one of the limited edition of 25. Rather, the amp he cloned was one of the six or so post-limited-run Two-Rock JM Circuit amps. Now, these post-production amps could possibly have slight changes to them from one to the other, which would explain the differences.

[martin manning]

I don't know how far into the weeds this thread should go on the particulars of TR amps. Given the subject, I think only as far as certain TR examples can help to inform the understanding of Dumble SSS amps.

[pompeiisneaks]

I also still think that this thread is a classic example of a bad sticky. The super important data rolls over many many pages of posts, and it's not summarized into a single first post that can be edited by OP or mods as needed to reflect the conclusions found later. It instead is just like all other great, but long, complex threads about this type of thing. You need to read them all carefully to be able to remove errors, fix misconceptions, ensure you get the latest of the latest, etc.

A sticky, if done right, needs a single first post that shows all the layouts/schematics/gutshots, etc and has detial on the builds/variants etc. Then some discussion can be had about maybe found problems, then the OP updates the first post with the 'right' data so going forward anyone coming to that page has it.

Again, not sure if we 'need' one, but this is yet another outstanding, deep thread of content that doesn't fit well in any sticky, and fits more with the expectations I've seen in this forum of letting people do their own research, and find what fits them best, and use that? no? yes? let me know.

~Phil

[martin manning]

The 14th post is at least collecting links to the various resources here on TAG. I think this thread could be divided, with posts 1-13 being left here, and posts 14 and onward moved to the Dumble files section and renamed SSS links or some such.

[talbany]

I also still think that this thread is a classic example of a bad sticky. The super important data rolls over many many pages of posts, and it's not summarized into a single first post that can be edited by OP or mods as needed to reflect the conclusions found later. It instead is just like all other great, but long, complex threads about this type of thing. You need to read them all carefully to be able to remove errors, fix misconceptions, ensure you get the latest of the latest, etc.

A sticky, if done right, needs a single first post that shows all the layouts/schematics/gutshots, etc and has detial on the builds/variants etc. Then some discussion can be had about maybe found problems, then the OP updates the first post with the 'right' data so going forward anyone coming to that page has it.

Again, not sure if we 'need' one, but this is yet another outstanding, deep thread of content that doesn't fit well in any sticky, and fits more with the expectations I've seen in this forum of letting people do their own research, and find what fits them best, and use that? no? yes? let me know.

~Phil

I agree we should keep the TR stuff out of it
It would seem we have enough info to do both an 002 and an 004 Layout...We should also devote a separate sticky here like "What we know about the Steel String Singer" including the features between the various SSS models. Maybe add in a few clips as well as some relevant info posted here. I will be glad to help collect and verify what I can as well as go through some of my collected data I have and chip in. Now as far as the Layouts goes I have put in my quota of layouts here at the AG but am willing to help anyone who wants to take on the project. As long as it doesnt take too much of my time. Right now I am off the road and have some time however I go back out in June.



Tony

108-0872_IMG-2.jpg

[Roe]

Some SSSs (e.g. bludo 150w/EJ) seem to use only five preamp tubes, including a cathode follower driver. To achieve this, a fender (AB763 etc) style typology with an added driver seems necessary:
V1: preamp/eq;
v2: reverb driver;
v3: mixer/reverb recovery (uncertain);
v4: PI;
v5: cathode follower driver.

But 002 and 004 use many more preamp tubes. I am not sure how much is gained by using an extra triode for the reverb signal prior to the reverb driver as 002 and 004 does (as opposed to the AB763 solution). And a more economical mixing of the dry and wet/reverb signals also seems feasible. Apart from the fender solution (with the noisy 3m3 resistor), there are at least two alternatives that should work fine:
- A single stage with negative feedback and two inputs, see https://www.aikenamps.com/index.php/des ... amplifiers
(negative feedback could also be beneficial for the first gainstage that drives the tonestack)

- A single stage with or without NFB, using two different grid resistors attached directly to the socket (I'm using 220k for the dry signal and 470k for the reverb signal on two twin reverbs with some JM tweaks).

Any ideas on what might work well, even if its not totally authentic?

[pompeiisneaks]

Okay I started a new thread and stickied it.

https://ampgarage.com/forum/viewtopic.php?f=5&t=32047

I may have time to work on a layout. I'll likely use visio, but use some known shapes I got from sluckey.

If anyone else volunteers, I'll be happy to let them

Let me know if there are other images I should add too.

~Phil

[martin manning]

Tony what are the serial numbers of the amps in the photos you posted above? Schematic is #002 per the file name, correct?

[talbany]

Tony what are the serial numbers of the amps in the photos you posted above? Schematic is #002 per the file name, correct?

Martin
They are in order 001/002 pic schematic below it/004 blackface

BTW.Your resistors just left here

Tony

[Roe]

It seems that,
v1 on #005 is similar to #004 (first two gainstages, typical dumble)
v2 is reverb recovery and wet/dry mixer probably
v3 is reverb driver
v4 phase inverter
v5 cathode follower driver.

I'm mainly interested in v2 as this setup is much simpler than the ##001-004 typology