TR Traditional Clean Circuit

[nicosci]

Hey all so the Traditional Clean is pretty popular these days for that JM tone and it has been pointed out that it's bouncier + tighter compared to the Wonderland/JM. This strikes me as I've {we) always wondered how TR or even Dumbles did that in contrast to other circuits.

Has there been any layout, schematic or info regarding the TC?

Cheers,
Nick

[dorrisant]

Any gutshots of it?

[rccolgan]

I am borrowing one to compare with the JM sig build. I need to still build a load box for both so I can bode plot them against each other. At first glance, it's Mayer-esque with a very different reverb circuit. I personally do not like the bright reverb it has at all. In my opinion, the JM Sig reverb is the pinnacle of spring reverb.

[rccolgan]

Here is a pretty detailed inside view

[rootz]

The mixing of the dry and wet signals seems to be quite different from the Wonderland. Also no big voltage divider after V1b? Not even a coupling cap either. Am I right the output of V1b mixes directly with the reverb recovery triode output? Reverb wet via the 68k resistor, dry signal after that resistor but before small cap next to the PI components?

[ijedouglas]

Not even a coupling cap either. Am I right the output of V1b mixes directly with the reverb recovery triode output?

I spent a while scratching my head trying to work that out I think you are right.

[nicosci]

Same questions I had in mind. Interesting, I think this theory is onto something.
So if that's true then there wouldn't be gain being dumped via a 68k shunt (in JM), but then theres no triode to amplify it in v4, but goes straight to the PI./?
Any possible components underneath the board Ryan?

What's the V1 voltage btw? This to me can finally confirm the 150k drag resistor makes the bouncier feel in these designs.

[rccolgan]

I have not done a trace TBH. I'll check for components under the board as we know sometimes TR will do that. Attaching my voltage chart notes.

[nicosci]

Thanks!! Ok very interesting as I imagined TC would have lower voltages (especially v1) based on its sound. But it has higher overall.

[rccolgan]

Have fun. I share so long as we share back any info you may find pretty please with a cherry on top.

https://photos.app.goo.gl/Ca1VJ2ZdBi7sy22E6

[rootz]

Thanks Ryan, those were really helpful!

I can't see wires under the board and shielded wires look like spaghetti to me, but I *think* this schematic comes close. Any input appreciated.

[dorrisant]

Thank for that Ryan! I'm camping out on this one.

[rccolgan]

Continuing the conversation here. I appreciate feedback and thank you so much for the schematic Rootz! I'll pop open the amp again and check under the boards.

https://docs.google.com/spreadsheets/d/ ... sp=sharing

I'm Bode plotting my JM Sig (Fairfield County Signature) vs the Traditional Clean and comparing the two. Above is my working document.

Siglent wave generator 1v pk2pk -> Device under test (the amp) -> speaker out to a Boss TAE reactive load -> FOH line out to Siglent SDS1104X-E

No effects were added to the signal, the reverb was turned down entirely on both amps, so it should just be the raw output of the amp.

Does the JM sig make sense based on our experience with that amplifier? I just want to double-check that my amp is correct. I'm always a little insecure lol. I'll add more analysis points to my working document above and will be doing a YouTube video on this topic at some point once I'm confident in the data.

[mojotom]

I did rewire my JM style amp to a TR clean to test that circuit and wire it back to JM specs a few days later to have a back and forth point of view (quite easy to do btw).

I noticed the JM got more volume and gain available, The TR is almost only clean even when maxed and overall volume felt lower.

I did notice less boomy bass content on the TR, less mid scoop and the JM felt brighter than the TR even with a Cut control on the JM.
So exactly on par with your Bode plotting Ryan. It was funny to read your post vs what I felt when I tested it.

It's also smoother on the attack/onset of the note when digging in compare to the JM (the JM felt faster).
I like the TR so far because I feel the JM was a bit too scooped, got a bit too much bass and brightness to my liking, besides its really beautiful reverb.
Maybe the TR feels a bit sterile being more flat sounding but I like the overall balance of that amp.
Might rewire it to a TR again this weekend.

I think I still prefer the JM reverb over the TR though.

If you take another look inside I would be interested in bias setting in mA and like I asked you in a pm I'd like to know what diodes they used on that amp.

[rccolgan]

Oh man this is the info I've been dying to learn! (Besides a clear gut shot of SSS #002) One day.. one day....

I'm really happy the JM plots are lined up to your actual experience! Also really interesting about the jmsig being brighter because it goes against the prior narrative about the amp.

I did more messing around this morning and I could not get that mid scoop on the TC to move at all. So many people assuming the TC is a JM sig so I'm happy to have everyone's support to get to the bottom of it. Off to more testing...

Side note: The tube screamer mid hump (John's go-to OD) of 720hz is strangely close to the scoop of the JM Sig!