Looking for minimal Tube Screamer mods for a more transparent tone

Started by nooneknows, March 05, 2021, 08:39:45 AM

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nooneknows

hi

I posted this question in other forums but I haven't received many feedbacks yet.

there are billions of mods around for the TS, what I look for is some minimal NO Mojo mod to:

- mantain the gain characteristics
- get a more transparent sound
- flatten a bit the mid hump without loosing the TS overall characteristics.

looking at the schem what comes to my mind is:

- replace the 2 NP 1uF electro with 2 1uF Film (better quality)
- replace the 47nF in the feedback loop with a 100 nF (a bit more bass)
- replace the tant. 220nF at the 1st opamp output with a 100nf film (to get a higher low pass corner)
- replace the tant. 220nF of the tone with a 220nf film (better quality)

(I don't believe the opamp sub can get a more transparent sound, I did it few times with my SD! with 0 results)

any idea about it?
much appreciate
thx

ElectricDruid

I'd have to play with a Sim to be sure (or build one, equivalently) but I think your ideas are definitely along the right lines. Certainly playing with the tone response (which is heavily shaped at every stage in the TS) is the way to go. Changing op-amps is ok for magic-mojo cork sniffers, but they're missing a much bigger picture!

Fancy Lime

The problem may be that you want to (1) maintain the Tube Screamer Character and (2) make it more transparent. In my, and I think most people's understanding, those are incompatible opposites. If you can describe in a little more details what you consider the TS characteristics that you'd like to keep and what you think of when you say "transparent", we should be able to help you. Putting sound in words is hard though. So the solution will likely involve some experimentation on your part. Do you have a breadboard?

Also, I second Tom in that changing opamps will not really make an audible difference (unless you use something really unsuitable for audio). Changing cap types to film will make a bit more difference but I don't have the golden ears to hear it. I'd use film caps in a from scratch build but I wouldn't change existing ones.

Andy
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r080

Clear acrylic case?

Take a look at Fulldrive 2 MOSFET schematics. The "Flat Mid" mode is a switchable feedback loop, which will flatten the frequency response some.

http://fuzzypedals.blogspot.com/2015/06/fulldrive-deadringer-mosfet-overdrive.html
Rob

choklitlove

Transparent is actually one of the first things I think when it comes to TS's.  Maybe all you're looking for is more range of the Drive pot when turned down?
my band.                    my DIY page.                    my solo music.

Halkbi

Like stated, the sound of a Tubescreamer is much about the mid hump. I never really got along with it and I imagine you'll be looking to extend it's frequency response without altering it's distortion characteristics too much. Sounds good to me, but it shouldn't really be considered a tubescreamer as such.

I'd suggest you raise the cap to ground in the feedback loop all the way to 470n. Haven't tried it in a tube screamer but I always do it in Distortion+/DOD 250 type circuits (which stock and with their gain maxed out out will give a similar low end response to a Tubescreamer) and anything less might not give you what you want. Cutting less bass will alter how the pedal distorts which may or may not be a good thing.

Lowering the 220n after the clipping stage may make it might end up more harsh sounding since it's post-distortion, but you could try and compensate by raising the 51p feedback cap in the clipping stage. If I'm not mistaken, raising the feedback cap in the clipping section is going to cut some highs before the clipping occurs and will therefore alter the characteristics of the pedal (again, for better or for worse). I also gather that with a TS type of gain control, a bigger feedback cap will also diminish highs as gain is increased. But you never know for sure what your results will be before actually trying it out. Use sockets and see what you like.

If more transparency is all about raising the distortion headroom, try and swap those silicion clipping diodes for red LEDs. I wouldn't bother about swapping other component types. Looking forward to hearing your results!

Mark Hammer

Tubescreamer transparent?  What?  Exactly what do you consider transparent about it?  The basic design of the TS is intended to provide relatively consistent clipping across the entire fingerboard.  So what is supposed to be changed or changeable to make that more "transparent"?

kaycee

Two suggestions:

1. Turn the gain down and the volume right up.

2.Add a clean blend circuit with the ability to boost the clean/input signal if needed.

slashandburn

The clean blend part of the Voodoo Labs Sparkle Drive might be worth looking at. No doubt its borrowed from elsewhere but its really handy.

That aside, I'm with everyone else wondering what you mean by transparent. If you want to flatten the mid hump I'd say it's no longer really a tubescreamer. Something like a Timmy might be a better option.

11-90-an

Have you tried looking at the EQD Westwood?

seems "transparent" to me...
flip flop flip flop flip

nooneknows

Thank you,

ok, maybe 'transparent' it's not the right word (btw my language is not english, so please excuse me if I can't be more precise) .

My main OD is the Timmy, I have a v2, if you compare TS and Timmy the difference is huge in terms of 'details', apart from the evident hump characteristics, the TS, at comparable gain, seems having a blanket on the amp cone, that's where my concept of transparency comes from. Timmy is definitely more hi-fi, but, as you know, it doesn't have really any mojo features, it's just a wonderful good design.

That said, the TS mid hump is really useful sometimes and its distinctive compression is so friendly in a band mix that I'd like to find something of a compromise between the two, to maintain both in my board, eventually using one to boost the other.

So ok the TS mid hump, a bit flatter and wider would be better, also, a bit more detailed sound would be welcomed, all that with the minimum no-mojo mods possible.

I built many pedals, I certainly could breadboard a circuit but what I was looking for was your opinions on the matter.

thank you all.



kaycee

Your English is very good indeed.

I'd certainly look into the pedals suggested above, but would once again make the case for trying a clean blend on the pedal you have.

I had a TS9 in the late 70's and never really liked it then, and my opinion didn't change much when I returned to guitar playing and took up effects building.

Having a crush on SRV at the time I built J.C's SRV special and added a simple jfet blend, and that I did like. Having the original guitar tone in the mix with the TS sound was really nice, it added clarity and detail to my ears. But, it only sounded good on low gain settings, at higher gain it was like a tinny buzzing in the background of the clean tone, horrible!

Much as I liked that, I eventually settled on a Klon clone (Harald Sabro's Workhorse) for that kind of tone, which does a similar thing in a more elegant way.

anotherjim

Maybe you'd be happier with the Marshall Blues Breaker type.
The operation of TS distortion is coloured by the diode switching response. The diodes switch at a particular speed and I think that is responsible for an upper halo of "fizz" distortion that has nothing to do with the pitches or harmonics of the notes you play. The Blues Breaker still switches the diodes but is softened due to having resistance in series with them.

11-90-an

Quote from: anotherjim on March 06, 2021, 05:35:01 AM
Maybe you'd be happier with the Marshall Blues Breaker type.
The operation of TS distortion is coloured by the diode switching response. The diodes switch at a particular speed and I think that is responsible for an upper halo of "fizz" distortion that has nothing to do with the pitches or harmonics of the notes you play. The Blues Breaker still switches the diodes but is softened due to having resistance in series with them.

And if you go with a blues-breaker type, a perfect breadboard-able (and great sounding!) example would be Mark Hammer's Wattbreaker  ;)

https://www.diystompboxes.com/smfforum/index.php?topic=126135.0

I don't think i would describe it as "transparent", though, probably as "tight"...

flip flop flip flop flip

nooneknows

Quote from: 11-90-an on March 06, 2021, 09:30:51 AM
And if you go with a blues-breaker type, a perfect breadboard-able (and great sounding!) example would be Mark Hammer's Wattbreaker  ;)

https://www.diystompboxes.com/smfforum/index.php?topic=126135.0


I had some trouble finding the schematics in the thread, finally I got it, very interesting, minimal and clever, I have to try it (although actually my aim was obtaining something with the TS9 pedal I already have)

Mark Hammer

As noted earlier, the intent of the TS design was to provide consistent clipping across all strings and frets.  It doesn't quite achieve that, but aims reasonably close by providing more gain for content above 720hz and correspondingly shaving off top-end as more gain is applied.  One of the results of the combined highpass and lowpass filtering IS the dreaded "mid-hump" - that point where highpass and lowpass filtering is negligible but gain is still applied to what lies in between.

Flattening out the frequency response, to avoid excessive midrange, or rather too-prominent midrange, can be achieved in a variety of ways.  One way is to increase bass response a bit and move the lowpass filtering over a smidgen.  So, that would imply increase the value of the .047 cap to .1 or similar, and decreasing the .22uf cap on the output of the clipping stage to something like .15 or .12uf.  Doing both of these expands the passband both upwards and downwards.

A strategy I've become fond of is that employed in both the Rat and the Bluesbreaker, which is to use TWO ground legs in a gain stage to provide a basic gain to the entire spectrum, and additional gain for content over some point of interest in the spectrum.  The TS uses a single ground leg and choice of rolloff such that less and less gain is applied to frequencies below some corner frequency.  The "two-leg" strategy provides constant gain for everything below the point of interest, just less of it.  You get to keep your bass, but goose the mids and highs a little more to bring them closer to the clipping threshold.

nooneknows

Quote from: Mark Hammer on March 06, 2021, 12:44:46 PM

A strategy I've become fond of is that employed in both the Rat and the Bluesbreaker, which is to use TWO ground legs in a gain stage to provide a basic gain to the entire spectrum, and additional gain for content over some point of interest in the spectrum.

this sounds interesting: if I understand correctly what you're saying, in the blues breaker schematics I see a 4K7+10nF with a corner at 3386Hz, and another combo with 3K3+10nF ,but I think the other 10nF cap in series affects the value, so it could be a 3K3+5nF that means 9645Hz (is it correct?).

what values would you suggest for the TS?

thank you

POTL

Hello Earthquaker Devices already did it for you. find schemes Dunes and Plumes, they have these very mods. It's hard to think of something new for TS mods in 2021.

ElectricDruid


iainpunk

Quote from: ElectricDruid on March 06, 2021, 03:25:36 PM
Quote from: POTL on March 06, 2021, 02:24:42 PM
It's hard to think of something new for TS mods in 2021.

Lol, Amen to that! ;)
that sounds like a challenge, where can i buy a cheap ibanez TS? i need to mod it in a way no one has ever done before! [[chainsaw mod???]]

cheers
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