YES We have Tubescreamer But is there a Jfet Screamer for emulation thingy ?

[askwho69]

is Tubescreamer good enough for tube emulation Jfets? any ideas?

[Galego]

is Tubescreamer good enough for tube emulation Jfets? any ideas?

A Dr. Boogie sounds way better with a tubescreamer pushing it.

[petemoore]

  Snag the buffer design, toss the rest of the TS schematic..it's either that or try to go telrigio and design an opamp using discrete Jfets.
   Suggestion to use or toss: Jfet buffer stage feeds gain stage 1. GS1's 'gain' control feeds GS2 which distorts a little.
   Put that on a board and get it working good, boosting a lot/distorting a little.
   Then put GS3 in, this one could be a minibooster and do lots of gain and distortion work, or it could be simply another Jfet gain stage...or could be an opamp stage [see tube Reamer and all other OA disto stages..when using clipping diodes, where and what...where are they placed [softclipping like TS or hardclipped to ground like Distortion+?]..what the signal strength feeding them is and what the threshold voltages of the clipping diode configurations for signal + and -.
   Appreciation for the TS's popularity and design aside, a more 'amp-like' [and less TS-like] tube screaming sound can almost certainly be wrought out of Jfets.   
   The Fetzer valve article and GEO are excellent Jfet biasing infosources, the signal input/gain/power supply voltage and voicing can all be used to get some or a ton of distortion from Jfets, the BSIAB, the tube emulator circuits at ROG and the Vulcan are all worth schematic look-ats, the ROG samples give a good idea of what 'this number jfets' in 'these positions' with 'this type of pickup' set for 'this much gain' etc''....tend to sound like.
    If the idea is to be TS-Like in sound, cut too much bass [opinion] and some treble. Otherwise the suggest to try getting 2 [or more] stages both contributing some distortion]...the first stage can be just a signal-prep stage, bringing up impedance and boosting enough signal strength for the 'actual' [latter] distortion stages have sufficient input to make them distort.

[askwho69]

Ohh yeah i tried the tubescreamer im just looking for something new mmmh maybe a tubecreamer without opamp just use tranny ?

Petemoore i absorb some of your thought but its kinda blurry to me cant get a picture

[CynicalMan]

Why do you want to emulate the Tube Screamer when the Tube Screamer does the whole Tube Screamer thing so well?
Cut bass before clipping, cut treble after, and you'll get in the ballpark. I still don't understand why you want to reinvent the wheel.

[Electron Tornado]

Better yet - build a pedal using discrete components from the schematic of the 4558 chip itself. Tweak to taste. 


Now, you know what could happen - we'll end up with some people getting on a kick of only using discrete components instead of chips. Then there will be claims that only by using discrete components can you capture that true mojo tone you're after, since discrete components allows for much more detailed and "accurate" tweaking...er, trimming.....er, adjusting...er, calibrating. (And you'll know that from the 10 trim pots seen in the schematics that will start cropping up. ) And, of course, since only the "original", "vintage" 4558s gave the Tubescreamer the "best" tone, using discrete components is the only way to get that vintage tone. 

On the bright side, however, all the discussion that would generate might result in some folks taking a closer look at, and learning more about the internal workings of the chips we all use. It's also an opportunity for another myth buster video. 

[derevaun]

Keeping in mind that the "tube" in Tubescreamer is a presumed tube amp farther down the line, then, simply putting a TS in front of a tube emulation circuit like the ones at RunOffGroove would seem to work well. Reports are that they do:

http://www.diystompboxes.com/smfforum/index.php?topic=47326.0

It would be interesting to combine them and eliminate redundant parts (buffers, e.g.), though it doesn't seem like there would be much to cull.

[WGTP]

http://www.diystompboxes.com/pedals/schems/Shaka%20Discrete.pdf

How about the first part of this? 

[arawn]

transistor versions of the tube screamer already exist just look at the blue magic by Jake Nagy, odie and the peppermill at Run off groove.

[WGTP]

http://www.aronnelson.com/gallery/main.php/v/KHE/Boss_ROD10_Schematic.jpg.html?g2_imageViewsIndex=1

Check out ODII for a discrete TS. 

[askwho69]

Thanks all for the reply.. by the way iw as thinking using Diode compression as opamp gonna try it