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Vintage threads from the first ten years

Re: Super Tube Screamer

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8/16/1999 6:22 PM
Aron	Re: Super Tube Screamer Someone was nice enough to send the schematic of the Super Tube Screamer. I will have it up soon. Aron

8/27/1999 5:02 AM
matt	Hi Everybody, Its been a while since I've been on here. Saw this thread,must say that the price on those STS is a bit steep.I have a STS and I think I paid around A$80 for it.I dont think they are quite as good as the TS-9 or 808,but I'm not a great fan of the tube screamers anyway. Matt

8/19/1999 10:08 AM
AMZ	Save yourself $1825 and build your own. Aron now has the schematic up on his web site. http://surf.to/stompbox/ From the looks of the schematic, someone paid about $1725 too much. -Jack

8/19/1999 4:52 PM
marrk	Jack, I couldn't access the schematic from your link. When I went to Aron's page, I couldn't find it. Mark http://www.geocities.com/BourbonStreet/Delta/2133/stompbox

8/19/1999 5:42 PM
Aron	My page had to move due to Geocities. rrrrrrrr!!!!! The new page is here: http://members.tripod.com/~triparon/ look under Ibanez.

8/19/1999 8:23 PM
marrk	Thanks Aron. I got a funky error message, but was able to fake it out and get to the schematic.

8/19/1999 10:18 PM

Re: Super Tube Screamer - Chip choices

I see that the STS uses two dual op-amps. In the case of the TS808/9/etc, there is but a single dual op-amp. Since one wants the best sounding overdrive, you pick up one of the magic chips (JRC4558D, RC4558, etc.), and do your damndest with your soldering iron. Whether both op-amp stages require a magic chip or not, the other stage is along for the ride.

In the case of the STS, it is not readily clear that all stages REQUIRE the services of one of these magic chips. Indeed, given the Son of Screamer design at DMZ, I'm not even sure the STS needs all 4 op-amp stages (i.e., the input buffer stage is superfluous with hard-wired bypass switching).

(Given that an 8-pin package is as small as you're going to get, using a single op-amp for the distortion stage and additional transistors for tone shaping yields no advantage in terms of assembly/size, so I imagine Ibanez simply made frugal use of the space by using a dual op-amp for the original. The STS really only needs 3 op-amps, but once again, why use a single op-amp and transistor buffer if two op-amps fit in the same space as a single, and cost the same as a single?)

So the question arises, where OTHER than the stage with the clipping diodes, does one receive benefit from a select op-amp? The related question is this: if this design only really needs 3 op-amps, can you stick in some single op-amp alternative to the dual JRC chip for the distortion stage, use any old dual op for the subsequent tone-shaping stages, and expect to get the same sound? If so, what would such an op-amp conceivably be from among those which are readily available commercially?

Incidentally, am I correct in assuming this is ostensibly a regular TS9 with a variable frequency mid-boost stage before the tone control?

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