Tbe screamer tone cap question

[daz]

I have a TS5, the plastic one that sounds really good. But i also have a new behringer clone that i have on my board to replace the TS5 because it's jacks and pots....everything have been repaired numerous times and it's working but unreliable. They sound very close but the mid tone in the behringer is a tad more nasally and doesn't quite have to low mids. The buffer resistors that denote the difference between a 808 and TS9, 10 etc are the same in both. But i found the behringer uses a electrolytic off the center of the tone pot while the TS5 uses a tantalum. Both the cap and resistor in both are the same value but for the electro vs tant. Do you think thats the likely reason for the tone? It will be a bitch to swap and if i don't have a .22 tant i will have to buy online and probably pay $5-10 to ship a stupid cap. Heres the schematic.... (won't allow a gif to be inserted in post)

http://www.geofex.com/article_folder...h/tsxtech6.gif

EDIT: Nevermind, took the tant from the TS5 and put it in the behringer. Seems to have worked.

[Helmholtz]

Difference in frequency response could be caused by different capacitance (not cap technology).
Ecaps tend to lose capacitance over time.
Most reliable would be a film/foil cap.

[daz]

The behringer with the Ecap is brand new tho.

[Helmholtz]

Might be ecap tolerance.
You could try adding smaller caps in parallel with the existing one to increase capacitance.

Is the Behringer really an exact copy including the Fet switching?

I found that the 4558 chip makes a difference.

[Enzo]

The behringer with the Ecap is brand new tho

Brand new doesn't mean same value. A cap of 22 with a 10% tolerance could be anywhere from 19.8 to 24.2 and still be perfectly fine as to spec. SO it is possible two "identical" caps could be as different as 4.4 in this example. I am with Helms here, I bet it is more likely the difference was the measured capacitance of the individual parts rather than the type cap.

[daz]

Might be ecap tolerance.
You could try adding smaller caps in parallel with the existing one to increase capacitance.

Is the Behringer really an exact copy including the Fet switching?

I found that the 4558 chip makes a difference.

Yep, far as i can tell. Same buffer and yes, 4558. The difference is slight but enough that it bothered me having been using the TS5 for decades and being very used to it's sound. Now the behringer has that sound. I measured the caps and they were too close for that to make any difference. Besides, i've had a bunch of screamers/clones including another ibanez and they all miss the mark on that aspect of the tone the TS5 has....till now that is. So i know it's the cap and i can't see the slight value difference mattering. And the fact is, regarding type, there are tons of people who believe that including me because when i was building tube amps i spend a crazy amount of time A/B'ing types and manufacturers and i have no doubt about my finding and i'm quite familiar with placebo effect and how i am affected by it and how to eliminate it.

[g1]

Why not swap those caps between the 2 units and give it a listen. Then there can be no doubt (assuming capacitance for both measure same out of circuit).

[Helmholtz]

See EDIT of post one.

[daz]

Why not swap those caps between the 2 units and give it a listen. Then there can be no doubt (assuming capacitance for both measure same out of circuit).

I would but i just lifted one leg of the electro to get it out of circuit to try the tant because 1- i wasn't sure it would make a difference and if not i'd put the electro back in circuit, and 2-it's hole thru and a bitch to work with in cramped quarters. So i just left it like that. I'm not gonna go back in a fetch it. It's back on my board. Maybe i'll try a different .22 electro in the TS5 one day just to get it going but to be honest i have no desire to find out. I just wanted that sound from the behringer and i have it so unless at some point i get a wild hair out of curiosity, i'm done.

[daz]

Oh, i see now you didn't notice the edit thans to helmholtz. I thought u meant swap and try both with the different caps.

[g1]

I was actually curious if putting the electro in the TS5 would degrade it. But I can understand having no desire to do that.

[Chuck H]

I would test the actual value of the tant from the TS5 and get a film cap of that value to put in the Behringer.

[mozz]

I think the old distortion+ was known to use tantalum capacitors. I think there is more going on than just capacitance value. Whether you can measure the parameter i don't know. My bench LCR can measure dissipation and if you measure a really good cap such as a mica or a polystyrene, you get a lot lower value than if you are measuring a disc/electrolytic/film cap.

I know a lot of people can hear no difference between caps. Someone else may be able to hear a difference. I've made pedals with film input caps and was told the pedal sounds more hi-fi than when i used a electrolytic. In the hi-fi world you would be hard pressed to find tantalum in the signal path. Yet in a pedal it might just give that sound the pedal is known for.

[Mark Hammer]

People think there is something "magic" about tantalum. My sense is that MXR used tantalum because their older pedals used small-ish enclosures for the size of pots, switch, and jacks they used, leaving very little room for the circuit board itself. Tantalums allowed for higher-value caps to be bent over flat, just like the ceramic disc ones, yielding a very low-profile circuit board that could more easily slide in between the massive pots and the back plate of the enclosure. Trust me, in the '70s nobody was monkeying with cap materials to assess "best" tone. They used what they had, what they cold get cheap, and what could fit.

The Behringer pedals have a slightly ro0omier enclosure which, in tandem with surface-mount components, allows for polarized caps to be stood up straight, making use of tantalums unnecessary.

But to the matter in question...

The "nasal" quality of a TS (5/7/9/10/808) or any derivative by a different manufacturer, does not result from the tone cap alone, although certainly the Tone setting can exaggerate any existing nasal quality. The shaping of the tone comes from the .047uf cap n the gain stage, the 51pf cap in the feedback of the gain stage, as well as the .22uf cap that forms the fixed lowpass filter with the 1k resistor on the output of the gain stage. All of that is intended to do a few things. Among them, chiefly the .047uf/4k7 pair shaves off the bottom end to produce roughly equivalent clipping - or rather sensitivity to clipping - across the entire fretboard. The other caps listed tame the harmonic content generated by clipping to aim for a more "balanced" final tone. The combination of all of that results in the famed "mid-hump".

Many TS derivatives that employ clipping diodes in the feedback loop have opted for other approaches that can offer an even more balanced tone w9th more bottom and more top (i.e., less honk).