Tone Bender MKII Circuit Low Gain Trannys

[FUZZTX]

Does anyone have any experience with using low gain trannys in a MKII circuit?

I tried some OC76's that measured 37,38, & 39 and it sounded really good. With Attach turned down all the way it was in Fuzz Face territory. Full up it was quite fuzzy with a lot of sustain and went into nice feedback even at a fairly low volume. Biased at 7.5 volts sounded nice and tight. Biasing down to about 6.5 - 7 volts actually increased the fuzz amount slightly and smoothed the tone out a bit. Both sounded killer.

No other low gain transistors I have sound good, though (2N1305, 2N13082N404, 2N1370, 2N1377, & a number of Russian's)! Only the OC76's worked! I don't have any other OCXX Transistors to try.

I have read that The Captain has built MKII's with low gain trannys, but also understand that the measurements are a trade secret and I fully respect that.

I am honestly baffled at good it sounded!

Any ideas, comments, or experience?

[capricorn_1]

i have done a few MKIIs a while ago with relatively low gain OC71s that sounded pretty cool to me.
last couple i have done have been quite a bit higher.
all with external bias controls.

[FUZZTX]

Thanks for your response. I'll keep experimenting with low gainers. I tried some high gain combos last night and those sounded cool, too!

[Taller76]

Higher hfe usually means higher lc...which usually means more noise and less definition...or sometimes a constipated sounding pedal with all of the noise biased out.
I happen to like the lower gain stuff in most of my MKII builds... They are not quite as low as yours typically...but still lower by a lot of peoples standards.
Dont get too hung up on hfe...pay attention to the little details (like bias and lc)...experiment with different flavors of OC7X and OC8X and any other transistors that work...they all have their own flavor....bottom line, let yours ears guide you.

Good Luck

[Laundromat]

Higher hfe usually means higher lc...which usually means more noise and less definition

This isn't necessarily the case in my experience.

[Taller76]

Thats why I said usually
Its all relative I guess...but lc over .30 mA usually makes for a useless transistor in a MKII...way too much noise, and if you can get it quiet enough by biasing it differently, they usually sound constipated and not very musical...at least in my experience and opinion. The gain on the ones that end up with lc over .30mA are (in my experience) usually on the highest end of the gain scale when compared to the rest of a batch of the same transistors manufactured at the same time.

[Laundromat]

If you're using a Peak Atlas tester, the given value is Iceo, which is affected by both leakage and gain.

[The Captain]

'Forget about the fucking Toe!'

Good advice Mr.Tall. Ears be where it's at. I dig OC71's for low(er) gain happenings.

[psycho*daisies]

the dude abides....(who IS this dude, anyhow?)

[Laundromat]

Didn't mean to come off sounding like an asshole, but I think I just did. Didn't have time to come up with the usual funny bits.

I've also played around with OC71's and I like them. They're bit like little OC75. I also like how higher gain 71's and lower gain 75's overlap in values. I've noticed they take a little more work for me to get around some stutters and getting enough character out of them.

I'd be miserable if I had to make a MKII out of transistors with zero leakage.
High gain and leakage can get things too saturated and buzzy though. But like the Blue Öyster Cult song goes "Don't fear the leakage...".
Sometimes a bit more of it can get rid of some hiss.

the dude abides....(who IS this dude, anyhow?)