Tonebender Mk. 1.5 Transistor Suggestions

[squirrels]

I built a Mk 1.5 using the Creepy Fingers Fuzz Face layout and a schematic. It worked out well but I was wondering if anyone had any suggestions  or knew what the standard transistor gain was for this beast of a fuzz. It's essentially a Fuzz Face (or is the Fuzz Face a 1.5?) so would a typical Fuzz Face set yield better results than the MP21A/AC125  (65/80) combo I'm using now? It sounds great now but could something possibly be a little better?

[Travis]

There's not a standard

If someone looks at your hfe values and says something else will be better, ignore them. Just use what sounds good to you

[squirrels]

It sounds really good as is but I was wondering if anyone had any experience with this circuit. It's got quite a bit of gain with the lower gain stuff in there now so I was wondering would higher gain be over kill?

I did a lot of experimenting with my Oracle build and thought lower gain transistors sounded great but wound up with a 140/295 2N404 combo.

[Travis]

I guess to put it one way, it is probably unlikely that you have the "best" possible pair of transistors selected for this circuit, so by default there is probably some degree of room for improvement. But since "best" is subjective here, who is to say.

I don't know what you define as "best" or "overkill", but even if I did, looking at the hfe numbers doesn't tell me anything about the sound of the pedal.

Can you go higher? Yes. Can you got lower? Yes.

Should you go higher? Anybody that tries to answer this definitively is talking out of their ass. That is the problem with the question, it can't be answered one way or the other

[Travis]

Maybe this will be more helpful, I have built a lot of them and I don't really care about the hfe numbers too much

[squirrels]

Fair enough. I get fixated on "magic numbers" too easily I guess. It's all a matter of personal taste, right? I've learned quite a bit from you guys but I need to be more mindful of what sounds good to me and through my gear than what is supposed to be the accepted value of something. Thanks.

[Travis]

Yeah it's a matter of taste for sure, but more importantly, the hfe is just not a reliable way to determine how this type of effect will sound, especially when making substitutions.

I do measure the hfe when I am building these types of things, but I only use the numbers as a rough guide and a way to gauge the changes that I make to adjust the sound. So for example, if I know what hfe is currently in there, and I want to bump the gain up or down, I have a number as a point of reference, which helps me know that I'm putting something with more of this or less of that. I do not expect two transistors with the same hfe to sound the same, even if it's the same part number from the same batch and everything. This is one of those things you may notice when you do this more often, some transistors are just randomly more noisy than others etc, it really pays off to use your ears to get the best possible results

And with all that said, you really don't have to follow my advice either. The 70 120 hfe with 4.5V on Q2c is generally pretty reliable with this type of circuit. If you pop that in there chances are it will sound good. Sometimes, especially with tonebenders, I am chasing some specific quality. I want the attack to be a certain way, I want the decay to be a certain way, I definitely want the least amount of noice possible, etc.

I find that the conventional 70 120 hfe 4.5V setup does not leave me with much wiggle room when it comes to dialing in the sound precisely how I want, and in order to get that sound, I have ended up with very substantially different numbers. My favorite Vox TB clone is so backwards, I forget exactly what's in it but it sounds just like my quintessential Vox TB should and nobody in their right mind would tell you to try anything close to this. Likewise never seen anyone suggest the hfe that I've got in my favorite Fuzz Face

[squirrels]

Your advice is definitely appreciated as well as the help I've received from you and everyone else here. I took two 2N404s I had from an old set I ordered from Small Bear in there and it really came alive. It's a hotter set at 100/140 and through my OR15 it's phenomenal. It sounds great through my AC10 as well.

I've been trying to find a suitable project for my lower gain MP21As so I'll have to keep looking. They sound pretty good in my Greasebox clone but I think I need to bump Q3 up a bit from 65. I have a few AC125 ranging from 77 to 117 and they all sound horrible in anything I've tried them in. Sockets are a lifesaver.