Sola Sound Tonebender MKII- Couple of Questions

[phaeton]

Hey everyone, nice to come back after some time and see this forum is still alive and well

I've been listening to a lot of Brit Invasion lately and decided I needed an oldschool fuzz pedal.  So I put together the General Guitar Gadget Tonebender MKII circuit, in NPN Silicon flavor.  I didn't get one of their fine kits this time, I just built it on the breadboard.  Props to them, as it's great!  I'm certainly going to make a permanent version of this, but before I do I have a couple of questions...

1) How often (for Silicon) will I need to set/reset the bias of Q3?  I know Ge is temp-sensitive, but for Si is it pretty much a "set it and forget it" one time?  I ask because I'm considering putting a bias pot on the outside of the enclosure, but if I won't ever need it I won't bother.

2) This pedal is CRAZY loud!  Even with the gain all the way down it will overdrive the input of my amp with the volume starting around 9 o'clock. I googled this for a bit and I found a lot of people complaining that their MKIIs fall short of even unity gain.  Most didn't specify if theirs were Ge or Si builds, but I'm guessing Ge?  Granted, this is sort of a blessing in disguise, but since I've never seen nor played with another TB MKII before, is this normal for a Si build?  As long as it's fine, I'm fine

Thanks!

[nocentelli]

Oddly enough, I'm going to breadboard that very circuit this evening.

Silicon does not generally need bias adjustment once you've got the sound you like (much less temp sensitive than Ge, as you said). However, some folks would still stick a bias pot on the outside of the enclosure because they want to be able to access a wider range of sounds - You might be interested in dialling in some gated or glitchy sounds from time to time, along with the usual tonebender "classic fuzz" sound. If you're only interested in a standard tonebender fuzz sound, I'd advise a trimmer on the board or using a pot on the breadboard to dial in your preferred bias/sound, then measuring the pot resistance and replacing with a fixed resistor on the circuit board.

As for volume, it might depend on the transistors you've used (what are they, by the way?), or it might not... I'm not sure.

[phaeton]

Hey nocentelli, twisted minds think alike?

I used 2N5089s for all three transistors.  I might put on a bias pot just for lulz.  I'm also going to play around with a toggle-switchable diode set as an add-on.  With so much volume output, I feel I should do something with it.

[nocentelli]

I used 2N5089s for all three transistors.

They're pretty high gain, aren't they.

I'm also going to play around with a toggle-switchable diode set as an add-on.  With so much volume output, I feel I should do something with it.

Yeah, or maybe a tone pot or bass and treble controls? Or a diode clipping level pot and a tone pot.... or

It's going to end up as a five-knobber....

[phaeton]

I used 2N5089s for all three transistors.

They're pretty high gain, aren't they.

I'm also going to play around with a toggle-switchable diode set as an add-on.  With so much volume output, I feel I should do something with it.

Yeah, or maybe a tone pot or bass and treble controls? Or a diode clipping level pot and a tone pot.... or

It's going to end up as a five-knobber....

...with a beer tap and built-in video game!

Actually, I'm curious to see how your build turns out.  If you have a different volume level, then maybe I did something wrongly right, or rightly wrong.

[jsleep]

Check your bread board components and connections.  My silicon version is a bit louder than the GE version that I built, but not crazy loud by any means.  I don't think lower gain transistors will fix the problem, sounds like something else may not be right in the circuit.  I can tell you that the GE version I built is way over unity gain past the 12 o-clock setting.

I haven't gotten a chance to try any other SI transistors in it.  It sounded so good with the 2N5089s that I wasn't in any big hurry to try anything else. 

We should have kits and PCBs for the Tone Bender 3-knob available around the end of the month.  The SI version of the 3-knob turned out incredibly well too.  I'm sort of blown away how well the SI transistors work in the tonebenders.  It's nice to know you can have a stable pedal even on a hot day!

JD Sleep
General Guitar Gadgets

[phaeton]

A response by the legendary JD Sleep!  I'm honored

I will check over my build when I get home later this weekend.  In the past I've had some issue distinguishing violet/brown and red/orange on resistors, so maybe I've got some orders of magnitude off.  I'll pull them all and hit them with a DVOM.  If I figure out what I did I'll post it in case someone wants that sort of volume.  I'll also try a different amp- maybe the (cheap SS Frontman 15R) one I was trying it out on gets pushed over the edge too easily.

I didn't get the kit for it this time because I have all the parts for it.  Some years back I went on a parts-buying frenzy so I'll try to use up what I've got for awhile.  I *am* interested in the 3-knob kit though.  I really like the pro-quality look that GGG kits provide. 

Also, I haven't built any Ge versions of this circuit, but after playing around with a few early fuzz designs your NPN Silicon MKII was *exactly* what I was looking for.  Dig it!

[nocentelli]

i've just tried this with BC549c transistors and it's no insanely loud. Probably around unity at 12'o clock on the volume knob - A100K, by the way. If you used a linear pot, it will seem much louder at lower settings, if I'm not mistaken. I replaced the 5k6 with a 10k pot in series with a 2k7 and I quite like the lower bias settings between 5k and 2k7, not sure if I'd bother using an external bias pot though: Above 6k is not really my cup of tea, there are other circuits that do the nasty splatty thing a bit better. 

[phaeton]

i've just tried this with BC549c transistors and it's no insanely loud. Probably around unity at 12'o clock on the volume knob - A100K, by the way. If you used a linear pot, it will seem much louder at lower settings, if I'm not mistaken. I replaced the 5k6 with a 10k pot in series with a 2k7 and I quite like the lower bias settings between 5k and 2k7, not sure if I'd bother using an external bias pot though: Above 6k is not really my cup of tea, there are other circuits that do the nasty splatty thing a bit better. 

Thanks for the update, nocentelli.  I looked over mine again, and all the components were correct.  So I tried it out in a couple other amplifiers and that seemed to be the ticket.  In both the Laney AOR and Reverend Goblin the output level seemed about what it should be.  It *does* however sound significantly different in different amplifiers (as some pedals do).  In the Laney it was smoother with more of the low-end flatulence (but not flabulence), and in the Rev it was tighter and more trebly. Both are great sounds but now I think I'll put the 3-knob version on the breadboard and see if I'd rather have the tone control on it.

Regarding the bias, I agree with you.  I think the classic TB sound is what I'm going to want out of this pedal, and I can seek out splattier circuits on the side.  Many years ago I came across a circuit called "Joe's Garage Fuzz" or similar.  It was designed to mock the really bad, splatty fuzz designs of the 1960s.  I lost track of it in my hiatus and need to find it again.