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Tone Bender Mk.II - Help Needed

Started by LJN, February 04, 2016, 01:44:55 AM

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LJN

Hi, everyone. I'm working on a clone of the Tone Bender Mk.II professional and I can't get it to sound right. I'm using AC128 transistors with the in the 60s up to the mid 70s. Leakage is in the 200-300 uA range. The circuit has output and way too much gain. It produces a very long sustain that fades into pure oscillation and glitchy noises. I built it from the fuzzcentral schematic and used a 47k resistor on Q2 collector and a 10k resistor on the base of Q1. Also, turning the guitar volume down doesn't clean up the distortion as it should. It just causes it to become very gated. Any suggestions on what may cause this problem? I should also mention that I left out the power filter cap. Thanks.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

LJN

I figured it out. There was something wrong with the battery I had been using. It read okay on my multi meter, though. Changing the battery solved the problem. It has plenty of sustain and doesn't get too clean when the guitar volume is rolled back, but does get a bit more articulate. It's also very bright sounding.  More bright than my Mk. I clone.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

Cool  :dbtu:
All batteries "measure" fine when loaded 1M (or 10M), the multimeter input impedance  8|

You had also skipped the supply decoupling cap, no wonder it squealed and misbehaved as soon as the worn battery showed high internal impedance.

LJN

That particular battery never worked right in any of my fuzz pedals. I did finally put that power supply cap in there earlier and hopefully, it'll solve any future low battery issues. This is a bit different than I expected it to be. It can get pretty crazy sounding, which I don't really mind. With so much sustain, there's not much need to crank the attack control like one has to do on a Mk. 1.5 or fuzz face. And it's a lot brighter than my Mk. 1 tone bender, as well. I knew it was worth the trouble. It doesn't really clean up too much with the guitar volume, either. It does get a different sound by backing the guitar volume down a bit, though. Thanks.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

LJN

I was able to improve the clean up just a bit by placing a 100k resistor in parallel with the 47k resistor on the collector of Q2. I think this will be good enough for now. At least until I can order a matched transistor set. I was able to get close to the "In My Time Of Dying" tone using my Zippo lighter for a slide (I think it sounds better than conventional slides, but it can be awkward) . Thanks.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

LJN

Here's the pedal. I cut and folded this enclosure from 1/16 inch sheet aluminum. I'll try to get a gutshot later. I think there's still room for improvement (and a bypass switch) .
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

J M Fahey

Cool  :dbtu:

What paint did you use?

Looks like the one used in some original Tone Benders.

LJN

#7
Thanks. :tu:
Believe it or not, that paint is Rust-Oleum Hammered Silver spray paint that you can buy at Wal-Mart. I love that stuff! <3) I also refinished two of my vintage fans with it. It's difficult to get a consistent texture in the finish and you really have to follow the instructions on the can. Plus, make sure you use it a well lit place so you can check your work.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

LJN

 I can finally say this one is pretty much finished. I ordered some transistors from LIC Pedals and received them yesterday. The guy also sent me a proper layout and I completely rebuilt my clone using axial lead electrolytic caps and some of those old carbon composition resistors (I tested them first with both of my multimeters) . It sounds great and cleans up nicely with my old Kay Effector guitar, but not with my Epiphone LP. I guess it's the different pickups. The effect even has less noise than before.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL