Tonebender problem

[tungngruv]

I just finished JD Sleeps "Boutique Tone Bender". I bought the parts from Staeve at Small Bear (Great guy and service)!! Anyway, I hooked it up and the bypass works (no effect) but when I switch to the fuzz, it's a real weak signal and it's only barely working on the low E and A strings, barely. I used the matched Trans that Steve sent and I put them in this order: Q1 was lowest #, Q2 was next up and Q3 was the highest # on the outside of the package. I'm going to start debugging it after I eat but just wanted to see if anyone has experienced this same problem and could save me some headache. By the way, I perf boarded the effect. Thanks

[hellhound]

 I am experiencing the same problem with a tone bender MkI build. I get a very faint signal when a guitar is plugged in and the amp volume needs to be cranked to hear the signal. I am using a bread baord for the build and I am leaving out the true bypass mods for now.  I built the audio probe shown here on the forum. What I have found is that the signal dies somewhere in the feed back loop of the transistors, and the voltage from Q2 collector to ground is less than 1 volt. I have tested both transistors and swapped them out with others; they all tested good and  I still get the same results. I haven't figured out how to fix this problem.

[m-theory]

I think DIY clips touch the boundry of dimishing returns...

Far beyond it, imo.  My time is worth something.  It makes no sense to spend an hour making something that costs pennies to buy. 

[petemoore]

  Debug 'em !
  and the voltage from Q2 collector to ground is less than 1 volt. I have tested both transistors and swapped them out with others;
  Sounds about right, Q2C on my FF's are about 1.15v from ground.

[hellhound]

It is working now. One must follow the schematic. I did not ground the sleeve of the input jack. Does any one have any ideas about how to quiet down the buzzing? Or has anyone used a device like HUM X from Ebtech with good results?

[Timebutt]

What do you mean 'buzzing'? Are you talking about hum or hiss? If it's hum and you're using a wallwart it means the power isn't filtered (the ToneBender is quite sensitive to this), you could check this by using a battery and see if the hum disappears. If it's hiss you're talking about it could depend on a lot of things, bad components, etc.
Building a voltage regulator/power filter for an unregulated wallwart is a fun project by the way

[hellhound]

No wall wart I'm using the battery. It has a lot of that 60 cycle hum going on. I want to quiet it down. Hissing I'm not to worried about. Its a fuzz pedal so I expect and get some hissing. But the 60 cycle hum is almost as loud as the guitar signal.

[Timebutt]

If you're using a battery it has to be a grounding problem: take out a schematic and verify with a meter if every component that should be connected to ground is actually connected (use a DMM continuity test and probe at the leads of every component, important if you're using sockets for the transistors: basically you're probably looking for a cold solder joint). What I like to do is to check a component and then indicate it on the schematic that it's done, this way you can verify everything. Hope this helps?

[newfish]

FWIW, I noticed a *lot* of buzz on my breadboard projects - also when using batteries.

*Then* I switched my Soldering Iron off - and voila!  No more hum.

Simple, but it had confused me for some time...

[frankclarke]

Does it hum with guitar volume on 0?

[hellhound]

yes it hums with the volume on 0, and it picks up a radio station when the volume is turned to 0. When i turn it up, as it gets to about 3 the radio station goes away and then just hums quite loudly. I will check all the connections again. I know I was having problems with the ground in the beginning because I thought I was smarter than the schematic. I figured I didn't need to connect the sleeve to ground because the ring and the sleeve on a mono jack are the same point and the ring was connected to the + side of the battery. So on a mono jack I figured that I would be shorting the + side of the battery to ground. Well dah! Its a + ground circuit. So I have purchased the Electro Harmonix humdebugger. I will pick it up tomorrow and see how well it works.

[DavidRavenMoon]

yes it hums with the volume on 0, and it picks up a radio station when the volume is turned to 0. When i turn it up, as it gets to about 3 the radio station goes away and then just hums quite loudly.

Is it in a metal case?  Are you using shielded cable on the input?

[hellhound]

yes it hums with the volume on 0, and it picks up a radio station when the volume is turned to 0. When i turn it up, as it gets to about 3 the radio station goes away and then just hums quite loudly.

Is it in a metal case?  Are you using shielded cable on the input?

it is on a Bread board, no I'm not using shielded cable for the input, I'm using the little wire things that come with the bread board and everything plugs into the bread board. I just had the pleasure of inspecting a real untouched Vox tone bender from the late 60's with SFT337 and SFT363E transistors. It used shielded cable and it is was really cool. Now that I have seen the real deal I have a better understanding of how they worked. The DAM 1966 is spot on for layout, etc. The original did some of the same things that mine does picks up radio stations when the volume is lowered to 0. It is not as noisy though. I think the noise level has a lot to do with the input transistor being the SFT337. I believe it is a low gain transistor. I plan to experiment  with using low gain PNP 0C 44, 45, 70, 75, for T1, and an OC76 for T2.  I am hoping that combination will be what I'm looking for.  The gain on the original is very low compared to mine. The original had an 8.2k fixed bias resistor. I would not carve it up since it is all original, I do feel that the 20k trim pot in modern clones is a definite improvement. I also got a hum debugger the same day I got to inspect the Vox. The humdebugger works. When in use with the Tone Bender it should be inserted just after the Tone Bender not before. I plan on getting some shielded cable for the final configuration. I am really inspired with this project. I plan on building the whole series of tone benders MK 1 Mk 2 Mk3, and a range master.

[DavidRavenMoon]

High gain circuits like fuzzes will pick up a lot of noise when they aren't in metal boxes.  It's fairly normal to have a lot of noise going on while you are prototyping things. 

I have test basses with wires and circuits hanging out the back that hum like crazy until everything is secured and shielded.

[hellhound]

High gain circuits like fuzzes will pick up a lot of noise when they aren't in metal boxes.  It's fairly normal to have a lot of noise going on while you are prototyping things. 

I have test basses with wires and circuits hanging out the back that hum like crazy until everything is secured and shielded.

Thanks for the info. I will box it up now. I plan to shield it like crazy.