Sola Sound Tonebender 3 Knob

[mow]

Hey guys,


I was bored yesterday, so I decided to build a pedal that I´ve always wanted to build!
The Sola Sound 3 Knob Tonebender.


I used this Schematic and built it on vero:

http://fuzzcentral.ssguitar.com/3knob.php


Now, the Fuzz works fine, and sounds pretty good already, but i get huge amounts of hum when the guitar volume pot is up. If i turn it down all the way, the hum stops.

So i thought this is probably a grounding issue and took a look at the schematic again. I wired the battery plus to the tip of the input jack and to ground, and the sleeve for effect in. The output jack has the sleeve wired to ground and the tip to the volume pot (signal).

Is this correct? This is my first PNP build, so I´m pretty confused with all the positive ground etc. wiring tbh.

I hope you guys can help me out!

I posted a picture for you aswell!

https://www.dropbox.com/s/8hq48b00ngytnxz/tonebender.jpg?dl=0

[duck_arse]

mow - the tip never connects to supply, either + or -. only the sleeve (and the ring, when power switching) connects to supply, and then usually only to the (nominated) ground.

I think you need to swap the connections on the input jack, so red+black/white go where black/green is now. the out jack appears correct.

when you've done the resolders, get yr meter, measure resistance from batter snap (+) [it is positive ground, yes?] to each jack sleeve and to the board ground connection.

your jacks as shown are not usable as power switch-off-when-unplugged. you need a stereo, tip/ring/sleeve type for that.

[mow]

Hi,

thanks for your answer, i think it got quite a bit better.  Im measuring <1R on all the spots.

I still get a strong hum, whenever volume or gain is maxed. Turning the guitars volume pot changes the hum. Guitar completely off = no hum. And i get a big treble loss, when i turn down the guitars volume pot.

Is this simply due to the circuit, or are there any other reasons for these phenomenons? I haven´t tested/matched the transistors yet though.


Greets

[Bret608]

I've built two of these and they will hum with the fuzz maxed. This should quiet down some when you have it boxed, however. Does your guitar have single coils, and if so, are any of the combined positions hum-canceling? That would seriously reduce anything within the normal hum for the circuit. The fact that the hum disappears when your guitar volume is turned down tells me you don't have any weird grounding issues or anything, especially since you followed DA's good advice on the power/ground connections.

This circuit will lose treble when you turn down the guitar's volume knob. In my experience it does not do the volume knob reduction thing as well as a Fuzz Face. But when it rips this much, who's worried about that? 

When you do get around to matching transistors, you'll want 40-60 hfe and low leakage for Q1 and Q2 and 100-120 hfe with some leakage (over 0.200mA) for Q3 if possible. It seems like folks building this circuit sometimes go for transistor sets that would be better for a MkII (e.g. 70-90-120). Anyway though, this is a pretty forgiving circuit so go with what works for your ears!

[Fast Pistoleros]

I would try swapping out transistors , some old ones are really loud and hiss/hum and really cant be used for audio applications in my humble opinion.