ROG ToneMender FINALLY works!!

[audioguy]

After MANY MANY build attempts I finally got my Tonemender up and running. Turns out the problem I had all along was I had a bad switch I kept using on each build... I guess it was causing some strange feedback loop causing a nasty squeel. Oh well... live and learn.

Anyway... I like the box quite a bit!
I'm using an NE5532 chip and I seem to have some hiss/noise. Its not a ground issue, its just a really subtle ssss almost not noticible. I want to play with different op amps to see if I can kill the noise. I dont know if I have any TLC2272's or not- I would imagine that I dont otherwise I would have dropped that in first off. Is the 2272 quieter than the 5532?

Second question- Can this unit be run at 18v?

Thanks guys!

AG

[stm]

Good you finally made it work.

The TLC2272 and NE5532 are relatively similar in performance with respect to noise. The difference is in the rail-to-rail capability, however for guitar signals there shouldn't be much trouble, unless you use the level control near full boost.

The NE5532 would work fine with 18 volts. The TLC2272 is rated for 15 volts max, and considering the rail-to-rail capability that extends the output dynamic range, it is not recommended/necessary to feed it with more than 9 volts. If you already have 12 or 15 volts you may go ahead though.

To trace down the hiss:

1) You may try as well with a TL072 (LF353) or RC4558 opamp and see how they do.
2) If the effect is just after another pedal instead of the guitar itself it may be amplifying the previous effect's noise (remember frequencies above 1 kHz can easily reach a 20 dB boost (10x) when treble is at max).
3) Also, your noise may be coming through the power supply. Did you use the 100 ohm + 100u capacitor to ground?  Try placing 0,1 uF ceramic capacitors in parallel with each of the 100uF electrolytics shown in the original schematic (two in total).
4) Disconnect the guitar's input and short the input to ground and see if the hiss is reduced. If this is the case, then the Tonemender is just showing you what you are feeding in!

Good luck

[audioguy]

I was using a Godlyd power adapter- I have not had any hiss trouble in the past with it- and no ther pedals involved before or after. I think its more of an issue of the unit showing me what Im feeding it. If memory serves me the hiss was greatly reduced when plugged into humbuckers. I'll try to do some more experimenting when I get home tonight.
Thanks for the help!

AG