Distorted sound on Little Angel Chorus

[GrooveChampion]

So I built this, the V4:



Works and sounds AMAZING, except it gets distorted when I hit the lower strings, same with chords. Also, there seems to be a lot of background noise, or is this normal?

I ran out of NE5532's so I used a TL072 instead.

I played around with the 1M resistors and added another 1M in parallel to each of them, no change what so ever. I tried to replace the 78L05 with a L7805 and nothing.

Suggestions?

[Travis]

Unless there's a mistake somewhere that could be a bad 2399

[GrooveChampion]

I hate how finicky these things are

[GrooveChampion]

I went through 4 of those and with the same results, I noticed they are labeled DTC.....

[Ciaran Haslett]

Try adding a green or yellow LED, anode to pin 7, cathode to ground.  You're looking for a diode with a Vf of around 2.5ish volts.  A string of bog standard 1n4148;s will work too....so long as the combined forward voltage is near 2.5V.

[GrooveChampion]

I added one....I suppose that's not enough...

[GrooveChampion]

So I tried daisy chaining 4 of them and I tried 2 LEDs, no dice. I went with an input gain control and it worked wonders.

[Travis]

If you have 4 bad 2399s from the same seller for example it won't help you to use those. Do you have a working 2399 circuit that you can use to test the ICs?

As you probably know they should say "PTC"

Again there's no way I can know if that's actually the problem or not just an educated guess

[GrooveChampion]

Here's the deal, the circuit sounds awesome, I will order some proper PT2399's from small bear.