Nurse Quaky very IC sensitive?

[amz-fx]

we may well share the same problem. I'm currently wrestling with a version of the Quack circuit

Test some transistors and find one with a low hfe and try it...  hfe<100 would be good

regards, Jack

[Mark Hammer]

Thanks. That may well be the issue. I think both the units currently in there are >200.

[hilbi]

I have a 3904 in it, i think it will be around 150, i will see if I have a smaller hfe tranny at home and try that.

[Joe Kramer]

Hi!

I haven't built a Quacky, but I had some distortion problems with a filter of my own design.  Here's what helped: relatively massive caps as "power reservoirs" on all the supply points in the circuit, especially the envelope opamp, which hogs all the power from the rest of the circuit every time you strum.  It's as if the circuit is getting punched in the gut every time it tries to belt out a note.  I used 180uF in four or five spots and this cleaned up most of the distortion.  Give it a try.

Joe

PS: 741 (1458 = dual) worked better than TLOXX as the envelope opamp for me.

[hilbi]

The 3904 i have at home are all around 160 hfe. Also the other trannys are higher, wich models should i look for for the lower hfe?