suggest opamps for LFO's

[Brian Marshall]

In my quest to create a modulation pedal, I have always had one of two problems with with the typical integrator/comparator type LFO's.  I've tried TL072's, which seem to have some linearity problems due to the voltage difference on the power rails.  Power supply noise is also a big prolem.

I've tried Jrc4558/4559's which seem to be more linear, and create less power supply noise, but not quite there.  

I have noticed that some older pedals used TL022's.  I have tried them, but they arent quite there either.

It seems to me that an opamp with lower a higher output impedance, and lower power consumption would cure these problems to an extent.  Anyways, I'm going to place  a mouser order this week... anyone have any suggestions?

[Gringo]

IIRC the small clone uses a lm358 (dual oa) to drive the lfo. Cheap as dirt, too.

[Joe Kramer]

Hi!

I like the TL062 for that type of LFO.  At full output, it does tend to squash one half of the waveform (linearity problems, as you say), but I've found this to be musically enhancing.  It's a low power consumption chip, too.  A TL062 can give a sweep of almost 5V p-p with single-supply circuit--that's pretty decent, and better than I could get with any bipolar op amps.

Make sure you use a big cap (100 uF) on the supply line.  If you get ticking, try a tantalum cap of about 33uF between (and as close as possible to) the power supply pins of the chip.  This has worked for me.


Joe

[puretube]

LM324.

[gez]

http://diystompboxes.com/sboxforum/viewtopic.php?t=29802&highlight=icl7621

Plenty of suggestions, including my favourite (and RG's now?)  

[Brian Marshall]

http://diystompboxes.com/sboxforum/viewtopic.php?t=29802&highlight=icl7621

Plenty of suggestions, including my favourite (and RG's now?)  

thanks man

[Fret Wire]

TLC2262CP?
http://focus.ti.com/lit/ds/symlink/tlc2262.pdf