[Raj]

Hi David,

What's the coup with this? I found this message on the diy audio forum


Grataku

Many modern high-speed op-amps can become unstable due to the increased parasitic capacitance introduced by ic sockets. It is best to keep these devices as close to the ground plane as possible. If interchangability is a must, it is usually recommended that pin racks be used.

Geoff

I have my op-amps on sockets, is the above really a problem?

Thanks
Raj

[JohnR]

Well I'm not David ... but if you look at the datasheets for some of the really fast opamps I believe they will say that parasitics can indeed cause RF oscillation. I'm not entirely sure that there's any audible benefit to going *really* high BW w/ an opamp. I've used LM1365 (50MHz? 70 MHz?) in a socket without any (audible...) problem.

I would be interested to hear David's opinion.

[davidw]

Raj,
      Ideally its best not to use ic sockets. You usually only get the stability problems mentioned in your post with fast or rf circuitry. I've never had any stability problems using sockets with any of my products - admittedly I always use high quality turned pin sockets. Some high bandwidth opamps like the LM6171/2 do sound very good so you have to be careful with these. That said I've used socketed LM6171s successfully but added extra decoupling - across the + and - rails as well as from + to 0V and - to 0V. I've never listened to a circuit with and without sockets in a search for audible differences - has anyone tried this?

David