IC for DC servo ?

[EchoWars]

Typical input bias current of 2pA, input voltage range extends below ground for single-supply operation, designed for true single-supply operation, but works fine on split supplies, and no phase reversal for voltages exceeding V+ or V- (as long as a resistor is in series with the input pin.)

Just seems taylor-made for the job at hand, and I've used it as a servo chip in several amps. I've never seen offset larger than about 0.3mV with this opamp used.

[KBK]

I've got a Parasound 1500A, which is working fine..but..I'm curious if overal sonic qualities will improve with a different op amp (DC servo loop).

I've upgraded the PS quality around the AD711, but I've no idea if this improved the sound quality or not. I don't think I'll ever seriously use the amp for it's sonic qualities. Amps with DC servos of that nature aren't high on my list of 'amps worth listening to'. ie, right down there with the Brystons and the like. Oops. Jim might read this, or evern worse..Stu. Brystons are great!!

The amp (while in my posession) is just for buying broken..and selling fixed, which I'm in the middle of doing. Amp is in perfect shape, now I need to do a bit of 'sonic rescue' to the amp, simply because it is in my posession - and it looks like it needs it. I'd hate to be caught selling someone a stock item......

[CBS240]

Originally posted by sam9
They even have AD797 in stock. It's not in the catalog, so I presume it is new. Actually both Digikey and Mouser often have items available that are not in the catalog. However, sometimes you find these are only available as a special order with a minimum quantity. Not in this case though.

As for Mouser, you can find new stuff by going to (for example) Fairchild's website and searching for new parts in the area you are looking for, copy and paste the part # on the mouser site. It may show up as page 9999 of the catalog, but not IN the catalog. Although most new parts Fairchild allows samples to be ordered. BTW, just a point of interest, Mouser has a couple new Fairchild mosfets(not exactly complements ): http://www.fairchildsemi.com/ds/FQ%2FFQA36P15.pdf

http://www.fairchildsemi.com/ds/FQ/FQA70N15.pdf

Pretty hefty SOA

[AndrewT]

Hi,
I thought LM411 was OK for DCservo duty, but the last mention was way back at post8.

What part of the spec makes 411 unsuitable for servo?

What improvements (specifications and realisability) are the newer ICs bringing to the table?