Q&D Compressor + Buffer

[markm]

Hi fellas.
I am in the process of building the Q&D Comp from Jack Orman and was wondering if
it would be a good idea to build an AMZ Buffer into the circuit.
I have been reading that a buffer in the signal chain is suggested when using all
true bypass effects and it is my understanding that the buffer is best at the beginning.
That said, the Compressor is usually run first in order so, would it be a good idea to combine the two?
Opinions wanted please,
    MarkM

[jrc4558]

I use a built in buffer in ly wah, whcih goes b4 my Anderton Compresson. No audible difference on the effect. Dunno how will go with a Q&D though.

[markm]

I guess I'm concerned about noise a bit.
Also, maybe it would be better to build a stand-alone
buffer so it can be move around in the chain for whatever reason.

[hairyandy]

If you're concerned about the compressor amplifying any noise the buffer might add, just put the buffer after the compression on the output.  I wouldn't think that it would make much difference as far as the buffering is concerned and I'm sure it would be quieter.  For that matter, I would think a combination compressor/Mosfet Boost would be pretty cool and would still give you the buffer.  I've been kinda into combos lately...

[markm]

Now that's an idea.
Interesting!
I'll give it some thought although,
I was thinking the signal may benefit more if the buffer was at the beginning but,
I could be wrong.............

[hairyandy]

You might be right but there's one way to find out, build it both ways!   

[Mark Hammer]

The datasheet for the SSM2166 indicates that the input stage on the chip (which is an onboard op-amp) has an input impedance of 180k.  That's ....okay....but not great.  A FET-based unity gain buffer might not be such a bad idea.  Keep in mind the chip was ideally designed for use in "control strips" for voice mics.  While they "work" for a simple single-chip compressor pedal, they expect to see something with a lower output impedance than a guitar usually provides.