selectable pre-amps: silly idea or not?

[soldersober]

I am building a pre-amp with arduino controller for volume, inputs and outputs. So it got me thinking to put more than one pre-amp circuit in the box, and select one just as I would select inputs.

Candidates are BA-3 gain stage, B1, DCB1, DCG3, first three I have in various stages of completion

So far the main reason to do this is because I can. What do you guys think?

Asking in this forum since the pre-amp will drive F6 or F5T or maybe Aleph 5


Edit: I am not too crazy, thinking about two circuits only, a buffer and a amp

 

[delecoy]

GFP-750

 

[soldersober]

OK

 

[Nelson Pass]

So far the main reason to do this is because I can.

That's my usual reason.

 

[Kirchhoff]

I'd suggest to have one of them with tone controls. In the end, and to the dismay of the "purists", it may prove to be the most pleasing one.

 

[JMFahey]

You need *very* transparent switching, or it will obscure minute differences.

 

[soldersober]

You need *very* transparent switching, or it will obscure minute differences.

Any recommendations as to what to do and what not to do?
Volume control will be LDR, relays just normal Panasonic 12V, short wiring..

Thanks!

 

[AndrewT]

Some gain stages work optimally at only one gain.
Selecting different stages with a different optimal gain could result in better performance than using one gain stage with pre-settable gains of +0dB, +6dB, +12dB, +18dB

Buffer plus different stage gains could be installed to obtain optimal performance from any stage at whatever gain you require..

 

[formantjim]

Hi Soldersober I too did what you want to do because we can!

Look up my thread "Willow II" where I too used an Arduino together with a digital pot driving an F6.

My first preamp was the "Albert" relays R2R ladder and while this gives the most fidelity there was noise from the relay contacts which one could hear when listening with headphones. That's why my next preamp will be an LDR from the noiseless level changes.
Having a variety of preamps within one device sounds like a neat idea so one could hear the differences go for it!