TI Spec sheet shows a preamp WITHOUT a cap. SO, no turn on / turn off transients to worry about? OPA627?
Thank You
Thank You
Depends on how much you value your cartridge or tape head...
A good quality electrolytic capacitor like the Nichicon UES-series will have zero impact on the sound quality and will prevent excessive DC across the cartridge or tape head if anything bad happens. $ cost now vs a potential $$$ cost later. Your call.
Tom
A good quality electrolytic capacitor like the Nichicon UES-series will have zero impact on the sound quality and will prevent excessive DC across the cartridge or tape head if anything bad happens. $ cost now vs a potential $$$ cost later. Your call.
Tom
Yes, of course it is possible. If you worry about turn-on and turn-off thumps: create a muting circuit which guarantees the output is muted for the first N seconds after power-on, and which also guarantees the output is muted within X milliseconds after power-off.
Is it a good idea? Probably a matter of opinion and personal taste.
Is it a good idea? Probably a matter of opinion and personal taste.
Thanks guys - not worried about output thumps (covering that elsewhere) but possible magnetization of tape head.
Newvirus - where did you get Fig 9 from - looks wrong - inputs backwards and no gain - 100Kohm to ground maybe should be 100ohms?
Newvirus - where did you get Fig 9 from - looks wrong - inputs backwards and no gain - 100Kohm to ground maybe should be 100ohms?
OP37 datasheet, Figs. 8, 9.
Yes, 100 ohms not 100k. Looks like ADI was in a hurry.
However, I recommend the instrumentation amplifier topology in which the bias current flows through the resistors, as the coil goes between the inputs (as opposed to input & ground).