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In Reply to: Does anybody use a modified phono preamp as tape head preamp? posted by Pyeboy on January 21, 2004 at 01:16:02:
I'm not familiar with the Revox G36. I have all Ampex pro gear. I think you're better off in using the G36's preamps and maybe modifying them because without knowing the play head's inductance, or head bump EQ characteristics, it would be difficult to fashion the EQ without extensive test equipment. All heads have a bass bump. The slower the tape moves, the lesser the bump but it is still there. An RIAA preamp really doesn't address head bump. There are two schools of thought on interfacing a preamp to a tape head:1. low inductance head (2 mh)that is transformer coupled (balanced) to the preamp and 2. high inductance (650mh) that is coupled unbalanced to the first stage. There is also two schools of thought on EQ:1. get the gain up before you monkey with the EQ, 2. apply it in two stages. Six of one, half dozen of the other. Without seeing a schematic of the G36, I couldn't help. Most RIAA preamps are designed just for that and most multipurpose preamps are trying to be everything to everyone and kind of "hit and miss" the target. Stick with the G36 preamp and try to lower the noise would be my advice. If the first stage is a 12AX7A then you might try a 12AY7 that had been cascaded (two section tied together. But I would have to see the schematic for you would have to rebias the cathode. Good luck! James
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Follow Ups
- Yes! - j.l.guillebeau@att.net 06:12:13 01/21/04 (3)
- Re: Yes! - Pyeboy 07:12:22 01/21/04 (2)
- email me the G36 schematic. - j.l.guillebeau@att.net 08:32:05 01/21/04 (1)
- Re: email me the G36 schematic. - Pyeboy 07:02:07 01/28/04 (0)