tape head amplifier

[Davide82]

Hi!

I have an old reel-to-reel home recorder (late 60s).
I would like to record some tapes to PC maintaining the highest quality.
Since it has valve amplifier, I think the best way to get the signal is right at head output before any kind of signal amplification.
The question is: can I do a good tape head amplifier using only an opamp? If yes, how?
I would not like to buy a tape head amplifier IC until necessary.

 

[burbeck]

hi David,
it is possible to construct a tape head pre amp, however this is not a straight foward job, the pre amp has to have tape EQ compensation and there are a few different specifications for this.
this along with the low noise and small signals involved make it quite a job.

how is the sound of the machine you have?

 

[Davide82]

Thanks, but I would do EQ with software... so I only need to know hot to hook it to a pc soundcard!

 

[Frank Berry]

You'll need a wide bandwidth chip which can also provide high gain. You might want to try a chip which is often used for video ... perhaps something like an AD847JN.

 

[Davide82]

Why do I need a wideband opamp? for amplifying bias frequency? sounds weird...

 

[lcsaszar]

I doubt if it is possible to build a better sounding (not better specs) playback amplifier than the original valve amp. What is the problem with it? The only one I can imagine is hum and it can be cured.

 

[tkwou]

A tape head amplifier is very similar to a phono preamp. It just uses a different equalization curve. They use to be very common at one point. Even the old Dynaco PAS3 had one. The equalization can be done passively or actively like RIAA in a phono preamp. Below are a couple articles about building them.

http://www.bottlehead.com/et/adobespc/Seduction/bottleheadtapeheadpreamp.htm

http://www.stiftsbogtrykkeriet.dk/~mcs/index.html

 

[Frank Berry]

Why do I need a wideband opamp? for amplifying bias frequency? sounds weird...

Wideband so you can gets lots of gain from a single chip and not attenuate the highest audio frequencies.