low voltage tape head amplifier

Status
Not open for further replies.
Jump to Latest
P

preludefan

Member
Joined 2011
#1
Hi all,


I am wanting to build a 6v op amp based tape head amp, for both recording and playback, can anyone suggest a suitable good quality op amp? most of the ones I find have a nominal operating voltage of around 12 to 15...




Thanks in advance,



Mike
 
#2
A good tape *record* system also needs a Bias Oscillator, which is not a job for an opamp.

The LM389 datasheet has a basic 6V tape deck plan. The LM389 is an LM386 plus three jelly-bean NPNs. Note that the power stage of these chips is NOT an all-purpose opamp, it has bias and gain resistors included. Note that the LM389 plan uses DC bias to the record head, which is very inferior to AC (oscillator) bias, suitable only for $13 cassette portables.
 
#3
Thanks for that,
Yes I would much rather use ac, but that can come from another circuit....


Will check out the data sheet!



PRR said:
A good tape *record* system also needs a Bias Oscillator, which is not a job for an opamp.

The LM389 datasheet has a basic 6V tape deck plan. The LM389 is an LM386 plus three jelly-bean NPNs. Note that the power stage of these chips is NOT an all-purpose opamp, it has bias and gain resistors included. Note that the LM389 plan uses DC bias to the record head, which is very inferior to AC (oscillator) bias, suitable only for $13 cassette portables.
Click to expand...
 
#4
Take a look at service manuals: hi-fi engine has a lot of them; Nakamichi, AKAI, Aiwa, NAD, HK, Teac, JVC, Sony, Denon, Marantz, ... Many decks run on +/- 6V up to +/-15V, most Dolby chips use +/-7V. Using low noise op amps, there shouldn't be a problem using lower voltage, you just won't get a lot of output swing. The biggest problem is to match EQ to heads. l would also recommend this group of tape maniacs for good reading Tapeheads.Net Home Page Alex, Pacific Stereo and others are very knowledgeable in decks department.
 
#5
pliedtka said:
Take a look at service manuals: hi-fi engine has a lot of them; Nakamichi, AKAI, Aiwa, NAD, HK, Teac, JVC, Sony, Denon, Marantz, ... Many decks run on +/- 6V up to +/-15V, most Dolby chips use +/-7V. Using low noise op amps, there shouldn't be a problem using lower voltage, you just won't get a lot of output swing. The biggest problem is to match EQ to heads. l would also recommend this group of tape maniacs for good reading Tapeheads.Net Home Page Alex, Pacific Stereo and others are very knowledgeable in decks department.
Click to expand...




Thank you very much! Will see how I go and get in touch!

I have ordered a Toshiba and sanyo chips that were used in early Walkmans. Will build a PB amp then do some experimenting with using the same chip to record. For the oscillator I was thinking to use a 555 timer,a decade counter and a resistor group to create a sine wave for the erase head. ..
 
Status
Not open for further replies.
Top Bottom