hi. could someone point me in the right direction for this project?
i would like a circuit for a reel-to-reel head. it would need to play, record, erase, and stop.
that is it. just imagine that i have the head right now and nothing else. i don't need any tape movement circuitry.
any ideas? thanks. i don't have a head yet, so any recommendation on which one to remove from an old reel-to-reel would be great.
looking forward to your responses!
i would like a circuit for a reel-to-reel head. it would need to play, record, erase, and stop.
that is it. just imagine that i have the head right now and nothing else. i don't need any tape movement circuitry.
any ideas? thanks. i don't have a head yet, so any recommendation on which one to remove from an old reel-to-reel would be great.
looking forward to your responses!
Heads for reel to reel are typically built for the specific purpose and are separate units. The playback head has very small gap, the record head a larger gap and the erase head is different again.
You can get combined record/play heads which are a compromise.
An amplifier for a playback head is pretty straightforward. High gain and with the correct response curve (NAB ? from memory).
Record amps are also straightforward but you need the addition of a high frequency bias current to be passed through the winding in order to move the magnetic properties of the head onto the more linear part of the B-H curve.
Lots of things for you to look up there
and you can find lots of circuits on the web or from old service manuals.
You can get combined record/play heads which are a compromise.
An amplifier for a playback head is pretty straightforward. High gain and with the correct response curve (NAB ? from memory).
Record amps are also straightforward but you need the addition of a high frequency bias current to be passed through the winding in order to move the magnetic properties of the head onto the more linear part of the B-H curve.
Lots of things for you to look up there
and you can find lots of circuits on the web or from old service manuals.Your post raises WAY too many questions:
Do you already have a tape transport mechanism? What tape width? What tape speeds?
The physical space available in the headblock of the mechanism will determine (or eliminate) a number of head types. And if you want to do both recording and playback, you will need at least 3 heads. So-called "combo" heads were/are? available but were sonic compromises.
After answering these questions you can start with the circuitry. For erase and record - I "steal" the actual circuitry from a well regarded machine. Finding the necessary transformers / inductors will not be easy - suggest that it is better to find commercial record/playback electronics - listed regularly on the Bay - and go from there.
Charles
Do you already have a tape transport mechanism? What tape width? What tape speeds?
The physical space available in the headblock of the mechanism will determine (or eliminate) a number of head types. And if you want to do both recording and playback, you will need at least 3 heads. So-called "combo" heads were/are? available but were sonic compromises.
After answering these questions you can start with the circuitry. For erase and record - I "steal" the actual circuitry from a well regarded machine. Finding the necessary transformers / inductors will not be easy - suggest that it is better to find commercial record/playback electronics - listed regularly on the Bay - and go from there.
Charles
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Ok I'll answer the questions and narrow it down for you :
Yes I already have a tape transport mechanism and circuitry to make it go.
1/4" tape
Not sure about exact tape speed, but my range is huge. The motor can go from 1 rpm up to 4000 rpms. I didn't calculate the ips's yet with the flywheel and all that.
Physical space in headblock is unlimited.
Both recording and playback.
*
Isolating just the head playback and record circuit from the entire schematic is my issue. So looking for a good head to use and a circuit that i could have buttons of play and record. Like I said nothing is needed for the tape transport.
thanks!
Yes I already have a tape transport mechanism and circuitry to make it go.
1/4" tape
Not sure about exact tape speed, but my range is huge. The motor can go from 1 rpm up to 4000 rpms. I didn't calculate the ips's yet with the flywheel and all that.
Physical space in headblock is unlimited.
Both recording and playback.
*
Isolating just the head playback and record circuit from the entire schematic is my issue. So looking for a good head to use and a circuit that i could have buttons of play and record. Like I said nothing is needed for the tape transport.
thanks!
OK. Finding a "loaded" headblock is probably a good way to go. Heads (especially playback)"sound" different tho. Revox/Nortronics are better than Japanese.
Do you want to start "from scratch" with an electronics design? Salvaging the electronics from another deck (especially one compatible with the headblock) would be a LOT simpler - especially the record / bias / erase circuitry.
Charles
Do you want to start "from scratch" with an electronics design? Salvaging the electronics from another deck (especially one compatible with the headblock) would be a LOT simpler - especially the record / bias / erase circuitry.
Charles
ok I would go with the better playback of the Revox/Nortronics. unless the price is astronomical or something?
simpler is good. i just don't need all the mechanism circuitry, so my initial thought would be to copy the audio heads circuitry design, but use all new components and solder up a new board. to replace the old stuff that may be worn out and also condense the size. do you think there is a better way?
also does anyone know if activating the playback and record functions is as simple as a switch that closes the circuit to the head? only talking about audio here, not the mechanisms keep in mind.
thanks for the help! really appreciate it.
simpler is good. i just don't need all the mechanism circuitry, so my initial thought would be to copy the audio heads circuitry design, but use all new components and solder up a new board. to replace the old stuff that may be worn out and also condense the size. do you think there is a better way?
also does anyone know if activating the playback and record functions is as simple as a switch that closes the circuit to the head? only talking about audio here, not the mechanisms keep in mind.
thanks for the help! really appreciate it.
i think i'll try to gut a reel-to-reel.
would want to get rid of supply reel motor, take-up reel motor, drive motor, speed button, large/small button, counter.
keep all the audio controls and pinch roller solenoid activation circuit.
my problem would be what electronics to remove along with the physical pieces. any ideas how to go about this?
ty
would want to get rid of supply reel motor, take-up reel motor, drive motor, speed button, large/small button, counter.
keep all the audio controls and pinch roller solenoid activation circuit.
my problem would be what electronics to remove along with the physical pieces. any ideas how to go about this?
ty
I just realized that there is another way to go about this that may be the simplest from a "rehab" perspective. Buy a "clunker" Revox A77 or later-series machine - Quarter track; nonworking; they go for peanuts. All the record/playback/erase electronics are on separate plug-in boards. Manuals are on the web. You might even find one with good heads - would further your project even more.
Charles
Charles
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