Which Machine Best To Convert to 2-track>

[stevieb]

By 2-track, I mean a R2R machine that records two tracks on one pass, using the entire tape width, rather than it recording two tracks on one pass, then two more on the "return" or other-direction pass.

I have the following, all working or easily repairable:

Revox A-77 2-track/quarter track/ 1/4"

Fostex R8 8-track/full track/ 1/4"

Teac 3340S 4-track/ 1/4" (from the Quadraphonic days, seems to be usable as a 4-track/full track or a 2-track/quarter track machine.)

TASCAM 38 8-track/full-track/ 1/2" machine.

I hope I am using the terms quarter-, half- and full track correctly. I mean to say:
quarter track- each pass records two tracks (stereo) on each pass, then can record two more going the other way.
full track- only recordable/playable in one direction; uses the entire tape width for X number of tracks.

Is it cost-effective to convert one to a "one-pass" pass machine, that would record only two tracks? Which one would you suggest I do it with, if at all? I know the Revox was available in quarter- and half-track options, perhaps that would be the best? Any one have a source for the parts?

Thanks.

 

[jpmorris]

Generally, full-track seems to mean full-track mono, i.e. one track across the whole tape. Half-track is what you're thinking of, where two stereo tracks are spread across the entire tape, and quarter-track is two stereo tracks in opposite directions (though there are also mono configurations for quarter and half-track).

Of those machines? I'd say the A77 and the Teac are the best bets in that there are heads extant for those machines which will do the trick, though it might be costly. The Teac probably uses the stock BR20-type heads which I think may still be available. I think you can even get A77 compatible heads, but be prepared to spend some money for that.

For the 38, I do not think there were ever any heads available in that configuration which means you'd have to get some custom-made. That is going to be a bit expensive.

For the Fostex you might be able to scrounge A2 or E2 heads, but I don't imagine it would be easy.

 

[evm1024]

The quickest to convert is the Tascam 32

Getting heads for the 38 to run half-track would cost more than buying a 32. I have looked into that.

1/4" half track heads are available and much more common than 1/2" half track heads.

Regards, Ethan

 

[ofajen]

Generally, full-track seems to mean full-track mono, i.e. one track across the whole tape. Half-track is what you're thinking of, where two stereo tracks are spread across the entire tape, and quarter-track is two stereo tracks in opposite directions (though there are also mono configurations for quarter and half-track).

I think "half-track" refers to mono recording in two directions on the tape. The NAB standard track width was 0.082" for half-track mono.

I think what you want is two-track stereo (both tracks in one direction). The Euro standard is two tracks of 0.100" (2.8 mm) track width, while, IIRC, the NAB standard is two tracks of 0.082" (2.1mm) width and the Ampex standard was two tracks of 0.075" (1.9 mm) track width.

Euro stereo gives you an extra 1.5 dB of S/N and low fringing with a full-track calibration tape, but requires a very wide erase head (often just a full-track erase head is used) and has increased crosstalk.

Just thinking out loud here... you could really improve your two-track stereo S/N on 1/4" stereo (relative to NAB) if you had Euro track width and used MRL's proposed studio mastering eq with 6300 Hz transition frequency instead of NAB. On the high end, I think you would gain at least 5 dB in S/N!

Cheers,

Otto

 

[dodgeaspen]

Most of the machines you listed I know nothing about. However, I have read that the Revox parts are harder to come by these days(not that I would know it) The 38 heads would cost $$$$$$$$$ Someone mentioned the Tascam 32. I've had an eye on that machine for some time now. What shape is your 38 in? Have you thought about selling? Let me know.

 

[ofajen]

If it were me, I wouldn't even consider trying to convert one of those machines. I'd look for a good deal on a solid two-track stereo machine and be done with it.

However, I will say that I've been checking out the schematics on my M-23 1/4" machine to look at the possibility of modifying my spare record and repro cards to do MRL's proposed studio master eq, rather than NAB. While I'm at it, I may give a call to MRL and other folks who sell heads and see if I could get a good deal on compatible Euro width stereo heads to go on my spare stack plate. Right now, it just has heads that were tested by MRL and found to be no good. As I alluded to in a previous post, switching to the MRL eq gains you about 4 dB of S/N in the high frequencies, and 2.8 mm (0.1") wide tracks gain you another 1.5 dB across the board. That's about like switching to 1/2" tape!

Cheers,

Otto

 

[Blue Jinn]

I know very little about doing this, nor about Revox decks, but why couldn't you replace the 4 track stereo head on teh Revox, with a 2 track stereo head? AFAIK you can get replacement heads from JRF Magnetics. Don't have any idea the cost, but website indicates they have 1/4" Studer heads. Flux Magnetics mfg replacement Ampex heads and Studer A80, don't know if interchangeable.

If I'm reading the original post correctly the Revox is a 4 track. (2 tracks 2 directions.)

(I thought about converting my Teac A3300-SX into a A3300-SX 2trk, but AFAIK, the motors are different on the latter.)

However, I opted for getting a dedicated two track Otari.