4 Track Head On Studer A810

[astrotoy]

Don't know about the geometry of the B67 headblock. My experience is that Greg Orton (Flux Magnetics) made a 4 track stereo playback head for my Ampex ATR-102 1/4" head block (there is room for four heads in the head block.) He installed the head into the head block and put a little switch so I could switch between the 2 track and 4 track playback heads.

Flux Magnetics

Flux Magnetics is a company devoted to the design and manufacture of state-of-the-art analog pro-audio heads for the recording industry

www.fluxmagnetics.com

Larry

 

[jdza]

I’m in progress of fitting B77 4-track head to my Studer B67. There is almost no information for doing it. This is already 12 years old post but only piece of info for doing it I have found so far.

If you are still online and have that unit or if somebody else knows about that. I would like to know more how you arranged switching between two heads. And how you fitted your head in place of record head. I don’t get the point from the original post about the switching.

After my measurements it seems that for fitting the B77 head you have to just make a new hole to the bottom place and lift the head little bit higher. But it would be nice to see how you made it.

It was really a long time ago and detail is vague. The A 67 became transport only with outboard Bottlehead Electronics. The stock Studer heads were of too low inductance and were replaced with higher inductance Nortronics Pro heads. John French supplied these and prepared them for use in a Studer. The stock Studer wiring was used and disconnected at the card inputs. The wires were then brought to RCA outs that were installed on the front panel.

It is still in use in the B system and sounds much better than the 1/4 track Revox G36 I also have. That in turn sounds much, much better than the 1/4 track Revox A77 I had.



A more ambitious project was for the A system where an A80R was turned into a Reproducer only. The Rec Head was replaced by a 1/4track FluxMagnetics head and the replay head by a 1/2 track Flux Magnetics mastering head. 2 Card cages are used: 1 with updated Studer cards set up for NAB use and 7.5 ips eq and the other for CCIR 15ips the (much modified) output cards of a Mark Levinson ML5.





One cannot believe how good old 7.5 1/4 track commercial releases can sound on this machine

 

[saamu]

Thank you a lot.

After my measurement I ended up to the conclusion that difference between B67 and B77 fixation thread is 2,11 mm ~ 2,1 mm. I mean center point of the fixation points is 2,1 mm different. B67 has M4 screw and B77 has M3 screw. So if I make a new hole to this base plate of head stack:



And If I use the whole B77 head with outer cover I should lift it up 1,38 mm ~ 1,4 mm. If I place the B77 without the outer cover to the B67 head's base plate I should lift it up 1,33 mm ~ 1,3 mm.

On that way I should end up to the correct spot.

At first I could add just slide switch to choose between 4-track and 2-track heads.

Another dream is to add second 4-track head upside down to be able to digitize whole 4-track tape in one run. For that reason I could have two head stacks. One for double 4-track heads and another one for 2-track + full track.

For double 4-track heads I would like to check if it is possible to put 2 additional repro card in place of record cards and route signal through them.