Cello Audio Suite Playback Electronics

[newmedia]

Folks:

Does anyone have experience with the Cello 4-channel RTR playback electronics?

Sony bought quite a few of them for mastering use with Studer 820's and three of them went on auction last year.  I wound up with one of them, with the plan to one day set it up with my Otari MTR-20.

No Cello PSU but I plan to use a pair of HP bench supplies at +/- 30VDC -- unless that seems like a bad idea.

A few have shown up on eBay -- w/ one seller asking $8K for the whole shelf -- so I'm wondering if any have found their way into this elite community.

Mark Stahlman
New York City

[ironbut]

Mark, one of our members "stellavox" Charles King is using the Cello (603?) modules currently. He has the PS module too but I believe he's currently using a supply he built. You should email or PM him to find out more. I'd really like to get my hands on a couple of channels of record modules but $$$ is a little too tight to consider that right now.

[newmedia]

Hello:

Yes, I know Charlie pretty well.  He has been very helpful with my Stellavoxen.  Currently that collection consists of an SM8, SU8, SP8, AMI48 and a flock of SI7's.  Various others have come and gone.

The Nagra collection is now down to one IV-SJ and a Nagra D (which was used on "Eyes Wide Shut"), with many S/STC/SJ's come and gone back into the big pond.

If I understand it correctly, Charlie acquired a stock of parts and pieces from the Cello diaspora, which he has been putting to good use.  Can't think of anyone else who is better equipted to explore the limits of these "rarified" vintage electronics.

My Cello Audio Suite is a "split-rail" chassis with two independent sets of P603 + P301 plugins.  It would be ideal for three-channel stereo playback (i.e. its intended purpose at Sony) if any 1/2" 3T (or 4T dubs) ever surface.

Mark Stahlman
New York City

[stellavox]

Mark,

You do have most of the important Cello elements for a great playback system.  Yes the Suite (and modules) require regulated plus and minus 30 volts from a separate power supply - lab supplies should work fine - need at least an amp (two or three even better) capability.  Cello tended to use the Lemo (or whatever else the special Swiss connectors were called) so connecting the heads (and outputs) to/from the modules can be a problem. 

Then there's the issue of "setting it up".  Best way is with the ST 1500 and associated test tape.  Adjust the 1K pots for overall gain at 1Khz (to +3, +6, whatever turns you on - the modules don't clip till +23!); set the 10K pots for smoothest high frequency response and the 31.5 pots for smoothest low frequency response - although I've had better luck with a variable resistor right at the input (across the head).  once set up for, say @ 15ips NAB, you'll have to redo the high and low freq pots again for IEC. 

[newmedia]

Charles:

Thanks for the reply.  I figured that a pair of back-to-back HP 6433B's (40V, 12A) would probably do the job.  At around $65 each (+ shipping), it beats paying $2500+ for a Cello supply.

The Cello ins-outs are Fisher connectors -- presumably more rare and thus harder to "copy" than Lemos.  Fortunately, I have the original Studer A820 head cables (yes, Cello Strings), so I just need to fashion the head-block mate for the MTR-20. 

I was indeed planning to set this all up with the SD 1500 but have been looking for a copy of the tape.  Might you know where to find one?

I actually have the SD TR150 test record.  Maybe I should dub it from vinyl to tape?

Mark