862 words as of 3 december’98
Part One: Studer V-Eight mechanical review by Eddie Ciletti.

This review is for evaluation purposes only.

Please contact Eddie via email or by phone: 212-529-8225
 
 
 
MANUFACTURER: Studer 

APPLICATION: Eight track digital tape recorder 

SUMMARY: Adat-compatible 16-bit mode. MD-20 compatible 20-bit mode. 

STRENGTHS: Reliable, proven medical-grade transport. Includes RS-422 interface, Time Code and AUX (linear analog) tracks, built-in 8x2 mixer. Excellent shuttle and jog control. "Quality" indicator lite and easy access error rate display. Recessed side-panel slots for glide rails allow the unit to easily slide out from rack for routine service (head cleaning). 

WEAKNESSES: Unit could be more serviceable. 

OPTIONS: Space reserved on back panel for… 

Please detail all of the options and prices 

LIST PRICE: 10 billion dollars

I have taken the unconventional liberty of splitting the Studer V-Eight (super adat) review into two parts: the mechanism and the "interface." I am uniquely qualified to explain how the medical grade transport will make this the most reliable adat ever made. But as a responsible journalist, I must emphatically report that, "this is not your father’s Studer."

WHAT EXACTLY IS INSIDE?

The Studer V-Eight is a variation of the Alesis M20. The main parts are supplied by Alesis, assembled by Studer and augmented with front panel/electronics and A/D/A converters. The tape mechanism is by Panasonic. It is built from a rigid, cast-metal deck plate that is machined to tolerances hitherto unseen in previous versions of adat.

The Alesis portion of the V-Eight consists of three boards: Main System, Motor Driver and I/O. The latter includes MIDI, WORD, OPTICAL, VIDEO, TIME CODE and RS-422 ports. Studer has added an eight-by-two mixer with headphone jack (for local monitoring), a parallel interface and a blank panel for an optional ??? The power supply is housed in a ventilated steel case with its own fan.

FAST, PRECISE and SMOOTH

With separate direct drive reel motors (and no tires to wear out), the Panasonic transport is super fast. It can "Locate Zero" from 44 minutes in 43 seconds with no overshoot. (An XT takes 75 seconds to complete the same task). A front panel knob has two positions: in / jog and out / shuttle. There are corresponding lights to indicate precise transport status — direction and mode — at all times.

Shuttle works like you’d expect, from the center "détente" position, the machine moves in either forward (cw) or reverse (ccw) mode under capstan control. The further away from "détente" the faster it goes. Shuttle is limited to about 135 degrees rotation on either side of center. Jog allows a remarkable degree of control for precise "scrubbing." In Jog mode, the knob moves continuously throughout 360 degrees and behaves as if it were the capstan motor — like an Ampex ATR-100 or an Otari MTR-90 — in either direction.

COVER POPPIN’ DADDY

Of course I popped the cover on the V-Eight straight away. I carefully observed tape handling under all conditions and immediately noticed two fixable bugs. Just before the tape meets the first precision guide there is a nice, heavy brass Impedance Roller to smooth out tape flutter as it exits the cassette shell.

Like the nearby full-track erase head (not connected), there is a support brace to the left of the impedance roller that must have served some function for Panasonic when this tranport was used in their medical grade video decks. In the V-Eight, neither serves any purpose except that the brace can (and did) bend enough to impede the impedance roller. (I removed the offending device.)

Since both Shuttle and Jog modes move the tape under capstan control, I knew it would be the perfect test for revealing potential flaws in the tape path. Indeed, it did. On the opposite side of the head is a fixed guide (just before the Capstan Motor) that supports the lower edge of the tape. In the forward direction (Play, Shuttle or Jog), the tape bottomed out and began to curl. In reverse, the tape skewed up toward the top flange revealing that the motor's ever-so-slight deviance from "square" was the culprit.


FIGURE ONE: Arrow indicates guide where curl occurs

FLYING TOOLS

There was no way I was going to put my master tapes in the V-Eight until the tape path problem was resolved. The audio signal is not recorded to the extreme edges of the tape, but a transport as good as this one should be able stand a tweak and stay there.  I found that exerting pressure on the top of the capstan housing either exaggerated or resolved the problem. So, unlike most reviewers, I started removing components until the capstan motor mounting screws became accessible. (I won’t mention that I took a Dremel motor tool to these parts to make them more service-friendly.) I will mention how Studer has implemented additional steps into their quality control procedure.


Figure Two: Colored Arrows indicate where head PCB and HEAD connections impede screwdriver access to capstan mounting screw.
Black Arrows indicate places where metalwork makes this part difficult to remove without first removing the solenoid assembly.

As a test, I created a shim that would hopefully move the capstan shaft into a position that would be exactly perpendicular with tape travel. This shim was 3 mils (.003 inches) thick. I was close; 2.5 mils would have done the job. I then proceeded to polish the opposite mounting hole until 2.5 mils had been removed. Voila. The tape path is perfect and consistent. Now I can proceed with a long-awaited 24-track remix.


FIGURE THREE: Black arrow improves serviceability.  Blue arrows indicate where trial shim was used.
Yellow arrow points to hidden flange which was polished to remove 2.5mils of material to improve perpendicularity.

WISH LIST

I wish that Studer had been involved at the very beginning to bring their expertise to the design of the MD-20 / V-Eight. While it should be very reliable, I found that several steps could have been taken to make the machine more serviceable. The most obvious omission is access to the bottom of the transport. Currently, the steps involve either removing the front panel or the motor driver board and then the transport. Both steps make the unit inoperable and all steps are unnecessary, "if only..."

The "Studer" method would have been to engineer a hole into the chassis and put the motor board on a hinge — with enough wiring slack — so that it could be safely positioned out of the way. The transport should also be mounted on a tray — or some way to improve access to the mounting screws, four of which are underneath the motor driver board — so that the transport can be removed without disassembling the rest of the unit.  Then, for example, if one needs to check the tach head clearance of the capstan motor, there is infinitely less labor required.

Instead, every place you look, wiring harnesses are exactly to length, on both sides of the front panel and motor board, a practice that restricts movement in any direction. These are fixable problems that in the long run encourage technicians to take the time to do the best job possible.

The front panel could also be redesigned on hinges so that it can be folded down — again with enough wiring slack and connectors to permit service. The optional glide rails mean that the front panel does not need to support the unit.  In a rack, they only lock the unit into place.

Finally, I wish Studer luck with this machine. No adat clone has successfully been marketed or sold by a third party until now. The advantage to buying the Studer V-eight is having the additional features (especially the converters) as well as the Studer support team. Studer has over thirty years of experience interfacing with world-class studios — their clients and technicians — around the world.

Click Here For ALL Adat Audio Specifications

Next month… A real-world review.

e-mail edaudio@interport.net

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