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Subject: Re: [newmellotrongroup] Re: Another 4-Track update (she's nearly done)

From: lsf5275@aol.com
Date: 2009-11-17

In a message dated 11/16/2009 6:30:53 P.M. Eastern Standard Time, pocotron@yahoo.com writes:
Very nice, Frank.  It's a clean machine.
   Here's a few nosey questions-
-Is that bar that the tapes pass over made of nylon?  Is the friction it induces due to static build-up?
-What circuit is in the box in back of the control panel? 
-Was the flywheel pulley belt standard sized?
 
  Thanks
  -Bruce Daily
 
Bruce,
 
The roller guides on the tape frame were all difficult to spin. I fixed that. The roller guides that the tape return springs pass over were the same way. I fixed them. The nylon bars across the front and rear of the guides that the tapes pass through at the head block are very smooth and cause little if any friction. Whether or not they impart static electricity to the tapes remains to be seen. I have not experienced any signs of that yet.
 
The flywheel appears to have the same diameter as any other at the point where the belt passes over it, but the diameter of the capstan is smaller than that of a M-400. The M-400 capstan has a 20mm diameter and used 6004 bearings while the 4-Track capstan has a 3/4" diameter and takes R-12 bearings. The belt is stock and the drive pulley and timing sprocket are stock.
 
If you look at the photos in the album I posted on the Yahoo site, you can see one of the 4 pre-amp boards. The pots are connected to the boards themselves. Here is a photo of what's inside. The preamp boards for each track plug into these edge connector sockets.
 
That's all that is up top except for the on/off switch and the pitch control pot. In the box below where the power supply is there is a SMS-3, a transformer, two capacitors and a few other components. Not a Bulgin anything to be seen. It looks like all connectors are Molex connectors. Even in a standard power supply, if you have an SMS 2, 3 or 5, you really only need the large 4000 microfarad capacitor and the 1600 microfarad capacitor next to it. The rest of them can be used to make neat devices to shock the shit out of your friends or even total strangers. Handle with care. The swell pedal connector is a DIN connector.  All four tracks run to it and then to the lines out, much like a M-400.
 
Notice the scientifically designed, human engineered, user friendly piece of Velcro to the right. This is the hook side; the loop side is attached to the lid. This is to keep the lid closed if you happen to be playing outdoors in heavy wind.
 
The 4-Track appears to have been designed and built by the Gilbert Company. It is constructed very much like something one might build with an Erector Set.
 
One last thing. There are seven 1/4" output sockets on the back of the cabinet. Three above four. As near as I can tell, they are configured as follows.
 
                   Left channel out.        Line out (normal mono)         Right channel out
 
 
          Track A (clean)         Track B (clean)          Tack C (clean)          Track D (clean)
 
By clean, I mean that the signal from the head stack does not run through the preamp and therefore the player has no control over volume or panning. I suppose you could run the lines out through 4 separate volume pedals though. I think the intent is to run the dry signal directly to a recording desk.
 
The left and right channels can be used for live performances and go through the swell pedal and allow panning of the separate tracks by the player during recording or live performance. The mono line out is for the guy who just wants to plug it into his amp and make some noise.
 
I like it!
 
Frank