[QuadList] Ampex XVR-7500 details

[Don Norwood]

Hi Bill:

As always, thanks for the excellent first-hand info.  The great work on the 7800 obviously led to the 7900 series.  I still have a couple of VPR-7900's, and they perform beautifully.  Several listmembers have seen them, and I think they wiould tell you that with the very high band carrier and a TBC-7, they look like Type-C.  They are also 5-motor transports, but there is no slo-mo function.  Instead, the 5th motor drives the capstan during wind modes.  All-in-all, a pretty smooth transport, and an amazing 1" machine for its time!  Those were interesting times in the industry.

Don Norwood
Digitrak Communications, Inc.
www.digitrakcom.com
  ----- Original Message ----- 
  From: Bill Carpenter 


  Hi Chris and everyone!


  Yes, the VR-7000 type products could have been much better with torque motors. 

  When I started with Ampex in Nov of 1965, I had six years of design experience with Govt. magnetic recorders and before that I had three years of running my own wedding recording business, "Tru-Sound Recording" using an early three motor audio recorder, made by TDC, which had very low W&F and fast winding. 


  The VR-7800 was the first machine that I worked on from the start w/ Barry Guislinger as project engineer and I designed all the controls, mechanical interfaces and the i/o areas. 

  When we went into production in 1968 (Barry had moved back to Ca, to work on the AVR-1) I moved up to project engineer. 



  The 7800 had five DC motors, scanner, capstan, supply & takeup, and slo-motion (this was a small Globe motor w/ a teflon felt drag system for stable low speeds). 

  This was the first capstan servoed machine, the first use of Yaskwah printed circuit motors, and the first tension servoed machine and the first editing machine.
  Another interesting point was that the "Assemble" mode was fully servo locked, unlike all previous Quad's.


  IVC had great tape handling, but in a head to head shootout, the IVC-960 vs. VR-7800 for the EBU (European Broadcast Union) in Paris in 1969, we won hands down on the signal handling quality in both PAL and SECAM.

  I had spent 2 weeks in the summer of 1968 in Paris, at the ORTF labs, since they bought about 15, VR-7800's, and I went to tweak the tension servo's since the factory setup caused some problems in Secam. 
  It worked well and that caused the shootout, the next year.


  Bye for now, Bill & Gewyn & Ginger (whoof...whoof)


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