Archive for Gates

Gates Sta-Level

Posted in Repaired, Restored with tags , , , , , , , , , on January 22, 2014 by AnalogAudioRepair

A client gave me a beautiful original Gates Sta-Level to bring back to life.  It had all original components but had not been turned on in over ten years.  After testing all the tubes, I brought it up on my Variac with just a solid state rectifier installed.  The power supply filter caps were good, but not great so they got replaced first.  With the new PSU caps and the tubes installed the unit was working ok, but had a very strange frequency response.  Above 1kHz it was fairly even, though not quite up to spec.  Below 1kHz it increased steadily to about +12dBm at 30Hz!  It turned out the feedback caps from the 6V6 output stage to the 12AU7 were leaky.  I replaced those and the coupling caps and things are now back to factory spec.

Vintage Gates Sta-Level

Original Gates Sta-Level

Gates Sta-Level original guts

The guts – dead stock!

Gates Sta-Level power supply re-cap

New Power Supply Caps

Gates Sta-Level capacitors

Replaced Film Caps

 

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GATES Discrete Microphone Preamps

Posted in Racked Modules, Restored with tags , , , , on December 29, 2012 by AnalogAudioRepair

This is a pair of Gates broadcast discrete transistor mic pres.  These microphone preamplifiers were used in Gates radio boards and have transformer balanced inputs and outputs.  They have 37 dB of gain and I racked them with a level control ranging from 20-37db.  The position of the level control is immediately after the input transformer so there is no need for a pad on the input unless you are overloading the transformer!  These units were re-capped and wired for 150 ohms in and 600 ohms out.  This was a super simple and clean rack job so they only have XLR in and out, level control, and a power switch for the outboard +30v power supply.