Archive for the Repaired Category

Telefunken V72S Transformer Replacement

Posted in Repaired with tags , , , , , on February 26, 2013 by AnalogAudioRepair

This is a rare Telefunken V72S – the “S” is a higher gain version.  Unfortunately this one had a bad input transformer.  The frequency response of the transformer looked like this: /   A rebuilt original was too costly for my client, but Sowter offers a replacement that works just fine.  The hard part is removing the original and mounting the new one!

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Fender Re-Issue Amp Repairs

Posted in Repaired with tags , , , , , , on December 29, 2012 by AnalogAudioRepair

I recently serviced a pair of Fender Re-Issue tube amps from the 1990’s.  One was a Deluxe Reverb with a shorted output tube, the other a Vibrolux with a blown cap (literally).  These ’90s re-issues are much like their predecessors, but with printed circuit boards which make it a bit more of a pain to work on them.  At least the Deluxe has connectors for the front panel controls rather than soldered wires like the Vibroverb!  It had some 2 watt resistors that were so charred they almost burned through the PCB.  I had to scrape away as much carbon as possible and seal the board with epoxy before replacing the resistors and power tube.  The Vibrolux had a capacitor which actually burst and both amps had very weak Chinese made 12AT7s.  While I was in the Deluxe I added the de-clicking cap to the vibrato circuit.

Altec Coke Bottle Mic PSU

Posted in Repaired with tags , , , , , , on November 28, 2012 by AnalogAudioRepair

A client sent me a vintage Altec M11 “Coke Bottle” tube microphone that needed re-capping.  The 518A power supply has a lot of caps, but the new ones are much smaller.  After re-capping and a new tube the mic sounds great!

Acoustic 126 Bass Amp

Posted in Repaired with tags , , , , , on October 15, 2012 by AnalogAudioRepair

This is a vintage Acoustic Control Corp. model 126 bass amplifier.  I received it non-functioning with no power cord or fuse cap.  Replaced two output transistors, re-soldered an inductor in the EQ section, and cleaned the heck out of the pots and sliders.  Added a new power cord and fuse cap and it fired right up.  These ’70s Acoustic heads really sound good!

Sovtek Mig 100

Posted in Repaired with tags , , , , , on August 6, 2012 by AnalogAudioRepair

Sovtek Mig 100 vintage tube guitar amplifier.  Fixed hum issues, tweaked, and SOLD.

Neve 5442 Mixer

Posted in Repaired with tags , , , , , , , , , , on August 5, 2012 by AnalogAudioRepair

Neve 5442 8×2 Mixing Board.  Built custom power supply and replaced failed tantalum caps.