Repairs – Repairing and modifying Ampex tape machines is nothing new here at Mystic Valley Studio, as I run the studio exclusively with them. After all the repairs and refurbishments I’ve done here over the years, I’ve become somewhat of an Ampex expert, specializing in the MM-1000, MM-1200, and AG-440 series. I do “on-call” repair work for a handful of studios in the area and I’m now offering “mail-in” service of any of the modular components of these old beasts. Chances are, I’ve encountered your problem before, and I have an MM-1200, AG-440 and AG-440C here to test out your parts.
I have many parts in stock here, including the obsolete ICs and switches found in the MM-1200. Repairs, rebuilds and upgrades can easily be done on any of the modular cards found in any of these machines, as well as card-cages, electronics units, and power supplies.
Upgrades – A favorite upgrade of mine is to upgrade the reproduce cards. With the wonderful RTZ cards a thing of the past, the only way us Ampex freaks can upgrade the performance of our sound cards is if we do it ourselves. The old noisey carbon resistors get replaced with Dale military-grade, 1% tolerance metal-film resistors; your aging 40 year old capacitors get replaced with new and better replacements by Wima, Nichicon, or Panasonic; the transistors are replaced with new versions and are upgraded where possible, and 4% silver solder is used throughout.
For the audiofile or mastering engineer looking for even more performance out of their Ampex, the stock transformer on the repro card can be upgraded to a Lundahl LL1550 amorphous core. This transformer upgrade will uncover yet another layer of transparency, yielding more transients and detail, greater sense of depth, and a clean, natural low-end.
Of the three audio cards (bias, record, repro) upgrading your repro card will yield the biggest sound improvement, however, an upgrade to your record and bias cards will offer you yet better sound, and much more stable record tones. After upgrading, there is no noticeable drift in tones or sound during a day of tracking like you can get from your stock cards, and the sound will be even more detailed and clearer with better frequency response. There are also some upgrades to be done within the card-cages of an MM-1200, and within the electronics units of an MM-1000, or any of the 440 models by upgrading the audio coupling capacitor. All of the audio passes through this capacitor and as they dry out, your low-end will suffer.
Repro Upgrade: $95 per card (for Lundahl transformer add $137 per card)
Record Upgrade: $85 per card
Bias Upgrade: $65 per card
Repairs and other upgrades: $40/hour+parts
Contact me for a reasonable quote on all repairs.
Ampex Field Engineering Bulletins
- MM-1100 ADDITION OF 1-INCH TAPE TENSION ADJUSTMENT CONTROL
- MM-1200 MDA UPGRADE KIT, PARTS LIST AND INSTRUCTIONS
- MM-1200 PURC SCHEMATIC DRAWING ERROR CORRECTION
- MM-1200 1100 SEARCH MODE NOT CANCELLED BY END OF TAPE FUNCTION
- MM-1200 BIAS LEAKAGE
- MM-1200 MODIFICATION TO IMPROVE DOLBY OPERATION WHEN PURC CARD IS INSTALLED
- MM-1200 REEL MOTOR DRIVE AMPLIFIER IMPROVEMENT
- MM-1200 RESISTOR FAILURE IN POWER SUPPLY
- MM-1200 TAKEUP TENSION CONTROLLER UPDATE Nov 1982
- MM-1200 MDA STABILITY IMPROVEMENT
- MM-1200 DOLBY INTERFACE MODIFICATION
- MM-1200 TRANSPORT CONTROL PWA
- MM-1200 SEARCH TO CUE MULTIPLEX BEAT
- MM-1100 CONTROL BOX MISWIRE
- MM-1200 REDUCTION OF SERVO TONE
- MM-1200 LAST MDA REVISION SCHEMATIC
- MM-1200 AUDIBLE NOISE FROM REEL MOTORS