For sale is a vintage Pye Communications Equipment Type 3755 CD tube limiter.
Fully functional, sounds incredible. This is incredibly rare item with a legendary status on par with other vintage compressors like Decca, Fairchild, Lang, RCA, Altec etc. You aren't likely to find another one of these anytime soon, they hardly ever show up for sale. Grab this while you can!
This just got back from professional service check-up Pye expert and it is good to go. He noted this is an incredibly rare unit and he has never seen one of these before. Here are some notes from the tech:
Pye 3755 (Ser #110) tube compressor:
Input Impedance = 10k ohms balanced from 10Hz - 16kHz and only drops down to 9k ohms beyond
Output Impedance ≈ 600 ohms balanced
Input signal must be 12.5dBu or greater to start compression
Power requirements = 240 VAC
Time switch changes from Slow CCW to Fast CW
Note: Limit switch doesn’t appear to do anything. Increases distortion and noise at CW setting. Unfortunately we don't have schematics to identify the function of this switch.
Some work performed:
- Tightened rotary switches
- Insulated fuse at bottom
- Cleaned contacts
- Phase corrected (it was out of phase)
- Square wave looks great
- Dated from late 1967 to early 1968
- Plate voltage is 236 vdc, heater voltage 6.3 va
