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Adcom GTP-500 Hi-Fi Preamp

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This is a FULLY RESTORED rare white-faced Adcom GTP-500 Preamp/Tuner. This Adcom unit offers exceptional sound through both the Lab and Norm RCA outputs. The GTP-500 combines an outstanding tuner and preamplifier on a single chassis, conceived and designed for use with a wide range of power amplifiers. The GTP-500 is a highly acclaimed product which heralded the end of the receiver. The preamplifier section provides optimum S/N ratios at both the phono for those who enjoy vinyl and along with high level input devices. The tuner section is Quartz-Referenced and Digitally Synthesized with a tuning accuracy of 0.000025 percent. The tuner accuracy translates into audibly lower distortion.


FM Tuner Section: IHF Sensitivity

Mono: 9.5 dB/f

Capture Ratio: 1.5 dB

THD Stereo @ 1 kHz: 0.09%

Max S/N Ratio mono/stereo: 85/75 dB

Freq. Resp.: 30 Hz 15 kHz

Pre-Amp Section: THD 0.01%

IM Distortion: 0.005%

Freq. Resp. 20 Hz 20 kHz +/- 0.1dB

Overview of restoration service:

  • Replaced all faulty apacitors, resistors, and transistors required to get this preamp working again using quality components comparable or better than the originals.
  • Checked all power supply rails for proper voltages as detailed by Adcom in their service manual.
  • Replaced all power supply capacitors and every other electrolytic capacitor using quality Panasonic FM and FC series capacitors.
  • Checked the frequency response of the preamplifier through the standard audio spectrum and ensured that it meets or exceeds the manufacturer's specifications.
  • Ensured that equal input signals to both channels produced equal output signals from both output channels.
  • Cleaned the inside and outside of the preamp and applied oxidation preventive solutions to maintain the health of the metal parts.
  • Cleaned or lubricated all controls, switches, and RCA input jacks.
  • Played this preamp in our lab for at least five (enjoyable) days under ideal listening test conditions using various amplifiers. Actually, I'm listening to it now!
  • This preamp passed all the tests before it was listed.

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This Adcom GTP-500 has been fully tested and is fully functional.
It will arrive in complete working order.

8 on a 10 pt. scale

Weight : 13.2 pounds

Height: 7 "
Width: 21
Length: 15"
(all figures are for packed items)

  • Your product will be packed & shipped securely using quality boxes and packing materials.
  • We pride ourselves on secure packing. Check our feedback for further evidence.
  • In the USA, we ship large packages via FedEx and smaller items via the United States Postal Service.
  • International shipments are via USPS priority mail and generally take 7-10 Business days.
  • Speaker shipping will be double the ebay calculator unless otherwise noted.

2007 Black Swamp Audio

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