Adcom Preamplifiers

Customers have been delighted. They describe a more open, transparent, focused, clearer, articulate, 3D, liquid and tube-like sound quality. Add to all of this add a new level of detail, neutrality and intelligibility.

Our modification to the existing circuit boards include changes in power supply caps, bypass caps, Op-amps, coupling caps, etc. In some cases we add bypass caps that were not there in the original circuit. It is a relatively extensive modification.

No kits available for these modifications, so these are all installed prices.

• GPX Mod (for 555/555 MKII preamps) - $399
• GPX Elite mod  (for 555/555 MKII) - $499
• GPX Mod (for 565) - $499
• GPX Elite mod (for 565) - $599
• GFP-750, 715, 815, Elite mod - $699
• GFP-750, 715, 815, Ultra mod - $799 for Ultra version

>We no longer service the Tuner/Preamp combo products.<

>We do not service Home Theater products.<

MC-3 Preamp Circuit board

Phono, line and power supplies are on board. Make no mistake! This is a "State of the Art" sound.  Factory installation available for the PRO-10 and others. The OPS-8 listed below is always recommended, and sometimes required. Some preamps require the OPS-8(see below). 

 

• Phono stage with excellent RIAA response
• Adjustable DC offset in phono eliminates need for output capacitor
• DC-Coupled line stage with very wideband performance
• Totally discrete transistor circuitry, no ICs
• Totally dual-mono construction on one board
• Dual-Mono regulated power supply
• Completely independent power and ground systems 

MC-3 circuit card:  $599 installed  

Important Note: tone controls/filters are eliminated.

For  greater clarity, transparency and naturalness of Elite versions, add $100 for Line Stage/Power Supply - ( Elite includes OPS-8 or PRO-10 outboard power supply tweaks ), Add $100 extra for Phono stage Elite mods.

Outboard Power Supply

<<<NEW PICTURES SOON>>> What can you expect from an outboard power supply? Getting the best is an enduring investment. The sound is its own reward. Many of our customers wanted custom power supplies so we offer a range of options.

The Sound

• Excellent dynamic scaling from pianissimo to crescendo reminds you more of the real event
• Low noise, beyond the risk of hum or buzz a subtle ‘dirty window’ effect goes away
• Tonal purity, excellent dynamics and low noise contribute to low coloration
• Maintenance of distinct instrumental clarity at even high volumes
• All models includes IEC power cord socket and appropriate standard power cord.
• All are custom built, bench tested and supplied with shielded output cable

OPS-9S(Standard):  $299 transformer only - with AC output, to be rectified to DC in target device not recommended for MC-3 installations

OPS-9D(Deluxe):   $499(+ DC output)

OPS-10:  $799 gorgeous case, premium parts

Installation:  $75 labor for any model for most preamp installations

OPS-9 Deluxe and OPS-10 models have one +30VDC and one -30VDC output(values approx). They are equipped with a quiet toroid transformer.

>>>>These power supplies can be delivered with alternate voltages AND for tubed preamps with B+ and heater power supplies.<<<<