Sold: Gorgeous GFA-545 II

Sold to Maxim in NYC!

—————

And the amps just keep on rolling! This is the nicest GFA-545 II I’ve ever restored. Cosmetically, It’s pretty close to perfect! The face is nearly flawless. There’s just one scratch that I’ve touched-up on the top cover, towards the back, and a two barely noticeable scuffs on the sides. Click on the photos to see it in hi-res. Overall, it looks just about brand new.

But it’s better than brand new! This is a complete tear-down and restoration using every trick I’ve learned about Adcom amplifiers.

20151026 14-55-55 20151026_145555

GFA-545 II Restored

wpid-20151007_233711.jpg

    • Power supply capacitors upgraded from 10,000uF to 15,000uF Panasonic TS-HA 105C for higher current reserves, longer life, lower DCR and more ripple current capacity.
    • All electrolytic capacitors replaced with carefully selected audio-grade capacitors from Nichicon and Panasonic. Signal capacitors upgraded to WIMA MKS.
    • Transistors in the critical input stage are matched for gain. This step is important to assure low DC offset at the output, and low distortion.
    • Circuit boards cleaned and all solder joints re-flowed and inspected.
    • New power switch and spark-supressor capacitor.
    • New and higher-rated surge-protection MOV. I replace them even when they test OK. They’re known to develop latent failures due to exposure over time to moderate spikes.
    • Sealed Bournes trim-pot installed for precise bias adjustment and better reliability.
    • Heat sinks added to the transistors in the thermal protection circuit. (These are known to run hot and burn the board.)
    • Emitter resistors changed from 5% tolerance sand-cast types to mil-spec DALE LVR 1%. These are more reliable, and frankly, prettier.
    • 25A bridge rectifiers replace original 10A.
    • Heavy-duty gold-plated binding posts.
    • A high-quality snubber capacitor is installed across the AC  power input to reduce RF interference and reduce noise.
    • All wiring is obsessively neatened.

wpid-20151007_233832.jpg

I measured 130WPC into 8 ohms, just before clipping.

As a listening test, I’ve been using this amp to power my mid-range drivers for about a week. It sounds so sweet!

Contact me here if you’re interested…

More pictures…

20151026 14-56-48 20151026_145648

20151026 14-56-39 20151026_145640

20151026 14-56-20 20151026_145621

20151026 14-55-55 20151026_145555

20151026 14-55-30 20151026_145531

20151026 14-50-02 20151026_145003

20151026 14-50-47 20151026_145047

20151026 14-50-58 20151026_145058

20151026 14-51-40 20151026_145141

20151026 14-53-28 20151026_145328

20151026 14-55-17 20151026_145517

Panasonic 15,000uF HA 105C capacitors replace original 10,000uF. WIMA poly bypasses installed.
Panasonic 15,000uF HA 105C capacitors replace original 10,000uF. WIMA poly bypasses installed.

wpid-20151007_233734.jpg

wpid-20151007_233749.jpg

wpid-20151007_233806.jpg

wpid-20151001_182706.jpg

wpid-20151001_182753.jpg

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s