Hey folks, I haven’t had any amps for sale for a while. I’ve been super busy with restorations for people… But these two are nearly ready for adoption! Both are in like new condition cosmetically, and have been given the full restoration and upgrade. All caps are new, including the big cans in the power supply.

GFA-555 II. All the boards are done, new binding posts, zobel filters, power cord, transformer wiring, installed input board local supply bypasses, matching input transistors, etc. I just need to mount those caps on the chassis, install the big copper bus-bar and wire it all up. (Then torture testing, bias tweaking and listening tests.)

Continue reading Amps on the way: Adcom GFA-555 II and GFA-535 II

Sold to Maxim in NYC!

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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.

Continue reading Sold: Gorgeous GFA-545 II

UPDATE: Sold to David in BC.

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Folks, this is the nicest GFA-555 II I’ve ever restored. What a beauty! The previous owner was a cellist for the Milwaukee Symphony Orchestra, who took excellent care of it. Cosmetically, it’s about as close to mint condition as they come. There are a few small ticks in the finish here and there, which I’ve touched-up, and are hard to notice, and the face is totally perfect! Click on the photos to see it in high-resolution.

Since this one is so nice, I pulled out all the stops and installed every enhancement I know for Adcom amps.

Continue reading Sold! Beautiful ADCOM GFA-555 II with all the mods

…just some thoughts and pictures from this Adcom GFA-5802 I’ve just restored for Jeff in Washington.

This was Adcom’s biggest and most expensive amplifier. A 300WPC monster, with 16 HEXFET output devices per channel. Minimalist in circuit design, with only three gain stages, but maximalist in execution.

Continue reading Some notes about restoring a GFA-5802

Scored a really beautiful, near-mint condition GFA-545 II the other day. I’m having a good time restoring it.

It’ll be for sale some time next week. I just need to order some nice new power supply filter capacitors for it, tweak the bias and put it through my battery of tests. Let me know if this amp sings to you.

So, here’s the kind of work I do. I’m obsessive about these amps, and I tear them down to the bones and inspect and rebuild everything. My primary concern is reliability. I don’t want these amps breaking down in the field, and so far, not a single one has.

Before:

After:

Hi folks, this is a fun little amplifier project I slapped together yesterday… (Well, carefully slapped together.)

I have lots of spare parts for Adcom amplifiers around, including a fully restored output module for a GFA-535 II, and a few chassis with power transformers.

So, I thought it would be fun to piece together a mono-block amplifier, capable of driving a 2 Ohm load using TWO power transformers for just one channel! This should give close to double the current to just one amp channel. This is the same basic idea as my Super High-Current GFA-535 II that I created from the remains of a GFA-2535. (The 2535 is basically four channels of GFA-535, with a double-size power supply, and I modified it to drive only two channels.)

Continue reading A fun project: Adcom GFA-535 SUPER-HIGH-CURRENT MONOBLOC

I really like this Musical Spectrum Analyzer plugin for my favorite—and free—music player, Foobar 2000.

The spectrum you see here is an ostinato bass-line from a Boards of Canada track called Happy Cycling. (The really low stuff starts around the 5:00 mark.)

The lowest note in the bass line is centered around 25Hz, is pretty loud, and it is absolutely musical in nature. Lacking a subwoofer, or suitably large main speakers, these musical notes are never heard. Many systems struggle to cope with such energy, and transform these sounds into higher-frequency harmonic distortions.

Just an interesting illustration…