I bought and rebuilt my first Adcom amp., was / always have been a Hafler amp builder and fan. I will say it publicly... I was not fond of the sound of Adcom amps... like a photo with poor color saturation, poor black levels (poor grey scale) congested or opaqued and smeared top end.
I gutted the wretched factory power supply, the trapeze wiring effect spaghetti'fying the chassis pan. It is no wonder the Service manual requires the use of shielded cable with the stock (rapid assembly) wiring mess.
The character of this amp is so different, virtually all of the things that were done to suit uniform manufacturing process production ease and cost, result in gross deficiencies in the approach to the amps power supply.
I chose a mono supply as I am modeling components for a Hypex amp that I am ordering parts for. So the Adcom 545v1 and 545v2 serve purpose outside of immediate build... If I hated them, I could cannibalize the chassis for the new build...
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I want to clean up and compress the wiring harness, shield and bury the AC deep in the chassis, away from audio circuits. The rectifiers were an inch away from the input circuit on the right channel. I wanted to jump one voltage rating above stock (57 volts, measured, on a ..cheap.. 63 vdc filter cap) I wanted big film bypass caps, on the board immediate to output transistors. I wanted stiff, direct DC feed to the boards and opted to go direct to the rail the outputs were mounted to. I wanted to use Mills resistors on the emitters.
I budgeted my costs to maximize the net gains based on identified weaknesses in the amplifier assembly to render its greatest performance. No load lines, time constants, or feed back adjustments were done. [Cardas RCA, 5-way bp, on my list, but just outside of budget]
This amp has a top end, a sense of openness and effortlessness, that is much like my Atma-Sphere OTL amps... it is really amazing, how good it sounds.
**Expressions not meant to offend any Adcom owners / builders
I gutted the wretched factory power supply, the trapeze wiring effect spaghetti'fying the chassis pan. It is no wonder the Service manual requires the use of shielded cable with the stock (rapid assembly) wiring mess.
The character of this amp is so different, virtually all of the things that were done to suit uniform manufacturing process production ease and cost, result in gross deficiencies in the approach to the amps power supply.
I chose a mono supply as I am modeling components for a Hypex amp that I am ordering parts for. So the Adcom 545v1 and 545v2 serve purpose outside of immediate build... If I hated them, I could cannibalize the chassis for the new build...
List of hierarchy
I want to clean up and compress the wiring harness, shield and bury the AC deep in the chassis, away from audio circuits. The rectifiers were an inch away from the input circuit on the right channel. I wanted to jump one voltage rating above stock (57 volts, measured, on a ..cheap.. 63 vdc filter cap) I wanted big film bypass caps, on the board immediate to output transistors. I wanted stiff, direct DC feed to the boards and opted to go direct to the rail the outputs were mounted to. I wanted to use Mills resistors on the emitters.
I budgeted my costs to maximize the net gains based on identified weaknesses in the amplifier assembly to render its greatest performance. No load lines, time constants, or feed back adjustments were done. [Cardas RCA, 5-way bp, on my list, but just outside of budget]
This amp has a top end, a sense of openness and effortlessness, that is much like my Atma-Sphere OTL amps... it is really amazing, how good it sounds.
**Expressions not meant to offend any Adcom owners / builders
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Clean, compact wiring harness
After looking at noteworthy amplifiers in this generation, I was starting to go nuts with the wretched wiring on so many amps that I would not even touch, want to work on or rebuild. I struggle mentioning the Bryston line of amps, they got me thinking about traits in design, a horrible wiring harness (so common) if you can call it that.
The result of my thoughts, my angst was to reason a way to compress and to better shield the AC power wiring, to isolate it from the AC signal wiring, to reduce or eliminate the electro-magnetic and electro-static coupling, that was likely the source infecting the wiring and sound of these amps. I think that it worked, the amp is velvety smooth and dead quiet. A noise or low level grain is now absent from this amp.
The other goal was to reduce the nasty AC wiring blob on the back of the amp, to get the AC input and fuse assembly compressed into the back panel of the amp, it was too sloppy and risked infecting the amp.
After looking at noteworthy amplifiers in this generation, I was starting to go nuts with the wretched wiring on so many amps that I would not even touch, want to work on or rebuild. I struggle mentioning the Bryston line of amps, they got me thinking about traits in design, a horrible wiring harness (so common) if you can call it that.
The result of my thoughts, my angst was to reason a way to compress and to better shield the AC power wiring, to isolate it from the AC signal wiring, to reduce or eliminate the electro-magnetic and electro-static coupling, that was likely the source infecting the wiring and sound of these amps. I think that it worked, the amp is velvety smooth and dead quiet. A noise or low level grain is now absent from this amp.
The other goal was to reduce the nasty AC wiring blob on the back of the amp, to get the AC input and fuse assembly compressed into the back panel of the amp, it was too sloppy and risked infecting the amp.
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