I never got around to posting pictures to this thread, until now. Better late than never, I guess.
As I get time and the necessary combinations of parts and materials, I build amps in my home workshop. Mostly on a hobby basis- but I have wound up building and selling, both after-completion and on prior commission, various amps, over the last six years or so.
I tend to build mods and improved versions of some of the classic designs. As the great Isaac Newton said: "If I have seen further it is by standing on the shoulders of giants." Some of these older-generation designers were quite gifted- by learning and using the ideas they created, it paves the way for me to create my own ideas...
First off, the first amp I built from scratch. As in drawing the schematic, putting together the parts lists, punching and drilling the chassis, and assembling the parts. It's based on the classic Magnavox paraphase PP circuit, using 7C5 (loktal version of 6V6) output tubes:
This started out as a blank rack-mount chassis, which I punched, drilled and painted. Power transformer was from a large color TV, and output transformers were from a Knight integrated amplifier (a bit heavier than the original Magnavox transformers, and with 4, 8 and 16 ohm taps). Input tubes are 12AX7s.
In all, a satisfying 12 watts per channel.
Regards,
Gordon.
As I get time and the necessary combinations of parts and materials, I build amps in my home workshop. Mostly on a hobby basis- but I have wound up building and selling, both after-completion and on prior commission, various amps, over the last six years or so.
I tend to build mods and improved versions of some of the classic designs. As the great Isaac Newton said: "If I have seen further it is by standing on the shoulders of giants." Some of these older-generation designers were quite gifted- by learning and using the ideas they created, it paves the way for me to create my own ideas...
First off, the first amp I built from scratch. As in drawing the schematic, putting together the parts lists, punching and drilling the chassis, and assembling the parts. It's based on the classic Magnavox paraphase PP circuit, using 7C5 (loktal version of 6V6) output tubes:
This started out as a blank rack-mount chassis, which I punched, drilled and painted. Power transformer was from a large color TV, and output transformers were from a Knight integrated amplifier (a bit heavier than the original Magnavox transformers, and with 4, 8 and 16 ohm taps). Input tubes are 12AX7s.
In all, a satisfying 12 watts per channel.
Regards,
Gordon.
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Sort of keeping a chronological order- my second scratch-built amp was based on a recovered Pilot SA232 chassis (it had been in a fire). Chassis was stripped, polished, and re-drilled to fit the new components.
The amp is loosely based on the Stromberg-Carlson ASR333, except simplified. This is an integrated amp, with three inputs, a 6CG7 input tube, 6U8 drivers and 6BQ5 PP outputs. Power transformer is again a color TV unit, and output transformers are from a hefty Seeburg jukebox, that originally used 6973 output tubes.
This turned out to be a little power-house of an amp- easily 17w/ch or more, with prodigious low bass output and quality. A friend of mine wound up with this amp- it actually booted an Audio Research CA50 integrated amp out of his system, if you can believe that.
Regards,
Gordon.
The amp is loosely based on the Stromberg-Carlson ASR333, except simplified. This is an integrated amp, with three inputs, a 6CG7 input tube, 6U8 drivers and 6BQ5 PP outputs. Power transformer is again a color TV unit, and output transformers are from a hefty Seeburg jukebox, that originally used 6973 output tubes.
This turned out to be a little power-house of an amp- easily 17w/ch or more, with prodigious low bass output and quality. A friend of mine wound up with this amp- it actually booted an Audio Research CA50 integrated amp out of his system, if you can believe that.
Regards,
Gordon.
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Hello Tim
Really nice looking setup. But your work bench is just to neat
Cheers
neat!?
not all the time, that was cleaned up after i finish the amps
I was given a box of very old tubes. In the mix was a new pair of black metal tube RCA 6N7s (tested 80%). There seems very little schematics for this tube as a preamp but lucky my electronics engineer mate knocked up a design.
The preamp runs from a 18V 2.2A wall wart and uses a step down tranni backwards to produce 255VDC HT. The sound is punchy, deep driving bass, clear, clean and crisp. Best preamp I have ever made. Dead quiet at idle. I have called the preamp "Heavy Metal" after the metal tubes.
The preamp runs from a 18V 2.2A wall wart and uses a step down tranni backwards to produce 255VDC HT. The sound is punchy, deep driving bass, clear, clean and crisp. Best preamp I have ever made. Dead quiet at idle. I have called the preamp "Heavy Metal" after the metal tubes.
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My Heavy Metal preamp with the RCA 6N7 tubes has made my whole CD, hard drive based high-rez music and LP selection sound like new. This morning I connected up my Cowon S9 to use it's FM tuner for ABC Classic fm to find it also sounds sooo much better.
Not sure what makes this preamp so good. It must be the tubes.
Not sure what makes this preamp so good. It must be the tubes.
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