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PostPosted: 23 Mar 2015, 20:35 
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I had drilled a 3U 19" rack Mount for a 1500W Class D amp. But PS and amp would not fit. Fortunately for me a 250W IR amp module arrived which would fit. So here it is. Caps are Mundorf Mytec, LESR,47,000uf. Differential PS so 2 are required. When I discharged these caps with a 100ohm resistor I could draw out a blue flame, not a spark.

The amp sounds good. About 100W into 8ohms or 200W into four with THD 0.05%.
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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
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PostPosted: 25 Mar 2015, 06:06 
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Here are some more images. I had to replace the transformer because the amp was going into over-volts protection. All good now. And the amp is sounding very sweet. Off to power my friend's $30K Brodmanns tomorrow.
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Attachment:
Inside.jpg


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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 26 Mar 2015, 18:44 
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I spent and afternoon and evening with the new Class D with two pairs of very expensive speakers in two expensive systems. I have a price of $970 on the amp. On one system the guys interconnects cost $2,500. The amp performed exceptionally on both systems. On one the speakers have inverted berilium tweeters. Sibilance was a bit spitty here but on the other, Brodmann speakers with silk domes, none of that.

On the Brodmanns, a Peter, Paul and Mary track, played exceptionally well presenting the three voices as just that, three distinct voices. Never heard this track played that well on any system. Tons of bass and great transparency on all music played. This is what I find on my home system, is the transparency. Very pleased.

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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 06 May 2015, 07:59 
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This amp powered some Yammy NS1000Ns today. Sound realy good. The louder it got the better the Yammies sounded.

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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 06 May 2015, 08:11 
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It looks very good!

Great job! :)


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PostPosted: 06 May 2015, 17:13 
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HT Performance wrote:
It looks very good!

Great job! :)

Thanks mate.

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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 12 May 2015, 07:54 
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I recently did some upgrades to PS and amp module not performed originally. The inside image shows the latest changes; I have upgraded the PS adding some 10uf polies across the storage caps. I believe this improves mids and highs. Also the input 22uf electros have been replaced with some high quality Russian audio caps.

Listening notes to follow.
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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 23 Dec 2015, 07:02 
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My Tripath T4 Class D has been sold but even before it had gone I was using this IRS class D to drive my highly efficient 12" Beyma concentrics. Levelling the tweeters to -7db (flat) this combo is really execellent. Also I use "L" pad to reduce tweeter level. They comprise a series resistor and parralel resistor. By putting a 2.2uf audio quality cap across the series resistor I can get better sparkle above 10khz rather than everything from 1600hz being reduced.

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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 14 Jul 2016, 20:39 
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I have been listening to this Class D for some weeks now instead of my massive 300B. Yesterday I put the 300B back in my main system. Hard to decide which actually sounds better. When I swapped the D in weeks ago I felt it was much better than the 300B. But now I'm not sure. I may have to get someone else in to help compare. A guy who has bought a fare bit of my tube gear uses both tube and and SS power amps. He could be the guy I need.

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Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


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PostPosted: 14 Jul 2016, 23:16 
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Tubes vs. SS, even linear SS vs. switch-mode classes are apples and oranges, IMO.

But as always, trust your ears :up:

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