[SonnyMarrow]

I just finished an amp heavily inspired by the EC Studio T. Instead of the Tribute nanocrystalline interstage and Cinemag outputs, I’m using Monolith nanocrystalline IST and Electraprint silver OPT.

The rest of the amp uses unnecessarily expensive meme parts for fun since there aren’t that many resistors and caps.

The big challenge was figuring out the high frequency filament supplies used in EC amps. They are Wein bridge oscillators using LM3886 for the outputs, then toroids to step down the voltage and provide isolation. In EC amps, those toroids just hang by the windings, which I didn’t like. My version of the heater supplies has a mounting place for them. The EC boards are also a slightly higher frequency than mine, but I’m happy with how these came out. The scope shot is showing that the voltage is pretty consistent bewteen toroids, so my winding was pretty good.

The case was designed by me in Fusion and then Protocase took it from there and did a phenomenal job.

Right now I’ve got beater tubes in it for testing and it’s simply lovely. Can’t wait to get nicer tubes and really enjoy this project.

 

[bobmysterious]

Wow, very cool!

 

[roadcykler]

That looks phenomenal.

 

[kevin gilmore]

there is a reason why the eddie current filament supply runs at 50khz. if you run anything lower than 44khz you might find that there are beat frequency's with some d/a converters resulting in strange noises riding on the music. the high frequency filament is actually a really good idea but needs a better implementation. none of the chip amps really like anything over about 25khz.

 

[SonnyMarrow]

there is a reason why the eddie current filament supply runs at 50khz. if you run anything lower than 44khz you might find that there are beat frequency's with some d/a converters resulting in strange noises riding on the music. the high frequency filament is actually a really good idea but needs a better implementation. none of the chip amps really like anything over about 25khz.

The EC filament runs at about 46khz (both as advertised and measured myself). So far, 43.65khz has been fine? I don’t hear anything out of place. Regarding the chip amp (LM3386), EC uses it and it seems to work alright? Pete Millett has an interesting high frequency supply that does 100khz but he never finished the design.

 

[PcChip]

that looks outstanding Sonny, your work never fails to amaze me