Hi sir anatoly, i have in me 2pcs of this tube from a russian friend. I plan to use them in a monoblock pp for sub around 200watts. But with your project i m thinking of a stereo SE amp like yours. I also have 6p15p tubes to drive. How i hope to build one like yours. What imp of opt u use? Thanks.
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EDCOR - CXSE25-5K
I can't give you the final design, but all ideas that I used in this amp were discussed here. However, members of the forum almost always ignored my advices, but I gave them. ;-)
I can't give you the final design, but all ideas that I used in this amp were discussed here. However, members of the forum almost always ignored my advices, but I gave them. ;-)
The blue thing that holds the boy on the picture
But it has nothing to do with audio, it is OT here.
Just a row of 4 FL-152 tubes on a perforated aluminium sub-chassis for 2x100W PP amp.
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Yes. I used a transformer from the batch that I ordered for my Pyramid amps, 2xGU-50 per channel. I had to add some Flathead tranny, to get 90V more for B+ and to compensate the drop on a choke, and +62V to power G3. There was no other place for it but under an output transformer, so before tubes get heated there is some barely audible 60 Hz hum in one channel.
Transformers were made for my specs. If I decide to run production of this amp, I will need to order special transformers for it.
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if you tell me your required specs, i can design a power traffo for you so you can ask edcor to make one for you...pm me detailed spec if you please...
My latest creation: PP/84 Iiro. Nothing different, new or special. Just a class AB push-pull in a very traditional configuration, with a 6U8-A serving the voltage amplifier and phase splitting duties, and a pair of EL84's in ultralinear mode as the outputs, 12dB of GNFB. Bias is fixed, and the output tubes have a balancing pot. Not very unlike a Dynaco ST-35, then. Output power is 12 watts just before onset of clipping, and THD+N at full power is 0.78%, measured with AP System One.
The output transformers are from my old stash, made here in Finland and sadly discontinued a long time ago. These OPT's had been collecting dust for like ten years on my shelf, and I wanted to give them a new lease of life.
Power supply is CLCRCRC with a separate LCRCRC-chain for each channel. From previous experience I wasn't completely comfortable with the thought of using just a cap filtered supply for a push-pull output stage, so I gave both 'em channels a choke.
Wiring turned out less messy than I first feared, even though not up to the highest standards. Still have to finish the chassis, but having only tried this idea on a single channel lab prototype, I wanted to hear how this thing sounds in stereo before touching up the metalwork with paint, aluminum front panel and wooden sides.
The output transformers are from my old stash, made here in Finland and sadly discontinued a long time ago. These OPT's had been collecting dust for like ten years on my shelf, and I wanted to give them a new lease of life.
Power supply is CLCRCRC with a separate LCRCRC-chain for each channel. From previous experience I wasn't completely comfortable with the thought of using just a cap filtered supply for a push-pull output stage, so I gave both 'em channels a choke.
Wiring turned out less messy than I first feared, even though not up to the highest standards. Still have to finish the chassis, but having only tried this idea on a single channel lab prototype, I wanted to hear how this thing sounds in stereo before touching up the metalwork with paint, aluminum front panel and wooden sides.
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Maybe I'll post some more photos when I'll get the finishing done. For now it's just quickly thrown together since I was too impatient to wait while paint dries. Had to hear it sing before I tear it apart again so I can paint the chassis and give it some decorations to make it livingroom worthy.
Fest-O 12B4
I had a couple of old Festo air cylinders which looked just too nice to dump, so I decided to build a preamp with them, the Fest-O 12B4.
This is the result. I 1st tried a LED CCS, which caused a lot of hiss noise. A straight resistor was dead quite but the DN2540 sounds the best (just a small amount of hiss)
Even with relative large heatsinks the CCS still gets to 38°C, which is acceptable to me.
Together with my Mullard 4-20's, and Fostex FE207's they sound fantastic.
I had a couple of old Festo air cylinders which looked just too nice to dump, so I decided to build a preamp with them, the Fest-O 12B4.
This is the result. I 1st tried a LED CCS, which caused a lot of hiss noise. A straight resistor was dead quite but the DN2540 sounds the best (just a small amount of hiss)
Even with relative large heatsinks the CCS still gets to 38°C, which is acceptable to me.
Together with my Mullard 4-20's, and Fostex FE207's they sound fantastic.
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I recognise the motorpotentiometer, but the relayboard - your? or eBay-ish?
can you hook up the aircylinders to the amp and have the chassis wiggle to the music?!
Realy board also eBay. Had it left over from another project, it uses spdt relays, thus I use 2 for stereo in/out. One set is for CD and other set is for an aux. source.
Maybe I should connect some smoke to the festos for some effects.
My PSE 6AS7 General Electric and 6J9P. output power more than 9 W per channel, pure tube amplifier, all components are only R,C,L, without pressing factors FBs and SS in amp. tracks, /Shotky diode rect/. Structure is two monoblocks in one closure. Two PTs. Common are wall AC PS and ground wire.
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