The sound was excellent on the bench. Now that it's in the box, I have 3 issues:
But to your original question, it sounded nice before casing, now need to fix the above issues and move it to living room on my Magnat speakers.
- mechanical hum from power-transformer. I tried a DC-blocker, not better. I think it's a bit overloaded with my 230V. Will try to use DC for heater, at least to confirm that a reduced load would help.
- 50 Hz hum, even with shorted inputs. I'm not sure how to cable the input coax cables in regards to audio ground. Currently only the internal cables red+black are used between PCB and RCA input sockets, I will try to connect the coax shield to the audio ground on the PCB side.
- intermittent "sound crashes" in the right channel. Need to swap tubes, I guess one is dying.
50 Hz is from heating voltage. Twisting wire would help
This is a EL84 with a 12AU7 driver, deliver clean and nice sound, most from used parts lying around in the garage, mix and match is not always perfect, but a finished project out of the garage is always satisfying.
Nice. What's the finish on the wooden parts?
The wood is black cherry and the finish is 5 coat of tung oil lightly deluded with a citrus solvent (3 o 1).Nice. What's the finish on the wooden parts?
Yes the OT are hided inside, the top part was a box that I had made for an other project, it was to slim to have the OT on the top with the tubes and they din't have any bells to be pretty. The transformers were from a garage sale find. They were about to find there way in my next garage sale... but I find inspiration with the wooden box. I was just not deep enough to hide all everything in so I added the extra step, and empty some of its inside for extra room. Finished with Tung oil, it makes the grain pop out beautifully.splendid wood work Felix ! Did you hide the OPTs in the box ?
PSE 4P1L 4.5W/CH
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Very nice PCB layout Alex. Looking forward to seeing how it comes out.PP amplifier EL 34, schematic LMO and PCB by alex mm Work in progress .Power supply and delay (green PCB)
BR
Alex
Thanks, will post more pictures, when will be ready, and functional !Very nice PCB layout Alex. Looking forward to seeing how it comes out.
BR
Alex
I recently bought a kit in Walmart, an entry level tube amplifier. The chassis has almost perfectly stamped holes for my Edelweiss amp, also it has power and output transformers that may fit, let's check. I was thinking of building one more, improved, version of an Edelweiss prototype before going to production, when I saw this kit for sale. I punched a bigger hole for a Compactron tube, since I need a twin-pentode for the Edelweiss, and painted the chassis. It was hard to punch and drill, since the steel is either hard-carbon, or stainless one.
Stay tuned!
Stay tuned!
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Nice little amp you have there!
I got a request to "refurbish" a Dynaco MK VI amp. Unfortunately 1 of the power transformers had a short and the chassis is in bad condition so i decided to build something new.
Now both amps will be painted in a later state:
The schematic is incomplete but very close to the finished amps.
Very clean and powerful !
I got a request to "refurbish" a Dynaco MK VI amp. Unfortunately 1 of the power transformers had a short and the chassis is in bad condition so i decided to build something new.
Now both amps will be painted in a later state:
The schematic is incomplete but very close to the finished amps.
Very clean and powerful !
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I recently bought a kit in Walmart, an entry level tube amplifier. The chassis has almost perfectly stamped holes for my Edelweiss amp, also it has power and output transformers that may fit, let's check. I was thinking of building one more, improved, version of an Edelweiss prototype before going to production, when I saw this kit for sale. I punched a bigger hole for a Compactron tube, since I need a twin-pentode for the Edelweiss, and painted the chassis. It was hard to punch and drill, since the steel is either hard-carbon, or stainless one.
Stay tuned!
Are You kidding me?
Lucky You, being able to buy a tube amp in the local mall!
I'm longing for Walmart opening a store here in Sweden! What did it cost?
Are You kidding me?
Lucky You, being able to buy a tube amp in the local mall!
I'm longing for Walmart opening a store here in Sweden! What did it cost?
https://www.walmart.com/ip/6N1-6P3P...Single-end-tube-Power-Amp-Amplifier/160088719
How lucky you are in Sweden that you don't have Walmart.I'm longing for Walmart opening a store here in Sweden! What did it cost?
These are not something you're going to find in a store, but rather the Walmart website is taking an order and some vendor on Ali Express is fulfilling it.
Just curious, before you modded it, did you try it in it's stock form? Not something I'd rush out to get, but I also don't know the 6P3P tube and no idea what design approach it takes.
Just curious, before you modded it, did you try it in it's stock form? Not something I'd rush out to get, but I also don't know the 6P3P tube and no idea what design approach it takes.
Sure, when I was a kid, in a scouts camp we designed and built amps using almost the same schematics.
However, filter caps had much smaller values, like 20 or 30 uF.
Chinese 6P3P is a copy of Soviet 6П3С that was a licensed from RCA 6L6GT.
The kit is kind of weird. It has some obvious errors, and no assembling instructions. In order to build it you need to have an experience, but if you have an experience, you will never build it as is. But a chassis is exactly what I need, not sure yet about quality of transformers. I never "modded" it, I just use some parts from it. Warning: not all that you see on the pictures come with the kit!
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Thx Wave! Interesting assessment: "In order to build it you need to have an experience, but if you have an experience, you will never build it as is." I guess I'm not too surprised. It's just that with PS iron, output iron, chassis and tubes, it seems hard to NOT try it. At the price it COULD be a decent foundation for playing around. For the moment, though, I have enough projects on my bench.
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