Thanks. Oh, and a few remarks about this amp. This was an excercise in making things simple and relatively cheap, but still maintaining a pleasant listen.
This whole thing got started when an editor in chief of a local audio webzine asked me how simple a tube amp could be made. I provided him with a schematic of a spud I'd made some time ago with just a E55L per channel. When he asked if I could make an article of the design, I declined telling it wasn't a real world amplifier, more of a curiosity and a study on simplicity. But then I couldn't resist going a little bit further, taking things from "as simple as possible" to "as simple as is meaningful". That's where this amp started
But back to the amp itself. Not much to point out, though, it's an EL84 SE-amp on a PCB. The OPT's are Hammond 125DSE, since I wanted to use stuff available from local shops. The front panel markings are etched into the aluminum using the saline sulfate method. The wooden side panels are Khaya mahogany stained red. So, just my signature look...
The circuit itself is really simple. The power supply is a normal CLCRC-thing with solid state rectification, input stage is a common cathode stage with an ECC81, followed by an EL84 output stage triode connected with a 5K anode load and cathode feedback from the OPT secondary. Distortion optimisation is done by distortion cancellation of the input and output stages. Sounds decent, and considering it's the cheapest amp I've made to date, I'm even slightly proud of the sound.
i new build to SE UL ... EL 300 / ECC 83
Good work JM!
Did you listen it?
How output impedance you charge the EL300?
6Watt?
EL300, Does is like french 6dq6?
Best Regards
hello Dady ,
good sound ...
the OPT is 3.5 K / 4-8-16 Ohms UL Hexacom , power out to 8 ohms is up 8 W ...
and EL300 is 6FN5 , not compatible , so look only datasheet for tested !!
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I got four of them, always planning a different think.
I meet this valve here in Europe, is 17 watt but looks like high perveance tetrode and the size and something remember me the old 6DQ6 that we used in many places like audio and Radiofrequency amplifiers, always in DIY devices.
Maybe with a better output transformer you can get better bandwidth, the sinus you show is with which frequency and power? Did you saw with Square wave ?
At the first spot the pic show a good wave.
Best Regards
the power out is +/- 9 W to 1 Khz , and 8 W to 100 hertz +/- up 17 khz +/- , me old proto use mode " Triode " to EL / PL 504 , the idéa islink to very good job :
Trioden – Eintakter mit EL 36, von Hans Koch
very nice build for the small EL 36 ...
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Beautiful. The mismatched knobs are giving me the shakes though
+1 but everything else beautiful!
Beautiful. The mismatched knobs are giving me the shakes though
Thanks for the feedback! They're not sitting quite right with me either.. In my head they looked good together.. haha.
I was wondering what other people thought of that.
I've actually got 2 aluminum colored knobs, so I think I'll change to those.
Hmmmm... changing the knobs to match versus mismatch.
I can not decide. Please send amplifier and knobs to me so I can study and judge in person during a long term evaluation.
(hey, when something looks that good, you can't blame a guy for trying, eh?)