• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Photo Gallery

I used my old cell phone's case it came in , i its crazy but you'll find the darndest things to put an amp in , it works well , and looks good i think ? :) .

I used 6cg7 as the inputs and 6922 as the outputs.

No, i got the original "broski" pcb, not that i'm affiliated , and or promote his boards over others , in fact i sent him several email afterwards asking some basic pointers and got no reply :dunno: , but i suppose thats why its called DIY :smash: , but he did send the pcm fast considering im on tha other side of the world.

Oh and the monitors are Fostex PM2 , they sound fantastic as they are , but with the preamp the music takes on a new character (smooth , sweet, detailed, yet fast and dynamic) ... i did have slight hum at first but sorted that by biasing the heater Ct (ac heaters), im just experimenting with a few output caps, to increase the bass a touch , it probably rolls off at around 80-100hz (becaue of the ipod) , but a 1uf should fix that , i would like it to start at around 30hz.

An externally hosted image should be here but it was not working when we last tested it.
 
my last creation, a Single End amplifier with EL84;
 

Attachments

  • setup.jpg
    setup.jpg
    42.8 KB · Views: 2,429
What did you use for xfmer covers? Don`t like valve rectification?
I bought the molded plastic x-fomer covers at www.roehrentechnik.de where i also bought the transformers, i chose not to use a tuberectifier because of the powertransformers lack of windings for that purpose, i opted for solid state rectification with fast diodes and a lot of powersupplycaps.

Minimalistic outside, but surely not inside :cool:
 

Attachments

  • trafo.jpg
    trafo.jpg
    44.7 KB · Views: 1,999
Just a little "how-NOT-to" from my second project. This just looks too dangerous, so I HAD to take a picture :D
This is a stereo KT88 SE amp, built from Mikael Abdellah's schematics, waiting for its chassis. I'm using a very old Telefunken ECC85 in it right now, and I think I like it more than the 6N1P so far. The PSU is all MKP motor run caps and will be on a separate chassis due to the size (the largest transformer in the picture is not used, BTW). James OTs, Jensen copper coupling caps etc. etc. :)
 

Attachments

  • dscf0281.jpg
    dscf0281.jpg
    91.1 KB · Views: 2,147
planet10 said:


Do you have some detail on that... i have quite a few ECC85 in my junk box, including a whack of TFK.
I'll admit I don't know much about this, I just know the pinout is the same... I checked the max. ratings and popped it in without any modifications. Sounds pretty good to my ears. :)
I've seen audio amps using ECC85, but not many. Mine came from an old radio.

--
Rolf
 
Se3x6550

Single ended triode/ultra linear mono amplifiers based on 3 x 6550 power tubes. Low distortion, medium power, shunt feedback design.

At the work bench:
An externally hosted image should be here but it was not working when we last tested it.


Night view:
An externally hosted image should be here but it was not working when we last tested it.


Some key figures:
- Single ended, no global feedback.
- Bandwidth (Po=10W): Triode: <10Hz-70kHz (-3dB), UL: <10Hz-75kHz (-3dB)
- Max power output rms: Triode: 24W, UL: 45W
- Distortion (Po=10W): Triode: 0.6%, UL: 0.3%
- Damping factor: Triode: 6.9, UL: 5.3

Distortion pattern 400Hz sine, Po=10W
An externally hosted image should be here but it was not working when we last tested it.


Square wave 10kHz, Po=10W
An externally hosted image should be here but it was not working when we last tested it.


Custom made transformers and chokes by Sowter.

Jan E Veiset
NO-6600
 
My Hybrid

Well, i have finally finished my hybrid ( http://www.diyaudio.com/forums/showthread.php?threadid=78576 ), now i only need to get a decent PSU for it.
The enclosure is from a 3,5" HDD to USB externall case.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.