after a long delay due to priorities/commitments, I've almost completed my aikido
Here are the pics:
http://img404.imageshack.us/my.php?i...4mediumns7.jpg - In this photo you can see the amp PCB and the DC heater supply for the tube. The tubes used at the moment are RCA 8CG7 cleartops and 6H30. I got other pairs of 6CG7/8CG7 that I can roll.
The volume pot is a cheap-o switch but the Vishay-Dale resistors has been handmatched by myself. In case this one sucks (I bought cause it was cheap and I want to try), I have a stand-by Elma with handmatched resistors to use. I'll be using an extension bar so I can have the volume knob at the front.
The green caps are Russian 2.2uF 400V PIO and the silver looking ones are 0.1uF Russian teflon. The black ones are Solens. They were used in places that are not as important
The caps used in the DC supply are CDE 381LX 56000uF and 4700uF. Very long life and size is smaller than others.
The heatsink is used to cool down the LT1083. It's similar to LM317 except that it has a lower voltage drop-out and it's rated up to 7A. I
Also as you can see the headphone jack has not been mounted. I still need to work on the front panel. It need a 45.5mm hole for the volume knob.
Wires has been color coded as well. blue is right channel while white is left. Except for the AC mains wires, all wires are teflon coated. 18AWG for the B+ and heater supply. 20AWG for the NE555 delay supply and LED. 22AWG for the left and right channels.
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Another shot of the amp from a different angle:
http://img259.imageshack.us/my.php?i...5mediumpj0.jpg
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Here's the photo of the B+ circuit:
http://img138.imageshack.us/my.php?i...6mediumqq2.jpg
It's choke-input and the capacitor is a 10uF Solen + a 2.2uF Russian PIO. it's not big at all but since it a regulated supply, other people have said it's not much of an issue. The SS parts you see are for CCS. Output current can be set by adjusting the trimmer. It's set at around 82mA at the moment. It was designed by Gary Pimm. He has remove all the DIY stuff from his site but I have a copy in case you're interested.
There was a change of PSU from series to shunt. And then the intended shunt design doesn't seem to work with the tubes that I have. So I decided to buy a few VR tubes just in case.
In the end, I went with the VR tubes bypassed with 2x 0.1uF Russian teflons (the silver tubes in the photo). It has the added benefit of not needing a heater and it glows!
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Here's a shot of the chassis top (though it's upside-down since I am testing it):
http://img259.imageshack.us/my.php?i...7mediumor2.jpg
The silver tubes that you see are 100uF 430VAC ASC motor run caps. The coke-bottle tube is the VR tube while the straight bottle tube is a 5AS4 (which will be replace by a coke-bottle version just because coke-bottle = sexy!)
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here's a photo of the other equipment used for testing:
http://img404.imageshack.us/my.php?i...9mediumes9.jpg
it's our Sony DVD player and a cheap headphone. These were used just because my main CD player is at work and I wouldn't used good headphones when testing a newly built amp!
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photo of ground-loop breaker and ne555 delay circuit:
http://img259.imageshack.us/my.php?i...0mediumzu0.jpg
In my experience, ground-loop breaker helps in eliminating/minimizing noise. the NE555 circuit is used to delay the AC supply of the B+. So when the 8CG7 and 6H30 are already hot when the full B+ kicks in.
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another photo:
http://img138.imageshack.us/my.php?i...2mediumnp8.jpg
In this photo, the 2 resistors and orange drop are used to reference the DC heater ground to B+. I believe this extends the life of the tube. (Tubes has a maximum rating for heater-cathode voltage)
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just a close-up of the DC heater supply:
http://img138.imageshack.us/my.php?i...3mediumzc2.jpg