I may change the blue wires for something else, green or purple, Russian paper and oil capacitors and preamp sockets, PEC potentiometers, the red resistors are TAKMAN carbon film HiFi, the domino is a NOS MENCO capacitor couple with a ceramic cap, boards from RJGuitars (well done RJ ), Magnetic Components transformers, RFT old stock EL-34 power tubes, blank chassis $17.00 : http://shop.ebay.com/lkschmit/m.html?_t ... 4340.l2562
How much a selector should be rated for voltage and amperage for this kind of power +/- 30 to 35 Watts?
I will post some more pictures as the work progress.
Thank Jean
Last edited by godi on Mon May 30, 2011 7:33 pm, edited 1 time in total.
As usual Jean, nice build. I'm not sure about the impedance selector. The purists go with a Stackpole. I have heard they are a pain to wire however. rj sells a good selector. I've had no problems with mine. As far as the old fashioned lettering for the rear of the chassis, those label makers can be bought on the cheap at Walmart etc. (I don't know if you guys have 'em in the great white north). I bought one, but the labels did not stick well to the textured surface of my chassis. Anyway keep up the good work and post some clips when you are done.
Jim
Almost finish. I diden't use the impedance switch, not strong enough, so I temporary connect the output directly to the output jack, one is 8 Ohms and the other one 16 Ohms untill I receive the correct rotary impedance switch. I did not install the pilot light yet because I need to finish the wooden front face plate first.
Ready to try ...
They are (typically) unused Russian military surplus. They need to be tested for leakage and value though as they aren't as good quality-wise as American made PIO's.
I know how to tell the difference between PIO caps and poly caps usually but these have the ends painted in green so you can't see if there is an epoxy seal or not. How do you tell the difference Jelle?
Yes Colossal simple ideas are sometime ideal. WOW, I'm simply astonish, this amp is relatively small, light, but it is very loud and very punchy, I don't want to be chauvinistic, but I don't see any tweek to do, it is just perfect like it is, thank Ken for the great simple design!
I don't need my JTM45 anymore !
I know I need some break in time, but so far I think that the paper and oil cap are very appropriate with this design, I've got good bass and no harsh high, very well balance tone, I'm amaze !
Both transformers are running cold. Next is a curly maple cabinet and some demo clips.
Cliff Schecht wrote:I know how to tell the difference between PIO caps and poly caps usually but these have the ends painted in green so you can't see if there is an epoxy seal or not. How do you tell the difference Jelle?
I got it from the russian datasheets.
Also there are pics of the guts of these K40Y and K42Y caps online. They tell the same story.
And again, that's a killer looking amp!!
As for the impedance switch, I use the NKK Nikkai (HS13).
Several places sell them. Mouser used to have it, CE Dist/AES, Hoffmann amps.