i used 2mm thick aluminum for my chassis...
the owner wants wood on the sides, i may have to argue with him over this,
not a good idea imho....
Everything underneath except tubes and main PSU traffo.
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you must be thinking of another amp, here i use tubes as per Tim design...
mine are svetlana 6j32, so far so good...
your tubes from moscow arrived fast, mine arrived after 8 months, i was about to give up of those....
Yes, mine are also original Soviet era Svetlana. All 18 arrived in a factory cardboard "ammo pack". Looking at the physical design, they appear very rugged. I've tried 6 of them so far in the amp without matching and all were OK. BTW, I'm about to connect two high quality speakers to the amp for the first time. Wish me luck!!!!
OK, the first thing to say is that I used 2 150 Watt bass LS speakers because my two full range Fostex speakers were a little too delicate to take a chance, if the amp suddenly went faulty. So as far as all frequencies from very very low to about 350 Hz they sound great. There is a great downward extension of bass response that I have not experienced with any of my solid state amps, including my rebuilt vintage Quad 405 Mark I. I won't try full range speakers until I'm happy with the amp's reliability. Another outstanding feature is the complete absence of any hum, sizzle or hiss. Chris (cnpope) was spot on with that aspect. So, so far so good. I'm now going to install the test points for 1 Ohm plate current measurement resistors. I had this weird notion that 1 Ohm would show up in the output chain and bring down the output level, but I'll take you at your word about there being no ill effect on the design. Thanks.
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Better photo.
I think this shot gives a better idea of how the amp looks. Here I'm trying out some Svetlana 6J32Ps. I'm going to cook the heaters of all 18 for 24 hours before I match them into pairs. BTW, I think the rosewood side panels and chromed handles look well together.
I think this shot gives a better idea of how the amp looks. Here I'm trying out some Svetlana 6J32Ps. I'm going to cook the heaters of all 18 for 24 hours before I match them into pairs. BTW, I think the rosewood side panels and chromed handles look well together.
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The ventilation is through the 6 mm gaps above the tops of the tube bases. A large slow-turning fan, mounted on the inside of the bottom cover, blows lots of air up through these gaps and up the sides of the 6C33Cs. I tried it with no fan at first but as you say, the inside bakes without it, so it's essential. The fan also takes the temperature of the chassis surface down a full 20 degrees Centigrade. Thanks for the complimentary remarks about the chassis.