Page 1 of 2

"The Russian Rocket" 6C41C SET Amp

PostPosted: Thu May 18, 2006 12:49 pm
by EWBrown
OK, get your Roger Ramjet Secret Decoder Rings out, and try to figure this one out:

http://circulator.bravehost.com/6C41C_small.htm

if everything works out properly, it should look like this:

http://circulator.bravehost.com/6C41C_s ... age102.jpg

/ed B in NH

PostPosted: Thu May 18, 2006 1:50 pm
by sorenj07
broken links ;)

PostPosted: Fri May 19, 2006 6:02 am
by EWBrown
This site seems to be somewhat "moody"... sometimes it works, sometimes it doesn't Yellow_Light_Colorz_PDT_20

Basically, how to build an amp, with lots of photos and a schematic, but very few words, and lots of garbled code... Yellow_Light_Colorz_PDT_09

/ed B in NH

PostPosted: Fri May 19, 2006 7:38 am
by sorenj07
that is entirely ridiculous. i've never seen any soldering even approaching the organization and structure of that job. it looks like a 3-d city or something. crazy. my preamp definitely won't look like that 0_o

PostPosted: Fri May 19, 2006 1:11 pm
by EWBrown
That's the "magic" of single point (or star) grounding, hand-wired style.

Looks crazy, but it is the key to hum-free design.

FWIW, the DF3A can be substituted with an EF180 / 6688 which is much more available.

I found another more practical (read that simpler) 6C41C SET design elsewhere, I'll post it when I can find it again...

/ed B in NH

better late than never...

PostPosted: Fri Nov 03, 2006 7:05 am
by EWBrown
A couple more 6C41C locations (actually it's the same thing, just two different pointers)

http://www.audioasylum.com/forums/tubed ... 18548.html

http://home.zonnet.nl/horneman/6c41c.htm

This one is in English, so no captain midnight decoder rings are needed...

Basic amp schematic here:


Image

The cap marked 1,056 uF should actually be 0.056 uF. One of the Russki 0.056 uF, 500V teflon caps would be "da ballz" here. Yellow_Light_Colorz_PDT_01

/ed B in NH

PostPosted: Fri Nov 03, 2006 9:14 am
by TomMcNally
I wonder how an 832A would work in SET ?
One tube for stereo with a simple one tube
driver ... might be pretty cool. hmmm

PostPosted: Fri Nov 03, 2006 9:41 am
by EWBrown
IT should work, IIRC, the 832 has a single "common" cathode connection, but this shouldn't be a problem, I've "cheated" on simple SV83 "Zen Clone" and used a single resistor and bypass cap for two tubes.

I would SWAG that a 6SL7 and 832 (or any of its relatives like 5894 or 829B, etc) in SE mode should work just fine.

I have a couple of NOS Raytheon RK34s whih I had similar plans, the power out would be 1WPC or less, for SET mode, but any ST shaped tube with two plate caps has a certain "cool" factor which outweighs mere wattage.

/ed B in NH

PostPosted: Fri Nov 03, 2006 10:17 am
by TomMcNally
This amp shares a common cathode resistor and cap also.
It's still one of the sweetest sounding amps I have.

Image

PostPosted: Mon Nov 06, 2006 10:52 am
by WA4SWJ
Actually I think the construction of that 6C41C anp is beautiful!

Tom's 832 amp is nice too. I'm building an 832 amp too but I haven't worked on it in months. Too much travel!!

PostPosted: Tue May 20, 2008 2:08 am
by alexg_ht
TomMcNally wrote:This amp shares a common cathode resistor and cap also.
It's still one of the sweetest sounding amps I have.

Image


Hi Tom,

What driver are you using for this amp? This is an SE amp?

I have few pairs of 832, I already tried a PP version using 6j5 as driver and an autoformer for phase inverter, it sounds great. I might do an SE version too.

Thanks.

PostPosted: Tue May 20, 2008 6:14 am
by EWBrown
I recently picked up, for a good price, two NOS NIB Amperex 5894As which are a more modern version of 829Bs, perhaps a little less maximum power and voltage capability, but more power capability than 832As. They have the same pinout, and use the same "septar" sockets.

They look like this:

Image

RCA data sheet here:

http://www.mif.pg.gda.pl/homepages/fran ... 5/5894.pdf


I have used these tubes before, in their original purpose as VHF (144 MHz) RF power amplifiers, wich excellent results. There are a couple of 144 MHz repeaters in southern NH that still run great with the tubes that I installed in them.

trying these tubes in audio will another "after the move" project....

The driver for the 832 amp uses 12AT7s, in a circuit fairly similar to that of the ST-35, voltage amplifier and "cathodyne" phase splitter.

/ed B

PostPosted: Tue May 20, 2008 6:25 am
by TomMcNally
Alex -

The 832A are dual section tubes, so the amp is push pull using
one tube per channel. The drivers are 12AT7's
Links to the original schematic on my website at http://tmamps.com

CWA

PostPosted: Tue May 20, 2008 8:07 am
by EWBrown
Here is the Russian Rocket's big brother, the Cold War Amp, as shown on Bottlehead:

http://www.audioasylum.com/forums/bottl ... 28027.html

Image

/ed B

PostPosted: Tue May 20, 2008 9:31 am
by hasafraker
that thing is sick... :o