Need Tube kits of above 75W Single Ended Class A amp

[MashBill]

While not strictly a kit, there is more than enough documentation available for you to source all the parts with thinking about it too hard. You'll need to fabricate a chassis, or buy a professionally drilled one from an outfit like Front Panel Express. This amplifier is a single ended design using the 6B4G as the output tube. It is roughly comparable to the 2A3.

http://www.diytube.com/phpBB2/viewtopic.php?t=3382

I built one recently, and I'm pretty pleased with it.

+1 on the GSG! I can send you a Front Panel Express file that will make the metalwork easy.

You can check mine out here:
GSG Photo Album

Bill

 

[ChrisA]

i only see 8w or 16 W....anything higher like 35w - 50w SIngle ended?.

Because whole purpose of building this monster is power the Electro static speakers once i have enough money.

DO not want to waste too much time on headphone amp. i won't be listening in headphone anyway.

The reason you don't see 50W Singe Ended amps is because they are not practical to build.

A great example here is the "Mesa Buggy 5:50" amp. This amp has a switch. Normally the amp runs as a 50W class AB push/pull with two 6L6 tubes. Flip the switch and one 6L6 tube is removed and the amp runs as a 5W class A in single ended mode. The power is cut by a factor of 10X. By the same logic you'd need 10 6L6 tubes in parallel to get 50W in SE mode. But where would you find an OPT that could handle the current? Like I said 50W SE is not practical.

In the 50W range you are going to have to use a PP class AB amp. Take a look at the Dynoco ST70. Or something like it.

 

[Richard Ellis]

I've been working on this one over a year now...an SE with the 813.
I really haven't tallied up how much it's going to be. It will have to be done in stages to 'spread out' the costs. Have not finalized the power supplies yet....but I did find an output transformer for appx. $255 usd each. Power output at 45 WPC.
__________________________________________Rick..........

 

[oldmanStrat]

I've been working on this one over a year now...an SE with the 813.

__________________________________________Rick..........

wow 900v in UL no less... just curious, what is the 1.2K resistor in the heater on the 813 for?

 

[Tubelab_com]

just curious, what is the 1.2K resistor in the heater on the 813 for?

Cathode bias. In the 813 the filament is the cathode.

 

[w5jag]

I've been working on this one over a year now...an SE with the 813.
I really haven't tallied up how much it's going to be. It will have to be done in stages to 'spread out' the costs. Have not finalized the power supplies yet....but I did find an output transformer for appx. $255 usd each. Power output at 45 WPC.
__________________________________________Rick..........

MFJ makes some power transformers that might be suitable for the B+.

Their 2009 catalog at page 71 lists an 800V at .5A xfmr with 120/220 volt primaries for $46.56, and a 900V at .5A with buck/boost 120/220 volt primaries for $132.00.

These are for SSB service, but you could probably get 200 - 225ma continuous out of either one.

I got a NOS Merrit 10V / 10A filament transformer at our local hamfest for $10.

That 833 amp is a real beauty - it's too pretty for my ham shack unfortunately, and I am not sure I want that kind of voltage in the living room or my office.

Win W5JAG