Sir.Byrd's Push-Pull 6V6GTA tube build

[GordonW]

700VCT, after rectification, will give close to 400v on the B+ line, without a LOT of dropping somewhere. Even with a 5R4.

That's pushing a 6V6 a little too far, IMHO. That kind of voltage is much more appropriate for 6L6s... but they would need appropriate higher output transformer wattage, and PT current, too...

EDIT: Actually, with a 5R4, it's probably fine. You'd need to use a 150 ohm 10 watt resistor in a following RC stage after the first cap (from the rectifier). That would give around 355v. That's OK, with 6V6GTAs in cathode bias.

Regards,
Gordon.

 

[Sir.Byrd]

Okay, have the transformer issue sorted out, will use a choke. Also, since the 6.3V winding should have been center tapped, I will wire it up with a hum pot. I don't understand everything entirely yet, but I have some local talent helping me.
I have most of the parts, and the full-size print of the aluminum plates just showed up today, photos soon!

 

[Sir.Byrd]

I can also scan the schematic.

 

[lha1992]

Sooo many projects.......Sooo little time haha

Nice tube project going up dude! Gotta see what you have done so far next time i'm down there!

 

[Sir.Byrd]

Sooo many projects.......Sooo little time haha

Nice tube project going up dude! Gotta see what you have done so far next time i'm down there!

This will be done by april 24th or I won't graduate.

 

[GuyK]

This will be done by april 24th or I won't graduate.

Nothing like a deadline to add some spice to a project, eh?

 

[Sir.Byrd]

Nothing like a deadline to add some spice to a project, eh?

Indeed.
I had one project where the deadline was so dead that if I didn't finish by then it would make the project cost an additional $400.

 

[GordonW]

Okay, have the transformer issue sorted out, will use a choke. Also, since the 6.3V winding should have been center tapped, I will wire it up with a hum pot. I don't understand everything entirely yet, but I have some local talent helping me.
I have most of the parts, and the full-size print of the aluminum plates just showed up today, photos soon!

Choke-input supply? That should work. Looks like about 300v DC with a SS rectifier or low-loss tube rectifier (a.k.a 5AR4 and such). Should be a pretty stout supply.

Regards,
Gordon.

 

[ehoove]

Jim

 

[Sir.Byrd]

 

[stoutblock]

this is about the coolest school project I can imagine!

 

[Sir.Byrd]

The only way it would be cooler is if the school had funded it!

 

[Sir.Byrd]

Plates should be coming in this week...

 

[bman22]

Our amps are going to end up being pretty similar, aren't they. I'm sure yours will look better though!

 

[Sir.Byrd]

Our amps are going to end up being pretty similar, aren't they. I'm sure yours will look better though!

You have two less tubes than I, but other than that, I'll have to be careful not to send you the wrong plate!

 

[roline]

What was the choice for output iron? The lowest cost outputs that I could find were the Russian 6P3S. A pic of a set in PP with Hammond 6.6k iron at 360V B+.
Post more pics of your project. I love the creativity that can be expressed in glass and iron, so many ways of accomplishing the same goal! Enjoy.:thmbsp:

 

[Sir.Byrd]

What was the choice for output iron? The lowest cost outputs that I could find were the Russian 6P3S. A pic of a set in PP with Hammond 6.6k iron at 360V B+.
Post more pics of your project. I love the creativity that can be expressed in glass and iron, so many ways of accomplishing the same goal! Enjoy.:thmbsp:

All transformers are Edcor.

 

[cableguy]

Looks good on paper ;-)

 

[Sir.Byrd]

Literally.

The plates are out for anodizing today. I might have them by friday.

 

[rage]

what a cute little power transformer.