Class B output transformer good for push-pull AB?

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

Post Reply
User avatar
WRC34
Posts: 184
Joined: Fri Dec 19, 2014 3:40 am
Location: United States
Contact:

Class B output transformer good for push-pull AB?

Post by WRC34 »

I recently acquired an old Thordarson OT, type T-6753 (see stats in link below) it’s a nice healthy size and looks like it’d be a great candidate for an EL34 or 6L6 pp amp (possibly w/upwards impedance mismatch to reflect 5.8K to the primary). The only strange thing in the description is that it is a “Class B” OT. I know OTs do not actually have a class of operation and that class of operation is a description used to discern the way the amplifier is achieving power and how the tubes are making said power, but can anyone see how/why this OT would not be suitable in a reasonable push-pull guitar amp design?


http://www.bunkerofdoom.com/xfm/THORDAR ... 400_09.jpg
User avatar
pompeiisneaks
Site Admin
Posts: 4244
Joined: Sat Jan 14, 2017 4:36 pm
Location: Washington State, USA
Contact:

Re: Class B output transformer good for push-pull AB?

Post by pompeiisneaks »

The bigger question that sheet doesn't seem to answer is what's the current rating of the thing. Am I missing that somewhere? That may be the class designator, I think if an amp is in class A it pulls more current, so maybe that's what it implies? Sorry, not sure that's super helpful, but to know if that can work, you need to know if the secondary winding(s) have the ampacity to handle the load.

~Phil
tUber Nerd!
User avatar
didit
Posts: 1115
Joined: Thu Sep 25, 2008 3:37 pm
Location: Canada

Re: Class B output transformer good for push-pull AB?

Post by didit »

It will be fine. The 2K9 primary suggests a moment or so of load-line arithmetic. There is a notional 120mA spec'ed. That's doubtless maximum.

Best .. Ian
User avatar
pompeiisneaks
Site Admin
Posts: 4244
Joined: Sat Jan 14, 2017 4:36 pm
Location: Washington State, USA
Contact:

Re: Class B output transformer good for push-pull AB?

Post by pompeiisneaks »

didit wrote: Sat Mar 31, 2018 4:55 pm It will be fine. The 2K9 primary suggests a moment or so of load-line arithmetic. There is a notional 120mA spec'ed. That's doubtless maximum.

Best .. Ian
oh is that what the M.A. meant? ugh changes in convention to confound us all! :P

~Phil
tUber Nerd!
User avatar
WRC34
Posts: 184
Joined: Fri Dec 19, 2014 3:40 am
Location: United States
Contact:

Re: Class B output transformer good for push-pull AB?

Post by WRC34 »

Thanks guys - I figured it would be ok but wanted to see if there were some secret knowledge I wasn’t privy to. As you can see in the stats it’s quite large and weighs a substantial amount as well, at least as big as your average 50 watt OT.

Gonna go for it!
User avatar
didit
Posts: 1115
Joined: Thu Sep 25, 2008 3:37 pm
Location: Canada

Re: Class B output transformer good for push-pull AB?

Post by didit »

Some KT-88 run on relatively mid/low voltage.

Best .. Ian
User avatar
Kagliostro
Posts: 549
Joined: Wed Dec 30, 2009 12:09 am
Location: Italy

Re: Class B output transformer good for push-pull AB?

Post by Kagliostro »

Only one thing

remember, the lower the voltage the higher the current for the same Power Output

Franco
Post Reply