a0-35 ot?

[rp]

i am going to make the ao-35 to a ghia or spitfire. just wanted to use the output trans that i listed. i already own it so why not use it. so can it be done putting a 4k on 2 el84's instead of a 8k. would the be adavantage or disadavanges

With my Lightning clone with TDS iron just figured Sampson did the hard work for me and left it at that. Hasn't even occurred to me to try an 8 ohm cab on the 4 ohm tap and see what I hear. I must get on it.

Did I just say see what I hear?

[M Fowler]

I see that some used the 4k primary for 15 watts with lower plate voltage.

350v x 350v plate voltage for push-pull divided by 18watts = 6.805 or 6k8 primary OT

250 x 250 plate volts divided by 15watts = 4.166 or 4k primary.

Mark

[paisley_tele]

What's the pt on an ao35 put out?

[M Fowler]

The original schematic doesn state but many have said it is 8k the PT is 290-0-290

[rp]

I see that some used the 4k primary for 15 watts with lower plate voltage.

350v x 350v plate voltage for push-pull divided by 18watts = 6.805 or 6k8 primary OT

250 x 250 plate volts divided by 15watts = 4.166 or 4k primary.

Mark

Mark, what Matchless ran EL84s @250V? I thought running these tube flat out was their MO? Mine with the TDS iron is at 345V. Sounds wild, and just like the real thing. Hope it doesn't eat my GEs like a lab finding a dropped burger at a BBQ.

[chopstuck]

To do what Matchless did you would use a 16 ohm load. Just know that those little hammond OT's aren't built any tougher than they have to be. I blew one up last week in a similar amp.

[M Fowler]

RP it is just a formula to find the impedence.

I was not implying that was the voltages Matchless used.

From the schematics for both Lightning and Spitfire it appears Matchless used 285-0-285 secondary PT and 4k OT.