SE Amp Project

[Rontone]

I have a few salvaged parts that I would like to put into a little champ style SE build,

The mains transformer would be 250-0-250 running though diode rectifier so about a 350V HT

The output transformer has a centre tapped primary at 3400 ohms and was set up push pull, I have seen 3000-8000 as figures for 6V6 single ended and thought it may be possible at first, but then also read about P-P output transformers not being great for single ended as the cores are different and can restrict power or other magnetizing/saturation problems

The O/T had about 15w on it set up as push pull, its very chunky and dense so I wonder if a 6V6 running at a low wattage would pass through it,

Is it worth a try, or will it smoke and fry?

[kagliostro]

I see Smoke & Fry far from your scenario but weak result about quality of sound

may be with 2 or 3W of output the situation will be a bit better

Franco

[Rontone]

I might as well get rid of it and get the correct SE 6V6 one for a champ really, I'm looking at the AA764 Champ style circuit, with a treble and bass control,

I see a 5000 ohm OT to run with a 6V6 at Primary Windings UK so that should work nicely,

I presume those type of Champs were a 4 ohm speaker?

[shooter]

I see a 5000 ohm OT

an OT has 2 spec's the primary as you stated, AND a 2ndary value.  you match the speakers impedance to the OT's secondary impedance value, you get the primary value

[Williamblake]

Why would you use a push pull OT for SE? They are different for a reason. Get an SE OT from an old radio.

[Rontone]

Why would you use a push pull OT for SE? They are different for a reason. Get an SE OT from an old radio.

Yeah, I was just checking, I was hoping at first it may be as simple as omitting the CT but now see why they cannot, and yes I have seen some radio OT's on eBay, unsure of the wattage but will keep checking

The primary windings UK OT's are a bargain so may just get a new one for it

an OT has 2 spec's the primary as you stated, AND a 2ndary value.  you match the speakers impedance to the OT's secondary impedance value, you get the primary value

I was thinking if I follow the Fender AA764 schematic, the feedback resistor [2700 ohm] will need changing as I mostly have 8 ohm speakers so would attach the feedback on that tap, reading in Merlin's Guitar Preamp book I think it may need to go up by √2 to 3900 ohm ish? 

[Williamblake]

SE OTs don’t go for much more than shipping. Knock yourself out. Plenty of good reading and advice on this forum.

[AmberB]

I see no reason why you couldn't use an output transformer that's rated for an 8 ohm output load in the AA764 circuit.