add another output transformer

[h2mster]

hi lads,

i ordered an ubt-1 by one electron for an valve amp. by the 2 EL34 design the 8 watts are a little low to drive the 50 watt speaker (weber dt-15)to it's qualities.

is it recommended to enhance the output stage to 2*2 E34 and than run 2 ubt-1's in parallel to sum em up? I orderes 2 matched pairs of the EH EL34. I am scared of leveling out frequencies this way..

or is it better to do a 3-EL34 output design and level the plate voltage up to 400 volts? to get ~15-18 watts..

yours
andy

 

[Printer2]

hi lads,

i ordered an ubt-1 by one electron for an valve amp. by the 2 EL34 design the 8 watts are a little low to drive the 50 watt speaker (weber dt-15)to it's qualities.

So why are you running the tubes in triode?

is it recommended to enhance the output stage to 2*2 E34 and than run 2 ubt-1's in parallel to sum em up?

I guess you could, expensive way of getting 16W though.

I orderes 2 matched pairs of the EH EL34. I am scared of leveling out frequencies this way..

Something lost in the translation.

or is it better to do a 3-EL34 output design and level the plate voltage up to 400 volts? to get ~15-18 watts..

yours
andy

I am assuming (and I could be wrong, been many times before) that you are using this design,

http://www.one-electron.com/amps.html
http://www.one-electron.com/Randall/Randl_p1.pdf

using this.

http://www.one-electron.com/Trans/UBT1_20.pdf

Not quite your average guitar amp. Although if you used the 6SJ7 and the EL34's in pentode, unleashed the 6SN7's, might be killer.

Might want to look here.

http://www.valvewizard.co.uk/se.html

 

[h2mster]

mm I'd like to stay on the triode design to stay with classA for the harmonics. so i guess another output trans had to be bought.

but thx for the helpful answer Printer2

 

[Printer2]

I like Class A amps. I have a little Champ amp on beside me right now. Pentodes work in Class A also, more harmonically rich than triodes though.

 

[h2mster]

thx printer2

k i'll review the calculations again.
thx a lot,still come back with more later

 

[h2mster]

ordered the BFT-1B and another UBT-1 let's see

reviewed the randall schematics after that i think of using 2 rectifying tubes, too.. but i wonder if this makes much sense in a single ended guitar amp..