Cheap project competition

[andrew ivimey]

What if I said, Citizen X sold me a pair of silver amorphous tranformers for £10

Yeah right!

It is easy to cheat and I know, that isn't the point. My favourite output tranformers for ths sort of thing cost $13-95 the pair (they are $28-95, now!) and they are still for sale at www.tubesandmore.com - replacements for Fender Champ amps.

And my valve of choice is 6DN7, a very close relative of 6EM7 of course.

The cheapest has to be (???) 6S45PE. After that, ecl82 springs to mind.

But what about the 6AS7? - NealG's little amp is probably too sophisticated anyway!

I'm going for cheap as my original loftin white was v.close to only £300.

But it doesn't mean flea power has to have fleas though. Esoteric stuff will only make things more interesting, hand wound jobbies or not. I think we should have as few rules as possible with the emphasis on fun.

[steve s]

I have a few 30's output pentode that show only 7% distortion at 6-8 watts

i sort of wonder how they would sound.. running at lower output the distortion would be quite low ish.. in dht territory...

examples are pen44, pen 45, ac4/pen, ac5/pen.. etc etc

whole new world to me really...

I would be in for this sort of competition...

i have a nice pair of german output transformers that cost me £2 out of a old radiogram....

A guy down my street has just dropped me off 4 pages of a4 on how to calculte the power supplys using different topoligies.. so i may even get that right...

he was a lecturer at the university specalising in ..power supplys.
i wish I had 10% of his knowledge...

cheers steve

[James D]

Steve,

Any chance of scanning them and posting the result?

cheers

James

[steve s]

I've no scanner...
i don't mind photo copying them and posting them to you.. pm your address??

I've had a quick read

they cover choke input, cap input, and r-c smoothing,
merits and 'buts' under each heading,

theres quite alot on load resistance, the effect of caps on it, and calculating ripple etc

and lots of calculations and notes.. written in simple terms

great..

steve

[pre65]

Hi Steve-i you want to send me a copy i can scan it and e-mail to any interested member.
PM me if interested.


Philip

[Martin213]

Hi you lot

Sounds fun to me too,would you like a venue?
I was considering hosting WithamFest 2 on the weekend of November 25th/26th if that helps

Kindest Regards

Martin

[Martin213]

"It did occur to me I have a cheap high voltage transformer that Stuart Dean only charged me something like £10 for that would make the gm70 sing."


How high a voltage Paul? Could that said tranny and a pair of GM70's form the basis of you building me an amp on the cheap?

Kindest Regards

Martin

[Martin213]

"But what about the 6AS7? - NealG's little amp is probably too sophisticated anyway!"

Although Neal's amp wore a 6AS7 (Paul knows more about that valve than myself),being pedantic the amp' was actually a 6080 amp'.

[Darren D]

They are both the same valve. 6AS7/6080

[Martin213]

Originally Posted by Darren D

They are both the same valve. 6AS7/6080

Not quite Darren,there were subtle differences.
Paul is the best person to share his knowledge on this,i believe