Search found 6963 matches

by Paul Barker
Mon Sep 30, 2019 10:31 pm
Forum: Valves
Topic: uTracer 400V upgrade kit available...
Replies: 30
Views: 7765

Re: uTracer 400V upgrade kit available...

I haven’t sent it yet I forgot.
by Paul Barker
Sun Sep 29, 2019 9:32 am
Forum: Everyones Projects
Topic: We are delighted to announce ...
Replies: 21
Views: 766

Re: We are delighted to announce ...

The transformer losses are usually made up for by underwindin the primary, so at it’s rated currentand “nominal” mains voltage spec you get 6.3v. Then the better transformers would additionally provide plus voltage and minus voltage tappings on the primary to accomodate variation from “nominal” supp...
by Paul Barker
Wed Sep 25, 2019 5:02 pm
Forum: Beginners
Topic: Speaker cables (different send & return)
Replies: 5
Views: 527

Re: Speaker cables (different send & return)

There is no send and return there is a waveform equally reliant on both cables’ quality.
by Paul Barker
Sun Sep 22, 2019 8:55 am
Forum: Assorted Stuff
Topic: General Raspberry Pi stuff
Replies: 22
Views: 5247

Re: General Raspberry Pi stuff

This conversation is showing me I’ve fallen so far behind.
by Paul Barker
Sat Aug 31, 2019 3:47 pm
Forum: Assorted Stuff
Topic: lathes
Replies: 37
Views: 8139

Re: lathes

Three jaw chuck are not usually perfectly centred so you have to mic and shim to centre them if you need to turn object round or you’ll get a step. If you can get a four jaw Chuck you can centre it perfectly with a micrometer on a stand to adjust the offset.
by Paul Barker
Sat Aug 24, 2019 7:34 pm
Forum: Everyones Projects
Topic: Remember These?
Replies: 723
Views: 47156

Re: Remember These?

Not too bad, and sounds like you have a plaan.
by Paul Barker
Wed Aug 21, 2019 1:52 pm
Forum: Speakers
Topic: Fane 12-250TC Retro Speaker.
Replies: 284
Views: 34540

Re: Fane 12-250TC Retro Speaker.

I vaguely remember the famous magazine article on OB by the man who invented Q57’s the resistance of baffle was key in the design
by Paul Barker
Tue Aug 13, 2019 9:59 am
Forum: Everyones Projects
Topic: The Other 13E1 SE-OTL
Replies: 135
Views: 12740

Re: The Other 13E1 SE-OTL

You’re vigilance at this stage has saved us all from a thread fault finding it later which may have taken some time to zero in on.
by Paul Barker
Fri Aug 02, 2019 8:57 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 116
Views: 7857

Re: Inverted OTL with 6SN7/6AS7

Interesting
by Paul Barker
Sat Jul 27, 2019 3:58 pm
Forum: Assorted Stuff
Topic: The Audio-Talk Motorcycling thread.
Replies: 513
Views: 53574

Re: The Audio-Talk Motorcycling thread.

Its a good day out for families. My kids liked the smells most.
by Paul Barker
Fri Jul 19, 2019 9:28 pm
Forum: Everyones Projects
Topic: Small Push-Pull Amp.
Replies: 19
Views: 1481

Re: Small Push-Pull Amp.

Nowt wrong with triode strapped valves. Some prefer gk71 over gm70. I liked 813 triode connected as much as I loved 211 for their unique stand out extra not heard in most amplifiers. Entirely different to each other yet only mood or tastes depending on which way your preference lies.
by Paul Barker
Sun Jul 14, 2019 4:40 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 84
Views: 4194

Re: GM70 PP

Might find examples on Russian enthusiast forums, using a translator to help you find the talk. Or maybe a search under images will pull up a circuit.
by Paul Barker
Sun Jul 14, 2019 4:33 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 84
Views: 4194

Re: GM70 PP

I’m not up to date on gm70 sweet operating position. Depends on so much. There must exist examples of pp gm70 circuits. Otherwise you’ll have to create push pull compound characteristic curves put in you’re loafline which links the two and choose you’re operating Point and limits. Should all be in R...
by Paul Barker
Sun Jul 14, 2019 4:15 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 84
Views: 4194

Re: GM70 PP

Not relevant for our use of the valve. Look at the characteristic curves.
by Paul Barker
Sat Jul 13, 2019 7:57 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 84
Views: 4194

Re: GM70 PP

On valve choice, 813’s on sale sh which I bought were wildly different transconuctance , I expect due to used ones, because of their intended use got a real pasting. Nos barely available. To find four used matching near impossible.

Get the new gk71 or gm70