Search found 6952 matches

by Paul Barker
Sun Jul 14, 2019 4:40 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 35
Views: 328

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: 35
Views: 328

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: 35
Views: 328

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: 35
Views: 328

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
by Paul Barker
Sat Jul 13, 2019 1:07 pm
Forum: Valves
Topic: uTracer 400V upgrade kit available...
Replies: 28
Views: 6266

Re: uTracer 400V upgrade kit available...

I killed my utracer a long time ago now. Decided to enquire from Ronald about a new 400v one built by him. But he came back offering to repair mine free. He truly is the most supportive inventor / supplier I’ve worked with. But I’ve replied asking him to repair and update mine, but I told him I want...
by Paul Barker
Sat Jul 13, 2019 8:04 am
Forum: Assorted Stuff
Topic: The Audio-Talk Motorcycling thread.
Replies: 452
Views: 36369

Re: The Audio-Talk Motorcycling thread.

jack wrote:
Fri Jul 12, 2019 8:10 pm
I had one of those on my desert Jeep...

Never ask a man walking away from camp with a shovel in his hand what he's up to...
Burying his daughters boyfriend?
by Paul Barker
Thu Jul 04, 2019 12:54 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

Looks organised.
by Paul Barker
Sun Jun 30, 2019 6:07 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

Addendum I see the up dated 400 max bolts utracer is only £283 built by Ronald. Worth every penny, but he’ll also send the upgrade to 400v for 15 💶 (they used to be 300v as is my one.)
by Paul Barker
Sun Jun 30, 2019 5:46 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

Plotting characteristics is easy, measuring is hard because you have to give a short burst of power (i.e the specific volts/current at the specific grid voltage) so as not to damage the weaker component parts such as grid. Best get or borrow a curve tracer. Mine broke and I’m so far from electronics...
by Paul Barker
Sat Jun 29, 2019 4:48 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

Sounds like a nice recipe
by Paul Barker
Sat Jun 29, 2019 12:13 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

But the 6as7 inverted curves look high in 2nd harmonic yet you say how great the amp sounds. Same story for usual orientation 6as7 se. Sounds real good with all it’s 2nd! The 5687 inverted lines look so linear you would think you accidentally mixed them up with 211. I’d prefer to build 5687 if only ...
by Paul Barker
Wed Jun 26, 2019 9:19 pm
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 59
Views: 2159

Re: Inverted OTL with 6SN7/6AS7

I might build a raw one without the stuff you’re planning wish 6as7’s that I have no’s.... well enough for mono. I once collected enough 5687’s but foolishly sold them. Have a few loose ones, not enough.
by Paul Barker
Sat Jun 22, 2019 10:14 am
Forum: Assorted Stuff
Topic: North West Audio Show - Cranage Hall
Replies: 17
Views: 806

Re: North West Audio Show - Cranage Hall

Thanks for the tip off , I don’t think I can spare the day though. I wish you and Nick all the best though. Go get em!
by Paul Barker
Mon Jun 17, 2019 2:00 pm
Forum: Speakers
Topic: Fane 12-250TC Retro Speaker.
Replies: 241
Views: 24266

Re: Fane 12-250TC Retro Speaker.

Totally with you.
by Paul Barker
Sat Jun 15, 2019 3:28 pm
Forum: Everyones Projects
Topic: The Other 13E1 SE-OTL
Replies: 117
Views: 7338

Re: The Other 13E1 SE-OTL

He wrote earlier he has varying mains voltage at home. So he’d like to keep the power consistent.