Search found 7202 matches

by Paul Barker
Wed May 13, 2020 2:18 pm
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

It’s obvious to me that I’m out of my depth with fets and mosfets. So there shall follow a fairly lengthy pause while I observe. Just found a good Broskie page full of it. So far I haven’t found that the solid state discrete component useage is as well supported by the knowledgeable suporting the mo...
by Paul Barker
Wed May 13, 2020 2:10 pm
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

Presumably a good Spice model of the 801a should be accurate to at least 3rd order, Nick ? Well theres plenty of things my expression of humanity hasn’t grasped and one of those is spice. But when I’ve muddled on with my inate abilities however lacking they seem, I’ll publish the circuit values and...
by Paul Barker
Wed May 13, 2020 2:08 pm
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

Beautiful, thanks Nick, Id be as happy to wait until we’re together again at something if you could bring it and we just use it there. Whatever that future event is.
by Paul Barker
Wed May 13, 2020 12:46 pm
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

Ok so enough of theory. I stumbled ta the 211 because it transpires the characteristic curves found on Thomas Mayer’s block have confused me. I think there’s something wrong with those curves at the higher voltage, in the sense that the max power line out to the right gets crossed by youre loadline,...
by Paul Barker
Wed May 13, 2020 10:56 am
Forum: Everyones Projects
Topic: Inverted OTL with 6SN7/6AS7
Replies: 125
Views: 17882

Re: Inverted OTL with 6SN7/6AS7

The description u give sounds a bit like the experience of walking into Bruce Edgar’s room at VSAC. Also not dissimilar to my experience when I breadboardes the Glass Audio version of Rosenblit’s early adaptation of Futterman. I liked that and haven’t heard an otl I like as much as that early Futter...
by Paul Barker
Tue May 12, 2020 11:40 pm
Forum: Solid State
Topic: FET and mosfet: reading numbers.
Replies: 17
Views: 528

Re: FET and mosfet: reading numbers.

2sk170 and 2sk246


Ive figured its as looked at in same way we look at valves to see pin numbers from underneath.

my devices not in manufacturer’s box so no data with them, and as youve both said : not conveyed communicatively by the manufacturer’s in their data sheets.
by Paul Barker
Tue May 12, 2020 9:32 pm
Forum: Solid State
Topic: FET and mosfet: reading numbers.
Replies: 17
Views: 528

Re: FET and mosfet: reading numbers.

This is the problem it’s not clear in the data sheet drawings.
by Paul Barker
Tue May 12, 2020 7:38 pm
Forum: Solid State
Topic: FET and mosfet: reading numbers.
Replies: 17
Views: 528

FET and mosfet: reading numbers.

Are they like valves where numbering from left to right underneath or is it from above?

Thanks.
by Paul Barker
Mon May 11, 2020 1:26 pm
Forum: Everyones Projects
Topic: Help my memory
Replies: 2
Views: 122

Re: Help my memory

Paul Barker wrote:
Mon May 11, 2020 1:24 pm
I’ve lost a lot of my working knowledge having put this hobby down a long time ago.

This doodle appears to be CF calcs anyone recognise them?

Image
It’s not currently relevant but it’s annoying how much I’ve forgotten!
by Paul Barker
Mon May 11, 2020 1:24 pm
Forum: Everyones Projects
Topic: Help my memory
Replies: 2
Views: 122

Help my memory

I’ve lost a lot of my working knowledge having put this hobby down a long time ago.

My doodle appears to be CF calcs anyone recognise them?

Image
by Paul Barker
Mon May 11, 2020 12:28 pm
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

You are being a bit gentle on the 211 though at 500v 40ma. Very true but the starting point of all the valves in the project is the 801a operating point to compare them all at that. Then to see whta they’ll od in their own element. Here I’ve backed off from +20v grid to -120v grid and although curr...
by Paul Barker
Mon May 11, 2020 11:23 am
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

Thank’s Steve I appreciate and accept your’e offer. I had a beautiful small but sweet sounding 4.5k se transformers but I’ve lost them. They were the best bar none Ive heard at low level. Ho hum! So here’s the calc’s for the 211. Im using the curves on Thomas Mayer’s Tube of the Month on the 211. Be...
by Paul Barker
Mon May 11, 2020 9:40 am
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

yes to all that. Actually having refreshed some sleepy brain cells all of this is coming back to me, and my probable direction beyond this project is a Matrix amp. I’m so anoyed that at vsac i was stood next to Stephie and sorry my mind is older and ive forgotten the name of the man who writes Tubec...
by Paul Barker
Mon May 11, 2020 9:27 am
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

When it’s possible again, maybe I’ll bring it to try on youre speakers. The huge Tribute are all I can find thta’s anywhere near 10k and one thing clear as day; all these valves look bad at 2.5k my only other SE transformers.This is a shame because it all began with me wanting to just hook up a litt...
by Paul Barker
Mon May 11, 2020 8:24 am
Forum: Everyones Projects
Topic: 801a maximised class A2 excursion.
Replies: 131
Views: 2529

Re: 801a maximised class A2 excursion.

sorry that post is hard reading with all those mistakes. Im sick 0f editing everything ive posted straight after its posted . sorry if some people are very anoyed by my literary errors.