Search found 11914 matches

by Nick
Wed Nov 13, 2019 9:03 am
Forum: Everyones Projects
Topic: GM70 PP
Replies: 107
Views: 5622

Re: GM70 PP

Am I missing something
You may be missing what choke input means, its not just a power supply with a choke in it.
by Nick
Tue Nov 12, 2019 8:38 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 107
Views: 5622

Re: GM70 PP

Yes, remember the following cap is a short circuit at AC, so the choke has the full AC voltage across it and current through it. MJ covers it well.
by Nick
Tue Nov 12, 2019 8:35 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 10792
Views: 811103

Re: Nothing In Particular

pre65 wrote:
Tue Nov 12, 2019 6:50 pm
Nick wrote:
Tue Nov 12, 2019 6:38 pm
A bit like the way "Delhi belly" is used to describe the after effects of too much curry.
Yes, I get that, but the analogy would be using "Delhi Belly" to describe the result of having Pie And Chips.
Over time the specific meaning becomes more generalised ?
I give up.
by Nick
Tue Nov 12, 2019 6:38 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 10792
Views: 811103

Re: Nothing In Particular

A bit like the way "Delhi belly" is used to describe the after effects of too much curry.
Yes, I get that, but the analogy would be using "Delhi Belly" to describe the result of having Pie And Chips.
by Nick
Tue Nov 12, 2019 6:35 pm
Forum: Everyones Projects
Topic: GM70 PP
Replies: 107
Views: 5622

Re: GM70 PP

RhythMick wrote:
Tue Nov 12, 2019 6:30 pm
Not sure I'm following the concern, 60mA well under 200mA rating?
Yes, but choke input is much harder on a choke than cap input.
by Nick
Tue Nov 12, 2019 4:54 pm
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

Are there any disadvantages of this mosfet follower design Tempted to say transistor ear but... As the linked article says, the changing input capacitance may matter, but can be reduced by having a large d to s voltage across the mosfet. Also, theer will be distortion introduced by the source follo...
by Nick
Tue Nov 12, 2019 4:04 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 10792
Views: 811103

Re: Nothing In Particular

not necessarily accurate.
That's all right then :-)
by Nick
Tue Nov 12, 2019 3:02 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 10792
Views: 811103

Re: Nothing In Particular

transistor ear
Err, that sort of proves that whatever it is you don't like, its not transistor ear.
by Nick
Tue Nov 12, 2019 2:59 pm
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

Yep, the red spot is power dissipated, voltage * current, if one is low the other needs to be high.

I thought the "Power Driver" was just a mosfet source follower.
by Nick
Tue Nov 12, 2019 2:39 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 299
Views: 43538

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Thanks Mike - might be worth a try. This bit is on the PCB so adding it could be a touch fiddly. I'd just bung it across on the track side. :D Sadly it's a double sided PCB with insulated tracks... :( I think Mike means the side without components. You can scrape the resist of the tracks if there i...
by Nick
Tue Nov 12, 2019 1:05 pm
Forum: Everyones Projects
Topic: Dieselpunk Preamp of Doom and the Beast with Two Backs
Replies: 299
Views: 43538

Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

What frequency is the oscillation at?
Already asked that question.
by Nick
Tue Nov 12, 2019 1:04 pm
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

Ok, so you are running it with 0v bias then, so you could do that again.
by Nick
Tue Nov 12, 2019 11:01 am
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

And was the cathode connected directly to ground?
by Nick
Tue Nov 12, 2019 9:02 am
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

I think it was negative, what bias are you running at the moment?
by Nick
Mon Nov 11, 2019 11:55 pm
Forum: Everyones Projects
Topic: 833A (GU-48) Amp
Replies: 1170
Views: 135303

Re: 833A (GU-48) Amp

A) The input direct from preamp ? Yes, but you will need to add a adjustable bias to the input, whatever DC voltage is on the input will be on the output, thats how it works as a A2 driver. Cap coupler your preamp input to that. B) The output to 833a grid ? Yes And, what would be a good way to conf...