Search found 15705 matches

by Nick
Fri Feb 09, 2024 3:24 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 176
Views: 83893

Re: Valve amplifier service

I think from the above description, you might also point the finger at your CD player. What is the CD player? Is it Type II isolated or does it have a ground connection? You could isolate the chassis and safety ground on the amp from the signal ground with a small resistor, but I dislike that idea i...
by Nick
Fri Feb 09, 2024 9:38 am
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 80829

Re: C3g Aikido Phono

Hardly expert. The trick (as I have said before) with noise/hum I find is getting used to thinking in terms of current as being the driving aspect and voltage being a resultant. A lot of electronics (especially valve) gets us used to thinking in terms of voltage only. Bipolar solid state is about cu...
by Nick
Wed Feb 07, 2024 9:48 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 80829

Re: C3g Aikido Phono

Well done. Not sure about the buzzing. Does pressing on the valve case alter it? Is it 50Hz, or something else?
by Nick
Wed Feb 07, 2024 11:54 am
Forum: Assorted Stuff
Topic: Zero emission road vehicles.
Replies: 912
Views: 396625

Re: Zero emission road vehicles.

"Crash Test Dummy Engineer". I tell you, with AI nobody's job is safe :-)
by Nick
Sun Feb 04, 2024 10:29 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9394

Re: 6550 SE Amplifier

I cant get my head round the way from -5 to 0 the grid line spacing is smaller. So introducing 2nd distortion which wont mitigate the high 2nd distortion of the 6550. Do you mean at the righthand end of the graph? This might be on purpose to reduce gain at large negative grid - ergo, AGC may be app...
by Nick
Sun Feb 04, 2024 6:36 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 176
Views: 83893

Re: Valve amplifier service

If it is oscillating, I would have thought the output pentodes were more likely to be the cause, maybe grid and screen stoppers could be tried if not there already. Getting a ecc83 to do that seems unlikely at first sight.
by Nick
Sun Feb 04, 2024 7:52 am
Forum: Assorted Stuff
Topic: The Quackery Thread
Replies: 360
Views: 190203

Re: The Quackery Thread

Well we do have an electric blanket.
by Nick
Sat Feb 03, 2024 10:32 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9394

Re: 6550 SE Amplifier

Yep grid stoppers worth using.
by Nick
Sat Feb 03, 2024 6:25 pm
Forum: Assorted Stuff
Topic: The Quackery Thread
Replies: 360
Views: 190203

Re: The Quackery Thread

See they do earthing shoes as well. Wonder how much better they are than these https://www.safetecdirect.co.uk/products/fc03/portwest-fc03-compositelite-esd-anti-static-perforated-safety-clog-sb-ae?sku=fc03bk/6&gad_source=1&gclid=Cj0KCQiA5fetBhC9ARIsAP1UMgFkbbFmfdF8s-cusqsPlbcqOL7qDGJtfFLvNT...
by Nick
Sun Jan 28, 2024 6:17 pm
Forum: Beginners
Topic: You know how polypropyline motor run caps…..
Replies: 9
Views: 3840

Re: You know how polypropyline motor run caps…..

I guess it depends on the cap. But if not specifically DC rated, I would expect 1.414 of AC voltage would be a safe limit. Not sure where the justification for higher multipliers would be from other than optimisum. I checked motor start cap on RS, it had this in the docs "Direct current operati...
by Nick
Fri Jan 26, 2024 6:40 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 176
Views: 83893

Re: Valve amplifier service

But most of all a trip to Dr. Nick's I think!
Always welcome (though check before if weekend as I have a bunch of weekends planned for sprints this year).
by Nick
Fri Jan 26, 2024 9:47 am
Forum: New Users
Topic: Hi from Chicago
Replies: 10
Views: 1359

Re: Hi from Chicago

Its the one from here

https://www.audio-talk.co.uk/phpBB3/vie ... 46#p178046

I just added a new set of output valves. Doing nothing with it, so PM if you are interested.
by Nick
Thu Jan 25, 2024 9:38 pm
Forum: Everyones Projects
Topic: On My Bench.
Replies: 84
Views: 28573

Re: On My Bench.

Holy wound components batman. Very nice. Almost shoddy.
by Nick
Thu Jan 25, 2024 9:36 pm
Forum: New Users
Topic: Hi from Chicago
Replies: 10
Views: 1359

Re: Hi from Chicago

Hi, I have never heard any bad things about the Transcendant kit. I have one of the The Son of Beast OTL's here somewhere. I never built it, it was from another of this forum.
by Nick
Thu Jan 25, 2024 9:33 pm
Forum: Valves
Topic: PP3521 idht
Replies: 95
Views: 19644

Re: PP3521 idht

Oh my, I thought the primaries were acting as anode chokes anyway
Well, I guess its just semantics. A choke would normally be assumed to only have one winding, a transformer two or more. But yes, the valve sees the same in both cases.