Fun with Feedback

What people are working on at the moment
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8863
Joined: Mon May 21, 2007 9:42 pm

#136 Re: Fun with Feedback

Post by Paul Barker »

Cressy Snr wrote: Fri Jul 29, 2022 12:12 pm Music is my first love and it will be my last. Music of the future and music of the past. To live without my music would be impossible to do. In this world of Johnson, Sunak, Truss, rip off energy companies, climate change and complete utter bastards, my music pulls me through.
nice poem if somewhat plajurised, lol.

I have my ear buds in listening to my ITunes driving between jobs and at the gym. Until the music dies…. Miss American Pie.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#137 Re: Fun with Feedback

Post by Cressy Snr »

Paul Barker wrote: Sat Jul 30, 2022 7:09 am
nice poem if somewhat plajurised, lol.
Well of course :mrgreen:
Sgt. Baker started talkin’ with a Bullhorn in his hand.
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#138 Re: Fun with Feedback

Post by Mike H »

Image
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#139 Re: Fun with Feedback

Post by Cressy Snr »

Been tying up a few loose ends with the amp in time for Owston. The 14 year old Maplin 100K volume control was playing up, so that has been changed out for a 25K Allen Bradley job. I did a final measurement of the voltages. All seems well. Zero hum and a lovely overall presentation.

The sound had deteriorated markedly. I had had a hearing problem in the right ear, but even so, I knew the sound was not as it should have been: fuzzy as feck. Anyway the change of pot cured the fuzziness and some ear drops over a few days, sorted the remaining problem in the right ear. So... we are all set. Looking forward to playing it at the venue, which is not something I would normally be confident about doing.

Screenshot 2022-10-07 at 12.38.07.png
Screenshot 2022-10-07 at 12.38.07.png (194.92 KiB) Viewed 2063 times
Screenshot 2022-10-07 at 12.38.29.png
Screenshot 2022-10-07 at 12.38.29.png (180.61 KiB) Viewed 2063 times
Sgt. Baker started talkin’ with a Bullhorn in his hand.
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#140 Re: Fun with Feedback

Post by Cressy Snr »

Forgot to mention that yesterday, I also recapped the first stages of the power supply (the two Cs in the CLC setup.)
The existing caps were 15 years old and at the rate my mate had been using the amp, those caps had had over 87000 hours of use!
Sgt. Baker started talkin’ with a Bullhorn in his hand.
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#141 Re: Fun with Feedback

Post by Mike H »

Looking very interesting Steve. :thumbright:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#142 Re: Fun with Feedback

Post by Cressy Snr »

Something really interesting would be a 2A3 amp with GNFb, but I sold all my 2A3s years ago. Bah!
Sgt. Baker started talkin’ with a Bullhorn in his hand.
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8863
Joined: Mon May 21, 2007 9:42 pm

#143 Re: Fun with Feedback

Post by Paul Barker »

Have you seen that Brimar are making EL34’s again? I dont think true pentode EL34’s triode connected will give much away to 2a3’s. Their price is very fair.

My first experience of home made single ended triode amp was with my friend Richard Warwick of timetec, the guy who made his own style of plasma speaker.

Ill never forget that wanderful experience. EL34 triode is tonefull. Yanks always prefered beam tubes. I like 34’s and 84’s more.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#144 Re: Fun with Feedback

Post by Cressy Snr »

Paul Barker wrote: Sat Oct 15, 2022 8:20 pm Have you seen that Brimar are making EL34’s again? I dont think true pentode EL34’s triode connected will give much away to 2a3’s. Their price is very fair.

My first experience of home made single ended triode amp was with my friend Richard Warwick of timetec, the guy who made his own style of plasma speaker.

Ill never forget that wanderful experience. EL34 triode is toneful…I like 34’s and 84’s more.
I have to agree with you there Paul. EL 34s just sound ‘right’ to me. I always seem to come back to them. Triode strapped with GNFb, they are simply brilliant. I think I’ll just stick with them.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
User avatar
Nick
Site Admin
Posts: 15706
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#145 Re: Fun with Feedback

Post by Nick »

Paul Barker wrote: Sat Oct 15, 2022 8:20 pm Have you seen that Brimar are making EL34’s again?
Sadly I think their website is mainly future tense hopes. I think they are reselling valves manufactured elsewhere. I may be wrong, but can see no sign I am not. Their tag line is "Working towards UK valve manufacturing".

However they are all to be applauded as they are still it seems working towards actually making something. Looks like they have successfully made some type R triodes.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8863
Joined: Mon May 21, 2007 9:42 pm

#146 Re: Fun with Feedback

Post by Paul Barker »

Shucks…

“There are lies, damn lies… and Web Pages”
Abraham Lincoln.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Nick
Site Admin
Posts: 15706
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#147 Re: Fun with Feedback

Post by Nick »

I only read the same web page as you.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#148 Re: Fun with Feedback

Post by Cressy Snr »

The amp is now on its third fecking volume control.
The Allen Bradley carbon track pot became intermittent on the right channel yesterday afternoon, so now it has a TOCOS pot with poor channel balance as it’s all I have left in the spares box. Sometimes, using 50 year-old shagged out knackered bits and bobs is false economy. Anyway TOCOS pots are at least a known quantity and are reliable apart from the known channel balance issue at low levels.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
Neal
Shed dweller
Posts: 2299
Joined: Fri Aug 03, 2007 10:57 am
Location: From the land of the Bodgers

#149 Re: Fun with Feedback

Post by Neal »

Got a current leak flowing through it? The 1 meg grid leak resistor on the input valve may be too high.
Only the Sith deal in absolutes.
Cressy Snr
Amstrad Tower of Power
Posts: 10552
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#150 Re: Fun with Feedback

Post by Cressy Snr »

I’ll look into it.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
Post Reply