Search found 10571 matches
- Wed Apr 03, 2024 2:41 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
There is nothing simple, that can’t be made more complex. I needed to take a step back and ask myself if what I wanted to do was actually necessary? I seemed to be planning to up my solder connections, up the parts count, double my chances to make a mistake. Double my chances for failure, so I thoug...
- Wed Apr 03, 2024 1:16 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
Was going to go fixed bias (Gawd knows why.) Got all the way to building a pair of bias supplies. Tested them, they worked faultlessly then I wondered what I was playing at and thought, sod it!
Just enjoying the music instead.
Just enjoying the music instead.
- Sat Mar 30, 2024 9:12 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
I tried the silver mica caps from Simon, years ago. Didn’t like them I’m afraid: to call them screechy is being kind.
- Sat Mar 30, 2024 5:26 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
In the meantime, here is the newest version of the audio circuit:
- Sat Mar 30, 2024 4:32 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
I've fitted a dual 220uF, BG as the bypass cap(s) for the output stages and removed the bypasses from the input stage, which has reduced the gain, but the amp is so sensitive it's no great loss. It's the best I can do at the moment. Not tried it on music yet. That'll have to wait until later tonight...
- Sat Mar 30, 2024 2:38 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
Power supply now:
- Sat Mar 30, 2024 2:36 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
A layer of hash has been removed as it was last time. I have to ask. Did the layer of hash come back when you put the electrolytics back in last time? Yes, it was just a slight bit of fuzz around the treble. It's not a night and day difference with the motor runs in place but it's there nonetheless...
- Sat Mar 30, 2024 1:16 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
You knew I wouldn’t be able to resist didn’t you! :lol: :lol: :lol: :thumbright: And could you hear any difference? I'm guessing not as you didn't comment? Yep, there was a difference. I knew there would be as I'd commented before when I took the electrolytics out of the PSU. A layer of hash has be...
- Sat Mar 30, 2024 11:10 am
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
… I don't think I'd be able to resist trying the 80uF after the stacked lytics, to see if it sounds better than the electrolytics as the last cap in the audio circuit. :D You knew I wouldn’t be able to resist didn’t you! :lol: :lol: Enter 2 30uF 440VAC motor run caps in parallel, giving 60uF, which...
- Fri Mar 29, 2024 10:35 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
… the fading away thumping noise on switch off suggests low frequency oscillation. But not sure how. Could have been the PSU doing weird things, and amplified by the o/p stages. Just guessing. Aye it’s been a saga but I’m enjoying the fault finding and the general argy-bargy involved in wrestling r...
- Fri Mar 29, 2024 8:44 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
…I don't think I'd be able to resist trying the 80uF after the stacked lytics, to see if it sounds better than the electrolytics as the last cap in the audio circuit. :D Or I could just bung another blue LCR motor run in as the final cap and remove the electros altogether. Look…you’ve set me off ag...
- Fri Mar 29, 2024 7:58 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
Was getting more weirdness yesterday: a series of soft thumps at warmup and again on power-down. The thumps faded out as the HT drained away. I've finished up simplifying the power supply to a single channel but with an extra choke. Changed the rectifier to a GZ34 to keep the same voltages as before...
- Wed Mar 27, 2024 7:52 pm
- Forum: Assorted Stuff
- Topic: Nothing In Particular
- Replies: 16488
- Views: 4838005
Re: Nothing In Particular
Hope everything works out Phil.
- Wed Mar 27, 2024 11:31 am
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
Thanks for that Paul. I’ve started to realise that inadequately rated components and choke-input supplies don’t mix. It seems self-evident from the wobbler throwing telly, that the iron I have is not up to the job. A cap-input supply is perfectly adequate for my needs. The amp sounds great with the ...
- Tue Mar 26, 2024 8:51 pm
- Forum: Everyones Projects
- Topic: OK…so I’m on wi’ summat
- Replies: 193
- Views: 43569
Re: OK…so I’m on wi’ summat
So here are the mods: RC filters after the first cap now have 270R resistors as opposed to the previous 470R, which have been shifted onto the cathodes of the EL34s. EL34CinputPSU.png Because of the higher HT voltage, the OPT is now on the 5K tap, cathode resistor on the output valve has been change...