Search found 10585 matches

by Cressy Snr
Thu Mar 21, 2024 8:14 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

There's a lot more room in the chassis than in the Mk1 version of the amp, so, copying Paul, I purged the power supply of electrolytic caps by installing a nice pair of LCR motor run caps in place of the electrolytics that decoupled the input stages. Didn't think it would make a lot of difference, b...
by Cressy Snr
Mon Mar 18, 2024 10:48 am
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

It’s back in the system after the cosmetic facelift and power supply upgrade.
Sounds great with the LCRCRC supply. Glad I searched out the 450V transformer, despite the head scratching over the primary phasing.
IMG_0389.jpeg
IMG_0389.jpeg (142.2 KiB) Viewed 999 times
by Cressy Snr
Sun Mar 17, 2024 7:41 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Circuits:

1. Audio Circuit with measured voltages:
EL34Audiocct.png
EL34Audiocct.png (52.41 KiB) Viewed 1094 times

2. Choke input power supply:
EL34LCinputPSU.png
EL34LCinputPSU.png (82.34 KiB) Viewed 1094 times
by Cressy Snr
Sun Mar 17, 2024 7:38 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Amp undergoing soak testing in the system.
Soaktesting.jpeg
Soaktesting.jpeg (161.48 KiB) Viewed 1094 times
by Cressy Snr
Sun Mar 17, 2024 7:37 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Thanks chaps.
Amp is finished. Last two jobs were to cable the input sockets to the selector switch and to put a reinforcing piece of anodised aluminium L section along the bottom edge of the rear panel, to match the one at the front:
Interior6.jpeg
Interior6.jpeg (143.69 KiB) Viewed 1094 times
Rearpanel.jpeg
Rearpanel.jpeg (109.7 KiB) Viewed 1094 times
by Cressy Snr
Sat Mar 16, 2024 8:22 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

All the circuitry is done. Just the four inputs to cable to the selector switch.
It all works and biases up correctly:
IMG_0380.jpeg
IMG_0380.jpeg (167.86 KiB) Viewed 1205 times
IMG_0381.jpeg
IMG_0381.jpeg (100.04 KiB) Viewed 1205 times
by Cressy Snr
Sat Mar 16, 2024 1:02 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Cheers Ray.
Should be finished by Sunday.
by Cressy Snr
Fri Mar 15, 2024 9:17 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 13679

Re: 6550 SE Amplifier

👍
by Cressy Snr
Fri Mar 15, 2024 9:12 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

I was going to stop at around 4:00 today, but after tea, Melanie decided she was going to watch a recording of, "Celebrity Big Brother Live and Late!" :sleepy1: I didn't need much encouragement to leave the room, go upstairs and continue with the build. Got the power supply wired up and th...
by Cressy Snr
Fri Mar 15, 2024 8:55 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Oh pooh, really sorry to have to tell you this, honest I wasn’t copying you. I adjusted b+ in my amp to get g2A 425v the bias on the cathode 39v 48 mA. 21 watts dissipation. Totally better by a mile than the 6550.Diana just nuck up on me, I nearly jumped out my skin. “Gosh its sounds really……signif...
by Cressy Snr
Fri Mar 15, 2024 8:52 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Mike H wrote: Fri Mar 15, 2024 8:03 pm My experience has been, alu can't be bent twice, on the same fold. :D
Indeed!
by Cressy Snr
Fri Mar 15, 2024 3:56 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Earthing system is in place plus the choke snubbers:
Interior3.jpeg
Interior3.jpeg (163.05 KiB) Viewed 802 times
And of course we have heaters:
Heaters.jpeg
Heaters.jpeg (121.84 KiB) Viewed 802 times
That's it for today.
by Cressy Snr
Fri Mar 15, 2024 11:03 am
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47924

Re: OK…so I’m on wi’ summat

Mains and heater wiring are in and tested: Interior2.jpeg Had trouble with the primary 240V series connection. It's a long time since I used this particular Danbury mains transformer. I'd taken the labels off and lost the documentation. That was a good move wasn't it. :roll: I'd identified each half...
by Cressy Snr
Wed Mar 13, 2024 2:58 pm
Forum: Beginners
Topic: Pot Impedance
Replies: 3
Views: 2575

Re: Pot Impedance

Thanks Nick.
by Cressy Snr
Wed Mar 13, 2024 2:12 pm
Forum: Beginners
Topic: Pot Impedance
Replies: 3
Views: 2575

Pot Impedance

Just a quick question: I have a high quality, Khozmo shunt stepped attenuator, that cost three figures when I bought it for use in a balanced passive preamp. I'd like to use it with the valve amp rebuild but it is only 10K. Is there any reason not to use it in front of the 6SL7 input stage of the va...