5U4G substitution

[bob orbell]

Reading all this with interest, but this is a forum and a modification, as has been mentioned, most do and will respect HV valve equipment, with regard to Matthew, he does not sell this amp. as a kit with the modification in question as a product, so should not be responsible for any issues arising, but as Greg has said, a warning in the FAQ should be added. Bob

[snowman_al]

Richard, all,
I agree the modification is excellent. I see it as well implemented and a genuine cost saving.

I would hope that anyone who undertakes it has a good understanding of the risks it introduces, but from experience know some DIYs just follow the plans and pictures and have no understanding of how it works. And therefore are oblivious to the possible risks. As would 3rd parties be.

It just seemed sensible to point out in the instructions that there are / will be high voltages above the chassis following the mod. And warn them what not to do and why. That informs the people who do not know and reminds those who do. That was my suggestion in post #19...


No one 'deserves' to get a 400+ volt ‘belt’. It hurts and can leave a serious burn or worse. Alan

[Richard]

Originally Posted by snowman_al

Richard, all,
I agree the modification is excellent. I see it as well implemented and a genuine cost saving.

I would hope that anyone who undertakes it has a good understanding of the risks it introduces, but from experience know some DIYs just follow the plans and pictures and have no understanding of how it works. And therefore are oblivious to the possible risks. As would 3rd parties be.

It just seemed sensible to point out in the instructions that there are / will be high voltages above the chassis following the mod. And warn them what not to do and why. That informs the people who do not know and reminds those who do. That was my suggestion in post #19...


No one 'deserves' to get a 400+ volt ‘belt’. It hurts and can leave a serious burn or worse. Alan

Thanks Alan, I agree completely and have added a Safety Notice at the start of the article. Perhaps you and others familiar with these valves will take a look and suggest anything I've missed. I've tried to be relevant to these particular valves rather than cover all the dangers of our hobby. Thanks also for the updated circuit. I've also added voltages so a builder can see what's on the connectors

[Richard]

Updated article,

http://www.world-designs.co.uk/forum...ead.php?t=7971

Updated circuit,

http://www.world-designs.co.uk/forum...3&d=1607772909

[colin.hepburn]

Hi all
Yep, when I did the 6D22S upgrade in my JE. Labs single-ended Amp I was also talked through it by our Dr. John Caswell and Richard thank guys it’s the same circuit like the one described here. but using an RC. CL.CL.RC.filter supply. And I Can say with confidence it's reliably as well I've never had any fails with these I remember buying a stash of 12 valves at the time as backups and I am still using the first pair I fitted in the amp today. some 7/8 years later a recommended upgrade for all the amp suggested here'

The only error I made at the time was to use the top Cap for the 807valve which were to lose and needed the contact nipped up but these were replaced with the correct sized ¼ inch type here’s a link for the top cap I have
https://www.ebay.co.uk/itm/10X-1-4-g....c100227.m3827