Faulty KEL84

[Bizzie]

I've succumbed to a moment of madness spurred on by the reports of how good the KEL84 is and bought a faulty one off ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=009

I'll check that everything has been done to spec for a start but any ideas where to look for the fault would be appreciated as it not completely dead then I don't think that there can be too much wrong with it and think that it will probably be a silly wiring mistake.

[Mike G]

Originally Posted by Bizzie

I've succumbed to a moment of madness spurred on by the reports of how good the KEL84 is and bought a faulty one off ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=009

I'll check that everything has been done to spec for a start but any ideas where to look for the fault would be appreciated as it not completely dead then I don't think that there can be too much wrong with it and think that it will probably be a silly wiring mistake.

Hi Bizzie,

Depending on the age of this amp, it could be the earlier type where some components in particular the valve bases required soldering on both sides of the PCB. I forgot to do this on mine, which then had similar problems, to those outlined by the seller.

It's a pain taking the PCB out to check, but might be worth a look, if you cannot find anything else.

Regards

Mike.

[Bizzie]

Thanks Mike

Thats the sort of thing I reckon it could be, it does look quite an old one as it doesn't have the chrome style knob's.

He says that he will be posting it on monday so I should have it by the end of the week hopefully so I'll let you know.

[david counter]

Originally Posted by Bizzie

Thanks Mike

Thats the sort of thing I reckon it could be, it does look quite an old one as it doesn't have the chrome style knob's.
.

actually it looks pretty late to me, early ones didn't have chrome tx covers,

didn't they have problems getting knobs just before WAD went under?,

anyway a nice project for not a lot of money, well done,

[Bizzie]

Thanks Dave I stand corrected, I think that they had trouble getting everything just before WAD went under. It took me six months and loads of phone calls to get all the bits from them for my PreII PhonoII PSUII combo and even then the front panels don't quite match.

I thought that it would be Ideal for a bedroom system to use while the soaps are on telly, should be better than using headphones, only problem is the only small speakers I have are Mission 780SE's that are not an easy drive so I dont know if it will cope (could be an exuse to make some speakers).

[david counter]

it might surprise you with the Missions, I ran mine for a long time with some 773es

[Bizzie]

You might be right It is only a small room so doesn't take a lot to fill with sound but my Beam Echo mono block clones struggle a bit in the main listening room with them and they're supposed to be 35wpc.

Incidently anyone got any Idea why smilies don't work for me any more? they use to but nothing happens when I click on them now, I'll have to be carefull what I say on here don't want anything taken the wrong way.

[Baggy Trousers]

[quote=Bizzie;57546]You might be right It is only a small room so doesn't take a lot to fill with sound but my Beam Echo mono block clones struggle a bit in the main listening room with them and they're supposed to be 35wpc.

I'm not sure where the 35W comes from but I used to own the Avantic original (bought from Andre Rahmer himself) and this was nothing like 35W output. I think it was closer to the 20W of the Mullard schematic from which it was derived but it's difficult to remember all this stuff after nearly fifty years!

[Bizzie]

Yeah I know but that was the figure that was quoted on the web site as the original circuit was "enhanced" for higher power, and I always use mine in triode mode anyway which is supposed to be 16wpc.

But regardless of the real power of the mono blocks they are more than the 10wpc of the KEL84 hence my thought that it may struggle a bit but we'll see after I get it and get it working properly.

[david counter]

Originally Posted by Bizzie

But regardless of the real power of the mono blocks they are more than the 10wpc of the KEL84 hence my thought that it may struggle a bit but we'll see after I get it and get it working properly.

I thought a Kel84 was 15 watts