18Watt.com

I have just finished another 18watt lite built out of bits. An old scrap oscilloscope provided the valve bases, chassis and hardware. An old signal generator provided the Mullard EZ81, Brimar EL84s and the 300V, 6.3V transformer.
A welcome swop with a well known 18W correspondent provided a WEM 15 watt output transformer and hang on, I haven't spent any money yet ? oh yes the Mullard ECC83s cost me £4 each in a radio ham shop. The most expensive bit was the gold foil for ink jet printers from the stationers.
I fired it up today, didn't work first time, two missing links. Then it fired up, sounded like a bee trapped in a megaphone. Usual problem found 820K instead of an 820 ohm on the board. Wife said, sounds like the White Stripes ? I don't know if that's a good or a bad thing ?
Anyway, to the point of this drivel. I am going to use it as a test bed for different components and I intend to mount it ala Selmer style sitting in the bottom of a combo. What I need to know is has anybody got experience of the best sort of wiring to the potentiometers and jack socket ? which will be a couple of feet away from the Amp itself.
Pictures of the ugly test bed at StevesUK in the gallery.

Hi,


Old amps wired this way pretty much had long wires going from the jacks and pots.

I guess it wont hurt to use shielded wire, grounded on chassis. Or maybe both, on the top panel as well?

Thanks!

Nik

PS - 4 quids for Mullard ECC83? Man, I am definitely gonna ask my lil bro to do more shopping there in the UK!!

stevesuk wrote:the Mullard ECC83s cost me £4 each in a radio ham shop

I want the address! Purely, for general interest in ham radio of course....

Hey Phil,

Can you do a little Ham Radio Research for me as well?

£4!!!!!!!!!!! for an ECC83???????????

I only need a few of them please, pretty please!!!

No seriously . . . I need those . . . not kidding

Only two were new, the others were tested as new. I have 15 amplifiers so I have an insatiable appetite for ECC83s even used.. Sorry

Back to my remote control panel, I was of the opinion that if you earthed (grounded) a screened cable at both ends it introduced an earth(ground) loop which made the hum worse.......anybody ? If it is earthed at the amp end only, I can't see how the distance between the panel, with two pots, the input jack and 110V indicator (wired on the opposite side of the panel) and the amp itself can induce hum interference.