kel84 upgrade

[bearded fiddler]

Hi Greg,

I'd like to add that I went back to the old signal wiring (blue Soniqs shielded twin core). This brought me very close to the old sound I loved so much, but with some added benefit due to the caps. Now I can hear what they really do.

Jan

[Greg.]

Hi Jan,

That is good news and clearly you have a good result from the cap upgrade. I like silver plated copper wire in my systems but I'm careful not to use it everywhere as it can be too much and cause a bright sound.

Best wishes,

Greg

[A.N. Beal]

Dear Folks,

I've come rather late to this, building a KEL84XL this summer. I found the XL modifications rather are a two-edged sword. With the Schottky diodes the ECF80 heater voltages were too high at over 7 volts but the very helpful Matthew Snell at WD sent me the resistors and capacitor for the pi-filter modification. We worked out a reasonably tidy way to do this on the circuit board and this corrected the heater voltages.

The sound was bright and clear but I found treble rather too prominent, which spoiled the sound. This didn't get better with burning in. Suspecting the white silver-plated XL signal cable, I asked Matthew for some standard blue cable. This tamed the apparent treble peak and made the sound much better balanced. I can imagine that for a dull-sounding system the white cable could be just what it needs but for mine the blue cable gave much better sonic balance.

The sound was 'nearly there' but there was still a slight residual 'edge'. I wondered if this might be to do with the valves supplied (AEL ECF80 and Golden Dragon EL84), so I bought from Watford Valves a NOS pair of RCA ECF80s (made for RCA by Siemens, so possibly similar to Telfunken?). I have just swapped these in. The result is quite a big improvement - good clarity, low colouration and a treble which is less prominent and also smoother but also more finely detailed. I definitely recommend these valves. The KEL84 is starting to sound very nice and 'right'.

Interesting ...

Alasdair