Why no valve rectification with WD88VA?

[nightbird]

I have not read Hi-Fi world (or any Hi-Fi mags for that matter) for about a year now. I was thinking of transforming my unreliable Beard P100 mk2 into a Kat6550 if I could get a suitable transformer, as I thought the valve regulation would be easier on the valves. Sadly (or maybe luckily, who knows) that kit is no longer available and the WD88VA uses no valve rectification. I will need to get hold of the articles/backnumbers to catch up on this, but was there a problem with the 6550 amp? Also have all discontinued amp kits disappeared because of reliability? or have they been upgraded?

[andrew ivimey]

Doesn't your Beard use el84s? If so, if you want to change it, all that will be left is the chassis!


World Designs is not WAD, so all those WAD designs have gone as kits. The KEL84 stayed probably becasue WD bought up old stock, is a spiffing little amp and kept things ticking over until new amplifiers could be offered; which they now are.

Solid state rectification isn't bad, just different, and sure, a slow start GZ34 would be marginally easier on the valves, but not necessary.

Couldn't you get your Beard serviced? I had a Beard once (the wife made me shave :-). But it was excellent.

[nightbird]

Thanks for replying. The P100 mk2 uses two KT88's and an ecc 83, 81, & 82, per channel with hefty seperate power and output transformers. It has 550 volts on the HT and has been a pain since I bought it, although it sounds good (not as tonally satisfying as my Leak stereo 60) and has great seperation.
I thought I could make room for a 5U4G per side as Kat 6550 used only one driver, a triode/pentode. Also a tag board would be better than the existing PCB. The problem though is that the mains transformers lack a tap for the regulators, otherwise I think it would have been a feasible project.
I still have the suppliment with the schematic for the Kat88 somewhere and will have a look at that now.

[andrew ivimey]

And I thought old Bill only used el84s - okay! I had a superb Beard el84 monster, once.

I still think your amp should remain as is; get it serviced, or even sell it on.

Start afresh, the trouble with trying to make this amp something else (and the trouble with PCB kinda amps is that after lots of messing and compromising you could end up with nothing but lots of bits which are no good to any one.

who needs valve rectification; it looks good.full stop. But you need an amp that works.

[Gerry]

The P100 is a great amp. I have the P101, big brther to it. I'd be very reluctant to try and change it to anything else, as Andrew says....pcb design etc etc.
Chris Found, CF Media has all the Beard info. He used to work with Bill and designed a couple fo the amps. He still services them, so if a problem with it contact him: chris@beardaudio.com http://www.beardaudio.com

I did try thr Kat6550 which Mark at WAD let me run in for him before the Bristol show a few years ago. It was a lovely amp. I was trying it with KT88s.
The new WD looks to be very interesting too.

Regards

[NealG]

The new WD88VA is a belter of an amp.

At the Heathrow Show it even moved some die hard SE fans to comment on how good it was!!!

Dump the Beard get the WD88VA.

[Darren D]

Yet it did didn't !!!

I was so impressed with it I now have to think hard about wanting one for myself. It really was that exceptional !!!

Same goes for the speakers, I was impressed by the bass and the way it was so well controlled.
I had the chance over the few days I was there to have a listen to many of the rooms and there was only one other that made me go back for another listen. Twice infact. But the price put me off a little bit.

£35,000 for the power amp and then you needed the power supply, no, I didn't ask...!!
It wasn't better than WD's just different in some aspects.
That 88 amp is going to create quite a fuss...

[Paul Barker]

I agree.

[nightbird]

OK, Some interesting opinions here. Out of interest, what were the speakers used with the WD88VA? I use ESL63 which recently replaced my KLS3 mk1's.

This new amp sounds good, but why did Andy Grove (am I right in thinking it's one of his) go back to diodes and is it any different to the old Kit/Kat88?
I really must get a schematic for this beast.
Oh and believe me, this P100 has ****ed me off for the last time. I know I should have given it to Chris Found but it had already been modded & too much spent on it. Nice transformers though. Great forum too......

[NickG]

As a ex kit6550 owner, I am not sure (other than slow start) what the valve rect did for the amp. In a SET I would argue to the death for a valve rect choke input supply. But for a class A PP, not so sure its worth the extra hassle.

And yes, its a entirly different circuit to the kit88