My WADAR Amp - a few mysteries
 

Well, it must have been the heat on Sunday but I succumbed to a nice-looking "WADAR" amp in the auction. Actually I thought £130 was a very reasonable price for such a piece of Gerry Wells history.

Having got it home I started to look more closely. It does not have the signature "can" over the mains transformer (so no WADAR logo), and there seems to be a new Hammond mains transformer, and a smaller 5V Hammond under the deck, feeding the PEN45s via a dropper on each channel. The old mounting holes for the can are there, with flaked paint so it was probably removed at some point. (Shame it's not still with the amp).

Are these just replacements or would there have been any reason to do this originally? From the very helpful pictures on the front and back cover of the Autumn 2015 Bulletin, there's a lot more under the chassis on mine, and the grounding buses are a lot less tidily laid out. The output and rectifier valves in mine are in a straight line, unlike the Bulletin photo.

I can't find any circuits or specs other than the single page on the BVWM website. Any help gratefully received.

Mine has a single pair of phono input terminals (Gold - very non-Gerry) on the side, but still seems to have the dual input volume controls of the original.
There's an IEC on a plate on the back and the chassis looks deeper front to back. The output transformers are Danbury (correct, I think), connected in simple push-pull (despite ultra-linear taps).

Photos are attached.

So, do I have a (modified) WADAR or possibly a clone?

Any information (previous owners?). Can anyone enlighten me?

Thanks

Jeremy

Re: My WADAR Amp - a few mysteries
 

A couple of photos of the new mains transformer.

Re: My WADAR Amp - a few mysteries
 

I believe these were built by various volunteers at the museum using whatever parts were to hand or available at the time, so some variation in parts used and build quality is inevitable. There may well have been some tweaking of the circuit to suit the parts used too.

Have you tried it yet? If so how well does it work?

Re: My WADAR Amp - a few mysteries
 

Were these built to raise funds for the museum? Why use the the 373BX with a 700v HT sec when the PEN45 is a mains valve @ 250v? Seems odd or am I missing something? Also what is powering the htr's of the 45's? They run on 4v not 5v or 6.3v. This would indicate the Hammond 373BX is a replacement, no?

Andy.

Re: My WADAR Amp - a few mysteries
 

5A @ 6.3V looks a bit underrated for four PEN45s. Between them they'll take 7A @ 4V, then there's the front end valve heaters too. Maybe £130 wasn't quite so cheap?

Maybe change the output valves to 6L6s or even 807s?

Re: My WADAR Amp - a few mysteries
 

The under-chassis mains transformer feeds the Pen45 heaters. It's rated at 5V at 8.6A with small droppers to get 4V. Entirely adequate.
The main transformer only has to deal with the heaters for the rectifier and the smaller valves.

I don't feel like replacing the output valves - it's rather nice as it is!
I am still trying to find time (and space!) to run it up properly.

It does look as if the mains transformer had to be replaced (with TWO others).

Jeremy

Re: My WADAR Amp - a few mysteries
 

:-]

Should pay more attention!

Re: My WADAR Amp - a few mysteries
 

Perhaps a sign that the original transformer wasn't on a big enough core and bobbin?

Transformers would be very reliable beasties if people didn't push the too much.

David

Re: My WADAR Amp - a few mysteries
 

If it is of any help, this is my Wadar amp purchased some years ago before Gerry passed away. At the time it was to be the last one produced but several were built after that date by special request.

There were differences in the transformers.

The sound is absolutely brilliant. The PEN45 is an excellent Mazda valve and gives a good account of itself in the Wadar amps. John.

Re: My WADAR Amp - a few mysteries
 

Hi John,
How very interesting. I suspect still that mine has had a mains transformer transplant.
But comparison of all these variants is instructive.
Your chassis is the same colour and the same deeper profile as mine.
And the two grommets for the original transformer wires are like yours.
However, the underside of mine does not have the lovely neat grounding layout yours has so some delving is in order.
I wonder if the previous owner of mine has any information. (Please PM me if you are that previous owner! Anonymity guaranteed... )

Jeremy

Re: My WADAR Amp - a few mysteries
 

I have a couple of these, one I bought from Gerry back in 2004 when he was making them, a bronze finish. It's always been in regular use and it sounds great. I replaced all the pots with Alps blue velvet though, as they were low quality and crackly at times. And I fitted better quality 4mm speaker terminals.

I also picked up another rather tatty and ill treated one on ebay some time back at a similar price to yours. It has quite a brittle and hard sound to it and excessive mains hum and as I remember the HT on this second one is a little high for the Pen 45's. I must get it out and have a fiddle and compare the two...