WAD 5881 - resuscitation

[tubehead]

Evening all,
I've got a WAD 5881, the one with toroidal transformers. I've read the EI transformers is the one to have and at one time, there were upgrade kits available, I guess I'm a couple of decades too late for them.

Any how, can any one help me with a copy of the circuit diagram or build manual? Especially anything that has voltage test levels etc

Many thanks

[Richard]

Hi and welcome.
I'm guessing yours is K6L6. What's the full valve line up?

[Greg.]

Welcome to the forum.

Sorry, I can’t find any reference to a K5881 amp fitted with a toroidal transformer. I have build instructions for the Mk1, Mk2 and the PSE versions, all of which use E/I Tx’s. If any of these are helpful to you, please PM me your email address and I will forward to you.

It might be when you answer Richard’s question, we will have a better idea of which amp you have.

If I am simply ignorant of a toroidal version and if anyone has details of it, please can I have a copy?

[Richard]

Yes the valve line up should tell us.

If it's a standard WAD amp and has toroids it will be K6L6 fitted with 5881s (6L6=5881) or an early KEL34 which has been fitted with 5881s.

K6L6 is on the WD CD Nov 1995. I don't remember anyone ever posting about it and haven't seen any build sheets but all the details are in the article.

K6L6 and toroid KEL34 were similar but used different splitter valves (ECF80 vs ECC82). Both used 7 pin 6AU6 first valves whereas the 3 5881 amps used 9 pin first valves.

[Greg.]

Thanks, Richard, got it. Yes, I see it was offered for a very short while as a complete kit for £295. Obviously build instructions must have been available at the time although like you, I’ve not seen them and also cannot remember anyone posting about it on the forum. We’ll have to wait and see what tubehead comes up with.

[tubehead]

Originally Posted by Richard

Hi and welcome.
I'm guessing yours is K6L6. What's the full valve line up?

Thanks for the warm welcome everyone.

I went and checked, they're EL34 not 5881, not sure why I had 5881 on my mind.
It came with 4 x EL34, 2 x 6AU6 and 2 x ECC82.
Definitely toroidal transformers with a single green PCB.

[Greg.]

Ok, so you have the early KeL34 kit. Unfortunately I do not have build instructions for this model. However, I do have them for the later version fitted with E/I output transformers. I have checked the schematic and parts list for your amp as featured in the original DIY Supplement with these later build instructions and they appear to be identical. I can forward these instructions to you if you private message me your email address.

There are three articles in the original DIY supplements that relate to your amp. Oct 98, Nov 98 and June 99. Matthew (WD Owner) can forward a copy of his Platinum CD which include most of the DIY articles over the years including the ones for your amp should you be interested. See link...

http://www.world-designs.co.uk/cd%20rom.htm

[Richard]

Originally Posted by tubehead

Thanks for the warm welcome everyone.

I went and checked, they're EL34 not 5881, not sure why I had 5881 on my mind.
It came with 4 x EL34, 2 x 6AU6 and 2 x ECC82.
Definitely toroidal transformers with a single green PCB.

This was the first WAD amp I built and with hindsight was one of the best

They only did this version with 6CA7 valves (big bottle EL34) for 6 months and I never heard the later EI version so do not know if it was actually better or not.

Anyway, nothing else changed and the build sheets with all test voltages which Greg has are correct. It will be 23 years old now so I'd change all the electrolytic caps if they've not been done and you might want to swap the XLR speaker connectors for binding posts mounted on a small metal plate if you're ok with metalwork

[tubehead]

I'm not so good with wood or metal work, so the Speakon connectors will stay for the time being.

Look forward to getting it going.

[Richard]

Originally Posted by tubehead

I'm not so good with wood or metal work, so the Speakon connectors will stay for the time being.

Look forward to getting it going.

I wonder if yours have already been changed then as mine were definitely XLR as per the build sheets.