Operation of an EL/32W

[Richard]

Hi Pete, yes agreed with the others.
It's WAD Kit34, nicely built, but trace those toggle switch wires carefully and see what they're for.
Those miniture toggles may not be rated for 500V if they are UL/Triode change over switches but the wires don't seem to go where I'd expect.
The amp is UL as standard and pretty sweet anyway (I had one 20 years ago, they came out in 2001).
I can send the build sheets if you send a PM with your direct email address.

[orbscure]

Many thanks again chaps... unfortunately, its not currently my amp to modify, but I'll bear your collective thoughts in mind should I pull the trigger or pass them on should I pass... I'll also take another look at the toggle switches and see what their connected to... and a PM is on the way Richard

[Richard]

Hi Pete, info emailed. Good luck and let us know how it goes!

[orbscure]

Many thanks Rich... email received with thanks my friend...

Just to add, before I headed out for the day earlier, I had the bottom off the amp again and have uploaded a further three images via the link below showing the toggle switch arrangement and wiring. From tracing the twisted wires best I can away from each switch (brown/blue/orange) it appears that the blue and brown eventually connect to the positive speaker terminals whilst the pair of orange wires head in the same direction but are unconnected.

https://www.dropbox.com/sh/dw3j3lrz1...iSUFCKssa?dl=0

I've also uploaded a quick drawing showing the switch wiring in the hope that it may throw some light on what these toggle switches actually do...

[Richard]

Good pics but I can't see where the OP TX purple wires connect. Usually the green goes to Black post and the purple to Red post. I would snip those 2 white cable ties and seaparate the wires for a good look...
Also, are the speakers posts bi-wire (ie both the same for each channel) or are they actually differently wired? As I recall WAD amps of this era had just one pair per channel and 2 (bi-wired) came later with WDVA88.

[A Stuart]

As best I can work out this is where the wiring takes us in each switch combination. By "Down", I mean toggle position down so centre tags connected to top tags.

[orbscure]

Thanks again chaps...

Originally Posted by Richard

Good pics but I can't see where the OP TX purple wires connect. Usually the green goes to Black post and the purple to Red post. I would snip those 2 white cable ties and separate the wires for a good look...
Also, are the speakers posts bi-wire (ie both the same for each channel) or are they actually differently wired? As I recall WAD amps of this era had just one pair per channel and 2 (bi-wired) came later with WDVA88.

Having cut a couple of the cable ties off, I can now confirm that:

1. the two orange wires from the toggle switches are actually connected to purple wires from the left and right 7508 transformers. Also, a thin red wire is connected to each of these orange wires, as well as to a single left and right negative speaker terminals.

2. each pair of negative terminals are hard wire bridged

3. a green wire from the left and right 7508 transformer are connected to a single left and right negative speaker terminal

Hope that makes sense, I've added a couple more photos via the link above with the cable ties removed...

[Richard]

I was starting to think the switch might act upon the secondary (purple). One pair of speaker posts may be wired for Ultra linear (standard) and the other wired for Triode. If so you’d change speaker wire connections to the other pair of terminals and throw the switches but this is all guesswork at a distance.

“Also, a thin red wire is connected to each of these orange wires, as well as to a single left and right negative speaker terminals.” Could this be the global feedback wire connected to the red post of the UL terminals and not for triode? Check the switch connections and any components against the original circuit and draw out one channel fully - or just remove the switches and rewire as original.

In Kit34 g3 is already connected to k (pin1 to 8) so the usual way to switch from UL to triode would be to have the switch acting on the primary pink and grey wires (between 100R and TX) connecting g2 (pin4) via its 100R to the anode (pin3) for triode operation and then switching back for UL. There may be other checks and adjustments needed and it may be that neither mode would be optimum. Without further switching that would leave global feedback on both settings. Feedback affects sensitivity, distortion and maybe the sound so possibly that's why the builder chose to do it this way.

[bob orbell]

I completely agree with the last words of Richards second paragraph _ or just remove the switches and rewire as original. bob

[orbscure]

Thanks again chaps... once I've done a few chores this morning, I'll dig out a pair of cheap speakers, have a play and see what does what and how she sounds. As I mentioned earlier, I don't currently own her, so she'll have to remain as is for the time being... if I decide to pull the trigger though, I can decide then if any additional work is required...