WAD K5881 Circuit Diagram Needed

[yuming916]

Hi, this is my first post here. I recently got a partially built WAD K5881 without
circuit diagram and the Schematics. I believe this is a push pull built. See the attached pictures. Would you please PM me the relevant circuit diagram and the Schematics, and the instruction manuals, so that I could rebuild it? Any suggestion is welcome.

[John Caswell]

Well therein lies the rub. There were two versions of the 5881 push-pull, one using an EF86 front end and the other using a 7025.
The simplest way to check is to look at the front end valve heater pins.
If ONLY pins 4&5 for the heater wiring are used then it is a Mark I using an EF86. If pins 4&5 are connected together and the heater wiring goes to those two pins and also pin 9 then it is the Mark II using a 7025. Do not confuse the phase splitter valve, an ECC83, with the front end valve look carefully.
Circuit diagram and schematics are two words for the same thing. It is possible that a forum member will have the assembly instructions so ask nicely
If any further help is required, just post here and someone is bound to help you out.

John

[yuming916]

Thank you John.
In fact this kit belongs to a friend of mine and I haven't got this one because of lacking the schematics. From the pictures I got I can judge that this kit is probably Mark II. So I badly need the relevant schematics to rebuild the kit. Also, I have one question to ask, how could one check if those transformers are in good condition before rebuilding?
Sorry, if the front end valve sits in the middle, then it looks like pin4 and 5 are heat pins, then it should be Mark I. I have to confirm it.

[Wieslaw Lipowski]

Here is the older schematic.

[yuming916]

Wiesiek, thank you so much for the diagram and the instructions. Is this a push pull class A circuit?

[Wieslaw Lipowski]

Push-Pull - yes.

I don't think its' an A class amp, though. It's too strong to be in class A with these valves.

[yuming916]

Thanks， Wiesiek。
Can the diagrams be clearer? I can read the instruction without problem. But
to read the numeric values in the diagram correctly is a quite tough job for me.

[Wieslaw Lipowski]

I also have an MkII schematic. Perhaps you will it useful, too.