New 30W Valve Monoblock Project.

[SteveTheShadow]

I have a new valve monoblock push-pull pentode project ready to roll.

Two mono block cases and a passive control unit, incorporating a Khozmo stepped attenuator
and a pair of Sowter phase-splitting transformers, which will feed a balanced signal to
the power amps.
Cases are steel, powder-coated in metallic grey.
Once all the transformers and chokes arrive, their end-bells will also go for powder-coating.

I'll detail the build as it progresses.

[slinger]

Now that's what I call a PROPER jigsaw puzzle.

[SteveTheShadow]

Cases have been given oiled walnut front and rear panels:



Next job is to sully the pristine top plates, with a load of bulky heavy transformers and sockets for nasty high voltage
hot glass devices, but that is for another time.

[Fretless]

Looking good, Steve

That plastic sunflower gives 'em a nice rustic touch

[SteveTheShadow]

Have got both chassis' marked out :

[SteveTheShadow]

Here's a rough idea of the mirror image layout of the monoblocks:

[SteveTheShadow]

Chassis' are now punched, drilled and grommeted:

[Colin Wonfor]

lovely work.

[SteveTheShadow]

Thanks Colin.

[SteveTheShadow]

OK...
All the external hardware is now mounted.
I've stuck some valves in to give an idea of the looks.


Valve between the 2xKT88 is the output stage screen grid voltage regulator.
EL34 will be used as the output stage in the final amp.
Valve at dead centre is an E182CC cathode follower that drives the output stage.
Two front valves are Brimar 6BS7 input pentodes.
The pot is an adjuster to set up the two input pentodes so that their screen grid currents can be
balanced. This brings their static operating characteristics into line with each other.