London Power Standard - finished pic and soundclip

[JazzGuitarGimp]

V2, you might try rotating your PT slightly, if you haven't alredy. Toroids are known to be free of external magnetic fields, but they do in fact emit a field at certain points. If I remember correctly, it happens where the leads come out.

Cheers,
Lou

[V2]

V2, you might try rotating your PT slightly, if you haven't alredy. Toroids are known to be free of external magnetic fields, but they do in fact emit a field at certain points. If I remember correctly, it happens where the leads come out.

Cheers,
Lou

Thanks Lou. I will probably try rotating one or other toroids - unfortunately the OT leads are short now, so I will probably have to install a terminal strip or two for jumpers. I'll get Kevin's advice first (he returns to business tomorrow, I think).

-- John

[stephenl]

Sorry John, I haven't had a chance to post pics yet...holidays and kids off from school keeping me busy.

[stephenl]

My transformers are mounted at opposite ends of the chassis.

[V2]

My transformers are mounted at opposite ends of the chassis.

Smart - like the Stephenson amps layout.

[gingertube]

Stephen etc.
Some pics from my build before I loose them.

Cover the chassis with low tack masking tape to protect against digs and scratches during the metal bashing, Drill/Cut hioles for trannies, tube sockets, pots etc and mount them.

[gingertube]

Rear Panel stuff.
The Fixed bias pots and bias test points (2mm banna plugs take a mukltimeter probe), Cathode/Fixed bias Switches and Triode/Pentode Switches for each pair.
Hint: Note teh Switches are teh big mains power type switches which come with and ON/OFF face plate which locks into the switch bush keyway. Don't through those face plates away, stick them on the inside of teh chassis and last thing before tightening the switches down, wipe a bit of 5minute epoxy on those face plate wings to stick them to teh chassis so they act as anti rotation devices.

[gingertube]

Use a bit of C Section Aluminium Off-Cut under the power tranny. This holds the primary wiringterminal block.

[gingertube]

Then mount the Powerscaling board and teh Board which carries heater and B+ fuses and rectifier diodes. Note the Power Scaling MOSFET is bolted to rthe Aluminium C section for a heatsink.

[gingertube]

Trial fit the preamp eyelet card (un loaded) and mock ups (red cardboard for teh power amp board and effects board./

[gingertube]

Fit loaded but unwired preamp and power amp eyelet cards with flying leads attached but unwired - What a MESS.

[gingertube]

The wiring cleans up as you progress.

[gingertube]

Ditto the Power Amp Section.
Note 4 off 22uF in parallel for B+ filtering, add more or take a some out to taste.
Common unbypassed 470R 5 W cathode bias resistor for each output pair, these can be switched out for fixed bias.

[gingertube]

Build a "sexy" Snake Skin Tolex covered box with a 12" Weber Alnico "British Bulldog", connect it up and give it an acceptance test.
All done, happy friend (thats me testing it with his guitar).
Cheers,
Ian

[stephenl]

Here's some as-built pics of mine.

Still waiting on knobs and headshell and I need to assemble and install the LineOut board.