HUSS 6v6 layout

[hendrix1983]

Yeah that filter cap talk is way over my head. I'm in the process of cutting out my chassis right now, a pretty narrow long one to fit my can it's gonna be a tight squeeze. 100mm wide 50mm deep and 530mm long. Transformers up one end valves up the other.

[martin manning]

Post some pictures or a drawing of how you are planning to arrange the chassis before you get too far along.

The five large electrolytic capacitors are the power supply filters. Two are on the board (preamp filters), two are in the 32u/32u can (reservoir and screen filters), and the last is the PI (phase inverter) filter. I'm assuming that last one looks just like the two you have mounted on the board. Just attach it to the chassis near the can cap using terminal strips.

[hendrix1983]

I've still got a cup full of caps and resistors that I haven't used yet... I ordered all the parts on the parts list only to find only half of them were to be mounted on the turret board. Among those parts is an unused elec cap 22uf 450v. It's the same as the two mounted on the board, would that be it?

[martin manning]

That's the one.

I'd like more info on your chassis layout. The dimensions you quoted are indeed going to make things very tight. Be aware that the orientation of the transformers to each other is important to minimize inductive coupling and subsequent 50Hz hum in the speaker, and the tube sockets should be positioned close to their connection points on the board to keep the leads short.

[hendrix1983]

I'm probably having to buy another piece of alum box section 30mm wider to accommodate the pots they look like they will foul the turret

[hendrix1983]

Layout

[10thTx]

Just an FYI, a thought for anyone wanting to build a Plexi 6V6 ..............

Hoffman sells a Plexi 50w board using the Hoffman style layout which is remarkably quiet in my experience using it.

There are only a few minor differences between Huss's schematic and Hoffman's Plexi 50w schematic. It would very easy to convert this to Mark Huss's Plexi 6V6.

And there is lots of documentation with schematic, layout and bill of materials here:

http://el34world.com/Hoffman/files/Hoffman_Plexi50.pdf
http://el34world.com/schematics.htm#Hoffman_Plexi_50_

IF one used Hoffman's 18w PT and 18w OT (or a Deluxe Reverb OT 041318)
and used solid state rectification, my guess you'd get around 406v on the
6V6 plates? And Hoffman also sells a blank chassis that is 17" x 6.5" x 2.5".

The only thing to be mindful of (I think) would be to lower the value of some B+ dropping resistors (noted in blue on schematic)

This might be a nice approach for someone looking for a Plexi turret board.

With respect, 10thtx

[martin manning]

I'm probably having to buy another piece of alum box section 30mm wider to accommodate the pots they look like they will foul the turret :(

I think this is definitely going in the right direction, but another 30mm may not make enough room for an easy assembly and wiring process, and you don't want to build something that will be difficult to repair or modify later.

What are the dimensions of the circuit board? I would want the chassis width to be at least equal to the board width plus 3" (75mm) or so, but you are planning something unusual here with respect to the pot mounting. The length you quoted 20.9" (530mm) seems like enough, but depends on the board length.

Can you provide the footprint dimensions for the transformers, choke, and cap can? How will the chassis be mounted in its cabinet? Head or combo style? What does the chassis assembly look like viewed from one end?

[EL34]

I can create some new Plexi documents for 6V6's if there is any interest in using my Plexi turret board.

Does not look like to much work to fip over to 6V6's with the 18 Watt Heyboer tranny set I sell

Looks like a cool project Mark

http://hoffmanamps.com/MyStore/catalog/TurretBoard.htm

[hendrix1983]

Actually I just worked out how I can use this chassis I'm making, by mounting the pots and so on on a seperate piece of corner aluminium section I can make them float 2" above the chassis (mounting the chassis 2" lower in the cab), I could then cut off the top surface that pots are sitting on in the photos to give me full access to the wiring. I can attach the new corner piece via a couple of small bolts to make it serviceable if that makes sense...

[hendrix1983]

Thanks for the suggestions guys but your ideas are way over my head, I just wanna finish what I've got here already.

[Structo]

Is this amp going to be a combo amp or amp head?

If it's for a combo, you could build it like a fender with the tube sockets on the bottom side of the chassis, hanging the tubes from the bottom.
This gives a bit more room for wiring.

[img:800:600]http://www.bazaar-world.com/uploads/amp ... 2800-7.jpg[/img]

[johnnyreece]

Tom, that's a great idea! That would make it so much easier, and tweaks could be made in-cabinet, if necessary.

[hendrix1983]

That hanging idea may just work! Cheers