Low wattage Plexi

[sliberty]

Have you considered the Marshall JTM1? I found this schematic, but cannot vouch for its accuracy.

[dvnator]

This is a low watt plexi I built and I'm really happy with how it came out. It's basically the Mark Huss 6V6 plexi with 6F4P (ECL84) power tubes.


And here's a clip

http://youtu.be/8CjnO1aKpw0

[vibratoking]

Nice growl. Does it have any cleans? Is that a Lopo 1x12 cab?

[jazbo8]

Have you considered the Marshall JTM1?

+1 JTM1 Demo

[10thTx]

This is a low watt plexi I built and I'm really happy with how it came out. It's basically the Mark Huss 6V6 plexi with 6F4P (ECL84) power tubes.

Nice amp! Thanks for sharing the schematic! with respect, 10thtx

[Littlewyan]

Ah yes the 1 watt Marshalls. Unfortunately they have one too many valves, still an option though if I change chassis. Read a post on them and the first one was designed by a Marshall engineer as a home project!

I might just add an LND150 MOSFET to the P1 to increase drive to the output valve to give it some extra grind. Then I could add LED Clipping on a switch as a boost. I believe a 1 Watt Marshall uses LED Clipping as a boost and I think the engineer said he took it from the 2555.

I'll listen to the audio clip of the Plexi when I get home.

[jazbo8]

Ah yes the 1 watt Marshalls. Unfortunately they have one too many valves, still an option though if I change chassis. Read a post on them and the first one was designed by a Marshall engineer as a home project!

I might just add an LND150 MOSFET to the P1 to increase drive to the output valve to give it some extra grind. Then I could add LED Clipping on a switch as a boost. I believe a 1 Watt Marshall uses LED Clipping as a boost and I think the engineer said he took it from the 2555.

I'll listen to the audio clip of the Plexi when I get home.

It looks like there is enough room for another novel socket on the ampmaker chassis, perhaps they can punch it out for you, or you can drill it yourself. This should give you more flexiblity, a single tube/driver is barely enough to drive the power amp. A source follower is easy to add and save you a tube so why not...

[Littlewyan]

Where on the chassis were you thinking?

Edit: Also it will be two gain stages so it'll have some overdrive, just not on a Trainwreck level. Altho the source follower might help me get closer to a Plexi level of overdrive by lowering the loss of the tonestack. Having a 6V6 in Single End configuration running at 250V means it won't take much to overdrive it.

[jazbo8]

Where on the chassis were you thinking?

Edit: Also it will be two gain stages so it'll have some overdrive, just not on a Trainwreck level. Altho the source follower might help me get closer to a Plexi level of overdrive by lowering the loss of the tonestack. Having a 6V6 in Single End configuration running at 250V means it won't take much to overdrive it.

I think it can fit between the PT and the existing novel socket. You may or may not have enough gain with two gain stages and a source follower buffering the tonestack, but one extra tube will ensure that you do - anyway just provides more flexibility for clipping and tone shaping.

[Littlewyan]

Well I've got board going from top to bottom for the amp itself and a tag board above the PT going up to the board for the PSU. So not enough room really unless I squeeze it in between the current two sockets.

[jazbo8]

Well I've got board going from top to bottom for the amp itself and a tag board above the PT going up to the board for the PSU. So not enough room really unless I squeeze it in between the current two sockets.

I see, but I think that's going to be too tight, take a look at my 3Watter build, I fit the terminal board between the two preamp tubes and the 6SN7, similar layout as your plan to use a vertical board just skinnier. There isn't that many parts, so if you mount the tonestack parts on the back of the pots and/or on a separate terminal strip, everything should fit ok.

3Watter

[Littlewyan]

Now that looks smart.

Well I'll wait until I actually have the chassis in my hands as then I can picture the layout much easier. The P1 (design I'm pretty much using) almost has as much distortion as a Plexi so I think adding a Source Follower will get it there. Obviously I'd rather it be a Cathode Follower as the Source Follower would be transparent, whereas the Cathode Follower would add to the Tone.

[dvnator]

Nice growl. Does it have any cleans? Is that a Lopo 1x12 cab?

Thanks! It has some cleans but it does break up pretty easily. I thought about trying to tweak for more cleans but then I was going for a cranked up plexi OD sound and I think it nails that pretty well. I ended up just leaving it as is.

And , yep, that's a Lopo Line "large" 1x12 open back with a V30.

[Littlewyan]

Just listened to it myself, very nice!

[Cantplay]

Les paul straight in, no pedal.

Cell phone recording, sorry.

John