18w JCM800

[M Fowler]

Mikey that is a stick on zip tye holder available at local hardware store.

[Ken Moon]

Mark,

I've thought about doing an 18watt version of the JMP/JCM, but I was worried that there would be way too much signal swing from the PI to the more sensitive EL84 power tubes.

Were any of your mods intended to lower the PI output signal swing?

Also, do you remember what the B+ going to the cathode follower is on your amp? The CF seems to need at least a 300V B+ to get the signature JMP/JCM crunch, in my experience, and the higher the better. Any lower than 300V and the CF doesn't seem to have any effect on the tone.

Nice amp! Now I'm itching to try one!

[Reeltarded]

Damn Ken. You are only a coupleish hours away from me. Mark is way up north.

Use 6V6s in these latitudes. haha

[roberto]

Were any of your mods intended to lower the PI output signal swing?

I see mainly two ways: change the PI values to the 18W ones, or use the std PI values and a fixed LarMar mod after the PI.

in my experience, and the higher the better. Any lower than 300V and the CF doesn't seem to have any effect on the tone.

My experience is the opposite. I use high voltages on my designs, but for Marshall tones I like the 250-280V range on the preamp.

[M Fowler]

I had to increase voltage to get the amp where I wanted it to sing.

I can check voltages tomorrow.

Mark