Complete MARKIIb Options

[domglop78]

hello
would like to use all the possibilities offered by my mark IIB (export version 60/100w equalizer and reverb). and as I do not have the wiring corresponding to each jack I would like your help ... I posted 2 photos corresponding to the chassis of the amp. I followed the wiring of each jack by color to know according to the plan their functionality...
is the result good? can I connect the 3 jacks?

Premiere (preamp out/pwramp in)?
I think the jack should be standard ... to be able to connect the preamp output to the input of another mesa. (so just use the preamp as a booster)

second (Equalizer and Gain Boost)?
the jack must be stereo to be able to activate either on off the equalizer or the boost.

third (fw reverb?)
RCA jack for the commissioning or not of the reverb

do you have a wiring diagram for connecting jack outputs?
with signaling leds? no leds?

I saw that there were footswitch pedals available for the mark2b but I have a question:
the double footswitch indicates EQ & REV??
but when I look at my chassis it does not match...!!!
thank you for your help....i need it

dom


pics about Mark2b:
https://imgur.com/gallery/cFtw86w

 

[bsriaudio]

A IIb should have the loop on the back panel. The jack on the underside is for the EQ/Reverb switch, which is the 2-button TRS switch. The channel footswitch connects to the front of the amp.

 

[domglop78]

hello
thx for your answer...
i undestand but when a look at the schematic i think the stereo footswitch are not for the reverb ....
the connection for reverb exist with RCA .... right ?
i post the schematic in my comment.....i have 3 jacks ( one mono , one stereo ,and one rca) I think it is for footswitch all)

thx for your answer

dom

 

[b00g13mk2B]

This thread my help. Post is Footswitch for MARK2 B and poster was domglop78

http://www.forum.grailtone.com/viewtopic.php?f=27&t=85481

Sounds like the functions vary depending on what option are installed - reverb, EQ - or as a customer requested.

My Mark IIA has an RCA jack underneath that switches the Gain Boost found on Master I. No reverb or EQ on my amp, a plain Super 60

 

[dalepsmith]

My IIa super 60 has reverb, no eq. The rca jacks on mine go to/from the reverb tank.
There is another 1/4 inch jack underneath for the reverb foot switch. Never used or even tried it.

The schematic hints that this is (or can be) a stereo jack and the other signal can be for switching the "gain boost". That didn't seem to be hooked up on mine. (I've since changed the gain boost pull switch to switch in a different cap in the lead circuit to tighten up the bass instead of disabling the tone controls)

 

[b00g13mk2B]

You can email Customer Support. They may be able to shed light on your amp. Provide what features and maybe pics of front panel, back panel and underneath the chassis