Mark IV kind of problem

[The Crimson Sunset]

Hi guys, I have a small issue with my mark IV...

I used to switch channels on this amp by using the footcontroller that came with it. When switching channels you always get this little *click* sound, which is normal.
Since yesterday I'm using the FCB1010 footcontroller (behringer) to control both my Mark IV and G-major multiFX at once. So to switch channels I'm now using the external switches. But today when switching to the Lead-channel I noticed a louder *BANG* sound instead of the normal little *click* sound...

Does anyone know what could be causing this ?

Also, since yesterday I noticed that I was getting some microphonic noise when the lead-channel was selected (high pitched tone coming from the amp at higher volumes, even when the volume knob of my guitar was turned down to '0').
Could that also cause this louder *BANG* sound when switching to Lead ??


I hope all this is a little bit understandable. Ask if anything isn't clear.

Thanks in advance !

 

[The Crimson Sunset]

Also, since yesterday I noticed that I was getting some microphonic noise when the lead-channel was selected (high pitched tone coming from the amp at higher volumes, even when the volume knob of my guitar was turned down to '0').
Could that also cause this louder *BANG* sound when switching to Lead ??


I hope all this is a little bit understandable. Ask if anything isn't clear.

Thanks in advance !

I have experienced this high-pitched noise/hiss with my JMP-1 into Mark iv power amp (esp. when the output on the JMP-1 is dimed) when I kill the volume on the guitar by turning down the vol knob on the guitar. this was due to some problem with using the godlyke with dd-20 and wah pedal simultaneously. you can use the g major noise gate to kill that misc. sound...

The manual says that Microphonic Tube can cause that High pitched whistle sound.


Anyone knows what could cause the exploding sound when I switch to lead-channel ? It sounds like you pull the cable out of your guitar without having turned off the amp first.

 

[thindave]

When I had my G-System, I had a similar issue. After a few emails to both T and Mesa it was determined that the switches on the TC gear would not be able to switch all 3 channels on the MkIV since the mark IV needs an isolated ground (I think that's what it was, it was a while ago) and the TC unit shares the ground between it's switches.

So, I had to get an external midi switcher - I got the access cfx-04 - works like a charm.

If you search in the effects forum, you'll probably find my post with the exact info in it...

Cheers...

 

[thindave]

Here's the post that set me straight:


http://forum.grailtone.com/viewtopic.php?t=2426&highlight=gsystem

Basically, if you only switch 2 channels, you'll be ok but if you want to do all 3, you need something like the cfx4...

 

[The Crimson Sunset]

When I had my G-System, I had a similar issue. After a few emails to both T and Mesa it was determined that the switches on the TC gear would not be able to switch all 3 channels on the MkIV since the mark IV needs an isolated ground (I think that's what it was, it was a while ago) and the TC unit shares the ground between it's switches.

So, I had to get an external midi switcher - I got the access cfx-04 - works like a charm.

If you search in the effects forum, you'll probably find my post with the exact info in it...

Cheers...

Thanks for the info !

I also found out how to make the amp default to a certain channel when all the switches are in the off-state. So that way I can switch between the 3 different channels with only the 2 relays from the fcb1010 (no relay switching from the g-major involved anymore).


For those who would like to know how to make the amp default to a certain channel:

You have to have the FU-3 footcontroller plugged in. The channel selector (on the amp) has to have 'FT SW' selected.
Then you set the FU-3 controller on the channel which you want as default channel.

In my case:
FU-3 controller: RHY 2 selected
fcb1010 relay switch 1 controls RHY 1
fcb1010 relay switch 2 controls LEAD

relay 1 = ON & relay 2 = OFF : RHY 1
relay 1 = OFF & relay 2 = ON : LEAD
relay 1 = OFF & relay 2 = OFF : RHY 2