MK-IV FINALLY landed :) Question re. channel switching pops

[Itsik]

My search is over
I finally got my hands on one of the TWO/THREE MK-IV's here in Israel
It's a black tolex short combo with an EV speaker and on top of that, the guy threw in a home made open back cab, surprisingly well built to match the looks of the boogie, with a Celescion inside.
I'll post pics a bit later ...
Here's a question that I know has been asked before and I'm just wondering if any one has actually been able to solve it ...
I have a G-System. I've connected the relays with Y cables and the channel switching works like a charm. The only problem is that loud pop you get when you switch channels.
Here's what I noticed, the pop accures ONLY when switching from the R1 to either of the other two channels (from a clean channel to a drive channel), when you switch from R2 or the Lead to R1, switching is dead silent. When you switch betwin R2 and the Lead or vice versa, again, the switching is dead silent.
My setup is Relay A --> R1 & R2, Relay B --> LEAD & EQ, that means it has nothing to do with changing relays.
Here's the most interesting thing. I've switched the relay connections - meaning, I reversed the L & R cables of each relay. Guess what, now when you go from R1 to any of the other two channels, the switching is dead silent ... BUT ... when you switch from either LEAD or R2 to R1 there's that pop again.
Any ideas any one?

Thnx
Itsik

 

[Elpelotero]

not sure about that one...I would recommend editing the title of your thread to a question about popping so people with experience in the matter can chime in.

BTW, congrats! That sounds like an awesome rare find!

 

[Itsik]

Thnx for the congrats and the good advice.

The thread topic has been edited ...
It is indeed a very rear find ...

 

[thindave]

Hi, I had the same issue - when using the g-system, you can only switch between 2 channels safely (using the built-in relays). This is due to the switch grounding (I forget the particulars...). If you search the Effects section of the forum, you'll find the details.

I use an Axess Electronics CFX4 connected to the G-System via midi to switch the MarkIV - works like a charm, although you do have to shell out another $150 or so...

 

[jappy]

I get popping when I use the channel selector on the back of the amp!

 

[Itsik]

Thnx for the replays guys

Thindave,
I've had a long conversation over the phone with Mesa Boogie.
According to them, you can safely use the G-System relays to switch all channels on the MK-IV.
There is indeed a problem with this kind of channel switching and common grounding, but this exists only in certain newer amps which actually use a differant method of switching.
The list of those amps can be found on the TC Electronics support page.
Note that this is comming directly from Mesa Boogie.

Jappy.
According to the guys at MB, the switching cerquit has certain components (diodes I think but I don't remember exactly what they said...) that are responsible to mute the signal momentarily when switching channels. If you have those pops using the amps own foot switch, there's probebly some thing wrong with the switching cerquit. I'd try to check it with them.

Any one else has any ideas ?

Thnx
Itsik

 

[thindave]

Hmm, that's not what I was told a while back. I have a MarkIVa, so maybe thta's why, but I was told(I think - it's been a while) that since the g-system uses a common ground, it won't work properly on my amp.

 

[Itsik]

Finally took some pics of the beast

 

[Elpelotero]

that looks sick!!!

 

[MusicManJP6]

Nice setup. Do you like the G-system? I've been dying to try one out...

 

[Itsik]

Thnx.

MusicManJP6, the G-System, in my view, is the ultimate system.
The transparecy of the sound, the quality of effects,the controll options, the ability to integrate pedals into the system, all of this makes this the
best choice in my eyes.
The biggest disadvantage of this thing is it's price tag which is very high.
But if are a working musician and/or you can afford it, I think this is the best choice you can make.
I'm have an average of 2-5 paying gigs a week, and this thing simply works, whether it's with my own rig or connected to the venue's rig (providing it's decent of course :wink: ...).