Mark III channel difference

[Sixtiesvibe]

Just a question for all the Mark III owners.

I am noticing that there is a difference on channel 3 depending on the switch position of the channel 1/2 footswitch position. This may not be news to some owners but this is my 1st Mark series, It's a Black dot model.

If I have channel 1 selected and go to channel 3 its a good lead tone, a bit more clear and open. If I am in channel 2 mode and change to channel 3 on that foot switch then channel 3 (lead) has more grit and heavier tonality wise and has a bit more dirt on the sound. Its not a night and day difference but there is a noticeable difference.

Is this normal to see this difference in where channel 3 is being fed from?

Thanks for any info on this.

 

[darkbluemurder]

My purple stripe does this as well. It is a subtle difference but it is there. I am not sure what causes it as I have not yet looked at the mode switching in detail. I suspect that the cathode cap on V2a which is put in for the R2 mode to achieve the crunch gain levels stays connected in the lead mode when R2 mode is selected but I could be wrong. If I am correct this would explain exactly what you are hearing.

Cheers Stephan

 

[UpNorthMark]

My blue stripe does the same, when R2 is engaged along with lead it adds a bit more drive it seems.

 

[s-fresh]

It's because these aren't really channels, if they were you wouldn't be able to have more than one active at a time. It's more like multiple gain stages that can be individually activated.

So the options are:

• Rhythm 1 (always on)
• Rhythm 1 + Rhythm 2
• Rhythm 1 + Lead
• Rhythm 1 + Rhythm 2 + Lead

You'll notice the Mark III manual doesn't mention the word channel anywhere:
http://mesaboogie.com/media/User%20Manuals/Mark%20III.pdf

 

[darkbluemurder]

Fully agree - that's why I always speak of "modes" instead of "channels".

Cheers Stephan