Is my Mark Iv Sick?

[deuce42]

Hi all - I am a new poster here and look forward to learning a lot from you guys.

I have a Mark IV Version A combo which seems to have a volume issue on the lead channel when I engage effects and really confuses me.

I have a muti effects pedal plugged into the loop. When I engage channels 1 and 2 with the loop on or off, the volume is the same. With the multi effect unit in the loop on channels 1 and 2 there is also no change to volume, just the addition of the effect to the sound. But with the lead channel, once I engage the loop switch to bring in the effects ,the volume is infinitely lower. As soon as I take the loop switch off and use just the dry lead channel sound, the volume is loud again.

It seems strange to me that the volume with exactly the same effect patch is fine for channels 1 and 2. I thought maybe it was a problem with the lead channel and tried to insert a small patch cable between the send and return jacks and hit the loop switch to see if the volume would be effected but it isn't. As I say, its just the loudness of the lead channel when the same effect that was applied to channels 1 or 2 is applied to the lead channel.

Could anyone offer me advice or wisdom?


Cheers

 

[zodiac272]

hey welcome,

have you tried swapping out V3 for a different preamp tube? first area i would look at are tubes.

got pics of that baby?

scott

 

[deuce42]

Ha perfect thanks. Changed my V3 and all functioning fine now and she's a lot quieter too!

Will take some photos and post.

Thanks once again Scott

 

[zodiac272]

nice! I'm glad that worked! depending on how old the other tubes are, they may be due for a change as well


scott