Weezer mkI fx loop mod

[Lou Kash]

Hello,

I was wondering if anyone here could help me in my search for Weezer tone. For some background: Rivers Cuomo on the blue album used a MkI head into a vertical Marshall 4×12. To my understanding the amp was a 77 or 78 mkI with the push/pull boost and bright, 60 watt version, no reverb, no graphic eq. The only mod was an FX loop that made the master on the front a send and added a small knob on the back as a return. The mod was supposed to have been done by Mike Bendinelli in the late 80s or early 90s. I have been very interested in trying to figure out what this mod was as, to my understanding, it is a big part of the sound of the amp. Is anyone familiar with this mod? Is it the same as the FX loop used on other models? Possibly the one on the reissue? Or is it its own to thing for retrofitting fx loops to non FX loop boogies? (I've heard it was done to some other MKI and MKIIa) any thoughts or info is appreciated.

Thanks!

 

[Joey1970]

Had a 60/100 Mark I with this mod years ago. It helped with the volume issue and worked very well with an old Boss OD-1 overdrive pedal out front.

 

[mark1406]

Handy info

Have a look at a few circuits, the reissue has a send and return jacks.

Regards

Mark

 

[Joey1970]

The FX-loop mod allowed you to turn the front panel Master Volume control WAY UP, and the Post FX LEVEL rear control to dial back the insane decibels that would kill small animals. NOT the same as the re-issue even if they both had effects loops. That 1978 modded Mark I was a beast. But as all Mark I amps are, the louder you played it, the better it sounded.

 

[mark1406]

Hello,

I was wondering if anyone here could help me in my search for Weezer tone. For some background: Rivers Cuomo on the blue album used a MkI head into a vertical Marshall 4×12. To my understanding the amp was a 77 or 78 mkI with the push/pull boost and bright, 60 watt version, no reverb, no graphic eq. The only mod was an FX loop that made the master on the front a send and added a small knob on the back as a return. The mod was supposed to have been done by Mike Bendinelli in the late 80s or early 90s. I have been very interested in trying to figure out what this mod was as, to my understanding, it is a big part of the sound of the amp. Is anyone familiar with this mod? Is it the same as the FX loop used on other models? Possibly the one on the reissue? Or is it its own to thing for retrofitting fx loops to non FX loop boogies? (I've heard it was done to some other MKI and MKIIa) any thoughts or info is appreciated.

Thanks!

I think the loop will be a cathode follower on the send side and an anode/plate follower on the other side.

Valve Wizard version

Dumbleator loop

Regards

Mark

 

[mark1406]

I received a reply from Mike Bendinelli and the loops he installed were similar to the Dumbleator style loops.

There were no loops in place on the reverb section of the amp on amps with no reverb.

I hope that is of some assistance.

Regards

Mark Abbott