Boogie Mark chassis material?

[doc]

I think one of the Grail tones for me has to be the Santana Moonflower live version of Europa. I understand that was a Yamaha into a Mesa Boogie Mark I. Did those Mesas have steel or aluminum chassis?
If anybody wants to volunteer the major differences in circuit that makes a difference between a Dumble and a Mark I overdrive channel, that would be of interest as well.

[tmac]

Steel chassis.

[darkbluemurder]

If anybody wants to volunteer the major differences in circuit that makes a difference between a Dumble and a Mark I overdrive channel, that would be of interest as well.

The major difference is that the Mark I has two gain stages before the tone stack whereas Dumbles and Mark II-IV have only one gain stage before the tone stack. If you plug in the Mark I's input #1 the signal chain is

Stage 1 - Volume 1 - Stage 2 - Tone stack - Volume 2 - Stage 3 - Stage 4 (Reverb mix) - Master Volume - Power amp

The Dumble in OD mode would look like

Stage 1 - Tone Stack - Volume - Stage 2 - OD input trimmer - Stage 3 - Gain (or Ratio) - Stage 4 - OD Level - Master Volume - Power amp

The next most apparent difference is that most Dumbles did not have reverb. The Boogie Mark series amps have a reverb circuit that is similar to Fender and uses an additional stage (= the reverb mixer) which is in the signal path even if no reverb is used. This affects tone, too.

Hope that helps.
Cheers Stephan

[doc]

Thanks guys, that helps a lot. I may try to mod my Rivera Fender Concert to be closer to a Mark I circuit, and knowing that the chassis on both is steel is reassuring.