MesaBoogie ODS Revoicing

[Pacosipulami]

You need to just bite the bullet and use those chops to build a full blown amp now.

you can read my mind, didn't you?

I own an old Fender CBS champ (just the chassis, with PT and OT), since the PT is the same as for the vibro champ, there is room for 2nd 12AX7 tube....
Maybe this could be my boutique-bedroom/recording amp, who knows?

cheers
Paco

[Reeltarded]

A/B at the retirn insert on a loop and use it as the other channels. It sounds so great. More is better if it's really good.

[Pacosipulami]

Welcome aboard, that sounds real nice there. I would not change a thing.

TM

Just had a loooong A/B test....and guess what?

I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc - I should listen to ToneMerc -

damn....the skyliner is great, but the original tonestack had this nice breakup, something I never heard before - shhhh I'm stupid.....going back to the boogie tonestack....

[10thTx]

Edited out.

[Pacosipulami]

@10thTx:

Much thanks for the drawing!

Little correction from my side regarding the OD-stage: I accidently put a 0.001 cap in instead of the 0.015 on the 2nd stage - my bad, but it seems to work. I added a switch to put another 0.0047 cap parallel to it (it had a huge effect on the skyliner that's why I discovered my fault here), with the boogie tonestack there is was just a bit more low end.

Other corrections: cathode caps on V1 are 15uF, there is no 22k grid stopper on V1a and the (former Lead Master) 250k pot (with the switch - originaly LDR4 ) was removed.

I can confirm the rest! The Boogie drawing is very blurry - but I have a better looking MK2C+ (this is almost identical with the StudioPreamp circuit).

At the end - this is not a dumble by specs - this is just a revoiced mesaboogie, and I'm pleased with the results (now finally back on the boogie tonestack - Thanks to TM!)


greetings
Paco

PS: increased the coupler cap of the first OD stage from 0.002 to 0.012 - yeah! there is even more of that nice break up.....

[10thTx]

IF I am understanding your response, ......... this should be closer?

Is that 3.3M & 20p correct off of the V1-6 plate?

Another question ......... is the EQ & FX being used as in the original schematic?

And is the reverb being used as in the original schematic also?


With respect, 10thtx

[Pacosipulami]

yes....closer (the correct value on the coupler on V3a is now 0.012 not 0.0021) it was 0.0022 before....maybe I add a little switch here too - but first I need some food and fresh air - free my mind a bit!

EDIT: ...and put a switch over the 22k resistor below the cathode cap of V3b - sorry!

no mods on the rest of the preamp - correct!

Much thanks again for your help with the schematics -

cheers
Paco

[10thTx]

Paco,

THANK you for your responses!

I've attempted to edit your schematic to reflect your last response.

And as I am understanding you, the rest of the amp (meaning EQ,FX and reverb) are all actively involved as on the original amp? Correct?

With respect, 10thtx

[surfsup]

I think the 22k is to prevent popping...the switch goes across it to shortcircuit "in" the cap, or out. The 22k is always "in". Well that's how I understood it...

[Pacosipulami]

I think the 22k is to prevent popping...the switch goes across it to shortcircuit "in" the cap, or out. The 22k is always "in". Well that's how I understood it...

Yes - this is correct! The switch goes parallel to the 22k resistor - that's what I wanted to say!
English is not my main language - I might inarticulate myself when saying "put a switch over the 22k resistor"

Thank you for your patience!

greetings
Paco

[Pacosipulami]

here is a direct recorded clip - no post processing, not my best playing here, but you get the idea...

http://www.pacocasanovas.ch/mbdumbl.mp3