Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => PC Express and JSchem - Schematics and Layout diagrams => Topic started by: tubenit on December 31, 2010, 07:07:45 am

Title: Other D'Mars & Plexi Overdrive ideas
Post by: tubenit on December 31, 2010, 07:07:45 am

Just a couple of ideas of using a Marshall type amp with a Dumblish type overdrive.

Tubenit

Title: Re: Plexi Overdrive
Post by: tubenit on December 15, 2011, 09:00:06 am

Some more ideas here for an OD using a gain stage with cathode follower and tone stack.  Just ideas ...........  amp has not been built

CHECK for errors!

Tubenit

Title: D'Mars Special w/ FX on board
Post by: tubenit on July 27, 2012, 06:02:09 am

Some more idea that I think might be cool.   I included an FET idea also that could be integrated into this amp design.

With respect, Tubenit

Title: D'Mars ODS parallel board
Post by: tubenit on July 29, 2012, 02:41:16 pm

OK, I have actually built this one. Sounds great.  Nice rich harmonics.  Sweet musical tone.  Clean channcel is superb. When chording, you can hear every note very clearly.  

The OD channel can be dialed into getting a harmonically rich tone with some chime and cleaner ................. OR  the Dumblish vowel tone that has some blooming feature to it with the notes swelling and opening up.

An observation that I made is the cathode cap values on the gain stages PRIOR to the cathode follower are VERY important.  Very small changes there seem to have signficant results.  For example on this amp,  a 1.68uf has a sweet spot.  Less than that was thin and more than that had too much grind for me.

CHECK for errors!   Any discrepency ........... go with the schematic.

with respect, Tubenit