D'Mars ODS & FX (non-5879)

[tubenit]

I've been kind of hesitant to share this since the original D'Mars ODS is such a fantastic amp!!    I had a perfectly good D'lator that I used with the D'Mars but I've gotten lazier about hooking it up to the amp. And the D'Lator does help shape tone. So I decided to have the FX on board. Unfortunately, there wasn't enough room to keep the 5879.

So, I decided to build an active FX into the amp and get rid of the PPIMV & used the 5879 socket to 12AY7 for the FX. 

Sound comparison to the original D'Mars:

1) does not have as much chime or vowel/wah tone in the OD. The vowel tone on the original was incredibly good
2) OD is not as extreme as the original D'Mars.  It's maybe 60% or so as intense as the original, but still a good contrast between OD & clean
    So if you want alot of OD, keep the original design with the 5879.
3) OD is much smoother than the original D'Mars.  Honestly, much smoother!
4) easier to dial in a fabulous tone at a lower volume using the FX as a master volume. The PPIMV sounded somewhat thinner at the lower
    volumes in comparison
5) clean channel still sounds like the best clean channel I've had in any of my amps. No changes made on the clean channel
6) The FX is great master volume and I like it better than the conventional Marshall or PPIMV master volumes
7) amp is still very touch sensitive and articulate. No loss there in my opinion.
8) harmonics on the OD are very musically sweet with really great harmonics
9) I found that I very seldom used the PAB on the original, so I converted that relay into switching a .001 cap across the OD drive.
    I call this an accent switch since it gives a tighter sound to the bass notes and crisps up the high notes somewhat.
10)  This D'Mars ODS & FX has a much better OD foundation for using OD pedals. 
11)  The amp does NOT bloom as easily with the conversion. The original 5879 adds alot to the blooming.  Having said that, it does still
       do the blooming thing but maybe 60% as well.
12)  The amp is quieter at idle after this conversion. Not sure why, but something about the rewire made it quieter.
13)  Like the original D'Mars, it is easy to balance the clean and OD volumes and get great contrast between clean and OD

I found with the original D'Mars that I was playing the clean channel as much or more than the OD channel cause the clean just sounded
"that good".   With this D'Mars, I am playing the OD channel even more than the clean channel because the OD sounds "that good".

IF you want a really intense OD or some chime in your OD, stick with the original D'Mars.  IF you don't mind a more subtle OD that is equally
musically sweet and much smoother, then this might be a great alternative especially if you're also using an OD pedal. In fact, I can get more blooming using this D'Mars with the TimZee than the original with the 5879 pentode.

Note that I did this conversion using the Hoffman D'Mars board.  Very easy conversion. Amp is super super quiet at idle and it's a loud amp for 23 watts.  I play this with the volume on 4-6,  FX send on 5 and FX level on 5-7.

I have had so much fun playing this on overdrive that I played long enough to literally rip all the callouses off my fingers and actually cause my ring finger tip to slightly bleed ................. and I kept playing for maybe another 10 min.  It is that much fun to play. I am using this
with an Emminence Red, White and Blues.  I was using the original D'Mars with a Emminence Cannabis Rex.

Some notes on this.  I think one could use 220p across the OD plates instead of 390p.  I think the smoothing cap on the FX could be lowered to 82p like I did on my Tweed BluezMeister.  I originally had a .44 cap in the FX and lowered it to .1 which seemed to give me a better bass note response.  The FX level is on the front panel and used like a master volume. The FX send is on the back and kind of a set and forget. The FX send pot can really add OD or clean up the tone.

Lots of useable tones in this amp. I can even dial the OD to be almost as clean as the clean channel but it will have somewhat more sustain than the clean channel.  Again, there is plenty of contrast between the OD and clean if you want it.  And the volumes on each will balance well.

With respect, Tubenit

[SILVERGUN]

Thanks a lot for taking the time to do that......glad to see your having some fun playing  

The effects loop is exactly what I was envisioning for a simple built in D'lator and it would be very cool if the Fx level control could replace my PPIMV, or at least interact with it....It also addresses my desire for a "lead boost" ,,,where I could make the FX level higher when (foot) switched in  
The idea would be to have the loop switchable instead of V2 for clean/OD,,,,just keep my preamp in tact and have the loop switched in/out pre-PI like you have it

I'm working on coming up with a power supply to tap off of my filament windings to power built in effects,,,,and I see that as a "next big step"

If only we could squeeze a couple more hours into a day