I had my last DC-3 & Mark IV (A) at the same time, along with my DC-10. Nice problem to have, but it was over 2 years ago.
I seem to remember the DC-3 needing a little help in the bass department. I replaced the stock Vintage 30 with a Mojotone BV30H, Heritage 30 clone and was much happier. Still though, it seems like I did not like the 3's tone with my McCarty unless I had the Thiele cab under it. The Thiele didn't necessarily make the amp tubby or add bass that it didn't need. It did, however, add just the right amount of bass and some serious thump. Basically (no pun intended), it sounded like a very well tuned subwoofer!
I've never liked the fact that you cannot turn the bass on the Mark IV's up past 4 on the Lead channel!
I think that it is a serious design flaw to have a knob that goes to 10, but is only useable up to 4 or so.
This is because the IV has the EQ right after the 1st gain stage for all 3 channels. The DC's have a fake Tone Stack after the 1st gain stage to set the overall character of the amp, but the actual EQ that you can adjust is after most of the gain stages. This is how the DC's gain is so useable all the way to 10!
In the end, I had a shootout between the DC-10 & Mark IV A. I had already sold the 3 because we were closing our music store and I just didn't have the room for 20 amps at my house. :mrgreen: No matter how I tried to stack them! :mrgreen:
The IV and the 10 were very close.
The DC-10 won for a few reasons.
The DC-10 had way more useable BASSSSSSS!!!!!!!!!
I felt that the gain was incredibly close between the amps. In fact it took me about an hour to decide which lead channel I liked better. The IV had a tad more smoothness and sustain to it, but the 10 was CRUNCHY, and had more BASS BALLS!
The cleans were not really any contest though. The DC-10's cleans were just warmer and less sterile sounding than the IV's.
Plus, I thought that the factory circuit for R2 was just not anything that I was interested in using.
So....in the end, the DC won because of the crunchy goodness, warmer cleans, no R2, smaller footswitch, and the fact that the DC sounds the same in the same room with the same cords, pedals, guitars, speakers, etc. every **** time! That is something that the mighty Mark IV just could not do. Stabillity is essential to get the tone I want.