DSL40CR schematics & Bright cap C74

tmingle

Well-Known Member
Joined
Jan 24, 2008
Messages
520
Reaction score
601
Location
Mifflintown, Pa.
After watching the DSL100H mods video from Headfirst Amplification & comparing with the schematics for the 40c & 40CR, I noticed that several of the Headfirst changes have been implemented on the 40CR. The values are not necessarily the same but are in the general direction that Headfirst took & not all have been implemented. Rather than mod my 40C, I decided to see if the bright cap is indeed missing from the 40CR. The schematics posted for these a while back seem to be correct so far. There is indeed a spot for a bright cap(C74) on the Ultra channel. I installed a 330pf & to my ears, it was a major improvement. I also reinstalled the stock Marshall V1-V3 tubes & the stock V-type speaker. I have never been able to hear any difference between CP & NOS tubes in these amps. I probably have enough of them laying around that I should sell while the prices are up. I could probably come close to funding the Mark 5:25 that I have been looking at for a while. I noticed a few things while I was working on it. There is a foil shield inside the cabinet. The DFX board is attached with a screw so it wont vibrate loose. There are spots on the board for 2 more power tubes, which indicates it is most likely the same board as the 100HR. The power tubes are mounted directly to the PCB & not on the chassis like the 40C. The amp still probably needs an MXR 10 band in the loop, but I've been doing that for so long. I installed the cap on 8" leads so I could change values or make it switchable some time in the future.
IMG_5375.JPG IMG_5372.JPG IMG_5366.JPG IMG_5365.JPG IMG_5363.JPG IMG_5362.JPG IMG_5360.JPG IMG_5359.JPG
IMG_5375.JPG IMG_5372.JPG IMG_5366.JPG IMG_5365.JPG IMG_5363.JPG IMG_5362.JPG IMG_5360.JPG IMG_5359.JPG
 


Top