I need to correct the record. In some previous posts in this thread, and possibly elsewhere, I indicated that Ashdown may be shipping the CTM100 and CTM300 with some new component values designed to change the behavior of the tone stack. Dave Green from Ashdown his informed me this is not accurate and the amps are shipping with the same component values they have always used. He did mention that there are a variety of ways the tone stack may be tuned, and he has worked with some famous artists to tailor the voicing of the tone stack a bit, but the amps were later returned to the factory tuning.
There is a CTM100 tone stack mod floating around that can be found on Talkbass and also Basschat that involves simply installing new Bass, Mid, and Treble potentiometers with different values. Both threads reference Mr Green and use the same pot values, although there is some apparent disagreement on A, B prefixes which designate whether the pots are linear or logarithmic taper. Unfortunately this can be a confusing subject because the industry has not standardized the prefixes. The schematic shows the original Bass and Treble pots are log taper and the Mid pot is lin taper. I can't say if the updated pots should have the same tapers.
I believe the CTM100 and CTM300 preamp share a common preamp circuit. After playing around with a tone stack simulator, I believe the mod will change both the way the tone stack behaves and also revoice the amp somewhat. Those who have done the mod report favorable results, but let's keep in mind tone is subjective. I suspect the mod will result in slightly less interaction between the tone controls and more of a built in mid scoop. The mod should be easy and reversible since the pots are attached with flying leads.
Mr Green also pointed out the the output sections of the CTM100 and CTM300, "are designed to produce very different results." Apparently the CTM100 is intended to saturate and distort fairly easily and the CTM300 is not. I have never played a CTM100, but his comment is consistent with a review thread here on Talkbass where the amp was compared to an Ampeg V4B reissue. I believe users consistently agreed the Ampeg had more clean headroom. In contrast, my CTM300 seems a bit louder and tighter than both of my vintage SVTs.
There is a CTM100 tone stack mod floating around that can be found on Talkbass and also Basschat that involves simply installing new Bass, Mid, and Treble potentiometers with different values. Both threads reference Mr Green and use the same pot values, although there is some apparent disagreement on A, B prefixes which designate whether the pots are linear or logarithmic taper. Unfortunately this can be a confusing subject because the industry has not standardized the prefixes. The schematic shows the original Bass and Treble pots are log taper and the Mid pot is lin taper. I can't say if the updated pots should have the same tapers.
I believe the CTM100 and CTM300 preamp share a common preamp circuit. After playing around with a tone stack simulator, I believe the mod will change both the way the tone stack behaves and also revoice the amp somewhat. Those who have done the mod report favorable results, but let's keep in mind tone is subjective. I suspect the mod will result in slightly less interaction between the tone controls and more of a built in mid scoop. The mod should be easy and reversible since the pots are attached with flying leads.
Mr Green also pointed out the the output sections of the CTM100 and CTM300, "are designed to produce very different results." Apparently the CTM100 is intended to saturate and distort fairly easily and the CTM300 is not. I have never played a CTM100, but his comment is consistent with a review thread here on Talkbass where the amp was compared to an Ampeg V4B reissue. I believe users consistently agreed the Ampeg had more clean headroom. In contrast, my CTM300 seems a bit louder and tighter than both of my vintage SVTs.
. I sold my LB30 a few yrs back. 
