Carl Martin Bass Chorus or Chorus xII - help needed!

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Carl Martin Bass Chorus or Chorus xII - help needed!

Postby Le Basseur » 14 Oct 2016, 10:27

Just got a CM Bass Chorus (first edition,meaning ante-January 2016 production...the PCB says "ESR 2004").Great sound,vey useful dual function/settings.
As the user manual says,quote:
"Units built after January 2016 comes with the innovative Carl Martin DC/DC circuitry that delivers internally
+-12V regulated.
Power consumption: max. 130 mA
Power supply: 9 V DC (regulated), 200 mA minimum, 2.1 mm female plug, center negative (-)
PLEASE NOTICE: It’s not possible to use battery, only external power supply (not included)
ATTENTION: Please Use DC Power Supply Only! Failure to do so may damage the unit and void the
Unit’s built before January 2016 comes with a built in mains power supply either in 100 or 115 or 230 VAC
50/60 Hz, that deliver internally +-12V regulated Power consumption: 2,4Watts."

(end of quote)
...BTW,the same mention is present in the CM Chorus XII user manual,as well as in other CM pedals.
From what I understand,the older units (like mine) have a built-in PS wich consists of a 2x15VAC,dual-secondary mains XFMR,a small Graetz rectifier,78L12,79L12 and 78L05 regs and a minimum no. of electrolytics.
(yes,I already opened the metal case and extracted the PCB)
What I'm interested in is how the newer edition's PS looks like (again,AFAIK from the manual,it should be an external PS but the document isn't very clear about this).
The reason is that I'd really like to bring this pedal to it's best,PS-related...the +/- 12V fixed regulators and the +5V one show a rather modest figure regarding PSRR.Besides that,I have a DIY multi-DC brick mounted underside my pedalboard,so using a dangling AC cord in an,altough,very carefully-arranged pedalboard (AC-inducted noise-wise) isn't what I want since my DC ouputs exhibit a whooping noise level of -93dB.
Long story short,I'd like to rip off the entire onboard PS (especially the AC tranny) ,put a multi-pin DC socket of some kind on the chassis and use a way better external PS.For these reasons,I need any information about post-Jan2016 CM Chorus (or any other newer CM pedal) production,if possible with pics/schematic.
Le Basseur
Posts: 6
Joined: 01 Apr 2016, 16:49
Has thanked: 1 time
Have thanks: 4 times

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: Google Feedfetcher, marvilla and 8 guests