Bright Cap Mod
Posted: 20 Nov 2011, 17:36
Hello MA Lovers.
I just had the Fat lady (MA100C) opened to replaced a suspect JFET (board ID TR45) That could have been the cause of a load popping noise when switching from OD channel the Clean ... And I said to myself... why not get that Bright Cap remove or changed ... See, I play a Strat and for my personnal taste, I found the Clean channel way to bright... So someone out there know what is the bright cap capacitors board ID number ?
Maybe Mr Steeve D could share this with me, I wont tell anayone and since my amp is still opened and accessable ... Look like "C5" to me but anayway What is the actual value of the Cap ? Look like a 220 pf ?
By the way .. changing the JFET (J174) Board ID TR45 partialy fixed the channel switching loud popping issue ... Now It's only pop's when the reverb pot is turned on. If the reverb pot in turn off it doesn't pop at all strange no !
-- Mon Nov 21, 2011 4:30 pm --
Finaly ... I decided to perform the surgery anaway !
I first pulled away the 220Pf Bright Cap on the clean channel and replaced it with a 47Pf. It did the job The clean channel is much more mellow and less crispy but maybe a bit too much ... An planning next to try a 100Pf insted of the 47Pf but first I want to try this set up(47Pf) during a life gig !
I Also made a few changes on the preamp on OD side . I replaced the 470Pf cap on the top of the treble control for a 220Pf I also changed the Bass circuit resistor by replacing the 33k by a 100k.
Outstanding results !!!! I felt down my chair ! After that change ... I think I'm going to sell all of my over-drive and distortions pedals ... I just love that way my MA100C sound now..
The only negative observation that I saw, was a bit less Headroom on the OD side but still with the OD volume at 12 ,it played loud as hell !
Ciao
I just had the Fat lady (MA100C) opened to replaced a suspect JFET (board ID TR45) That could have been the cause of a load popping noise when switching from OD channel the Clean ... And I said to myself... why not get that Bright Cap remove or changed ... See, I play a Strat and for my personnal taste, I found the Clean channel way to bright... So someone out there know what is the bright cap capacitors board ID number ?
Maybe Mr Steeve D could share this with me, I wont tell anayone and since my amp is still opened and accessable ... Look like "C5" to me but anayway What is the actual value of the Cap ? Look like a 220 pf ?
By the way .. changing the JFET (J174) Board ID TR45 partialy fixed the channel switching loud popping issue ... Now It's only pop's when the reverb pot is turned on. If the reverb pot in turn off it doesn't pop at all strange no !
-- Mon Nov 21, 2011 4:30 pm --
Finaly ... I decided to perform the surgery anaway !
I first pulled away the 220Pf Bright Cap on the clean channel and replaced it with a 47Pf. It did the job The clean channel is much more mellow and less crispy but maybe a bit too much ... An planning next to try a 100Pf insted of the 47Pf but first I want to try this set up(47Pf) during a life gig !
I Also made a few changes on the preamp on OD side . I replaced the 470Pf cap on the top of the treble control for a 220Pf I also changed the Bass circuit resistor by replacing the 33k by a 100k.
Outstanding results !!!! I felt down my chair ! After that change ... I think I'm going to sell all of my over-drive and distortions pedals ... I just love that way my MA100C sound now..
The only negative observation that I saw, was a bit less Headroom on the OD side but still with the OD volume at 12 ,it played loud as hell !
Ciao