last one I promise (please help): I have to put it across the lugs (front? rear?) or its enough to hang it between a lug and a connector (I was thinking of using a pot to find the right value)

thanks a lot but please give me another chance ;-) : can I put a resistor somewhere over the output jack and tame signal more?

Steve,
this mod is working good but signal is still too loud for headphones I need to tame volume more... can you please suggest how can I reduce volume more when I plug my headphones in one of the outputs (low power mode on) ???

need help
Thanks a lot

great! thanks a lot

sorry but english isnt my primary language (regarding the headphones jack only): I can change one of the 2 outputs jacks with a stereo one leaving sleeve to sleeve and connecting actual Tip to both Tip and Ring of the stereo jack, have I got it?

thanks a lot for chiming in!! just to clarify you refer to the speaker jack I will add not to the ones where Id plug the headphones, am I rigth?

Hi,
I was thinking about wiring the speaker to the chassis with a jack and disconnect it while plugging headphones in one of the outputs in Low Power mode.. is this possible? I need to use it at home with headphones

Thanks for any help

think twice before modding this amp, I had 2 (one heavily modded) and vintage plexis, its perfect stock from the factory, its a little bit middier than the originals but its 99.9% there (I always played everything with my original '69 4x12 cab with G12H 55hz)

marshall vintage cabs with G12H 30w 75HZ ?? never saw or heard one... do you have any link to a sound file/vid? I had many vintage G12M both 55 and 75hz, great sound, I always thought I was done with cabs until I got my '69 cab with G12H 55hz, instant Page, Walsh, Gibbons.. got rid of all my G12M (e...

SteveD wrote:...His signature was going to facilitate both aspects and much more.

how I miss THIS amp....

... I might have bad ears, it seems others favor Greenbacks (with extra mids) with this amp and the stock combo speaker has even more mids, but I found the extra mids in those speakers made things worse with the JMP1. YMMV - I'm just sharing my experience. in my exp the GB is middier than stock one...

I pulled the trigger on a G10 greenback, once I get it I will let you know Did you get the 10' greenback? How did you find it? tried it... byt after some weeks I put back the original one, the greenback was warmer but with this amp it did not make it well, the lows did not get any better, I needed ...

hope it happens

nope, all great records with G12H30 have 55hz on them, the H has more highs than the 25watter M, the 55hz cone matches it perfectly. If you use late 60s plexis you will got lots of highs (depending on people taste), personally I lean more towards G12M.. each to his own

this is the greatest amp made by Marshall since mid 80s, great tone.. could have lots of highs paired with G12H30 but with G12M its pure perfection. Marshall replicated a '69 amp but tone and layout are same as a '68 one, truly fantastic... jumpering channels gives lots of sound.. love it