JimAnsell
Well-known member
i bought this off ebay.
its a mark IIB coli k133.
i've had one of these before, but this one sounded a bit different.
sounds like it has more gain, and tighter, bigger low end.
balls like you wouldn't believe actually.
it sounds absolutly phenominal.
there is something going on inside this thing for sure.
i compared the guts of this one with some photos i took of the last mark IIb coli i had which i believe was all stock.
i'm going to post some big pics of some of the question spots, and you guys who know these amps well can help me out. sound good?
ok, here goes:
first off, it looks like someone added a little something to the input and 1st volume knob:
there is a 168k resistor from the middle lug of the input jack, to the middle lug of Volume 1
and a 90k resistor (with a cap in parallel) going from the right lug of volume one, to the treble knobs middle lug
closer:
next: it looks a few resistors have been swapped out, and another resistor has been added with that black one there. the one i circled is a 330k, and it doesn't match the resistor there in my old IIB coli.
finally, there are 3 black plastic things glued to the chassis with wires in a grey insulated casing leading to the eq section.
it looks to me like 3 of the eq inductors went bad or something, and these were added in as replacements. the wires lead to the stock inductors on the 5 band.
this might be the cuase of the bigger low end, since the new ones are on the low 3 faders.
here is a full look at the pre amp section.
anyone notice anything else out of the ordinary?
i don't know if i want to send this to mike b, or just leave it as is.
i'm sure it'll need a recap soon, as one of the million big blue caps has already been replaced.
its a mark IIB coli k133.
i've had one of these before, but this one sounded a bit different.
sounds like it has more gain, and tighter, bigger low end.
balls like you wouldn't believe actually.
it sounds absolutly phenominal.
there is something going on inside this thing for sure.
i compared the guts of this one with some photos i took of the last mark IIb coli i had which i believe was all stock.
i'm going to post some big pics of some of the question spots, and you guys who know these amps well can help me out. sound good?
ok, here goes:
first off, it looks like someone added a little something to the input and 1st volume knob:
there is a 168k resistor from the middle lug of the input jack, to the middle lug of Volume 1
and a 90k resistor (with a cap in parallel) going from the right lug of volume one, to the treble knobs middle lug
closer:
next: it looks a few resistors have been swapped out, and another resistor has been added with that black one there. the one i circled is a 330k, and it doesn't match the resistor there in my old IIB coli.
finally, there are 3 black plastic things glued to the chassis with wires in a grey insulated casing leading to the eq section.
it looks to me like 3 of the eq inductors went bad or something, and these were added in as replacements. the wires lead to the stock inductors on the 5 band.
this might be the cuase of the bigger low end, since the new ones are on the low 3 faders.
here is a full look at the pre amp section.
anyone notice anything else out of the ordinary?
i don't know if i want to send this to mike b, or just leave it as is.
i'm sure it'll need a recap soon, as one of the million big blue caps has already been replaced.
