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this is just some notes I took to go along with the Marshall SE100 speaker emulator schematic on Steve A.'s site
http://www.blueguitar.org/new/schem/marshall/se100.pdf
(looking inside my own SE100) so it's easier to follow.
for "BACK PCB" page of schematic, connector "PL1":
pin #- wire color
1 - Green
2 - Orange
3 - Black
4 - Red
5 - Brown
6 - Pink
for "CHOKE PCB" page of schematic "FRONT PCB" connector:
1 - Orange
2 - Yellow
3 - Blue
4 - White
5 - Purple
6 - Black
7 - Brown
8 - Pink
for "CHOKE PCB" page of schematic, "BACK PCB" connector:
1 - Green
2 - Orange
3 - Black
4 - Red
5 - Brown
6 - Pink
Letters "A, B, C, D...N" indicate points on the PCB.
for "FRONT PCB" page of schematic, connector "PL" marked "to Choke Assembly":
1 - Orange
2 - Yellow
3 - Blue
4 - White
5 - Purple
6 - Black
7 - Brown
8 - Pink
(from another post) :
(at least in my unit) the main load (in the Power Brake) is 10R, not 8R2, so these loads in the SE100 and PB are not exactly the same. Also, "R2" (on the Blue Gtr. PB schematic) is 100R in mine and not 56R. Re: the SE100, the loads work like this: there are 3 loads from hot to ground (see schematic heaven schematic), the first one comes in for 6dB attenuation, and the output is taken from "C". The configuration is like this:
http://www.webervst.com/lpad.htm
where R1 and R2 make up the load from hot to ground in the SE100. On 12dB reduction, the first network is switched out, and the middle one comes in. On 18dB, both come in, output taken from the middle network. On "load", the third one comes in but the two other networks can be switched in in parallel.
There is a big aluminum heatsink which all the power resistors and 3 12.5mH inductors are mounted on. It's basically a rectangular piece bent into an "L" that is partly vertical and partly across the bottom rear side of the chassis.
To remove the PCB, pull off the knobs (try hooking a slightly fat string and pulling if you have trouble--this way you don't scratch the plastic on the knob), remove the knob nuts and PHONES nut, one screw on the inside holding down the PCB towards the very left, and remove the two connectors. Careful not to scratch the wire insulation with the PCB edges.
Aluminum electrolytic caps on the CHOKE PCB are "T.M." brand, "100WV", radial leads. The smaller inductors are (I think) ferrite core (cylindrical with a fatter part in the middle, marked "NDE" which is apparently some UK company), the 3 12.5mHs are iron core(?)--they look like Marshall chokes, marked "Drake Transformers".
http://www.blueguitar.org/new/schem/marshall/se100.pdf
(looking inside my own SE100) so it's easier to follow.
for "BACK PCB" page of schematic, connector "PL1":
pin #- wire color
1 - Green
2 - Orange
3 - Black
4 - Red
5 - Brown
6 - Pink
for "CHOKE PCB" page of schematic "FRONT PCB" connector:
1 - Orange
2 - Yellow
3 - Blue
4 - White
5 - Purple
6 - Black
7 - Brown
8 - Pink
for "CHOKE PCB" page of schematic, "BACK PCB" connector:
1 - Green
2 - Orange
3 - Black
4 - Red
5 - Brown
6 - Pink
Letters "A, B, C, D...N" indicate points on the PCB.
for "FRONT PCB" page of schematic, connector "PL" marked "to Choke Assembly":
1 - Orange
2 - Yellow
3 - Blue
4 - White
5 - Purple
6 - Black
7 - Brown
8 - Pink
(from another post) :
(at least in my unit) the main load (in the Power Brake) is 10R, not 8R2, so these loads in the SE100 and PB are not exactly the same. Also, "R2" (on the Blue Gtr. PB schematic) is 100R in mine and not 56R. Re: the SE100, the loads work like this: there are 3 loads from hot to ground (see schematic heaven schematic), the first one comes in for 6dB attenuation, and the output is taken from "C". The configuration is like this:
http://www.webervst.com/lpad.htm
where R1 and R2 make up the load from hot to ground in the SE100. On 12dB reduction, the first network is switched out, and the middle one comes in. On 18dB, both come in, output taken from the middle network. On "load", the third one comes in but the two other networks can be switched in in parallel.
There is a big aluminum heatsink which all the power resistors and 3 12.5mH inductors are mounted on. It's basically a rectangular piece bent into an "L" that is partly vertical and partly across the bottom rear side of the chassis.
To remove the PCB, pull off the knobs (try hooking a slightly fat string and pulling if you have trouble--this way you don't scratch the plastic on the knob), remove the knob nuts and PHONES nut, one screw on the inside holding down the PCB towards the very left, and remove the two connectors. Careful not to scratch the wire insulation with the PCB edges.
Aluminum electrolytic caps on the CHOKE PCB are "T.M." brand, "100WV", radial leads. The smaller inductors are (I think) ferrite core (cylindrical with a fatter part in the middle, marked "NDE" which is apparently some UK company), the 3 12.5mHs are iron core(?)--they look like Marshall chokes, marked "Drake Transformers".
and extremely informative as well...
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