Need a component identification chart for pcb JMP`s!

[Kennetiversen]

Hi there!

I have searched the web for identification charts for pcb JMP`s but could not find a single one.

If sombody got one please share!


Kennet Iversen

[neikeel]

Ok, lets try!
This is pretty much how your board should look (this is a 76/77 2203) it is dual purpose for 1959 and 2203 100w models
First resistor is 10k (V1a cathode resistor)
next is a blank spot where you would put a bypass cap (if a 1959)
Next is a 0.68uF capacitor (V1b bypass cap) next is the 2k7 V1b cathode resistor. These set the gain factor of your first preamp tube gain stages and really important to how the amp will sound/respond when playing.
Next are two blank spots where the 68k input resistors of V1a go. I recommend leaving these on your board but just removing the wires to them as I would use a shielded wire from the input jacks direct to pin 2 of V1 (with the shield only soldered to the gain pot bus) you can add a 33k or 68k grid stopper on the socket if needed.
Next is the coupling cap of 0.022uF (22nF) not it does not have a resistor in series with it. Next you have the 100k plate resistors of V1 (leave alone), below those the 68k inout resistors of V1b again leave the but not connected, just run the shielded wire from the input jack to pin 7 of V1 (this time you should use a 68k grid stopper for sure).
Next is V1b coupling cap 0f 0.022uF. Then the 470k 'mixers' resistors. On a 2203 one of these is wired to ground the other has a 500pF mica cap attached (the brown ceramic blob you see above). The mod 5 subs a 100pF cap there.
On the gain pot you will see a 470k/500pF resistor and cap combination between lo input jack and gain pot s weel as a cap across the gain pot input and output wires, the mod 5 has this as 5000pF.

I can go on if you want (go to do some work now!)

[Kennetiversen]

This is realy good information Neil! This will help me alot! Thanks! Looking forward for part 2

[Kennetiversen]

Hi again!


so I`ve started on this Idientification Chart for my PCB marshall, Can anyone tell me if this is correct and and help me fill inn the blanks?

http://www.mediafire.com/view/pkiwzaatq ... cation.jpg

Kennet Iversen

[neikeel]

Sorry, but that file comes up as private.

[Kennetiversen]

Now the link is fixed





Kennet