MARSHALL 6100 30th ANNIVERSARY PCB.

[zoblitz]

Hi everybody,



Right now I´m in the process of design a PCB for the preamp (Ch 1,2 & 3) of a 6100 30th anniversary. My goal is to rig up this pre amp and add a 50_W amplifier to the circuit with EL34.


I started to draw a PCB using ExpressPCB but I realized that doesn't make any sense try to invent something that is already built. That's why I started to search pictures of the circuit and actually I have found some good ones that were really helpful to place the components on the board for channels 1 and 2, I got nothing about channel 3.


Should be convenience to draw PCB traces at least alike the originals but I don't have information about it, I think pictures of the back side of the PCB will be helpful.



So anybody can share pictures of channel 1, 2 and 3 PCB (components and back side)?



While I was placing the components I realized there are a transistor called TR1, a resistance called R37 and a capacitor called C7 that maybe conform the gain mod of channel two (I'm not sure). This part of the circuit is not in my schematic so somebody has information about it?

Thanks in advance.

[g1]

While I was placing the components I realized there are a transistor called TR1, a resistance called R37 and a capacitor called C7 that maybe conform the gain mod of channel two (I'm not sure). This part of the circuit is not in my schematic so somebody has information about it?

See area B-4 on pg.1 of attached schematics.

[Enzo]

Hi
We don't even have the schematic you are using to compare, so maybe a link?

Does this look like what you are using?
http://bmamps.com/Schematics/marshal...eSchematic.pdf

Doesn't someone already sell bare boards for the amp? That would be a labor saver. And the amp may be 100 watts, but you could easily just leave out two of the power tubes and voila, 50 watts.

[Enzo]

Ah, simulpost from g1. His schematic that includes those parts is issue 4, while the one I linked is issue 9. Issue 9 is a couple years newer. Those parts are a mute, and it appears they eliminated the mute from that stage in later production. So leaving them out would make your board the latest revision.

[zoblitz]

Thanks guys I'm very grateful for your help,

After seeing the schematic that g sent I realize the schematic I have correspond to a different version of the amplifier and the picture I was taking as a reference correspond to an older one, in fact Im using the Issue 9, so problem solved by you guys.

Not sure if someone sells this i'm going to ask.

Thanks again!