RK Board Versions

[jvk]

Does anyone know the different board versions? (stamped on mainboard)

I think RK3 / RK4 are v1 board revisions, there must be more v2 revisions.

 

[Boogiebabies]

There are 4 revisions on the RK 1. I beleive Mesa kept track with serial number. I could never find a board revision on my old RK 1 version 4. If it had the factory diode upgrade, it is a revsision 4.

The RK II has the two versions and I do not see a revision on the board, but they are very different.

 

[jvk]

Hi BB

so

Road King series I has board revisions RK1 / RK2 / RK3 / RK4

and

series II has at least 2 because of v1 and v2 versions.

 

[jvk]

The difference between the series I RK3 and RK4 boards seems to be just in the reverb circuit.

On the RK4 the reverb return signal from the tank is no longer muted (grounded) and completely killed off when switching, instead the positive feedback on the 2nd opamp is reduced alot, so that the reverb is turned down instead of completely killed. With the RK4 the 1-2 second delay before the reverb is mixed with the dry signal after switching is still there, I don't understand what this circuit revision's for.

This one is a little mundane - also in the reverb circuit (rev. ext. switching bit), a few components were changed/added probably because of problems with external switching systems or pedals damaging the reverb muting transistor. A cap and transient voltage suppressor diode were added to protect the FET muting transistor from voltage spikes caused by switching.

 

[Boogiebabies]

Wait, you answered your own question.

You must have a schematic to know those changes ?