Randall RM100KH bias?

[KH Guitar Freak]

Hey guys. I need some help. I was looking at this matched quad of Winged C 6L6 for sale locally in my city. The seller has stated that the mA rating for the matched quad is 31.5/2.73. This probably means that the valves are rated at 31mA or 32mA. My question is this. Would I be able to just plug those straight into my Randall RM100KH and set each of the bias points to 31-32mA, or is there more to it than just that???

 

[eyeball987]

I am sure that someone else can give a more detailed answer but I just use the bias ranges given in the manual. I tend to bias closer to the middle or lower middle of the range just to be safe.

Check out my RM100KH. 1 of 3 that where made for Kirk.

 

[KH Guitar Freak]

Awesome. Those must be one of the first ones that were made after the final prototype...

Again, I could be wrong, but perhaps those valves were tested and given a mA rating only because its value was determined based on a known plate voltage???

 

[BigBrewtus]

I believe what you already have in mind is fine. You can safely set your bias with those tubes to that. I have mine set at 34ma. Sure they may not last as long but sound killer.

 

[Whoopysnorp]

Awesome. Those must be one of the first ones that were made after the final prototype...

Again, I could be wrong, but perhaps those valves were tested and given a mA rating only because its value was determined based on a known plate voltage???

Right, the plate voltage is going to be variable from amp to amp. Those numbers just express the fact that the tubes are closely matched; the current they draw in your amp is dependent on the bias, of course. Just bias them to a safe range and you'll be fine.

 

[KH Guitar Freak]

Update: I think all I need to work out now is the plate voltages that the MTS series uses. Some have mentioned that the plate voltage is 500V. If that is correct, I can definitely work out what the bias range would be...

 

[KH Guitar Freak]

Another update: Installed the matched quad of Winged C 6L6s into my RM100KH, and set the bias to 40mV for each valve. Sounds good now. In fact, more clarity and definition over the stock JJ 6L6s. Schweet... 8)

 

[sspiller333]

I am sure that someone else can give a more detailed answer but I just use the bias ranges given in the manual. I tend to bias closer to the middle or lower middle of the range just to be safe.

Check out my RM100KH. 1 of 3 that where made for Kirk.

Hi there do you still have this amp cause I have number 2 of 3

 

[eyeball987]

Hi there do you still have this amp cause I have number 2 of 3

I do not! But wish that I did. Got out of the MTS game for a bit during a time when I was moving lots of amps in and out. The RM100KH stayed around the longest, but something else new and shiny caught my eye.

Would have loved to try out the Synergy gear that I have now with it. Maybe you have my old one? Sold it to a guy in Cleveland, Ohio.

 

[sspiller333]

I do not! But wish that I did. Got out of the MTS game for a bit during a time when I was moving lots of amps in and out. The RM100KH stayed around the longest, but something else new and shiny caught my eye.

Would have loved to try out the Synergy gear that I have now with it. Maybe you have my old one? Sold it to a guy in Cleveland, Ohio.

 

[sspiller333]

I got mine like in 2011 it has different modules and Mesa recto style knobs it came with blackface plex and 1086 and haven't seen another one around till I finally saw this do you remember what number yours was by chance and this one came from Hollywood guitar center

 

[eyeball987]

I do not remember the serial number. Still had mine in 2011 though. The story that was told to me, from a Randall rep at the time, was that they made 3 of those for Kirk's personal use. Two went to him, and one did not. A friend of the rep bought the one that I had and then I bought it from him. Mine came with all three of Kirk's signature modules.

 

[sspiller333]

I do not remember the serial number. Still had mine in 2011 though. The story that was told to me, from a Randall rep at the time, was that they made 3 of those for Kirk's personal use. Two went to him, and one did not. A friend of the rep bought the one that I had and then I bought it from him. Mine came with all three of Kirk's signature modules.

Nice OK cool just checking cause mine had 2/3 death magnetic hand written on the tolex under tube 2 just wasn't sure if yours had the same kind of markings and I kind of heard a similar story though only 2 of the 3 had purple randall logo and the 3rd had pink so if your's was all kh modules I wonder if this was his vintage set up or prototype modules and trying to get a hold of Randall seems pointless they never get back with customers for some reason and thanks for helping me try to figure out the history of this amp