Does anyone out there have a lead on a schematic for a Rickenbaker M-11-A amp?
I have found the M-11 in a few spots. It's similar to the "A", but the "A" uses 12AX7's and has an added tremolo.
My brother picked this amp up recently, and wants me to get it up and running. I took a peak under the hood, it looks to be a '56 by pot and speaker codes.
I haven't begun to troubleshoot it yet, besides my brother initially turning it on. Sounded like leaky coupling caps or bad pots when sweeping the controls. I was hoping to find a schematic to help verify things before poking around.
Once I get working on it, I'll post some pics. Pretty sweet amp!
Thanks in advance for any help you can give!
In Search of a Rickenbaker M-11-A Schematic
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crookedtodd
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David Root
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Re: In Search of a Rickenbaker M-11-A Schematic
Perhaps the trem is the same as in the B16-A?
Off-topic, but I don't think I've ever seen a a pair of 6L6 run that hot in cathode bias before. 80mA Ik each tube! Pa >30W. Even 6L6GC.
Off-topic, but I don't think I've ever seen a a pair of 6L6 run that hot in cathode bias before. 80mA Ik each tube! Pa >30W. Even 6L6GC.
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Stevem
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Re: In Search of a Rickenbaker M-11-A Schematic
Unless you have a ton of time on your hands do not trouble shoot, shot gun it and you will have more time to enjoy playing it!
Replace all of the preamp plate coupling caps and spray down the inside of the pots with some WD-40 and see where that leaves Ya!
If all is well after,or at least a lot better after that the the power supply filters need to go along with the cathode bypass cap in the output stage if it has such a cap and also replace the that cathode resistor with one 2 watts or more greater in size.
Also in the power section on the filter nodes check the dropping resistors for any sign of getting hot and going brownish black in color and replace those also!
Replace all of the preamp plate coupling caps and spray down the inside of the pots with some WD-40 and see where that leaves Ya!
If all is well after,or at least a lot better after that the the power supply filters need to go along with the cathode bypass cap in the output stage if it has such a cap and also replace the that cathode resistor with one 2 watts or more greater in size.
Also in the power section on the filter nodes check the dropping resistors for any sign of getting hot and going brownish black in color and replace those also!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: In Search of a Rickenbaker M-11-A Schematic
Respectfully, I disagree with the recommendation for WD40. Use contact cleaner or a lubricant that is meant for electrical contacts like DeOxit D5. WD40 doesn't evaporate and will eventually collect gunk that you'll never be able to remove.
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Stevem
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Re: In Search of a Rickenbaker M-11-A Schematic
What do you think the lubrication portion is for example in Deoxit F5 ,lard, it's a oil.
Would you not agree that 95% of what makes pots noisy over time is the fact that they are made without lube and with out lube the resistive carbon track wares down and in turn makes the dust that makes the scratchy pot in the first place?
For near 15 years on vintage pots that I opened up to rebuilt in guitars and amps I have wiped on silicone based grease lube to the carbon track with no ill effects, this is a huge plus on guitars where you have to fish the pot(s) out thru a F hole and you do not want to do that every 3 to 4 years to a vintage axe that the owner plays a lot!
Even if a certain type lube may gum up in time at least you can flush it out with just a contact cleaner and the gummed up lube would have caused no harm to the resistive trace!
I do not mean to fully discredit what you are saying, but I have had zero issues with the use of WD-40, or silicone grease, other than WD-40 evaporating in the heat of some tube Amps, and I am not saying either of us are fully right or wrong, but this has been my experience that's all!
Would you not agree that 95% of what makes pots noisy over time is the fact that they are made without lube and with out lube the resistive carbon track wares down and in turn makes the dust that makes the scratchy pot in the first place?
For near 15 years on vintage pots that I opened up to rebuilt in guitars and amps I have wiped on silicone based grease lube to the carbon track with no ill effects, this is a huge plus on guitars where you have to fish the pot(s) out thru a F hole and you do not want to do that every 3 to 4 years to a vintage axe that the owner plays a lot!
Even if a certain type lube may gum up in time at least you can flush it out with just a contact cleaner and the gummed up lube would have caused no harm to the resistive trace!
I do not mean to fully discredit what you are saying, but I have had zero issues with the use of WD-40, or silicone grease, other than WD-40 evaporating in the heat of some tube Amps, and I am not saying either of us are fully right or wrong, but this has been my experience that's all!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: In Search of a Rickenbaker M-11-A Schematic
We can just disagree about it. It's not a big deal. I thought the person receiving the advice should be aware that not everyone thinks WD-40 is the appropriate choice.
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David Root
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Re: In Search of a Rickenbaker M-11-A Schematic
Since my post seems to have lost the B16A schem I had posted to show the trem, here it is again.
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crookedtodd
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Re: In Search of a Rickenbaker M-11-A Schematic
Thanks for the responses!
I checked the coupling caps and the showed no DC voltage on the control side, so those seem ok.
Sprayed the pots. The Volume cleared up, but the Tone pot still cuts out, except at the extreme ends of its travel. Looks like that will need replacement.
I'm trying to find a schematic just for reference. Voltages in power section seem to be as expected, but the preamp voltages seem very low, at least lower than I expected. I cant find any info on marked voltages or transformer specs.
Also, there are 2 12AX7's and 1 12AU7. There is nothing clearly marking what goes where. I have found a few posts discussing this tube order. Just wondering what stock would be, then use that as a starting point.
As I dig in more I will post some actually measurements, and any other findings.
Thanks again!
I checked the coupling caps and the showed no DC voltage on the control side, so those seem ok.
Sprayed the pots. The Volume cleared up, but the Tone pot still cuts out, except at the extreme ends of its travel. Looks like that will need replacement.
I'm trying to find a schematic just for reference. Voltages in power section seem to be as expected, but the preamp voltages seem very low, at least lower than I expected. I cant find any info on marked voltages or transformer specs.
Also, there are 2 12AX7's and 1 12AU7. There is nothing clearly marking what goes where. I have found a few posts discussing this tube order. Just wondering what stock would be, then use that as a starting point.
As I dig in more I will post some actually measurements, and any other findings.
Thanks again!
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Stevem
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Re: In Search of a Rickenbaker M-11-A Schematic
Well since you know what you have for main B+ voltage and if you can read what you have for the power supply dropping resistors and plate resistors , then with 15,minutes of using some math while knowing how much current each preamp triode section pulls you can figure out within a acceptable 15% what the rest of the amps voltages should be!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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crookedtodd
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- Joined: Fri Nov 02, 2012 12:14 pm
- Location: Upper Michigan
- Contact:
Re: In Search of a Rickenbaker M-11-A Schematic
right on ! Thanks Stevem! 
Hopefully I can get to it tonight.
Hopefully I can get to it tonight.