How Do You Overdrive?

Hi Thanser

I've got the 2*10sixty five with a preamp tube. Have had some good results recently for a warm OD with master at 6 and volume at 4. Have it set to traditional eq (6,3,2) and reverb on 4 and bright switch on (may want to roll off on guitar tone controls).
I used to be a fan of master on 10 volume on 3 but it is a loud bluesy sound (good for cutting through drums), but i've started liking the country tones the amp can put out.
To push it more Pedal wise the catalinbread wiio sounds great because it doesn't get muddy when a lot of distortion pedals have. I also run a zvex SHO boost to add a bit of sparkle. Still on a quest to make this amp sound the best it can though.

Levi

Hi there,
just curious - which version of the RP do you have? The earlier ones have no purpose-built distortion circuit in them. The GP-3 (EL-34/6CA7 tubes) and GP-3A with the 6L6 output tubes have a diode circuit similar to the clean channel in an RD (GD-2/GD-2A). For this type you can put a clean boost in front of the clipper circuit either before the amp or in the low level FX loop. The older (rarer) versions are harder to overdrive unless you play at uncomfortable levels. I would experiment with a modern mild OD or even a so-called 'underdrive' (google the 'yellow snow' pedal for an example). I'm sure other forum members would agree that you can get some fantastic sounds out of modern boutique type pedals today. When you have an amp that stays clean, you can use that to your advantage. Introduce a pedal in the chain that will both produce a suitable overdrive and adequate compression. Since the amp will not introduce mud and extra unwanted distortion, you can be pretty creative with your settings and it'll still sound 'big' and 'open' - because that's why we love the MM amps, isn't it?

Personally I've used BK Butler tube pedals with MM amps for over 20 years and I still haven't tried another combination that, to me, sounds better. It's all a matter of taste as Mike says, and there is just something so 'in your face' about a guitar with new strings right into a MM amp with the master volume close to 'dime' - it'll cut through pretty much anything.

Anyway, enough rambling....
Hmm, I may have talked myself into buying a Yellow Snow pedal to try it out ;)

Cheers,
Lars
RD-50 112 (really small rig)
65-112 Reverb (small rig)
130HD Reverb/210X/210RH (big rig)

As a drive pedal, I've been using a home brewed version of the Rockett Animal. Does the whole Marshally thing really well. In fact, I just built a second one for the main pedalboard and the older one will go to the small, practice pedalboard. They sound awfully nice for a distortion drive. Miie.

Lars and Mike know a lot more than I do about the various models... I'm just throwing in my 2 cents based on the 212 Sixty-Five I use.

When I want amp breakup on my amp - I run my channel volume between 6 & 10 (higher = more breakup), then use to master to control the output level only. I also run my amp in LO MODE. When in HI (at least on my amp) it has a lot more clean headroom, the opposite of what you want. You will need to EQ to taste... My EQ is dramatically different between clean settings, and an overdrive settings.

As for a pedal setup. I've been using an OD-3 for a light drive and a Tube Screamer for the leads for many, many years. Works for me.

OH - and FYI: I don't have a tube inverter in mine. Only power tubes.
Good luck - and keep in mind. I have never played an RP - my suggestions might not be right for that amp :)

By the way, test drove the new "animal" last night at the job. Sounded GREAT, right up until the time when the clouds opened up and the wind started blowing entire tables around. THAT's when we got the hell out. Welcome to Midwest weather! Mike.

Thanks, everyone. I like pedals, too, but I was looking at a better way to get a more natural breakup at half volume.

However, I was testing my MM 112 RP 65 again, trying to isolate what I thought might be a speaker buzz I heard last time. I had the amp up pretty loud and I noticed a few things I wasn't aware of until now.

For one, the gain pot really jumps from 8 to 10, like DRAMATICALLY. The amp gets very noisy but it starts making a fast clicking noise, like an old rotary phone. This is at 10, mind you, with my Epiphone Sheraton II plugged in.

What the heck is that? Is it internal or am I picking up radio interference? Or cell phone transmission? I shut off my iPhone thinking that was it, but it continues.

I just had this amp checked out at Aviator Audio in Edmonds, WA but I wonder if something isn't wrong that they missed. When it's cranked to ten it's very noisy and it begins this clicking sound.

This thing really doesn't sound like 65 watts, from my perspective. I've played Fenders combo amps that were louder.

Comments?

Going back to your opening post... Do you know what era this amp is? Is there a tube chart in the amp. Some of these amps had 6CA7 (EL34) tubes, and the latter versions had 6L6GC. Make sure the correct tubes are in the amp and make sure they are high quality as I stated earlier. Don't assume the right ones in there right now. I bought both of my Musicmans used, and on both occasions - the previous owner installed the wrong tubes. Both of my amps had the tube chart in tact so there was no reason for it.

Also - it doesn't matter what era it is, this amp is old. Has it had a filter cap job done? If not - it needs one.

What era amp is this?

My chassis number is 2165 RP.
Model Number 112-RP-65.
ID-2100.
Serial Number: DN01701.

Filter caps were not replaced when I had a checkup done, but they did have a backup of work and they kept my amp for over six weeks, which was a bummer. I had to keep asking for it and they finally coughed it up.

The tubes are Sylvania 6CA7 (EL34). I pulled one out, carefully, power off, AC unplugged, and the small black plastic collar that fits over the center glass tip fell out - it appears to be broken off.

Time for a new set of tubes? What do you suggest? Can I buy a pair at Guitar Center and put them in myself or does the amp need to be "biased" for these tubes?

The clicking "rotary phone" noise at gain of 10: it makes a different clicking sound in HI power mode compared to LO power mode.

I still haven't replaced the tube I just pulled and I'm not sure about putting it back in without the plastic tip cover glued back on or just sitting there. It's going to be pretty hard to get this tube back in like this...

So...now I'm dead in the water until I either replace the two tubes or take it back to Aviator Audio.

Can we conclude that the clicking sound at gain of 10 is not radio or cell tower interference? It's not your typical click or pop when someone flips on a light switch in the house.

Thanks, everyone.

If you don't have a guide pin on the tube, I wouldn't suggest putting it back in. If you get it wrong - it's hard to say how bad the damage could be.

Sylvania 6CA7 suggests original tubes to me. If you look in the back of the amp (at the speaker) one of the sides should have a tube chart on it. This would confirm which tubes are used. If it had the Sylvania's in it - that should indicate a pre 1980 amp. The logo should be a Silver Badge with black letters and characters. The amp does need a cap job... it really does. If that wasn't suggested to you by the tech - I'd suggest you find a new tech.

I put a set of JJ-EL34L's in my amp. Regular EL34's struggle with these amps (in my experience) but the EL-34L's seem to handle it. Others may have some suggestions of their own.

There should be no "clicking sound" coming from the amp.... however it's hard to say where that is coming from. Start with a quality cable (or two so you can swap) and try with different guitars. NO PEDALS! Don't blame the amp for that until you know for certain it is the amp that is causing it.

Start with new tubes.

To answer your question(s) only a shred of the tube chart remains and it's illegible. What remains is stapled to the inside of the cabinet.

I'm still not sure which tubes SHOULD be in this unit:

http://www.pacair.com/mmamps/Misc__Info/Model_Chart/model_chart.html

I'd head over to Guitar Center if I knew which exact tubes to purchase.

Thanks, everyone.

I forgot to mention that my logo badge on the grill cloth is BLACK with silver raised letters, not the reverse of this.

If the logo is BLACK with silver raised, it should indicate an 80's or newer model, but the 80's or newer should use 6L6GC tubes.

Your amp had Sylvania 6CA7's. Those haven't been available for decades, indicating that they should be original to the amp, not replacements. That would make the amp pre 1980, but the logo then should have been silver with black raised letters. That doesn't mean someone couldn't have put in the wrong tubes earlier in it's life - and I guess it's possible they changed logos earlier on some models. Those are things I don't know for certain.

I can't really suggest anything more with any confidence. Maybe Lars or Mike (or even Steve) can make a suggestion here :) Really Sorry! This is beyond my knowledge.

Again, thank your for your feedback and honesty, codamedia.

Based on this email thread and the information I posted, can someone verity that a matched pair of JJ EL4L tubes will work in this amp I have? Or should I use 6L6GC?

Also, the badge is black with raised silver letters, but it is very worn and faded - I doubt it was added or changed later.

Thank you, everyone.

If you have the black badge with 6CA7/EL-34 I'm guessing you have the GP-3 version of the RP amp. The only real way to tell is to open up the amp and look at the version number normally written on the main PCB. Of the four versions of the RP amp, only the very latest GP-3A uses 6L6 tubes. This version is by far the most common. I don't know if GP-2 existed in only silver badge or if it extended into the black badge era too. The only two combinations I would be dead certain of is that a GP-3A is always black badge and a GP-1 is always silver. The reverse logic (i.e. deducting version from badge colour) is not possible. Also, keep in mind that many MM amps have had their badges taken off and sometimes re-fitted - there may be several specimens out there with the wrong badge colour because the owner was not able to get the correct one (or didn't care).

Clear as mud?

In regards to relative loudness: It's easy to measure if the amp will produce the correct output power. Your tech should be able to verify that. If the power is not up to standard, it may be time for a new set of output tubes. Another culprit could be the speaker or the speaker wiring. Quite a bit of power can be lost in a speaker jack or cord with failing connection. If the speaker is tired, you may not get the same 'oomph' out of it anymore. My rule of thumb for guitar use is that a small MM amp (50/65/75) should be able to be loud enough to be annoying and painful indoors. A properly working HD type amp will be able to be equally painful and obnoxious in an outdoor setting. Of course YMMV.

Cheers,
Lars

Great - all I can hope is I just ordered the correct tubes for this amp (EL34L). Unless I take it in and they inspect the PCB board for the version number...?

Since you have to rebias the amp with the new tubes anyway, you can read the version number of the board when you have the amp open. If your amp had 6CA7 in it already, I'm quite certain you are fine with EL34/E34L. Don't forget, the bias should be adjusted with the amp in the 'hi' setting. Allow time to warm up the amp for 20mins or so before you can fine-tune. To ensure that you are within a safe operating area for the new tubes to start with, do a coarse adjustment shortly after powering on, then let it sit for some time and tweak until you get the 26-28mA on the lowest of the two. If your tubes appear to be very far apart at idle, you can try swapping them to see if that makes them closer (the difference between the tubes should work to compensate for the difference between the driver transistors, not amplify it).

If you are not comfortable doing this operation, I suggest taking it back to your tech.

Sincerely,
Lars Verholt

Thank you, Lars.

All I can do is wait until the tubes arrive and take it in for a rebias and changing out the filter caps. I'll ask him about the clicking noise I heard when it was cranked to a gain of ten.

Until then, I have no amp.

I'll be in touch with a follow up.

FWIW - Not all amp techs are guitarists. (One of the best in Cardiff, UK is a drummer! how dare he lol). So although all things may check out on scopes and meters, some nuances not to your liking may possibly slip through the net just sayin')
6L6GC would be my choice, and I'm currently waiting on a new set for mine.

Let us know how things pan out?

Hello everyone and Merry Christmas to all...

So I'm really baffled by all of this talk about Biasing, mainly because I've read several threads posted here on this forums site that states that Musicman amps are self biasing. It's extremely hard to know what to do and who's advise to take when one moderator says one thing and another says something else ?

Maybe it's more like if you change to a different type of tube other than what the amp calls for, then one should consider biasing the amp accordingly ?

Baffled in Redding, but loving my Musicman 210/65

Happy Holidays, Charles

MM's are NOT self biasing. That being said, there is one that is close. I thing the RD-50 (help me out here Lars!) is pretty much plug and play. The rest need some form of bias control. If the amp has a 12ax7 as PHASE INVERTER, it bias's(biases?) pretty much like everything else though the current levels are lower due to the extreme voltage. The SS drivers bias with a measurement of the resistors ON the driver board. You should check and adjust bias whenever you change tubes now because with the manufacturing tolerances today, tubes widely vary in control voltage required to keep them from going Chernobyl. It's not a matter of type but just the manufacturing variances. Mike.

I us the "Duncan Pickup Booster" set at about 16 dB gain boost pushing against the NOS Amperx Bugle Boy 12ax7 for nice crunch. Seymore Duncan has this nice pedal that you can add in between 6dB to 25dB of flat clean signal in front of the amp. It's very nice!! Its like having a overdrive stomp box but its not overdrive of the pedal your hearing, just pushing more flat gain signal and getting more of that great sound from your amp. It also has a switch for boosting single coil Pups and a switch for hummbucker's.

I have an early 210 Sixty-Five and I set the power switch to "Low" and the master volume to 10. Then I set the channel volume somewhere between 3 and 5. It breaks up beautifully when you run the power tubes at full throttle on the "Low" setting. If I need more for soloing I use an Xotic AC Booster or an Xotic RC Booster.

My tech put in a fresh set of (4) Masa Boogie el34 two years ago and they seem to now and only now be getting broke in. The amp is starting to sag more the way I like it. On low it is very compressed sounding. Very sweet smooth crunch. It is just getting better with time.

I guess if want new power tubes, all I have to do is put a new set of Mesa Boogie right in with out bias because all Mesa's tube are all so very closely matched from factory.

You CAN do that if you get the rating number off the mesa's and get the same number. Mike.

Thank Steve,
You just saved me some potential repair costs.
But would that be possible?
Just call with the rating number and get a quad of fresh tubes from Mesa without bias?

Uh, I'm NOT Steve but yes, just get the rating off the original box that the quad came in and order the same ones. Mike.