how to run RM50 combo VERY clean and loud?

[JudMan]

I'm new here, so please excuse any breech of etiquette.

I recently purchases an RM50 combo used that came with a Deluxe and a Modern module. It's my first tube amp, and my first amp that's loud enough to gig with.

I have a DigiTech GNX3 that I adore, and want to setup the RM50 to be loud and crystal clean. I realize I would probably be better off using a plain ole clean PA and speaker, but at $400 I couldn't pass up the all tube RM50, with the possibility of getting the best of both worlds.

I've done a bit of research and have determined that I need either the clean, the KH-1, or the blackface module, since the Deluxe module just will not get clean at high volume. I do have the older deluxe module that still has 470 ohm R1 & R3, changing those to 150 ohm will clean it up some, but maybe not enough. That test will happen soon, btw.

I'm interested in hearing what others suggest to help me get a crystal clean AND loud tone.

I have GT 6L6 tubes in it currently. Maybe a different type/make of tube can help as well.

My guitar is an '84 Kramer Pacer Imperial with Schaller pickups, which I hear are very bright/hot. I don't have a lot of experience with many guitars, this is the only electric I've ever owned.

I do love the tone of my guitar, when running through the GNX3, and fed into my home stereo, or headphones. It's just that now I need it loud, since I've recently started to gig.

I realized this may seem sacrilegious to some. But it would be nice to have a way to setup my RM50 to be very loud and very clean for one gig, and then for another, I set it up to be more dirty, by swapping output tubes/modules.

Oh, as for tone, I play a lot of Grateful Dead songs, so I'm looking for the Garcia clean sound.

Help a new guy out!

 

[Julia]

The clean signals are not compressed at all. Your peaks can clip your power tubes and especially your effects unit if you use one.

* very soft knee compression with peak limiting will help a lot.
* don't turn the gain up on your module past 9:30.
* if you run the channel volume up high without any compression in the loop you can clip in the phase inverter.
* compression in the loop can also smooth out volume differences between channels.
* use the neck pickup
* don't run the MV too high either.

mic the amp and feed it through the PA.

 

[robespierre]

I have a RM50LB, and I use the blackface to run with my VOX Tonelab ST.

It works fine, except you'll want to dial in the sound/tone by actually hooking your GNX3 up to the amp. I have about ten settings that I was using to record on the computer (using headphones to listen), but when I plugged it into the amp... ugghh!

With all these effects processors out there you'd think someone could make a good-sized "PA amp", if you will. -One where you use it to practice, or for small venues.

 

[kc2eeb]

.....and find a good pair of KT88s, or 6550s

 

[robespierre]

I have a RM50LB, and I use the blackface to run with my VOX Tonelab ST.

It works fine, except you'll want to dial in the sound/tone by actually hooking your GNX3 up to the amp. I have about ten settings that I was using to record on the computer (using headphones to listen), but when I plugged it into the amp... ugghh!

With all these effects processors out there you'd think someone could make a good-sized "PA amp", if you will. -One where you use it to practice, or for small venues.

 

[kc2eeb]

You can use the RM50 as a PA amp. Just don't use the front input.
Plug into the effects return and you basically have half of a RT2/50.

 

[JudMan]

@kc2eeb - My friend had just suggested the same thing! Total sync, I am definitely going to try that! So basically from guitar to GNX3, then GNX3 to serial fx return, and that should bypass the preamp modules entirely. Perfect, in theory. Can't wait to try it out tonight!

@kc2eeb - Tell me more about the KT88's & 6550's or point me to a good resource. I checked my tube bias and was shocked with how bad my current GT 6L6 are out of range, one was reading 20mv, when the other was at 40mv. So I ordered a new pair of JJ 6L6's.

@robespierre - I agree completely with dialing in the sound once the system is setup as will be played live, including actual volume levels. I've learned that I can dial in my tone and as soon as I really crank it up, I have to do it all over again. I am also aware that you need to set the output type on the GNX3.

@julia - you are awesome. I agree with everything, I didn't think of using compression. Duh, I should know better. I had thought of mic'ing the amp into the FOH PA. I have my Deluxe module gain set at 9 oclock, with the module volume around 3 oclock, and my Master Volume around 2 oclock.

 

[Mattfig]

+1 on 6550s...I like 'em better than 6L6s myself...Tung Sols are great tubes for a great price...

 

[kc2eeb]

Try dougstubes.com for KT88s. KT88s will give you the highest headroom.
I worked for Sam Ash on 48th St. NYC in the 70s. At the time
the Grateful Dead were using Alembic for sound. They were in love with
Crown DC 300 power amps and Alembic parametric equalizers.
Obsessed with CLEAN. Yes, all solid state.

 

[crankyrayhanky]

It's a mirage. This digital unit may appear to sound great through headphones and recording, but playing live in a band, it will sound sterile, ice picky, and flat out BAD. Do not expect that this unit will be the core of your tone...

You bought a killer tube amp, grab some clean & mid gain modules: a BFace, JTM, Tweed, Plexi. Get a great tone before applying fx.

My 2cents is that cheap digital machine will destroy your tone if you continue the course.

 

[kc2eeb]

P.S. I didn't say I liked the tone. That's just what they used at the time.

 

[JudMan]

kc2eeb - I tried bypassing the preamp modules as mentioned, sounded good, but not even close to loud enough. I did some more research on the KT88's and that seems like a good move, just going to wait until I try out the new JJ 6L6's first. And I'll probably invest in a clean module before springing for the KT88's. Yeah, I've looked a lot at how Jerry setup his rig. He used the preamp stage of a Blackface Fender Twin, which, eventually, was PA'd by a McIntosh MC2300. (Yep, another solid state amp, granted, a nice one) I don't plan on trying to replicate his setup, I do want to develop my own tone, not just copy his.

crankyrayhanky - I appreciate the advice. I don't expect my meager GNX3 to come close to the real items that it is 'supposed' to model. Having said that, I got it for free as a gift when my brother upgraded to a GNX4. I can't afford the real stuff all in one shot. So I do plan on slowly building my gear to the point that I can relinquish my dependence on the GNX3. This first step of this process was to purchase the RM50. Yay! I think my next purchase will probably be a clean module. I'm leaning toward the Blackface. I would love some input on which clean module. I did listen to a youtube vid where The Tone King compared clean/KH-1/Super V. I have no idea why he chose the Super V instead of the Blackface, but oh well. In that vid, I seemed to prefer the KH-1, but wish I could have heard the Blackface as well.

Ok, enough for tonight, Thanks to all who've responded, I'm learning a lot!

 

[kc2eeb]

Probably the cleanest set up using only the RM50 is the Blackface
module with KT88s. Leaving any outside effects out of the equation,
it becomes a matter of pick-up output and HEIGHT. The Alembic guitars
that I sold at Sam Ash, way back when, if I recall correctly, were low impedance and low output. Try this. Lower your pick-ups, I mean really
low, just don't have them thread out of their screws. Turn the master on the power amp fully up, and the master on the module fully up.
Then use the gain for volume adjustment. Remember, the tone stack
on the Blackface, just like the actual Fender, is passive and BEFORE the gain control, so, the treble, middle, and bass can be viewed as passive
volume controls for their respective frequencies. If you shut them all off,
you'll get no sound. You can also use a 12AT7 or even a 12AU7 as the
very first input tube, not in the module but in the amp. (It's the one closest to the input jack.)

 

[JudMan]

kc2eeb - I'm loving your tips, thanks a million. Your comment about the first input tube has got me very curious, are there schematics, or at least block diagrams for for the Randall amps/modules anywhere?

 

[kc2eeb]

I believe you can get schematics from Randall's customer service.
Call them, not email.
Re: tubes.
Besides the output tubes, the three tubes on the chassis (not modules)
are First, the input preamp tube, closest to the input jack.
Third, phase inverter/driver tube, the one closest to the output
tubes.
Second, effects buffer; send and return.
Also, if you have the built in reverb, something you should know.
The reverb pan has a PC board attached to it which contains the complete
reverb amp drive/recover circuit. That's all solid state and powered
by a 9 volt AC tap on the chassis. And, yes, it can be used as an
independent effect if you supply it 9 volts AC, not DC, from a small
wall wart transformer at around 500ma minimum.
Download the manual from the Randall website.
You have to ckick on "About Us" to open a menu, and then, click on manuals.

 

[speedemon]

Yes,

lots of good suggestions. I agree with Crankyray, the processor with the amp will disappoint in the long run. If you want some super clean, put a weaker tube in one of the clean modules, I would suggest a 5751 or 12ay7 over the at or au, though all will cut gain on the front end. The 12ay7 may be TOO weak, so try the others first. I had a NOS black plate 12ay7 in my Tweed for a few days, SWEET tone, but too QUIET.

Crate makes the power block, which is a small inexpensive SS amp that will drive cabs. SS may work better with the processor. Atomic makes an amplifier for the POD, it might do what you are looking for as well.

Good luck!

 

[JudMan]

An update:

I got a new set of JJ 6L6 tubes and was very disappointed to find that they were not balanced at all. At least I thought they weren't. Tube One was reading around 35mV while Tube Two was at 17mV. My gut feeling at this point was that something was wrong with the amp. But then I began to wonder if I'd gotten a mismatched pair of tubes. I finally came back to my original thought, there is probably something wrong with my amp.

I took it apart and behold, burnt trace very close to Tube Two. I'm guessing a tube went bad and obliterated this path on the circuit board. So I fixed it by running a wire. And now the tubes are biased perfectly with 0.8 mV difference between the two tubes.

OMG, my amp sounds incredible. I just thought it sounded good before. Now my Deluxe module is wicked sweet and much cleaner than before, and wow is this thing loud, and clean! Very happy!

Thanks for reading!