Your amp - down to the nitty gritty

[Mattfig]

After several configurations and testing:

Mine in a nutshell is as follows: 3 RM4s and an RT2/50 as the core....My preamp tubes in the RM4s are straight TungSolECC803 Gold Pins across the board for both the PI and Loop...

Effects are: Lexicon MX200, Rocktron Pro EQ (is set for each module to have it's own EQ settings via MIDI), TS808
Noise Control: ISP Gstring Decimator Pedal - AMAZING!
Tuner: Peterson StroboRack
Power: Two Furman Power Conditioners w/voltage readings and full protection as well as a Tripp Lite Voltage Regulator and Backup Power Supply which buys me a few minutes in the event of a power outage to shut everything down properly...Also reduces noise...
Controllers: Voodoo Labs GCX Guitar Audio Switcher and GCP Ground Control Plus to control all modules, EQ, effects, etc with the push of one button I can change everything! It's awesome...
Power Tubes in RT2/50 are SED "Winged C" EL34s and TAD 6L6GCs...Also run TungSol 6550s sometimes as well as JJ EL34s...
In the Serial Loop are Alesis 3630s- don't use the gates, just compression...Each RM4 has it's own 3630 to keep things simple for me...Plus 3630s are cheap and pretty good for what I use them for...Volume attenuation and VERY VERY VERY slight compression on occasions....

In each module:

Figmods Clean
V1 - JAN GE 5751
V2 - JAN GE 5751

Twinface
V1 - JAN GE 5751
V2 - JAN Sylavnia 12AX7WA

Figmods Top Boost
V1 - TungSol12AX7
V2 - JJ ECC803

XTC - Sacred Groove modded Blue/Red
V1 - JAN Philips 12AX7WA
V2 - TungSolECC803GoldHG*

Mashall Plus
V1 - TungSolECC803Gold
V2 - TungSolECC803GoldHG*

Benzin
V1 - Penta12AX7M
V2 - Ruby12AX7AC5HG+*

Terrier (soon)
V1 -
V2 -

Scorch
V1 - JJECC803S
V2 - TungSolECC803GoldHG*

Salvado Dlx
V1 - Penta12AX7M
V2 - TungSolECC803HGGold*

Chem Angel
V1 - TungSolECC803Gold
V2 - Ruby12AX7HG+*

Figmods Erecto
V1 - JAN Philips12AX7WA
V2 - TungSolECC803HGGold*

Mamba
V1 - JAN Sylvania12AX7WA
V2 - JJECC803HG*

***The tubes with HG mean rated at High Gain...Great in V2, awful in V1....

Cabs and Speakers
Ampeg 412 loaded with Celestion Vintage 30s
Randall 412NXT loaded with Celestion Neodymiums made specifically for the MTS line...Pricey but awesome....Also has updated cabinet simulation built in which is fun to mix lightly with the mic'ed speakers...Provides slight definition and are almost as good as some IRs I've played with...It's easy to use so I use it...Not for primary sound, but more as a filler, if that makes sense...

That's about it, hope it makes sense...I've done a lot of edits as my copy and paste from another program was a mess...

 

[m0jo]

Fig, that's insane!
Totally obliterates my rig, but here it is anyways:

Randall RM4
Tung Sol V1, JJ ECC803 buffers
Twinface: Tung Sol 12AX7, EHX 12AX7
Mash-all+: EHX 12AX7, Tung Sol 12AX7
Sloogie (custom Salvado): EHX 12AX7, JJ ECC83 / Tung Sol 12AX7 (going back and forth over this one)
XTC (stock): JJ ECC83 (high gain). Tung Sol 12AX7

I like my EHX and Tung Sol tubes! New Sensor stuff rocks.
The combinations and order of the tubes is by experimentation.
I found that putting an EHX in V1 (of the module) and a warmer tube like JJ's or Tung Sol after it, gives it agression with body, while the other way around brings out more mud anf fizz.. (so the character changes, while the EQ difference isn't that big)

Randall RT2/50
V1 Tung Sol driver, Balanced JJ ECC83 PI's
CH1: Electro Harmonix 6CA7s
CH2: TAD 6L6GC

Effects:
- Digitech GSP1101 (mustbebeta beta firmware)
- Lexicon MX200
The RM4 is in the loop of the GSP1101, the MX200 is in the parallel loop of the RM4.
So the guitar goes -> GSP1101 -> RM4 (MX200) -> GSP1101 -> RT2/50

And I'm planning to incorperate my pedals soon.
On the floor:
- Korg PitchBlack tuner
- Ibanez Weeping Demon
- Crybaby (modded to Jimi specs + TB)
In the rack:
- Boss SD1 (Keeley/Wylde modded)
- EHX Big Muff Pi
- Sovtek Big Muff Pi (older black one, probably 80s)
- EHX Riddle:Q-balls
- EHX Dr. Q
- m0jo MojoMuff (self built, gated fuzz, adaption of early muff circuit and Z.Vex SHO)
The whole rack is controlled by a Gordius Little Giant, a very flexible midi footcontroller.
I run some patches with preset sounds, some are looser with "stombox" setups

Cab:
TT-Cabs oversized vertical 212, loaded with Eminence The Governors
The oversized vertical setup means it's almost as big as a 412 (10cm less wide) but waaay more portable, also it's bright red! 8)
The extra size gives it some more body, the headroom of the Governors keeps it all a bit tighter than other speakers would be in there.
It's also a flex-back, with removable panel to go from closed to open-back.

 

[speedemon]

I think I stuck this elsewhere, but anyway, I will put it here too!

RM100

V1 GE gray plate 12ax7
V2 Mullard Reissue
PI JAN Phillips 5751

Mr. Scary - black plate 12ax7s, raytheon and rca
Tweed - GE 5 star 5751s
Voodoo Plexi - black plate 21ax7s, rca


Kress 2x12 cab w/ Scumnico 100w and Scumback H55 65w

soon to swap one for a Weber Thames ceramic

Mr. Scary actually better for old Rush tunes than Plexi...
:roll:

 

[Mattfig]

I think I stuck this elsewhere, but anyway, I will put it here too!

RM100

V1 GE gray plate 12ax7
V2 Mullard Reissue
PI JAN Phillips 5751

Mr. Scary - black plate 12ax7s, raytheon and rca
Tweed - GE 5 star 5751s
Voodoo Plexi - black plate 21ax7s, rca


Kress 2x12 cab w/ Scumnico 100w and Scumback H55 65w

soon to swap one for a Weber Thames ceramic

Mr. Scary actually better for old Rush tunes than Plexi...
:roll:

That, my friends, is a man who knows tubes...WOW!!!

 

[slashnstrings]

Nice rigs guys!! wow a MAMBA, i've wanted one so bad, since i first heard one, the Angel is really nice to.

@JKMV12 - your Treadplate is JF modded too?

 

[JKMV12]

Nice rigs guys!! wow a MAMBA, i've wanted one so bad, since i first heard one, the Angel is really nice to.

@JKMV12 - your Treadplate is JF modded too?

Yes it is. I bought it from rhequiem last July and it was mod'd in October of '09.

 

[slashnstrings]

Just took a look at my treadplate here and noticed that the Ruby tube in V1 was a HG, so since everyone says that HG's sound pretty bad in V1 I put the Orange in V! and the RubyHG in v2, dialed in your settings JKMV12.

Everyone's in bed so I can't give it a try tonight but I'll let you know how it goes tomorrow

BTW do you have your bright switch on or off for those settings

 

[JKMV12]

Just took a look at my treadplate here and noticed that the Ruby tube in V1 was a HG, so since everyone says that HG's sound pretty bad in V1 I put the Orange in V! and the RubyHG in v2, dialed in your settings JKMV12.

Everyone's in bed so I can't give it a try tonight but I'll let you know how it goes tomorrow

BTW do you have your bright switch on or off for those settings

I've messed with the bright switch before and it doesn't seem to work. But if it is working and i just don't notice, it was set to the right. I hope it works for you.

 

[slashnstrings]

I know I have posted this somewhere before, but all the tube talk made me read it again, you guys might find this very interesting.

The most important tube in your amp? The Phase inverter!
Many people think that V1 (the first gain stage) is the most important tube in an amp. This is true in some cases but not in all cases. V1 (usually the preamp tube closest to the input jack) has the largest impact on your tone and gain but has less impact on your output distortion touch dynamics and output stage distortion than the phase inverter. The phase inverter is generally the preamp tube that is the most close to your output tubes in most amps.
Let?s think about this for a moment. Today?s amps come in many ?flavors?. There are three basic amp topologies looking at things from one viewpoint.
? Non Master volume amplifiers
? Master volume amplifiers
? Channel switching amplifiers

In master volume amps we have pre and post phase inverter master volume controls. These work differently but for this piece of writing I will put them in the same master volume category. Rolling down the master does what? It allows the front end to be driven harder and thus we hear our front end distort. At some point we can drive some amps so hard in the front end that the tone becomes so compressed and distorted that even I can sound like a decent player! Your mistakes are covered up in the mush and distortion of ti all. This distortion is passed down the signal chain where it is reproduced and amplified by the output stage of the amp. This has nothing to do with output stage distortion. This type of distortion is not touch sensitive. This type of distortion is not something that most articulate players would favor for a sweet tone, blues tone, or even classic rock tones. This is NOT what people refer to as the ?brown sound?.
Channel switching amps. Many of these amps have so much ?junk? in the signal path that hearing tube changes in V1 is a pretty hopeless endeavor. When you do hear a change it is because the tube is closer to industry spec than another tube may have been. If you want to hear different great tones from swapping out V1 then listen to the tube under test in a more classic amp design.

Channel switchers continued. I get calls and letters all the time where people have a ?bonzo-3 channel gripmaster Mk III recto? or whatever. Many owners of these amps say: ?the owner?s manual says that V3 is used for the turbo channel? or whatever. Remember, V1 feeds EVERYTHING else down the line, EVEN IN THESE AMPS. The ?turbo channel? generally does not use JUST V3. The chain is fed by V1. V1, even in multi channel amps is still the most important tube in the TONE AND GAIN stage of most amps. If you want to change the ratio of preamp tube distortion to output tube distortion then we change V1 in some cases. Going from a 12AX7 to a 5751 will reduce front end gain. Going down to a 12AY7 will reduce the front end gain further and generally give one more clean headroom.
Back to the phase inverter. Taking a simple classis non-master volume amp (but this is the same for master volume amps as well actually).
I will try to keep things simple here with a few basics. If you have questions on all the complex versions feel free to contact me.
Fender Tolex era amps ? These generally used a 12AT7 in the phase inverter.
Marshall type amps ? These generally used a 12AX7 in the phase inverter.
There are many other differences in these amps but I will stick to the PI (phase inverter).
Some basic tube facts
? 12AX7
o Has a published spec gain of 100
o Has a publishes spec current output of 1.2 milliamps
? 12AT7
o Has a published spec gain of 60-70
o Has a published spec current output of 10.0 milliamps (ten times that of the 12AX7 as a side note)

As a third example, a 5751 has a gain which is almost identical to the 12AT7 but it?s standing current is 1.0 milliamps (about the same as the 12AX7). But, there is a third factor, transconductance, to be considered. The 5751 has a transconductance of about 1200. A 12AX7 has a ?TC? of about 1600 and a 12AT7 has a TC over 5000. These three tubes act quite differently. A 5751 and 12AX7 are much more closely related than the 5751 and 12AT7.
We will stick to the basic 12AX7 and 12AT7.
When you push your amp hard it is not as much the output tubes distorting as it is the phase inverter breaking down and distorting. We are talking output stage distortion here. We are not talking about how you may have messed up the signal with preamp tube distortion and compression already. The phase inverter may be the hardest worked tube in most amps. I cannot begin to count the times when I have found phase inverters that were long past their service life. When you change your output tubes change that phase inverter. At the least change it every other output tube change.
Many folks think that when they want to have their amp have more clean headroom they can insert a 12AT7 in place of the 12AX7. Very true. (By the way, the 12AT7 in a first gain stage is an awful tone generator in a guitar amp. If you want to drop front end gain use a 5751 (gain of 60-70) or a 12AY7 (gain of 40). The 12AY7 was the first gain stage in the classic Fender Tweed Bassman, Deluxe, etc.
Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps. Is this because the gain is lower in the 12AT7? 10% yes perhaps. The lower gain is a factor but the larger factors are:
? We have almost 10 times the current available to drive the output tubes before the phase inverter starts to break down.
? We have a transconductance of 5500 vs 1600 of the 12AX7. Keeping this simple, it means it takes a lot less input signal for a given output signal.
The output tubes are less important than many folks may think. Think about this. In the Hi-Fi world there have been many amplifier designs. Some such as the Scott and Fisher lines used EL-84 output tubes. McIntosh used 6L6 and 6550 / KT88 tubes. Dynaco and some British amps used EL-34 tubes. All of these amps, when operated at the rated specs generally stated that from 20-20,000 cycles at .5% distortion or less they were considered ?flat? by industry spec. The output tube type had very little to do with anything. In guitar amps we purposely push the output tube beyond their design limits to make them distort. The difference between a Svetlana 6L6 and an RCA 6L6 is the difference in the way the tube sounds when it is pushed beyond it?s design limits. Being in the ?tube business? this is not a great subject. What I am basically saying here is: Before you go to a pricy output set of tubes and a possible need to rebias the amp think about a simple phase inverter change. There are no amp adjustments necessary when you change the phase inverter.
In real life we rarely get to the point of pushing our output tubes to their limits. Our front end is going into distortion. Our phase inverter is breaking down too. The ratio of this front end distortion to phase inverter drive and breakdown is determined by amplifier design topology. You cannot make a Marshall into a Fender no matter how many people tell you that this can be done. Putting 6L6 tubes in a Marshall will NOT make it sound like a Fender either.

There are many 12AX7 types of tubes available. They are all different even though they are supposed to have the same specs. Even when one looks at the same tube type from the same maker out of the same production run we find HUGE variances. +/- 50% off spec is common. Most 12AX7s today show a current output of 0.6-0.8 milliamps where 1.2 milliamps is expected. You throw a 12AX7 in your PI slot with a 0.8mA output and you are 30% down on what the amp can do right off the bat. Your amp is not as full, tight, responsive, or just plain ?powerful? or dynamic. Many of today?s high production amps use the Sovtek 12AX7WA short plate as a generic 12AX7. I have issues with these in the tone and gain stage but staying with the topic of phase inverters, these are just awful (12AX7WA Sovtek) for the most part. In tests these show very low standing current. The Ei long smooth plate also shows low standing current, even though a long plate. Generally, large plate tubes will show higher standing current but this is not always the case. The JJ ECC83S has the highest standing current of any current production tube. The JJ is a short plate tube. The JJ is an exception. You might think the JJ would be a good PI. Not from my personal taste. The way the JJ breaks down is not as musical to my ear in most amps and I do not care for the touch response and dynamics of the tube in the PI position in most amps. What do I like? I like the Sovtek 12AX7LPS and the GT 12AX7M. The GT 12AX7M is also available as a matched phase inverter from the SAG over at GT as the SAG-AX7-MPI. There is also an SAG-AT7-MPI. I have talked about matched phase inverters in other places prior to this piece of writing. The 12AX7M and 12AX7R2 (Sovtek 12AX7LPS) are both long plate designs. In either case I check these for specs because in all cases there is a wide range of variables from tube to tube and run to run in production.

There are a lot of great NOS tubes. They have advantages in the tone and gain stage but they are not as available as production tubes made today. When you are on the road or on tour these are harder to find. In the case of the phase inverter we do not want to stock a bunch of Mullards or Telefunkens to burn up every output tube set change. There are great current production tubes that give us all we can ask for.
Other great phase inverters to consider are the 5751, 12AY7, and 12AU7.
The bottom line here is simple. The phase inverter is one of the most important tubes in your amp and the hardest worked tube in the preamp section of your amp. It is how this tube breaks down that provides your output stage distortion tone, character, and amp feel.

Myles S. Rose
www.guitaramplifierblueprinting.com
www.groovetubes.com

 

[speedemon]

Yes,

I read that article, and I believe I referenced it elsewhere, pretty informative stuff!

Thanks Matt, for the kind words. I wish they were true! lol I found that I simply prefer the long black plate to the gray plate. I wish I could sort them out. But apparently they get rebadged so much that it's kind of useless to try. When I read that article, I had a bunch of tubes tested, and sure enough, they were all over town; the ones tested higher sounded better, regardless of brand. Tube designs do vary among the modern tubes, so my brain imagined some of them darker, brighter or gainier. You will read EVERYWHERE that the old tubes are better made than new ones, so they can be used more reliably.

Has anyone tried to use a 12AT7 int he PI of an RM amp? At least one poster liked to use that in a module.

All my modules are stock, so its up to someone else to tell us if old tubes make a difference in the modded modules.

Que Julia to come in here and tell us what a bunch of idiots we are (ok, she isn't that mean!), that speakers make the difference, and the only thing I can say is "yeah, the difference between my cab with the new Scumbacks and my friend's with the broken in V30s is enormous."

 

[slashnstrings]

yeah im pretty sure i posted it like in Feb 2010, but couldn't find the post.
and yeah Julia has made her speaker argument very clear in the past but I still love messing with tubes though, all the time.

 

[Mister Joshua]

Yes i use 12AT7's in the PI of my RT2/50's. They sound pretty good. I find them to be a little cleaner and tighter but other posters have complained that they are weaker and thinner. It really seems to be up to the listener's ear in the end. It also matters what tubes you use elsewhere and your basic sound philosophy. So plug one in and see what you think. My amp rig:

RM4: Tung Sol 12ax7 throughout.
Loneclean: Tung sol 12ax7 in both
Plexi: Tung sol 12ax7 in both
Deadplate: JAN Philips 5751 in v1, Tung Sol in v2
Xtacy: Tung Sol 12ax7 in both
Blackface: EHX 12AY7 in both
SL+: Tung Sol 12ax7 in both
Angel: Tung Sol 12ax7 in both
1666: JAN philips 5751 in v1, Tung Sol 12ax7 in v2
RT2/50: Tung sol 12ax7 input, EXH 12AT7 PI, Tung sol 6L6gc and EL34b power tubes.

I'm still playing around but that is where i am right now.

Peace, Joshua

 

[Hamner1]

RM4
V1: 12AU7 Chinesse
Others: JJ ECC803

Tweed:
V1: JJ ECC803
V2: JJ ECC803
* I may try a GT 12AU7 in V1 to see what that yields

SL+
V1: JJ ECC803
V2: JJ ECC803

Mr Scary
V1: JJ ECC803
V2: JJ ECC803

Grail
V1: 12AX7WA
V2: JJ ECC803

GTO
V1: :?:
v2: :?:

 

[paul525715]

Not strictly a Randall amp as I sold my RM4 and built a hand-wired 4 channel head but the circuits for each preamp are 99% identical to the circuits from the modules I used to use in my RM4 (and FWIW the output stage is based on an SLO).

Input:
JJ ECC83S (1st half of shared tube with Deluxe V1)

Deluxe:
V1: JJ ECC83S (2nd half of shared tube with Input)
V2: 12AX7EH

Top Boost:
V1: JJ ECC83S
V2: 12AX7EH

Plexi:
V1: Shuguang C9 12AX7
V2: Shuguang C9 12AX7

Rectified:
V1: Shuguang C9 12AX7
V2: Shuguang C9 12AX7

FX Loop: ECC82EH
Reverb: JJ ECC83S
PI: Shuguang C9 12AX7
Output: Shuguang 50yrs Treasure 6CA7-Z

 

[slashnstrings]

Very nice amp Paul. what is the bottom portion of it? a recorder?

 

[paul525715]

It's a boss gt-pro. Whilst it's not the best fx unit in history, it does the job!