Looking to warm up a modeler

[RandomHero]

If I put a tube preamp in between my modeler's output and my amp's in, would it warm up the signal noticeably? I'm trying to get rid of the "boxy" sound of my modeler, but don't have much money to just upgrade...

[UnklMickey]

sounds reasonable, but tube pre-amps ain't cheap either. might be pretty similar in cost to add the preamp vs. upgrade the modeler and trade in or sell the old modeler.

[Keebo]

A lot of the folks on the POD forum noticed a small improvement upon adding a tube pre in the chain initially. But if memory serves me, it was mostly short lived.

I ended up warming my POD xt by sending it through an Atomic Reactor 112 tube amp made especially for modelers. A bit pricey but the modeler sounds much better and it also sounds great with any guitar pre amp like my Rockmaster.

[lou]

I'm using a Vox Tonelab SE, it's the best modeller I've tried for tone and feel, but in the never-ending quest for MORE I tried my ToneBone 12AX7 pedal in line as well.
..it didn't make a big improvement, due to the fact that the Tonelab's pre gain modelling is pretty durn good already, and the 12ax7 on the output of the SE is also doing a good job.
The ToneBone is a great pedal, but just didn't make enough difference, in this setup. It does well in other setups I've used, but just not in this one.

However, there's still a difference between the modelling Tonelab's tone and a really good tube amp.
I know, I know, the tradeoff using a modeller is a much quicker/simpler setup, more variety, no maintenance, etc. but a little voice keeps telling me there's a magic combination out there somewhere...

..which leads to my next quest (and question..)

I'm considering one of two options:
1) Rebuild my mid 70's champ with one of the 'vintage 60's' mod kits to use before/after the Tonelab, or
2) Buy a new small CrateV58 or Crate V1512 to put either before or after the Tonelab, or in Tonelab FX loop.

I've tried the Crate by itself, pretty nice tone. Haven't tried a modded Champ yet by itself, and don't want to spend the $$ on the mod unless I'm sure it's going to work.

Any opinions on any of the above before I ignore all the advice, dive in and do whatever I want anyway?

Lou

[dunkelfalke]

tried it out. sounded worse than alone. i doubt anyway that a preamp can add any warmth

[Runewalker]

I'm trying to get rid of the "boxy" sound of my modeler, but don't have much money to just upgrade...

I don't know if "boxy" is a universal term but it certainly nails the tone issues I have found in modelers --- its as though the output is though a baffled refridgerator cardboard box. That ugliness is vexing.

I use a GNX2 which is the same as a GNX3 without the 3 minute record feature.

I am happy with it for the most part, although the 'perfect tone" holy grail quest is still eluding me. But I am able to get serviceable ranges of modeling, distortion, effects and stomp box combos.

I have approached the dreaded "boxiness" serveral ways. I don't know about Pod or Tonelabs, but the GNX always gives you two amp choices per setting, unless you start morphing them into wild combos.

So you can set both amps to the same base, say a Marshall stack, then EQ each at opposite ends of the spectrum so you emulate a 6 band eq. These extra bands help dial out the boxiness, which seems to reside in the mid and lower mid frequencies.

It also seems the cabinet tuning accentuates boxiness, and must be used judiciously if at all.

I have thought about a 10 or more band dedicated EQ between the modeler and amp, but then you have variable settings between patches, so the best thing is still to dial it in the modeler if possible.

Finally, I changed the the tube amp settings of my Fender Twin brain, moving from low power amp output, high preamp, to the inverse. This warms up the edginess of the modeler, but has little impact on the boxiness sound.

So I question any tube "warm-up" having success in eliminating or softening the boxiness. That effect seems endemic to the modelers, expecially acute in some amp and cabinet emulations.

There is another aritifical artifact that also surfaces which is sort of the opposite of the boxiness. I don't have a term, but the symptom is a somewhat solid state type jagginess in the upper frequencies, that is like too much gain there, but not enough to clip. For that symptom the tube warmth is quite helpful.

One last comment, is that in my experience the modeler "does not play well with others." For example I have taken basically clean Twin type (blackface) settings and run, say, a Ibanez Tube Screamer, pre and post. And the effect is disappointing, especially compared to the onboard Tube screamer stomp box emulator. Not having run multiple test of compatibility with other boxes, that one experiment was a letdown.

RW

[lou]

Got a crazy one for ya...
Not the cheapest solution, but one that works..
I bought a Crate V1512 and tried the Vox Tonelab through it, helped warm it up a bit but not a lot, and meant I was mono only to the board (SM57 on the Crate speaker).
So here's the crazy part- what about the reverse order?
-I tried it and it's the solution. Guitar to Crate amp, mic'd to Vox Tonelab pedal. Warm tube tone, killer dynamics- I run the Tonelab pretty clean and use it for stereo FX, some coloration and main volume pedal. The Crate is the crunch and warmth, the Vox is the rest. Best of both worlds.
It does require an impedance convertor (inline transformer) to get the mic into the ToneLab, and I have some other tone tricks (mainly Barber Pedals) but as far as making the modeller work, this is the bomb.
This has become my onstage setup, and it works great.

Lou

[dunkelfalke]

runewalker: so you use a digitech gnx2, right?

1) have you tried to use it either plugged into "return" instead of amp in or just to plug it into a poweramp?

2) i have heard that there are special patches that are much better than stock, called super models or so.

[Runewalker]

I forgot about this thread. And then saw the title on refresh, going alright, one of my favorite topics, only to find I posted long ago.

Posted by dunkelfalke on Today at 2:06am
runewalker: so you use a digitech gnx2, right?

1) have you tried to use it either plugged into "return" instead of amp in or just to plug it into a poweramp?

Yes I use the GNX2. It took a long time working with the Genedit patching program to carefully tweak settings to where I wanted them. I finally generated an array of, for me, satifying tones, that have also been lauded by real musicians. It is a remarkable device, but you have to invest the time to dial it up.

A key is to match patches to the destination. Basically if you are going to another Solid State device, expect a few "does not play well with others" moments. For example, if I use it in-line to the computer to record with, say, Guitar Track Pro, I expect that transistery graininess that can be so iritating about modelers or some of the dredded "boxiness." Therefore the best thing to do is develop patches for that application.

My current favorite tube amp needs new power tubes I have not put it into the shop for the biasing, a) because the backlog with the Austin musians flooding the shops means it sitting for 3 weeks before they even look at it, unless I pay an "expediting fee" --- extortion. b) I'm irritated I don't know how to do the biasing myself, because plugging in tubes is easy.

That amp as a destination needs its own tweeking, but it really smooths the edges of that solid state sound, turning the system into one scary, hide the women and children, jugernaut.

With the Fender resting, I am using a Solid State Behringer, which has its own fixed modeling patches. I just dial it clean and dry, adjust the bass, mid and treble a bit, then wail. However, to get to your question --- Finally, he says ---- it has the line in availabity.

So yes I tried it and found it flat and bassy. It would require the custom patch development described above to sound right, and since this is a temporary solution, and I have dialed it up to an acceptable level through it's pre-amp, I don't use the line in function.

That is the point though that I made. What ever your destination require customization to you patches. It may just mean minor adjustments or complete rebuilds, depending on where you are going.

2) i have heard that there are special patches that are much better than stock, called super models or so.

There is so EE dude who supposedly has sampled representative recordings -- Angus Young and his stacks, Dire straights, Metallica, Neil Young --- whoever and on and on.

He then waveform-spectrum analizes the representative samples, and programs the GNX patches with a side by side waveform generator until they are congruent. He has hundres and sells I think 1 - 2 CDs of patches that are pretty pricy --- seems like I remember $150.

Let me dig around to see if I have a link.

Alright, no link but my search revealed at least some of his samples he posted on the Digitech patches forum. He posts under the name:

guitar3456

I think he posts as sort of an advertisement to his patches.

But I have read about his process somewhere. Really, it's within the capability of the brains in this forum, but he has done the work already.

I have some of his samples if you want me to P-mail them to an address that takes attachments, and I have a few choice ones myself. Of course if you don't have the GNX2 you'll need to get the converter program from Digitech (free) for upwards or downwards compatibity.

The method I described in my earlier post regaurding setting up reference patches with the equivalent of a six band EQ is a notion I have not seen anywhere, and is a pretty nifty way to elongate the frequencies that may be adjusted. Also, I understand the EQ is parabolic, meaning if you adjust say the 2200 cps point up, that adjacent frequences fall off either side of the 2200 reference in a graduated curve.

These are remarkable devices. Most guitarist who trash them have not bothered with the learning curve, and that is understandable. They want to play, not program. But the factory presets range from limited to awful. I know a guy who spent $600 on the GNX4, and uses the factory presets only.

Reminds me of a favorite saying:

"Money is wasted on the rich."

Sorry this is so long, not many folks on the board seem fired up about modelers, so I guess I have some pent up demand.

[dunkelfalke]

no gnx yet, just have informed myself about gnx3000 because i have heard that if you plug that beast straight into poweramp it would sound nearly as a tube amp.

so i have written other things i have heard about those devices in a hope that it would help you.

i am using a behringer x-v-amp right now and it sucks.
still haven't given up on digital modellers though

i will definitely buy that gnx3000, just for recording alone and i am also thinking about a toneworks pandora px4d (would be a perfect fit to my headless guitar for rehearseals on the go)

[sumgai]

RW,

Count me in as a modeler, I've got the biggest, baddest one on the block a VG-88, v2. ;D

One thing that dunklefalk said bears repeating - you must use a flat frequency response amplifer and speaker(s) if you model or simulate any kind of guitar amp or even just a speaker cab. No modeler made and sold on the market yet has the ability to make a Fender Super Reverb sound like a Marshall stack, nor vice versa. Just a fact of life.

One thing I have done to make life, umm.... interesting, is to dig inside of one of my Twins, and bypass the entire tone stack. I just jiggered the Bright switch to become a bypass switch, and voila, the Normal Channel is now nearly flat (+ or - 3dB) from about 45Hz out to 6.8 or 6.9KHz. Not real good, but not too bad either. (Actually, I did this for my GR-33, but that's another story. )

Just something to think about, when you already have an amp, but don't have a lot of extra cash floating around waiting for you to spend it on yet another amp. ;D

My current favorite tube amp needs new power tubes I have not put it into the shop for the biasing, a) because the backlog with the Austin musians flooding the shops means it sitting for 3 weeks before they even look at it, unless I pay an "expediting fee" --- extortion. b) I'm irritated I don't know how to do the biasing myself, because plugging in tubes is easy.

Tell me exactly what model amp this is, and I'll give you the lowdown on how to bias it. Properly.

Scout's Honor!


sumgai

[Runewalker]

Sumgai, I am liking you more and more. I have an affection for Rolands gear, just little experience. At some point I'll be ready for a new generation model(er), but not now.

I just acted as a conduit for a friend of mine to buy a green strat. The seller also has an old Sherwood 80 watt tube stereo tube amp that I am thinking about as a back end to the modeler, as it has stereo outputs.

One thing that dunklefalk said bears repeating - you must use a flat frequency response amplifer and speaker(s) if you model or simulate any kind of guitar amp or even just a speaker cab. No modeler made and sold on the market yet has the ability to make a Fender Super Reverb sound like a Marshall stack, nor vice versa. Just a fact of life.

One thing I have done to make life, umm.... interesting, is to dig inside of one of my Twins, and bypass the entire tone stack. I just jiggered the Bright switch to become a bypass switch, and voila, the Normal Channel is now nearly flat (+ or - 3dB) from about 45Hz out to 6.8 or 6.9KHz. Not real good, but not too bad either. (Actually, I did this for my GR-33, but that's another story. )

I though D was talking about circumventing the preamp side entirely. If I understand your Twin mod, you stay out of the passive tone controls but still use the preamp? I only had the one amp to test direct into power amp, and that was unsatisfactory. But it sounds like you are saying something different. I want to understand that exactly.

Because:

My amp is a 1972--73 Super Six Reverb. A standard silverface Twin Brain, with a Six 10" Jenson cabinet (integrated cab, not brain plus). A big ol beast to move, but I have become attached the big landscape of sound that baffle array provides. A wall of sound.

Its the 100W not the 130W., and the link below has a hyper to the schematic. I don't think mine has the P/P master vol switch bypass. I use the Master Vol at 10 because I want only its clean overhead, not its distortion capabilities, which are mediocre.
At 5.2 ohms instead of 8 this sucker gets LOUD.

The clean overhead with the modeler is the key. And the tube amplification make a noticiable difference in the final sound combined with the modeler. It seems to take the SolidState edginess off the modeler.

I still think that there should be a SS amp that does the same thing, I and my budget have not found that yet. But hauling a 40W SS around would be better than the lubbing my Beast. However, I love the Beast. silverface and all.

www.ampwares.com/ffg/index.html

go to the Super Six hyper on the index.

Biasing:

What equipment is needed?

Schematic:

I can pmail you the jpeg, I just need an address that accepts attachments. Pmail me though the board if you want that.

[UnklMickey]

RW,

if you want to know what your Super6 will sound like with the tonestack bypassed, set the treble on 0, the "middle" on 10, and the bass on 0 ~ 0.5 . that setting is close to flat.


but don't even try to find a setting on a Vox or Marshall that's flat. they ain't no such animal.



unk

[sumgai]

Rune,

Well, as The Unkster says (I'm growing to really like that nick!), the tone stack settings are close, though there is still a small problem. But to answer your question, yes, I use the preamp stages in all their glory - how else am I gonna drive the power amp stage? Of course, if you use an amp with at least a "Line In", or better yet, a "Power Amp In", then you don't need to do what I've done. I suspect that's where dunklefalk is coming from.

OK, on with the show. The problem with the typical tone stack is that the Treble and Bass controls are typically the cut type. They center around a given pivot point, often somewhere just above 400, maybe 450 Hz. The Mid control is an attempt to emphasize that narrow range, thus making the overall sound less "surf-ish" or less "country-ish", if you will. Long story short, it was an attempt to appeal to broader musical tastes of the early 60's jazz audience.

Fast forward to right now, right here. What I'm saying is that I have a Twin, it was (and still is) my main gigging amp, so I proceeded to elimnate all the tone controls from the preamp stage - the veritable tone stack. The small cap across the volume control, all the caps and all the pots, they're completely out of the loop when I hit the switch. (As an aside, I did that bypass switch thing for comparison purposes only, but decided that there wasn't any reason to go back in and hard wire the unit one way or the other, so I left it alone, so there it sits to this day.)

Now, this was all for the purposes of using a GR-33, a guitar synth by Roland that is amazing to those of us who choose to keep some of our money in our pockets, instead of supporting Roland's (and the retail store's) greed when it comes to vastly over-pricing their synth products, usually keyboard in nature, but sometimes even just the rack mounted and midi compatible stuff. What happened afterwards, of course, for the purposes of this discussion, is that I subseqentially obtained a VG-88, the modeler in question. And I'm sure you can guess the number of nanoseconds before I plugged that into the "flat" channel of the Twin. Bingo! Wall-to-wall Marshall stacks, all over the place! (And if you've been keeping score at home boys and girls, yes, I have mentioned that I use a pair of Twins. I bought the second one after "getting religion" from the VG-88 experience. You need stereo to take full advantage of these things! ;D)

OK, what else? Oh yeah..... Uh, as a retiree who works to keep the old lady from bugging him all time with "honey-do" jobs , I have just about every Fender schematic and layout drawing they've ever released into the wild. I'll start another thread in a moment to address the bias adjustment topic.

IIRC, the '72 came with no p-p Master Volume switch, '73 was the transition year, some got it, some didn't, and all 74's definitely should have it. And yeah, it was a copout, all it did was to route some of the reverb drive signal directly to the third stage input (essentially bypassing the 3.3M resistor), it could have been done a lot better. Make that a lot better. If you know how to date your speakers, pots and xformers, that'll settle the question of this thing's age.

Home stereo hi-fi stuff is OK for fooling around with a flat frequency amp (to run your modeler through), but I wouldn't depend on it for anything more rigorous. I'm sure you know the drill by now. (Although, at one time, Sherwood was a pretty big name in the hi-fi industry. If this thing is truly an ancient tube monster, it might be worth some money. Just something to consider.)

And if my memory truly hasn't gone around the bend, then you might wanna check your output transformer. As I see it (and the FFG backs me up on this), the only place Fender used an 100watt, 8 ohm output xformer was on the single speaker Showman and the old Vibrosonic (not sure about the new ones, though). If you have it on hand, you might also riffle through the book "Fender Amps - The First 50 Years", they've got muy detailed information, too. In theory, you should be feeding a 4 output into that 5.333333 ohms, not 8 ohms. But that's still a formidible combination, don't let anyone tell you otherwise.

D4mn, will you look at that, the sun's come out. Time to make hay while it shines, I'll be back to start that bias thread this evening. (I'm in Seattle, in case you're wondering.)


sumgai

[njsedlacek]

Behringer Mic200 Ultra gain. 12AX7 tube preamp. i have one in my loop after my Vox tone lab. it's amazing, trust me. if you're looking to bust out of the somewhat not-so-full sounding modeler. add it. it's only $50. it gives your modeler a more full sound. it adds those impurities into your signal that solid state doesn't have, nor cannot unless there is a tube involved. it adds warmth to your tone, and give you a fuller sound.

[natas]

check out the Ampeg SVT DI.
great coloration!

[ChrisK]

If I put a tube preamp in between my modeler's output and my amp's in, would it warm up the signal noticeably? I'm trying to get rid of the "boxy" sound of my modeler, but don't have much money to just upgrade...

I have just this setup. It's called the VOX AD50VT (modeler->tube amp->amp) ;D ;D
(Sorry, I couldn't resist from a previous thread.)

Count me in as a modeler, I've got the biggest, baddest one on the block a VG-88, v2.

YEP, these are great!

One thing that dunklefalk said bears repeating - you must use a flat frequency response amplifier and speaker(s) if you model or simulate any kind of guitar amp or even just a speaker cab. No modeler made and sold on the market yet has the ability to make a Fender Super Reverb sound like a Marshall stack, nor vice versa. Just a fact of life.

I use my PA system or my Acoustasonic Pro for this exact reason (and I do have piezo equipped guitars).

One thing I have done to make life, umm.... interesting, is to dig inside of one of my Twins, and bypass the entire tone stack. I just jiggered the Bright switch to become a bypass switch, and voila, the Normal Channel is now nearly flat (+ or - 3dB) from about 45Hz out to 6.8 or 6.9KHz. Not real good, but not too bad either. (Actually, I did this for my GR-33, but that's another story. )

One of the things that Allen Amps does is to lift the bottom of the tone stack with a pot. It's called the "RAW" control since, well, the gain is increased and the tone gets raw. If this is coupled with a gain reduction pot section, it may well allow the incremental "flattening" of the freq response.


Now, if you could just figure out where to mount the tweeter....

[sumgai]

Chris,

Mount the tweeter as in, where to make if fit, physically?

I have been thinking of a Fender Acoustasonic, or one of its clones. Does almost too well on the straight magnetic pickups, all things considered. I haven't heard of anybody running a VG or a GR through one of these though.... have you, perhaps?

One of the things that Allen Amps does is to lift the bottom of the tone stack with a pot. It's called the "RAW" control since, well, the gain is increased and the tone gets raw. If this is coupled with a gain reduction pot section, it may well allow the incremental "flattening" of the freq response.

Got a schematic of this yet? I think you said that they don't use the standard Fender-style tone stack (occasionally called a Baxandall circuit), they do something else, right? I know that in a Fender, the Mid control is lifting the bottom of the tone stack off of ground, which leads me to ask my question here......



sumgai

[ChrisK]

I was joking. ;D

Since your flat response channel goes out to 7 kHz, perchance a tweeter will extend the response beyond what the 12" speakers can do. I'm not actually serious about you doing this.

The Acoustasonic is cool. While not as enjoyable as a G-DEC in making one want to continue to practice, the surround sound makes most of what I (mis)play "fun'er". Other amp types that can be used with a modeler are bass amps with tweeters and (gasp) keyboard amps.

(occasionally called a Baxandall circuit),

I believe that this schematic is more of a Bauxandall structure:

www.carvinmuseum.com/pdf/amps/ValveMaster.pdf

The Fender structure is really a mid control subservient to a bass control subservient to a treble control.

[UnklMickey]

chrisk said:

...The Fender structure is really a mid control subservient to a bass control subservient to a treble control.

Chris,

IMHO, you are being WAY too generous.

i'd probably call it a 3-knob circuit, with 2½ controls.


FWIW,

in addition to the slightly skewed (in a GOOD way) version that Carvin used in that amp,

Ampeg also uses a passive version (Peter Baxandall's original design was active) of the Baxandall.

and i just discovered this week, looking at a print, that Orange also used it.



unk

[ChrisK]

National Semiconductor's 1980 Audio Application Handbook (reprint). I do have an original somewhere...

(Of all of the things that I've lost, I miss my mind the most.)


www.audioxpress.com/bksprods/books/bkaa59.htm

[sumgai]

Chris?

Would you please do a careful comparison, component-by-component, between the ValveMaster's tonestack and that of any Fender tube amp, Black Face and later? Excepting the nominal value changes, I can't see any differences between the two.

Well, they're drawn in different orientations, but that's it.


And unk is correct, the original Baxandall design was active, but the name has been mis-applied to passive circuitry for so long..... Sorta like Leo's blind spot about tremolo and vibrato. ;D

sumgai

p.s. why the reference to the National Semiconductor book?

[JohnH]

If you dont have it, you guys should download the 'Tone Stack Calculator' - a great free gadget:

www.duncanamps.com/tsc/

The passive 'Baxandall' design is attributed to James - quoting fro the help file:

"The James control was described in Wireless World during February 1949, although it is claimed that Michael Volkoff first used this type of control in July 1939. Many would describe it as a Baxandall control, although the true Baxandall control was an adaptation of the James control using negative feedback."

it provides great insight into how ineffective amp tone controls can be!

cheers

John

[ChrisK]

p.s. why the reference to the National Semiconductor book?

Because it had one of the best description of tone control (and audio in general) circuits of the day (1980).

While the Fender tone stack and the James modified circuit in the Carvin look most similar, they are not.

When the treble is all the ways up in the Fender, the other controls have less effect. The output comes from the treble pot wiper. This is a treble-dominant series structure.

The James tone control circuit is a parallel structure (except for the structural abomination of the mid control). While passive in nature (little cut, medium cut, large cut), its treble and bass interactions are fairly separate. In the active Baxandall structure, they are much more separate.

This is a post regarding the differences between Fender and James structures. While I have skimmed it, I can't verify its accuracy. The author discusses boost, but neither of these structures render actual boost, just frequency variations in insertion loss. The real "boost" is post-structure gain.

www.duncanamps.com/technical/baxandall.html

Here's one that graphically shows differences and has a link to a tone stack simulator program.

www.duncanamps.com/technical/tonestack.html

[sumgai]

Chris,

.......
When the treble is all the ways up in the Fender, the other controls have less effect. The output comes from the treble pot wiper.

That's got my attention, lemme go test that theory right now, I'll be back in a few moments............

This is a treble-dominant series structure.

The James tone control circuit is a parallel structure (except for the structural abomination of the mid control). While passive in nature (little cut, medium cut, large cut), its treble and bass interactions are fairly separate. In the active Baxandall structure, they are much more separate.

It took me a moment to see how you got there, but I now follow you just fine. There's this "little" matter of ground connnection on the treble control that I missed the first time around.

This is a post regarding the differences between Fender and James structures. While I have skimmed it, I can't verify its accuracy. The author discusses boost, but neither of these structures render actual boost, just frequency variations in insertion loss. The real "boost" is post-structure gain.

www.duncanamps.com/technical/baxandall.html

Here's one that graphically shows differences and has a link to a tone stack simulator program.

www.duncanamps.com/technical/tonestack.html

Interesting presentation there. I'll have to devote some time to it tonight or tomorrow morning. Let you know what I took away from it after I've digested if for a day or two. ;D


sumgai