DIY Digital modelling: An idea on how to authetically valve up a solidstate rig?

[GrantsV]

Disclaimer: I am not saying either tube or SS are better (I own both types), nor am I saying that you don't need a tube poweramp, each to their own. This is purely a hypothetical example for constructive discussion - not the usual "SS sucks!" or "Why bother when you can buy a tube amp?" answers please.

 

All this talk about modellers and how they are trying to emulate valves gave me an idea. Especially the Valvetronix, how it uses a digital preamp (just like POD), then a powertube tube emulation, then into a completely clean poweramp for amplification.

 

We all know that if you listen to a CD of a great guitar player, he sounds great. And a CD/hifi is solidstate! So its not the reproduction/amplification of the sound thats the problem - its the creation of it. Even Van Halen only used his variac'd and powersoaked Marshall as a preamp. He then ran that signal to a Palmer Speaker Simulator/DI box into H&H solidstate equipment to cleanly amplify his signal.

 

So, if the powerstage doesnt have to add valveness to get an amazing tone, therefore your preamp sound is great enough to begin with, all you have to do is cleanly amplify it with a SS poweramp. But what about the feel and natural compression of tubes?

 

My idea is this:

Pick your favorite FX unit (GT6, Pod, VAMP... whatever you fancy).

 

Pick the cleanest poweramp you can find (eg. Samson Servo or anything!... all you want is to amplify the signal as cleanly as possible)

 

Either use full range speakers (if you rather use speaker sims) or guitar speakers (if you want to let the speakers shape the tone).

 

Now pick up a tube mic/line preamp (with adjustable drive and level) - usually used for mixing desk/recording applications. Place this between the FX unit and the solidstate amp.

 

The tube mic/line preamp will mask and round off some of the misgivings of the FX units modelling capabilities. Also giving the signal a nice squashed tube sound and feel. Most valve mic/line preamps have drive and level controls to allow you to choose the level of saturation required, so you can choose to taste the level of valveification you require.

[JimK]

I do like your idea, but....

 

Marshall already makes a hybrid amp that pratically does what you're describing. Their Valvestate line of amps has a tube driven preamp and a solid-state power amp. The complaint about this amp is that many people like the sound of overdriven power amp tubes, which this amp can't produce. Your plan falls into the same trap.

[Gabriel E.]

Yes. Eddie's rig still had a set of cranked power tubes - even if their output was attenuated after the fact.

 

THAT's the key to getting the "tube amp" sound - gotta have a cranked tube output SOMEWHERE in the chain.

 

Your setup is still missing that.

[g.]

Shuddup and play yer guitars ; }

 

 

<-- greenboy ---<<<<    do it with or without tubes. it's still about the music

[TurboDog]

Sorry Grants, but I disagree with the premise of cd/hi-fi sounding "great."

 

Most audio-philes will tell you that high end tube amps/receivers give a better sound than solid state. Look into some high end stereo equipment and you'll see what I'm talking about.

 

Concerning cd's...well, they only hold so much information. So you are limited to how much information you can put on a cd, usually causing you to drop the quality a bit.

 

My understanding is, studios who use tube powered equipment, recording purely analog, tend to produce a more pure copy of the live material.

 

It's also not just the power tube section that most guitarist crave. The preamp section is extremely important as well. The first preamp tube affects overall tone significantly.

 

Just my 2 cents worth.

[GrantsV]

Thanks for your replies but I think I miswrote or wasnt clear enough in my first post!

 

What I was trying to explain was - lets say your perfectly happy with the tone an FX unit is giving you (preamp+poweramp emulated tone eg. digital modeller) and you just want to amplify it. Well the usual way is to use a valve poweramp, guitarist usually crank this stage to give some powertube saturation to round off the digitalness of the FX chain.

 

My idea, was to use a solidstate poweramp but put a mixing desk type valve line/mic preamp in between FX and amplification to round off the digital edge of the FX unit. Assuming you were pretty happy with the overall tone (in character and punch) coming from the FX unit to begin, this should add that bit of tubeness to the chain. Much in a way digital synths are spiced up by a valve preamp before going into a mixing desk in studios.

 

Or am I incorrect thinking that a valve line/mic preamp would round off and warmup a digital device in this way?

 

Again... this is hypothetically thinking that your happy with the initial FX devices sound.

[JimK]

I use a Digitech GNX1. What I've found, and you can see similar comments on Digitech's user forums, is that a tube amp/whatever in the signal chain after the modeler doesn't usually produce good results. Many people have found that the tubes provide to much "color" to the GNX's output. The majority of people seem to like the sound of the GNX amplified by a solid-state PA or powered monitor. My experience is only with the GNX. It may be different with other modelers.

 

I do understand what you're saying, and it's not a bad idea. My results, however, have been different.

[Gabriel E.]

Or am I incorrect thinking that a valve line/mic preamp would round off and warmup a digital device in this way?

Sure it would. Sorry I misunderstood, I thought you were talking about using digital and pre-amp tubes to emulate the sound of a complete tube amp.

[DC]

GrantsV,

 

Well, the problem with your theory is that the cheap tube stuff sounds crackly and crappy. Most all of it is low voltage tube sound added to a solid state op amp for some perceived thickening but there's no way in hell you're gonna get the even ordered harmonics and natural tube compression out of the cheap stuff.

 

If you wanna run your Pod through an LA-2A, maybe you'll get close to what you're looking for, but you could buy a really nice Boogie and multi-effects unit for less cash and have what we're all looking for: TONE.

[Tedly Nightshade]

The trouble here I think is that the modeling device is putting out what's supposed to sound like an amp sound including speaker tone and power amp tone.

So to record that or send it into a DI to put through solid state PA or whatever, you would in fact want a very clean tube pre- most tube DI's are intended to give some amplike quailities themselves, which will change the overall sound of the modeler maybe more than you want. Or maybe just right!

Anyhow to preserve what's supposed to be a "finished" sound, if you follow me, you want a really clean tube pre and those are much more expensive than a good quality guitar amp.

I don't know if such a thing exists, but a modeler that was just replicating the pre-amp section might be very nice put through a small tube power amp.

This is electric guitar, anything goes. Brainstorms are in order.

Ted

[GrantsV]

Thank you for your response everyone.

 

I have posted this topic on 3 forums:

1) a guitar FX forum

2) a hi-tech recording forum

3) a tube guitar amp forum

 

The results have been very interesting, and the responses have been pretty much the same from each forum.

 

To summarise:

If I insert a studio type tube preamp between the fx and poweramp, the quality of such a device will generally be of such low quality that it will not add anything pleasant to the sound. And if I did use a very expensive tube preamp, the results may still not be worthwhile, but then we are also talking about enough money to buy a Boogie or something...

 

Its been found that whilst tube based preamps/fx units (such as Triaxis/JMP1) sound better through a valve powerstage. In contrast, digital modelling devices such as POD/GNX/GT6 emulate the sound of both preamp and the poweramp stage - so they are in their element through a transparent solidstate powerstage or PA. Of course some prefer a valve powerstage no matter what device they are connecting to it.

[Tedly Nightshade]

Some of us prefer a transparent tube PA!

Ted

[TurboDog]

Sorry if I misunderstood.

 

You're talking about running an effects unit into a tube preamp into a solid state power amp? And you're thinking this may add a tube tone to the final output?

 

My initial thought is you would have two preamps battling each other. But then again, effects units into a tube amp do the same thing. There are some effects units that sound great with tube amps and some sound like crap. So I would guess it's the same in this case. It may work, it may not.

 

I don't think the final tone would sound any more "tubelike" as the compression from power amp tubes would be replaced by the solid state power amp (which to me always lacks character and is too clean).

 

Then again, if you really dig the distortion of a tube amp's preamp, ie a Boogie or Marshall, you could use the tube preamp gain and not the effects unit distortion. I almost never like effects units distortion (although I hear the Boogies V-somethingoranother sounds great.)

 

Final thought...Hey whatever sounds good to you. I've heard guys get good tone out of just about any kind of rig imaginable, both S/S and tube. Never hurts to try.

[Vandenberg]

I hope I am not going off the subject but I am a pod pro fan like many others.When George Lynch played at a clinic up the street they had every kind of tube amp sitting there for him to use ... and he used a pod! (many pro's do also I'm told) The reason is simple - they sound great! But...When I play my pod through any solid state device it doesn't sound as good as if I plug it into my '57 tweed super! So I am now looking for a mono 50 watt tube rackmount power amp to go with my pod pro. Many pod users go through Boogie power amps also with killer results and will beat up on a rectifier's sound in general-- try it!.