Using a different power amp section

[VanHalen]

With real tube amps, I have already heard guitarists telling that they use sometimes a specific power amp section (tubes) not the one present in their head. For example, an IIC+ preamp section plugged into a JCM 800 Power amp section. Was it a practice very well spread in the past ? Today ? If I take at random two heads and plug the preamp section of one of them into the power amp section of the other, Do I have good chances to get a good tube amp sound ? It would be cool if we could do this with the Axe FX to explore new horizon.

 

[Wolfenstein98k]

Sure, some power amp sections are known for their kick, just like some preamp sections are known for their bite. The ability to mix and match on the Axe has been requested for a long, long time. I second it too - it'd be great to have as an option. I imagine it's very hard to program though.

 

[brokenvail]

You already have many tone stacks to choose from and you can change power tubes aka make the JCM 800 use 6550 power tubes. Other than not having every tone stack as an option am I missing something?

 

[dbun]

To be honest I haven't felt a need for this. There is already enough versatility within an amp block to push it in any direction you need, coupled with an amazing array of amps, I haven't felt a need for anything more.

 

[J.C]

You can tinker with this stuff forever.

 

[ps43203]

That's (part), of what the Black Box is for. Cab Ir's include Power Sections, etc....

 

[paranoid]

Cab Ir's include Power Sections, etc....

I think the op is asking about using the pre amp of one modeled amp with the power section of another modeled amp. not the power amp used to drive a cab when shooting an IR.


The tone stack can be moved to different locations and different types selectable, this gives many options, similar to running a pre of one amp to the post of another.

 

[notalemming]

That's (part), of what the Black Box is for. Cab Ir's include Power Sections, etc....

Actually, the new UR mic + DI cab IRs do not include the power amp used to capture them. IMHO, they sound much more open & natural this way!

 

[Shask]

I was thinking about this yesterday!


I was thinking about it because there is no Triple Rectifier model, and I was trying to think about how I could build one.....

 

[Clive]

+10 on this. This is something I already asked here : http://forum.fractalaudio.com/axe-fx-ii-wish-list/92889-choose-poweramp-type.html

I really love this idea. With the Axe FX, we can change the tonestack, its position, the graphic eq type, its position too (since FW19, thanks Cliff), we have a lot of parameters : lots of ways to explore.
Having the possibility to choose a different power amp section would be for me the ultimate tool. We have FAS amps in the Axe and having this possibility would be like having the possibility to create our own FAS amps, going beyond the traditional amps that already exist int real life.

(...) to explore new horizon.

Exactly.

 

[kavoo]

Dave Murray is a very good example - he uses rack preamp (JMP-1) plugged to power section of two JCM2000 DSL100s. To be honest I would love to have this option in Axe-FX, even simple plugin like BIAS Amp does it.

Maybe it would be possible with adding an option which makes the Amp Block act like whole amp, just preamp section or just power section. That would allow to put two amps in one preset (one directly after another) with "preamp only" option set in first block and "power section only" set in second one?

Anyway - I think that would greatly expand Axe-Fx's tone possibilities.

 

[guitarfishbay]

I have tried mixing Blackstar S1 104EL34 and Mesa Roadster pre and power sections and IMHO both sounded best just run with their own power sections. Putting the Mesa through the Blackstar power section killed the low end balls, and putting the Blackstar through the Mesa power section made it a bit unbalanced.

I'm not technically knowledgeable in amp design, but it seems to me that amps are designed to sound optimal with their own signal flow (pre and power amp). I would think that any success with mix and match is just luck rather than planning based on characteristics. On paper putting the Roadster pre through the Blackstar poweramp should've created a tight recto, but it just sounded thin. I felt I got better results just using EQ to cut low end. YMMV of course.

 

[APOGEE123]

with 200 plus amps, don't know why this would be necessary,, all the parameters you have to change things up :star: you can go to hell and back if you want

 

[Stratman68]

Is this the same "separate the pre amp & power amp discussion in disguise?

If so, the answer has been given-answered by Cliff-no?

 

[zenaxe]

Is this the same "separate the pre amp & power amp discussion in disguise?

If so, the answer has been given-answered by Cliff-no?

+1. What you are asking for is a cool idea but has been addressed as a "will not implement" by Cliff in the past on more than one occasion.

Some ideas:

1. Change power tube type,bias settings, etc. If you know what you are doing you can severely transmogrify the power section with the advanced params.
2. Chain amps: Amp 1 Power amp modeling off. Amp2 neutral preamp settings.

Honestly, I have NEVER felt the need for this when using the amp modeling in the AFX. The number of knobs to twiddle is already absurd. I absolutely cannot imagine EVER bothering to do this with two heads. Seems incredibly dumb and a PITA. There are so many amps out there; if you felt the need to do this you bought the wrong amp.

I COULD see a good use for this by running a tube premp into the FX return and using the AFX as a power amp cab emulator though; but I'm down to one tube preamp in my collection at this point and I haven't fired it up in about two years.

 

[vinnyburns]

One exception is Mesa's Simul Class where it is a pair of 6L6 and a pair of EL34 running together. Sounds different than choosing each of these types of output valves on their own.

 

[brokenvail]

although I wouldn't use what is being requested here a simple solution would be if every tone stack was there to choose from. That way you pick the amp who's power section you want to use and throw in the tone stack you want to use and your off to the races

 

[Clive]

Things are not as simple as that. Here's a thread I started last year with Cliff's answer : http://forum.fractalaudio.com/axe-fx-ii-discussion/85516-pick-up-power-amp-type-settings.html

(...) Now, I'd like to make other experiences but with Axe FX II only. I'd like to have a Mesa Boogie Mark IV preamp section plugged into a Mark IIC+ power amp section. If I use a USA lead amp block (Mark IV) and if I use the exact settings (power tube type...) I can find in the power page of the USA IIC+ block, will I reach my goals ? Do I need to change other settings ? Am I completely wrong ?

Cliff's answer :

Sorry but no. There are many parameters and data that are hidden from the user.

 

[VanHalen]

Dave Murray is a very good example - he uses rack preamp (JMP-1) plugged to power section of two JCM2000 DSL100s. To be honest I would love to have this option in Axe-FX, even simple plugin like BIAS Amp does it.

Interesting. Thanks.

Maybe it would be possible with adding an option which makes the Amp Block act like whole amp, just preamp section or just power section. That would allow to put two amps in one preset (one directly after another) with "preamp only" option set in first block and "power section only" set in second one?

The problem with this solution is that you’ll have use two amp blocks to simulate just one amp then you wouldn’t be able to use another amp in your preset. I prefer Clive’s suggestion : having a button in the Power section of the Amp block that lets us choose the poweramp type.

Anyway - I think that would greatly expand Axe-Fx's tone possibilities.

Totally

I have tried mixing Blackstar S1 104EL34 and Mesa Roadster pre and power sections and IMHO both sounded best just run with their own power sections. Putting the Mesa through the Blackstar power section killed the low end balls, and putting the Blackstar through the Mesa power section made it a bit unbalanced.

I'm not technically knowledgeable in amp design, but it seems to me that amps are designed to sound optimal with their own signal flow (pre and power amp). I would think that any success with mix and match is just luck rather than planning based on characteristics. On paper putting the Roadster pre through the Blackstar poweramp should've created a tight recto, but it just sounded thin. I felt I got better results just using EQ to cut low end. YMMV of course.

Interesting experience. Thank you for sharing it. I agree with you, heads and combos have preamp and power amp designed to work together. However, I really think we can make great associations of preamp and power amp just by adding something between : an EQ ! If you just plug one into the other I think you have good chances to not have a good sound. Remember this, preamps and power amps are sources of distortion, if you want to shape the sound, you’ll have to do this :
EQ -> Preamp -> EQ -> Power amp -> EQ
Fortunately, since FW19 we are able to do this because we have the possibility to choose the location of the GEQ in the amp block (we can set it to pre PA !). I think it’s a question of level between preamp and power amp. With heads or combos, the level is set by the designer of the amp/combo. If you want to make your own association, you’ll have to set the right level/EQ by yourself and it’s possible right now.

Is this the same "separate the pre amp & power amp discussion in disguise?

If so, the answer has been given-answered by Cliff-no?

No I don’t want to separate them. See my answer to kavoo.

I COULD see a good use for this by running a tube premp into the FX return and using the AFX as a power amp cab emulator though

Good idea too even it’s not what I am saying here, see my signature.

 

[ScotHessler]

The answer remains "No". A button to choose which power amp with whatever pre-amp is separating the two from each other and would allow the possibility of reverse engineering Cliff's code. He's been very clear about this. Multiple times.