What creates a bass amp's "voicing"?

[jnewmark]

It can also be the combination or melding of different approaches, neither one or another alone. There can also be additional elements added to appeal to a specific type of player or playing style.

There have been some interesting oversimplifications suggested in this thread as to why different amps sound different. As someone who has designed amps for quite some time, I do find some of the suggestions amusing as they represent common urban or internet mytholog rather than actual, factual operating mechanisms.

But would you agree that certain bass amps have a signature tone ? for example, the classic tone of the Ampeg B-15, or the tone of the GK RB series ?

 

[40Hz]

What is typically used in modern solid state amps? I thought that both of the tone stacks you refer to had interactive controls whereas the EQ section of modern SS amps are (I think) more like a graphic equalizer that only has four bands.

I'm not 100% sure these days. There are so many variations introduced by the boutique and smaller makers that it's hard to characterize what's going on with some of them. Is an FMV stack design with a parametric or semi-parametric midrange added really just an FMV stack anymore? And the design isn't restricted by whether it's solidstate or tube. You can do virtually anything with either although the engineering can get a little hairy sometimes.

I'll have to defer the bulk of your question to some of the real gurus and builders here who would know for sure.

But if you want to look at a reference design by TI, I think the preamp and FMV stack they've done is fairly typical of most designs. You can see the PDF here.

 

[SteveCS]

Here's a question for everyone .
What is the most transparent head and cab one can buy?

I've found my Genz Benz shuttle to be very transparent. As for colour, yes some tone stacks have a baked in contour and power supply capabilities can affect the dynamics, but IME more colour comes from cab design and driver choice than anything else. No amount of EQ can make a Celestion-loaded 4x10 sound like a Peavey/BW 1516 or an Eminence-loaded 1x12.

 

[Dave Hill]

Does an Output Transforner count as being "in" the tone circuit?

 

[NortyFiner]

I've always heard of Carvin amps as being relatively clean and transparent. Never played through one to know for sure though.

 

[JimmyM]

But would you agree that certain bass amps have a signature tone ? for example, the classic tone of the Ampeg B-15, or the tone of the GK RB series ?

I wouldn't, because you can change them up. Certain things one amp may do better or easier than another, but that can all be changed by the turn of a knob or a flip of a switch.

 

[KickingBass]

I've always heard of Carvin amps as being relatively clean and transparent. Never played through one to know for sure though.

They have so many tonal controls that yeah I think I was able to get mine pretty flat. Like Linnin says in my sig though... Flat is not where it's at.

 

[agedhorse]

But would you agree that certain bass amps have a signature tone ? for example, the classic tone of the Ampeg B-15, or the tone of the GK RB series ?

Certainly, either due to specific design elements or a combination of elements that all contribute to what the designer intended.

 

[peterpalmieri]

@beans-on-toast and @agedhorse thank you so much for your valuable input, others too. It's nice to get a real perspective on this.

 

[agedhorse]

Does an Output Transforner count as being "in" the tone circuit?

It would IF there was an output transformer. Most transformer differences are due to either defects in the design/implementation, or choices made with respect to opposing tradeoffs made during the design process. Sometimes, a tradeoff that might seem "bad" brings unforeseen benefits, these become "accidental features".

 

[40Hz]

There have been some interesting oversimplifications suggested in this thread as to why different amps sound different. As someone who has designed amps for quite some time, I do find some of the suggestions amusing as they represent common urban or internet mytholog rather than actual, factual operating mechanisms.

Fair enough. But maybe when you're done being amused, you could share some of your expertise and wisdom gained from your experience to enlighten the membership here by providing some clear and well-written explainations to correct any misconceptions and dispel some of those myths?

I'm always eager to learn what's real from somebody who knows whereof they speak because they've actually done it. (Pretty please?)

 

[Stu_Bass]

I have experienced great tone in a live setting by using my F-2b running the output of one channel into the input of the other. But then one day I had my brothers Mesa Boogie Mark 1 guitar combo amp with the cascading volume controls through a power amp and damn, there was the tone, the drive, everything I wanted to hear live but my brother won't part with it for anything. I see Mesa has deep switches built into their bass amps but I wonder if they even considered the cascading volumes? drool

I have a Boogie Colosseum that I have played bass out of . Kinda like a Boogie SVT. Makes a great bass amp. I believe that Charlie Daniels' bassplayer plays/played out of them.

 

[agedhorse]

Fair enough. But maybe when you're done being amused, you could share some of your expertise and wisdom gained from your experience to enlighten the membership here by providing some clear and well-written explainations to correct any misconceptions and dispel some of those myths?

I'm always eager to learn from somebody who knows whereof they speak because they actually have done it.

I have, quite a few times.

Obviously I can't get too deep into specifics because some of these things represent the IP of my current or previous employers, but consider the following example...

The "Fender tone stack" is one of the defining classic voicings of bass (and guitar) amps. By using the various elements of this complex filter (complex because of all the things that occur simultaneously, not the circuit itself which is quite simple) rather than the entire time stack itself, in combination with other filter elements, it's possible to flavor one approach with another. Add variability no you have new colors to paint with. Now combine this with non-linearity and you have added the new colors in another dimension.

This is just one example of the potential for creativity in design.

 

[TheRealKong]

First of all, a poweramp is supposed to make things louder. But different architectures equal (slightly) different sounds. Add this to different designed preamps, and you will solve the secret.

Preampwise I am thinking more that it is more about the ear of the engineer than parameters.

There are bassmen that lust for an amp that behaves like "a wire with gain" for an absolute neutral sound. This says to me that any component of the amp does something with the sound, just like paper or coil resistors you are able to find in lots of old amps. Users of this old amps are sure that modern resistors won't give you "the sound".

My GBE (600/750/1200) and my Magellan are able to mimic the tone of my GK 400 RB when I twiddle the knobs a bit. But I can't get the tone of one of those amps out of my Gallien Krueger. I am thinking about a much more "powerfull" (a mighty tool, as we say in Germany)

Talking of "baked in - tone" I am thinking of Gallien Krueger, Ampeg, Aquilar, Hartke LH 500 / 1000 and Peavey. And Markbass. I think that Glockenklang - Amps do it as "neutral" as I am able to think of. Just have a look at the Blue Sky with its EQ that is switchable. This is not only a feature that allows you to take a look at what twiddeling with the EQ does to the sound, this amps sound fantastic with the EQ switched out. But maybe "too neutral" for the most people, because of the "poopie in - poopie out" - thing that will happen. For myself I want to hear the sound, the charakter of my different basses. So the Genzler / GenzBenz - Stuff is good for me.

As I like the Ampeg - sound, I've got the feeling that they make my basses sound like - Ampeg. This suits lots of musical styles, like my heavy - metal - band, and a lots of basses. There is no P-bass - sound like played over an Ampeg Amp. So I still have a SVP Pro and a Class -H Poweramp (RedRock M 4.5, Made in Germany, available complete linear or (stock) with a bass boost, 19 lbs, interesting poweramp, google for it), and it sounds as an Ampeg is supposed to. This rack for me is the better SVT 4 Pro. So in my opinion its the preamp that has the baked in sound.

Try this out at home! Use one of your amps as the poweramp (poweramp in), and use the "preamp out" of the other amps. Now listen, is the amp sounding like the preamp? Or does the poweramp affect the sound?

 

[Passinwind]

I wouldn't, because you can change them up. Certain things one amp may do better or easier than another, but that can all be changed by the turn of a knob or a flip of a switch.

Heresy. Knobs are only for show and must never be tweaked. If the noon position is not true flat you must find true flat and leave them in that setting.

...or not.

 

[TheRealKong]

Hey!

poopie in - poopie out...... Whats about "freedom of speech"?

 

[40Hz]

I have, quite a few times.

Obviously I can't get too deep into specifics because some of these things represent the IP of my current or previous employers, but consider the following example...

The "Fender tone stack" is one of the defining classic voicings of bass (and guitar) amps. By using the various elements of this complex filter (complex because of all the things that occur simultaneously, not the circuit itself which is quite simple) rather than the entire time stack itself, in combination with other filter elements, it's possible to flavor one approach with another. Add variability no you have new colors to paint with. Now combine this with non-linearity and you have added the new colors in another dimension.

This is just one example of the potential for creativity in design.

Oh no! Now I have to resort to the abysmal search function here to find them!

I'm doomed.

Thx btw. That's the sort of thing I was talking about. I appreciate your taking the time.

 

[beans-on-toast]

I have a Boogie Colosseum that I have played bass out of . Kinda like a Boogie SVT. Makes a great bass amp. I believe that Charlie Daniels' bassplayer plays/played out of them.

I had one of those, used it with two 412's. I believe that it was marketed for wither guitar or bass.

 

[Ric5]

I'm surprised because i see references to GK's 'baked in tone' quite often.

I'm learning a lot from this thread.

Hmmmm Compared to my Ampeg it seems less colored ...

 

[40Hz]

Hmmmm Compared to my Ampeg it seems less colored ...

Ampeg definitely has its own "Ampeg sound." As does Fender, Marshall, and Vox. And as did Acoustic and Sunn.

Get away from hifi amps and you have a lot of colors to choose from.

Seems there's two schools of thought here. The first is the hifi amp admirers who mainly want a super-clean amp that mostly just makes the instrument sound louder, but still has a flexible tonestack so that very precise tonal shadings can be dialed in. The other school is the crowd who sees an amp more as an additional musical instrument and doesn't object to it bringing its own color and response into the overall mix. These old-style amps have a baked-in sound. But since it's the sort of sound their owner seem to want anyway, no worries.

Consider: a Fender PBass going through an old Bassman is a very different "instrument" than it is when played through and SVT or a B-15N. And it's a completely different beast if you plug it into a super-clean hifi amp. Same goes for whether you're playing through a folded horn enclosure with an 18", a ported 15" enclosure, a 4x10 cab, or something by Bag End or Greenboy. You can't completely isolate the player and the instrument from the amp and the cab. It's all one piece of cloth.

Some of the more modern amps do their best to keep things neutral and completely under the control of the player. Others don't. But either way, both have their pluses and minuses. It just comes down to finding the one that works best for your present preferences (which will usually change over time) and not worry too much about the details.

Or so I think anyway.