Do onboard preamps have a baked-in sound?

[wcriley]

I often read about people preferring the passive over the "active sound". Is the difference they're hearing strictly the effect of cable capacitance and loading at the amp input? Or do onboard preamps/EQs have "baked in" response curves (like many amp heads) even when all controls are set nominally "flat"?

When people prefer the sound of one onboard preamp over another, is it the difference in the frequencies and widths that can be cut or boosted? Or is it, again, that different models have different "baked in" sounds with the controls set nominally "flat"?

[SGD Lutherie]

I don't know about "baked-in", but an on-board preamp will often make the bass sound brighter when the control are set flat. This is because the pickups have been isolated from the cable and controls, which make the pickup sound darker or warmer, depending on your outlook.

Usually boosting a little lows and cutting a little highs gets you back in that sonic territory.

Different tone stack designs work different ways however. If it's a passive tone stack you might not get it totally flat, lie you would with some active designs.

[chicago_mike]

This goes into comparing ic chips and fets and all that. On a scope, sure, you could see differences till bacon goes out of style. But your ears are the judge , and if your ears dig "color", then its all good.

Quick story, talked to a tube amp guru years ago, I was thinking of building an OTL bass amp...One of those uncolored tube amps for hi-fi...he basically told me that you WANT color...you really do, because totally flat..is just that..flat, unimaginative, boring..bland...

[SGD Lutherie]

Originally Posted by chicago_mike

because totally flat..is just that..flat, unimaginative, boring..bland...

Not true! Totally flat will sound just like your bass. Is your bass bland sounding?

All those Motown bass tracks were recoded direct through totally flat audio gear. Probably a tube compressor, but nice and flat anyway. Sounds good to me!

What you don't want is a tube amp that has an over hyped cartoonish tube sound. Because you wont be able to get rid of that.

Anything else an amp does is pretty much the same as adding EQ.

[N.F.A.]

Can you name a couple amps that have the cartoonish sound you mention? I'm asking seriously, not as a disagreement. I have owned and played through Marshall, Matamp,Traynor, Mesa Boogie, Carvin and other tube amps and not knowingly experienced what you mean. Really curious to hear what you mean here.

[SGD Lutherie]

Originally Posted by N.F.A.

Can you name a couple amps that have the cartoonish sound you mention? I'm asking seriously, not as a disagreement. I have owned and played through Marshall, Matamp,Traynor, Mesa Boogie, Carvin and other tube amps and not knowingly experienced what you mean. Really curious to hear what you mean here.

SVT. They have a weird EQ curve built in that you can get rid of, and are overly grindy sounding. You either like them or not. I don't.

I have a Mesa 400+ and it's very hi-fi and flat when you set it that way. Tube amps do have a warmer low end than most solid state amps.

The other thing is some tube gear use "starved plate" designs, where they stick a tube in, but it's running at low voltage, like 9-18 volts, and not 300 like on a real tube amp. So that gives a tuby sound, but it's over done. That's what I would call cartoonish. They use that in distortion effects because the tubes have very little headroom and break up easily.

[N.F.A.]

Yeah, I have the 400+ too. Hi fi as you want. I will agree that my Marshall Plexi is colored, but I love that tone and it's the tone of rock to me. Not sure if it's considered cartoonish. The Matamp had color too, but in a good way. (It was a GTO btw.)

[bongomania]

Originally Posted by SGD Lutherie

All those Motown bass tracks were recoded direct through totally flat audio gear. Probably a tube compressor, but nice and flat anyway.

Baloney!

Yes Jamerson tracked through a DI not an amp, but every single piece of gear his signal passed through, even the mixer, was based around tubes and output transformers, and we're NOT talking about ultra linear McIntosh type gain stages--and then it was fed at high gain into tape, saturating like crazy. His tracks are FAR from any representation of "flat". Just listen to the isolated tracks that can be found on the web, and tell me if they sound like a P bass plugged directly into a high-fidelity sound card.

[bongomania]

Originally Posted by wcriley

I often read about people preferring the passive over the "active sound". Is the difference they're hearing strictly the effect of cable capacitance and loading at the amp input? Or do onboard preamps/EQs have "baked in" response curves (like many amp heads) even when all controls are set nominally "flat"?

Both. Usually when people are talking about "the active sound" they are referring to the elimination of loading from the cable, resulting in more high-frequency content and flatter mids. But it is also true that some onboard preamps are designed with some pre-shaping, because the designer in those cases was aiming for a market that likes a certain sound (typically a bit of mid scoop). For much of the 80s and 90s that was the preference of "modern" bassists, so there's a lot of it around. Really it wasn't until the 2000's that mainstream bassists started clamoring for "flat" and "uncolored" high-fidelity onboard circuits. Anthony Jackson was an early proponent of super transparent bass circuits, but his views didn't start to shape the market until he had been at it for some years. Also FET gain stages are popular precisely because they add a subtle fatness to the signal. Look around in this forum for a thread that has clips comparing the Creation Audio Redeemer (an ultra flat/transparent circuit) with a popular FET-based onboard preamp.

[chicago_mike]

Touchy subject, the subject of tone and electronic interference...

Not wanting to start anything, I'll stick with my opinion, that flat is, maybe great for studio and for blending in and not getting in the way..but wheres the personality in that? I contradict myself here a little because I DO like a clean modern tone, but sometimes..its just too much...

[SGD Lutherie]

Originally Posted by bongomania

Baloney!

Yes Jamerson tracked through a DI not an amp, but every single piece of gear his signal passed through, even the mixer, was based around tubes and output transformers, and we're NOT talking about ultra linear McIntosh type gain stages--and then it was fed at high gain into tape, saturating like crazy. His tracks are FAR from any representation of "flat". Just listen to the isolated tracks that can be found on the web, and tell me if they sound like a P bass plugged directly into a high-fidelity sound card.

Yeah, I've posted the isolated tracks here a bunch of times.

Motown Mix

Sorry, but I can get these exact tones going direct into my digital mixer. If anything the strings are really funky!

Regardless to how primitive the gear was compared today, it was after all a recording studio. The signal was as clean as they could get it at the time. And the tape wasn't all that saturated. More often the compressors would break up, as on the vocals.

But my point was he went direct, and not through an amp as many people think.

[SGD Lutherie]

Originally Posted by chicago_mike

I DO like a clean modern tone, but sometimes..its just too much...

I agree with you. Clean doesn't have to be sterile. When I'm using my Trace Elliot head, I also use an old Tube Works Blue Tube. I have a 12AU7 tube in it, and use it to dial in a little tube fatness. This way it's totally controllable. I can even get it to break up when I want it, but I'm not stuck with that as my only tone.

But a good rig sound sound clean and warm when flat, and be very supportive of your bass' tone. Just like your home stereo system is. That reproduces clean sounds and doesn't sound sterile.

[SGD Lutherie]

Originally Posted by bongomania

But it is also true that some onboard preamps are designed with some pre-shaping, because the designer in those cases was aiming for a market that likes a certain sound (typically a bit of mid scoop).

Cyrus, I'm not trying to split hairs here, or argue with you (you're a customer of mine too!) but I think that's more a product of the tone stack used.

On Fender style passive tone stacks, you only boost the bass and treble. If you have a mid control, it only cuts. On either type, if you boost the highs and lows you now have that notched midrange tone. Even with active tone controls, if you have them spaces far enough apart, you also end up with a mid scoop.

I've never seen an onboard preamp with an intentional pre-shape, but some tone stacks never go flat.

That's what I was saying earlier. Most simple EQ circuits will have some deviation from flat when set flat.

[kraigo]

I guess I'm a bit odd. My impression of most on board preamps is that they tend to scoop mids and compress the sound somewhat. I have no proof of this. I just know that I have yet to find an on board preamp that I like. At the same time, I like my cabinets more on the hi-fi side. I tend to use either all tube amps (old Traynors from the early 70's) or, more often, as solid state as I can get (AMP BH-420 without the "enhance" button engaged).

So, you're asking for an opinion, yes preamps have a pre-baked sound. I use David's (SGD Lutherie's) pickups in one of my basses without a preamp. It sounds great, IMO. I've listened to David's clips. He and I go for very different tones, yet his pickups satisfy both of us. Kudos!

KO

[colcifer]

Originally Posted by N.F.A.

Can you name a couple amps that have the cartoonish sound you mention? I'm asking seriously, not as a disagreement. I have owned and played through Marshall, Matamp,Traynor, Mesa Boogie, Carvin and other tube amps and not knowingly experienced what you mean. Really curious to hear what you mean here.

It's hard to get set a Fender EQ flat. It can generally be done but they're set up to scoop the mids and it's hard to avoid that.

[N.F.A.]

SVT was mentioned above as having EQ that may not be optimal to some. Does that amp use a Fender tone stack? I am pretty sure that my old Traynor used it. Not sure about my others.

[SGD Lutherie]

Originally Posted by N.F.A.

SVT was mentioned above as having EQ that may not be optimal to some. Does that amp use a Fender tone stack? I am pretty sure that my old Traynor used it. Not sure about my others.

No, it has a totally different tone stack. It was also designed to have the low end rolled off as to not be boomy in a large room, and then to make up for that there's a big hump at 250Hz. The Ultra Low switch actually notches the mids.

The Fender tone stack is a pretty standard circuit. The Alembic preamp uses it, as does a lot of other amps.

[dmusic148]

Originally Posted by SGD Lutherie

I've never seen an onboard preamp with an intentional pre-shape.....

Aguilar and East.

[SGD Lutherie]

Originally Posted by dmusic148

Aguilar and East.

But how do you know what the actual circuit is? I'm saying what you are hearing is likely the tone stack. If you boost the highs and lows you end up with scooped mids, but you didn't add any pre-shaping. There would be no reason to do it either.

Read what colcifer said above. That's what you are hearing.

[dmusic148]

East actually claims to pre shape. And most agree that the Aguilar units do, too.