Heavy Metal without Pedals or hot pickups

Re: Heavy Metal without Pedals or hot pickups

Jacew said:
Since the gain is limited by the headroom of the tubes in preamp, the high gain preamp produces pretty much same gain as any usual cranked 12ax7 preamp. It's just more distorted. Sure it does that with high gain signal in circuit, but preamp as whole doesn't have more gain.

I mean, you can't get more gain from a tube that it can deliver, no matter how much gain signal that goes in have? Or am I mistaken about it?
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You're right that a 12AX7 can only amplify so much, but there are other ways to increase the distortion a preamp generates. For comparison the Marshall 2203/2204 and Soldano SLO preamps are a great example because they're actually very similar. The simplest difference is that the Soldano has more gain stages than the Marshall. Since you can't get more gain from a single tube, use more of them. Second, both amps use what's referred to as a cold clipping stage where one or more of the preamp tubes is intentionally biased cold to reduce headroom and thereby increase distortion. Soldano uses a colder bias than Marshall which also increases the amount of distortion an SLO can generate compared to the 2203/2204.
 
Re: Heavy Metal without Pedals or hot pickups

dystrust said:
You're right that a 12AX7 can only amplify so much, but there are other ways to increase the distortion a preamp generates. For comparison the Marshall 2203/2204 and Soldano SLO preamps are a great example because they're actually very similar. The simplest difference is that the Soldano has more gain stages than the Marshall. Since you can't get more gain from a single tube, use more of them. Second, both amps use what's referred to as a cold clipping stage where one or more of the preamp tubes is intentionally biased cold to reduce headroom and thereby increase distortion. Soldano uses a colder bias than Marshall which also increases the amount of distortion an SLO can generate compared to the 2203/2204.
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Maybe it is a language barrier... You seem to relate gain with distortion, which I don't quite get. If amp lowers the headroom with bias, it doesn't have "more gain", it just adds distortion. Same with multiple tubes: The overall level of amplification preamp produces isn't distinctively "more" than single preamp tube. It just has more stages to overdrive.
 
Re: Heavy Metal without Pedals or hot pickups

Jacew said:
Maybe it is a language barrier... You seem to relate gain with distortion, which I don't quite get. If amp lowers the headroom with bias, it doesn't have "more gain", it just adds distortion. Same with multiple tubes: The overall level of amplification preamp produces isn't distinctively "more" than single preamp tube. It just has more stages to overdrive.
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That's the colloquial usage of the word gain amongst guitarists, yes.

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Re: Heavy Metal without Pedals or hot pickups

Jacew said:
Maybe it is a language barrier... You seem to relate gain with distortion, which I don't quite get. If amp lowers the headroom with bias, it doesn't have "more gain", it just adds distortion. Same with multiple tubes: The overall level of amplification preamp produces isn't distinctively "more" than single preamp tube. It just has more stages to overdrive.
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Gain and distortion are related. Clipping (distortion) occurs when the headroom of the circuit is exceeded regardless of where that occurs. If additional gain raises the signal level further, a larger amount of clipping occurs.

It gets complicated when you think about the total gain of a preamp in terms of volume (and compression). With the same power amp, a preamp with fewer stages or less cold clipping will probably be less distorted than one with more stages, more cold clipping, or both. The absolute volume should be similar with both preamps because the power amp itself only has so much headroom. With a theoretical power amp with infinite headroom, the preamp with the most total gain (measured input vs. output) would be loudest regardless of how much clipping occurred along the way.
 
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Re: Heavy Metal without Pedals or hot pickups

dystrust said:
Gain and distortion are related. Clipping (distortion) occurs when the headroom of the circuit is exceeded regardless of where that occurs. If additional gain raises the signal level further, a larger amount of clipping occurs.

It gets complicated when you think about the total gain of a preamp in terms of volume (and compression). With the same power amp, a preamp with fewer stages or less cold clipping will probably be less distorted than one with more stages, more cold clipping, or both. The absolute volume should be similar with both preamps because the power amp itself only has so much headroom. With a theoretical power amp with infinite headroom, the preamp with the most total gain (measured input vs. output) would be loudest regardless of how much clipping occurred along the way.
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Yep. That is exactly what I was trying convey, and why I thought "high gain" to be a bit of a misnomer.
 
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