What tube amps have you owned/played that don't do this?

M

Member 1963

A lot, maybe most tube amps, at least those along the lines of marshal with NFB sound very different at low volumes than stage volume. In particular, feel more than sound even. Highs become harder and more present and the feel becomes stiffer. Harmonic content tends to give way to more fundamental. At low volumes they will Feel smooth, have a sag to the feel and sound rich with a good balance of all frequencies. Some more than other. What amps of the master volume type that get a large potion or most of thier OD from the pre have you owned or played that don't have this issue to the degree most do? And yes, i do realize it's partially the speaker, the human ear, etc. I just want to know what amps you've experienced that do it the least. Not looking to buy an amp, i just want to study the schematics of amps like this and see if i can determine what it may be that alleviates the issue, if you wanna call it that.
 

fiveightandten

Silver Supporting Member
Messages
7,210
It's the nature of tube amps. Unless you're getting sound from the pre-amp, you will experience a vastly different tone from the amp at lower volumes versus high. Power tube response and saturation, speaker dampening and other affects of the NFB loop, power supply voltage swing, speaker breakup and response, and the response of the human ear. As cliche as it sounds, it's the nature of the beast.

As such, you will get wildly different answers from people for any given amp, depending on how they use it and what their preferences are. Case in point, for me a Mesa Dual Rectifier has a wildly different tone and response at low volume and high. I dial in very minimal gain on the amp and rely on the power amp to distort and compress. Most guys who use it would disagree with me because they use it differently. This will be true for all amps. It's just a fact that if you use an amp as you are describing, you will experience what you are experiencing.
 

BADHAK

Member
Messages
10,525
A lot, maybe most tube amps, at least those along the lines of marshal with NFB sound very different at low volumes than stage volume. In particular, feel more than sound even. Highs become harder and more present and the feel becomes stiffer. Harmonic content tends to give way to more fundamental. At low volumes they will Feel smooth, have a sag to the feel and sound rich with a good balance of all frequencies. Some more than other. What amps of the master volume type that get a large potion or most of thier OD from the pre have you owned or played that don't have this issue to the degree most do? And yes, i do realize it's partially the speaker, the human ear, etc. I just want to know what amps you've experienced that do it the least. Not looking to buy an amp, i just want to study the schematics of amps like this and see if i can determine what it may be that alleviates the issue, if you wanna call it that.



Are you saying that the amp feels/sounds better at low volume ?? That it will be smoother and richer ??
That has certainly not been my experience. Other way around actually !!
I will say though, that some modern, feature laden amps I've tried, didnt sound that much better turned way up. Didn't sound bad, but they didn't come to life like a vintage 2203 at band volumes.
 

fusionbear

exquirentibus veritatem
Platinum Supporting Member
Messages
11,745
The reality is that some amps are like prized racing stallions. They respond to every little nuance when turned up. If you are imprecise, it shows, if you do not know how to control them, they howl and scream like a pig. They are not for everybody. I cut my teeth on big iron amps. I went from a 30 watt Yamaha SS amp to a 100 watt Mesa MK1 with a EV12L and played that amp at some serious volume at 13!. Then it escalated to a half stack, full stack, and eventually played most of my gigs with two full stacks until the late 80's. Many times I would tell the sound man not bother to mike me. I would just match the volume to the PA.... Anyway, I am not saying this to brag, but this is the way many of us played out in the late 70's and 80's. This was the norm in my circle of hard rock and hair metal in the 80's. But, my experience is that the amps smoothed out the louder you got them (frequency wise), but were still like a big strong stallion. You had to learn to use the volume knob quite well. It seems that this has become a lost art. You had to learn that standing in a certain angle could produce different feedback notes and emphasize different fundamental notes. It was truly an experience that is a lost art. Maybe it is good in some respects that it is gone (the volume was brutal, no doubt). But, in another respect, I miss the experience dearly. The ferocity of the volume caused a certain level of adrenaline that was intoxicating not only to the player, but the audience as well. It was the inducement of an adrenaline rush of a rebellious, raunchy, edgy culture. You would lose yourself in the experience in many ways like those who abuse drugs.... Anyway, that's my story and I'm sticking to it...
 

C-4

Member
Messages
15,501
The only amps that I have played where the distortion didn't change radically upon upping the volume were Diezel amps and from watching the videos, Metropoulus amps.

This is a design thing which is hard to come by as a lot of designers don't take this into consideration.
However for higher wttage amps, I feel this is a necessity so that the player can achieve whatever tone and saturation point he or she is looking for at the volume they need.

This is also the reason why some players don't like master volume amps and prefer a straight ahead single channel amp, where they control the volume from their guitar.
 

hunter

Silver Supporting Member
Messages
8,904
Keep in mind the OP is talking about "amps of the master volume type that get a large potion or most of thier OD from the pre". I don't think non master volume amps do this. But a master volume amp with the gain turned up and the master down low will sound like the gain drops as the master is turned up. As the gain drops, the other side effects manifest and the amp will sound clearer and punchier, or harder/stiffer if you will, etc. And maybe more fundamental. I have master volume amps by Badcat, Matchless, Ceriatone and Roland modeler amps and the drive character changes on all as the master is dialed up with the preamp gain up. Typically the adjustments needed to compensate are predictable and repeatable.

hunter
 

billyguitar

Member
Messages
6,059
Sag at low volume is not really possible but Phase Inverter bloom is. Mullard Long Plate reissues help if everything else is correct. I don't know how it's done but I have three amps that will do it. My Redplate Blackverb Duo 88, my 1959 5G9 Tremolux and my Brown Princeton. There may be more amps that will do it but I don't have first hand experience with them. I suspect Jim Kelly, Dumble copies and Creamer amps will do it. If you have one of these try the Mullard Long Plate 12AX7 in the PI hole and let us know!
 
M

Member 1963

Keep in mind the OP is talking about "amps of the master volume type that get a large potion or most of thier OD from the pre". I don't think non master volume amps do this. But a master volume amp with the gain turned up and the master down low will sound like the gain drops as the master is turned up. As the gain drops, the other side effects manifest and the amp will sound clearer and punchier, or harder/stiffer if you will, etc. And maybe more fundamental. I have master volume amps by Badcat, Matchless, Ceriatone and Roland modeler amps and the drive character changes on all as the master is dialed up with the preamp gain up. Typically the adjustments needed to compensate are predictable and repeatable.

hunter

Thank you ! This is typical of what happens here when you ask a question and i was just going to abandon this thread, but you are the only one that gets it. As cascaded preamp/MV type amps go, i haven't heard many that DON'T do what i described. Some just do it worse than others and the question which was just ignored as usual was which amps have you found that do it least. And it's not necassarily that thats the gain drops, as i think you understand by saying "will sound like". But it does sound like it due to the change in feel and highs. I think if you retained that low volume tone at stage volume it would be too mushy. But my search is to retain it *to a degree*, not fully.
 
M

Member 1963

Sag at low volume is not really possible but Phase Inverter bloom is. Mullard Long Plate reissues help if everything else is correct. I don't know how it's done but I have three amps that will do it. My Redplate Blackverb Duo 88, my 1959 5G9 Tremolux and my Brown Princeton. There may be more amps that will do it but I don't have first hand experience with them. I suspect Jim Kelly, Dumble copies and Creamer amps will do it. If you have one of these try the Mullard Long Plate 12AX7 in the PI hole and let us know!
Sag at low volume IS possible and in fact i get a lot more of it from the type of amps i use than i ever do at stage volume. You're talking about amps that are NOT what i referred to in my OP. No offense, but seems like when you post here people read your post and just read what they want to see and pass on important details that would change thier reply or leave them with no reply. It's extremely frustrating.
 

hunter

Silver Supporting Member
Messages
8,904
Sag at low volume IS possible and in fact i get a lot more of it from the type of amps i use than i ever do at stage volume. You're talking about amps that are NOT what i referred to in my OP. No offense, but seems like when you post here people read your post and just read what they want to see and pass on important details that would change thier reply or leave them with no reply. It's extremely frustrating.

Keep in mind sag has an electrical meaning as well as a sonic meaning. Electrically sag is associated with voltage drops at high loads. Typically not associated with situations where overdrive is the result of preamp gain with overall low volumes. I assume you refer to the sonic implication of electrical sag as sag.

Probably a simple terminology gap.

hunter
 
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M

Member 1963

The only amps that I have played where the distortion didn't change radically upon upping the volume were Diezel amps and from watching the videos, Metropoulus amps.

Interesting. I found a deizel schematic and it has a master i have never seen before in ANY schematic. The master is wired as a variable resistor rather than a voltage divider ! And it's in the same location as the typical pre PI master in many marshalls. How this is possible i don't know, but the only way i can think of is a radically different custom taper master pot. So what you have thats different from any other amp is a master which does NOT introduce series resistance to the signal, just loads it gradually. But if you try to do that with any pot i know of, the volume will jump to nearly full almost immediately from all the way off. So i gotta think custom taper. Maybe the lack of series resistance allows the tone to stay the same and then the rest of the amp is designed around that to get a uniform tone from 1 to 10. i dunno. Curious tho, and it's gotta say something that this amp has a master no other has and it also happens to the the one amp mentioned that doesn't do what i described. Not much I could do if that IS how they accomplish it tho since a taper like that i think would be impossible to source. And even if i did i imagine the low volume tone would now be like the high, giving me the opposite of what i'm trying to accomplish unless i redesign the preamp to sound very different. Interesting never the less.
 
M

Member 1963

Keep in mind sag has an electrical meaning as well as a sonic meaning. Electrically sag is associated with voltage drops at high loads. Typically not associated with situations where overdrive is the result of preamp gain with overall low volumes. I assume you refer to the sonic implication of electrical sag as sag.

Probably a simple terminology gap.

hunter
I understand that, but you are talking about PA say and the amps i am talking about have it in the preamp. Doesn't matter how you generate it or whether it really is truly sag by electronic terms, IE: HV being pulled down. It;s the resulting feel that matter regardless. And yes, preamps CAN generate it. Not all do for any number of reasons but some do, especially mine because i designed them that way thru endless experimentation. It has a ton of that in the feel which quickly disappears as the volume goes up like many amp's i have owned, home built or production. I'm niot here to debate that, but to find out what amps don't lose that as they are cranked as much as most do.
 

hunter

Silver Supporting Member
Messages
8,904
Sag is not just a PA term. is that what you really meant? Just pointing out when you use the term sag, folks can correctly point out it is not happening at low volumes. Because sag has a meaning and it is an electrical meaning.

From Aiken:
"Sag refers to the drooping of the power supply voltage in response to large transient signals, which lends a certain dynamic "feel" to the tube amplifier that is not generally found in solid-state amplifiers."

That is not what is happening when your amp is at low volume.

hunter
 

Sirloin

Silver Supporting Member
Messages
17,996
I have a 2204 Ceriatone with a few tweaks to the circuit. I find that the amp with the pre max and the master at minimum volume, the amp is "easy" to play. Squishy with plenty of "distortion" in the signal.

As the volume goes up, the amp sounds cleaner and punchier with less sag and less distortion. It's more revealing.

This was also my experience with a vintage '79 2204 JMP Marshall as well as the Germino MGL 2204 amp I played.
 

Silent Sound

Member
Messages
6,651
Look to the PPIMV amps. That's about as good as you can find. Many amps, like the Marshall 2203, have their MV before the PI, so you don't get the distortion from the PI until you crank them. And that's a pretty important component to their sound. You might also look into power scaling or attenuation/reactive load reamping.

Though ultimately, like you stated in your original post, a lot of this has to do with how the power tubes and OT saturate, how the speaker reacts, how the power supply gets bogged down, and how the human ear hears. In other words, you may get closer with some designs over others, but you'll never actually achieve the sound of a cranked amp at low volumes. There are laws of physics and such that don't like to be broken. Of course, there's also the whole concept of opinion and bias to consider. One person will claim it "sounds just like a cranked 2203" and another will question if that person has significant hearing loss or has never actually heard a cranked 2203. It's a well documented fact that our ears can't be trusted. We tend to hear what we want to hear rather than the sound that is actually made. We also tend to read the things we want to read, and ignore the posts that don't jive with our preconceived notions. It's human nature. And my point with all of that is that since this is a personal decision for you, then you need to make that decision yourself, and not rely on the groupthink of strangers. In other words, get out there and try a bunch of different amps and find out which one's sound good at low volumes, and which one's don't. Then you can look at the schematics to try to find out why. Cause I can tell you from my own personal experience of the internet that 95% of the people out there have no idea what they're talking about, and the 5% who do aren't easy to suss out.
 

hunter

Silver Supporting Member
Messages
8,904
Look to the PPIMV amps. That's about as good as you can find. Many amps, like the Marshall 2203, have their MV before the PI, so you don't get the distortion from the PI until you crank them. And that's a pretty important component to their sound. You might also look into power scaling or attenuation/reactive load reamping.

Though ultimately, like you stated in your original post, a lot of this has to do with how the power tubes and OT saturate, how the speaker reacts, how the power supply gets bogged down, and how the human ear hears. In other words, you may get closer with some designs over others, but you'll never actually achieve the sound of a cranked amp at low volumes. There are laws of physics and such that don't like to be broken. Of course, there's also the whole concept of opinion and bias to consider. One person will claim it "sounds just like a cranked 2203" and another will question if that person has significant hearing loss or has never actually heard a cranked 2203. It's a well documented fact that our ears can't be trusted. We tend to hear what we want to hear rather than the sound that is actually made. We also tend to read the things we want to read, and ignore the posts that don't jive with our preconceived notions. It's human nature. And my point with all of that is that since this is a personal decision for you, then you need to make that decision yourself, and not rely on the groupthink of strangers. In other words, get out there and try a bunch of different amps and find out which one's sound good at low volumes, and which one's don't. Then you can look at the schematics to try to find out why. Cause I can tell you from my own personal experience of the internet that 95% of the people out there have no idea what they're talking about, and the 5% who do aren't easy to suss out.

I think this may be the opposite of what he is trying to achieve.

hunter
 




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