Tube preamp heads: Gimmick??

[mbart203]

Anyone that understands this better than me, please correct me if I'm wrong.
But it seems to me that the whole deal of putting 1 to 3 tubes in the preamp section of a class D amp like many manufacturers are doing, is little more than a gimmick.

I've tested a few of these tube preamp head's compared to just solid state head's with no tubes at all and I haven't found much of a difference.

Recently I tried out the GK MB500 Fusion (3 tubes in preamp) against the Aguilar TH500 which has no tubes and I found the GK didn't do much for me but damn the TH500 was meaty, ballsy & Tubey.

Furthermore I see some companies trying to further mislead possibly unaware consumers by lighting the tubes with LEDs to further enhance the "Tube Experience".
One of these companies is Bugera but I'm not surprised after seeing their far fetched wattage ratings that they claim as well.

Do you guys agree or are there class D head's with preamp tubes that really get a more tube like sound.
I've tried the Markbass heads of this type and also was not dazzled enough to understand paying more for this feature.

Thanks.

 

[BassmanPaul]

While I agree that putting an LED under a pre-amp tube doesn’t do anything, a tube can do stuff that SS have difficulty with. I use a honking great Class D power amp for my bass amp. I chose to design and build a two channel tube pre-amp to drive it. To my ears it sounds wonderful. I could have gone SS as I actually have a SS pre-amp already. I chose tubes ‘cos I love building stuff with them.

 

[bjelkeman]

My Mesa Carbine, with a tube pre, has an organic feeling to the sound that solid state stuff just can’t seem to emulate. That said, I mainly use a Darkglass M900 amp these days.

 

[Mvilmany]

I see a lot of amps that have 1 preamp tube being called a “tube amp”. (Go look at guitar center’s site for example, but there’s no surprise there) These are not tube amps. Tube amps have both tube pre and power sections. I’ve found that hybrid amps that have multiple tubes in their preamp will have a more genuine tube tone than those hybrids with just one tube.

 

[mbart203]

It may just be the tube preamp head's I've tried.
I really didn't think the mb500 fusion seemed that Tubey.

 

[silky smoove]

Tube amps have both tube pre and power sections.

I'd omit the part about tube preamps for a few very select cases. The old Musicman amps, for instance, were a tube power section with a solid state preamp and I thing by anyone's definition these would be considered a tube amp. Definitely a rare bird though.

 

[Killed_by_Death]

Some are great, some aren't. The least tube-sounding amp with a tube pre in it is G-K's MB Fusion 500.

 

[Gravedigger Dav]

I have been gigging a Rumble 500 combo and recently tried out a Fender Bassman 500 hybrid.
The Bassman is a Rumble 500 power section with a tube pre-amp. I bought the Bassman because of the sound difference. I do think it is an enhancement.

 

[Mvilmany]

I'd omit the part about tube preamps for a few very select cases. The old Musicman amps, for instance, were a tube power section with a solid state preamp and I thing by anyone's definition these would be considered a tube amp. Definitely a rare bird though.

Those music man amps were only made for short period of time, and they are hybrids. I can’t think of any other significant amp that used solid state pre and tube power amp. Those were decent amps for a clean guitar sound. I would say that most of where the “tube sound” comes from is the tube power amp tubes. The hybrids with solid state power sound nothing like tube amps.

 

[Omega Monkey]

Really depends on the implementation of the amp, and how you want to use it. I think all my bass amps at this point have tube pres (one also has a FET pre) and SS power sections. They all sound pretty good and they can all break up nicely when pushed. With a SS head you'd probably have to build in a separate circuit if you wanted that breakup, rather than having that natural gradation you can get with tubes.

 

[Roy Royerson]

Really depends on the implementation of the amp, and how you want to use it. I think all my bass amps at this point have tube pres (one also has a FET pre) and SS power sections. They all sound pretty good and they can all break up nicely when pushed. With a SS head you'd probably have to build in a separate circuit if you wanted that breakup, rather than having that natural gradation you can get with tubes.

I think this is the key point. If you aren’t pushing the preamp tube or tubes enough to get some natural compression and overdrive the difference between a tube and SS preamp won’t be as big and may not be worth buying depending on your wants and needs. SS will do amazingly well if you want clean headroom but the warmth, compression and breakup will not be the same as a tube preamp if you have you’re rig dialed to push the preamp tubes. I think if you want a great tube sound just go into the deep end and get an all tube amp without compromising any of the advantages of a full tube amp with valve powered preamp and power section. I use class D and no tubes anymore as I like a clean sounding amp. The practicality of lightweight gear that reflects the tone of my bass and sounds great gets me what I want. To me an LED lighting up a tube is gross and a gimmick as I feel like the manufacturer trying to fool somebody, but a tube preamp can sound very good.

 

[silky smoove]

and they are hybrids

While technically correct based on the notion that one component uses tubes and the other uses transistors, I think you're the only person I've ever seen refer to them as anything but tube amps since the power section was tube.

I can’t think of any other significant amp that used solid state pre and tube power amp.

Which is why I referred to them as rare birds. The only other one I can think of were those Crank guitar amps that were popular in metal circles in the mid-00s.

 

[blubass]

It depends on your interpretation of what a preamp tube does, and if you understand the differences in tone from what a "gimmick" preamp tube does compared to what you feel is an authentic preamp tube.

Some amps aren't designed to push the tube, it's there for its contribution solely with cleans.

It's easy to pigeon-hole something as a gimmick because it doesn't do what you want it to do, but that doesn't mean it's not a working part of the preamp.

 

[BassmanPaul]

I'd omit the part about tube preamps for a few very select cases. The old Musicman amps, for instance, were a tube power section with a solid state preamp and I thing by anyone's definition these would be considered a tube amp. Definitely a rare bird though.

the output tubes, 6CA7, were driven with SS circuitry in their cathodes. The control grids were in essence grounded just being fed from the bias circuity

 

[Roy Royerson]

It depends on your interpretation of what a preamp tube does, and if you understand the differences in tone from what a "gimmick" preamp tube does compared to what you feel is an authentic preamp tube.

Some amps aren't designed to push the tube, it's there for its contribution solely for its cleans.

It's easy to pigeon-hole something as a gimmick because it doesn't do what you want it to do, but that doesn't mean it's not a working part of the preamp

Good point and overlooked by the bulk of my previous post. I’m never mad at having a tube condition my sound at any point in the signal path. I use my Markbass compressore despite its bulk and how much pedalboard real estate it takes. I like many things about the compressore but in part I use it because I like the sound of tube compression that just adds a hint of warmth to the tone. And like bluebass mentioned the tube sound can be good for clean tone or for compression.

I do think the difference is much more subtle in those applications as opposed to when listening to overdrive or breakup where tube sound makes a bigger differance to my ear. As much as I like my tube compressor I might not be able to tell the differance in a blind (or should I say deaf) test of tube vs. transistor compression.

Can anybody justify the LED lighting up the tube thing as anymore than a gimmick? If the idea is it looks cool and not to fool people into thinking it’s the tube glowing, is it presented as such?

 

[Bassbeater]

In my experience many hybrids sound very very good, but they don't have the responsiveness and dynamic character of valve amp. They are both good, but different.

 

[seamonkey]

Some tube designs are nothing more than using a tube as a buffer.
Having a tube in the signal path is no guarantee of great tone.
"Solid state" was the buzz word of the day at one point in history. Everything had to have "solid state" in it's name. "Digital" got it for a while. Or "Analog".

It's not the tube, it's the designers intent. It's the circuits, virtual or otherwise, not the devices. Maybe some tones are easier with some devices, but some are not always the best choice.

 

[agedhorse]

The use of tubes as a design element has a lot to do with what the designer feels best captures his intent. That doesn't always mean that a tube is used to create an "excess of tone or feel" but sometimes just a little bit can go a long way.

It's a bit like cooking, some folks like a straight ahead bold, in your face, knock you upside the head flavor palate and others prefer a more laid back, refined, less pushy set of flavor, and don't like being smacked upside the head. It't up to the designers to develop products that fit all players and this rarely means one model or one approach.

As a practical example of this, the Shuttles were more laid back, subtle, refined, polite, whereas the Streamliner was much more an in your face tube approach. We had plenty of players in both camps, and the Stteamliner did not work for many players who found the Shuttle and Shuttlemax more to their liking. That doesn't make either player wrong, simply different.

 

[Wasnex]

I would say that most of where the “tube sound” comes from is the tube power amp tubes.

Anyone that understands this better than me, please correct me if I'm wrong.
But it seems to me that the whole deal of putting 1 to 3 tubes in the preamp section of a class D amp like many manufacturers are doing, is little more than a gimmick.

I've tested a few of these tube preamp head's compared to just solid state head's with no tubes at all and I haven't found much of a difference.

Recently I tried out the GK MB500 Fusion (3 tubes in preamp) against the Aguilar TH500 which has no tubes and I found the GK didn't do much for me but damn the TH500 was meaty, ballsy & Tubey.

Furthermore I see some companies trying to further mislead possibly unaware consumers by lighting the tubes with LEDs to further enhance the "Tube Experience".
One of these companies is Bugera but I'm not surprised after seeing their far fetched wattage ratings that they claim as well.

Do you guys agree or are there class D head's with preamp tubes that really get a more tube like sound.
I've tried the Markbass heads of this type and also was not dazzled enough to understand paying more for this feature.

Thanks.

Maybe you should try a hybrid with dual preamps, 1 mosfet and 1 tube, so you can get a better feel for the differences that tubes make. Consider Genz Benz GBE1200 or one of the Shuttlemax heads. IMHO neither of these amps try to capture the qualities of a tube output sections, but they do have decent tube and mosfet preamps that sound quite different.

Note tube preamps and tube outputs have different qualities that are considered "tubey." If you want the complete authentic experience, get a tube amp. If you want the qualities associated with preamp tubes, you might be happy with a hybrid. I haven't seen a hybrid that accurately captures the experience of a tube output section driven into heavy distortion. Some pedals get close.

Solid state can be modeled to exhibit some of the characteristics of tubes. For example a Genz Benz Streamliner might get you closer to the full tube experience than many other hybrids. Ampeg SVT8 Pro and Mesa Titan also capture a bit more of the all tube experience.

IMHO, strive to understand which tubey qualities you are looking for and then look for an amp that possess the desired characteristics.

 

[mbart203]

It depends on your interpretation of what a preamp tube does, and if you understand the differences in tone from what a "gimmick" preamp tube does compared to what you feel is an authentic preamp tube.

Some amps aren't designed to push the tube, it's there for its contribution solely with cleans.

It's easy to pigeon-hole something as a gimmick because it doesn't do what you want it to do, but that doesn't mean it's not a working part of the preamp.

True, that's why I was putting it out there for others opinions.
I also have not personally tried out many of the tube preamp heads out there.