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Solid state/class d vs tube amps

#981
bucephylus said:
I’m with @BurningSkies regarding amp topologies. Get what I’m after using a tube preamp into the Class D power section. Doesn’t mean I don’t like, and in some cases hugely appreciate some of the bigger all tube heads. They are great if someone else wants to move them around for me. And no, that’s not just being wimpy. I have no back issues and don’t mind breaking a sweat. It’s just I get what I am after with what I’m using; so, why do more work for essentially the same result?

My main cover gig is ampless. I finally solved that particular signal chain issue to my satisfaction by using the tiny but awesome Demeter Bass400 as my “DI.” As an amplifier, the Bass400 is pretty potent; but, the really interesting part is the preamp in it is basically a single tube version of the VTBP-201. I still have my 1.5 space VTBP-201 for comparison. And, going back and forth between the two, I honestly have to say I’m not sure which I prefer. The SS output 400 is just a fraction cleaner and quicker. The 12AT7 output circuit is just slightly creamier. The difference is mainly noticeable when you are sitting in a quiet rehearsal space going back and forth. It is subtle. Not really something to get excited about. The magic in that circuit is in the V1 position. THAT tube makes a huge difference in tone when you roll various types. I like the Sylvania GB 5751; but, that’s me.
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Part of my using class D power is weight v. power...I'm not a micro guy, in my world I realized that class D means I can have huge power with real-life unlimited headroom application...which leads to my other issue with 'all tube' setups. I can never keep the power section clean enough at some of the volumes I play at. Therefore a 300w or 400w tube section seems good in theory, but in application for me is just too 'sloppy' on the gig for what I want to hear. Those numbers are usually applied a good amount of THD which doesn't work for me.

So, my Class D power amp right now is a standard 2-rack space unit that weighs something in the low 20's for poundage. Not a featherweight and not what you're going to fit in your bass' gig bag. ;) But it'll do 2500w RMS all day long.

...imagine having a bass amp that you never ever have to think 'how powerful will this be in x-situation'. My only headroom limitations are based upon what my speakers can do. That's what Class D does, unlocks the potential to never worry about power amp limitations.

The piece that works for me tone-wise is that I have a couple REALLY nice tube preamps...The kind that are equally at home in professional recording situations or on stage.
 
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#982
BurningSkies said:
Part of my using class D power is weight v. power...I'm not a micro guy, in my world I realized that class D means I can have huge power with real-life unlimited headroom application...which leads to my other issue with 'all tube' setups. I can never keep the power section clean enough at some of the volumes I play at. Therefore a 300w or 400w tube section seems good in theory, but in application for me is just too 'sloppy' on the gig for what I want to hear. Those numbers are usually applied a good amount of THD which doesn't work for me.

So, my Class D power amp right now is a standard 2-rack space unit that weighs something in the low 20's for poundage. Not a featherweight and not what you're going to fit in your bass' gig bag. ;) But it'll do 2500w RMS all day long.

...imagine having a bass amp that you never ever have to think 'how powerful will this be in x-situation'. My only headroom limitations are based upon what my speakers can do. That's what Class D does, unlocks the potential to never worry about power amp limitations.

The piece that works for me tone-wise is that I have a couple REALLY nice tube preamps...The kind that are equally at home in professional recording situations or on stage.
Click to expand...
Yup. +1
 
#983
bucephylus said:
I’m with @BurningSkies regarding amp topologies. Get what I’m after using a tube preamp into the Class D power section. Doesn’t mean I don’t like, and in some cases hugely appreciate some of the bigger all tube heads. They are great if someone else wants to move them around for me. And no, that’s not just being wimpy. I have no back issues and don’t mind breaking a sweat. It’s just I get what I am after with what I’m using; so, why do more work for essentially the same result?

My main cover gig is ampless. I finally solved that particular signal chain issue to my satisfaction by using the tiny but awesome Demeter Bass400 as my “DI.” As an amplifier, the Bass400 is pretty potent; but, the really interesting part is the preamp in it is basically a single tube version of the VTBP-201. I still have my 1.5 space VTBP-201 for comparison. And, going back and forth between the two, I honestly have to say I’m not sure which I prefer. The SS output 400 is just a fraction cleaner and quicker. The 12AT7 output circuit is just slightly creamier. The difference is mainly noticeable when you are sitting in a quiet rehearsal space going back and forth. It is subtle. Not really something to get excited about. The magic in that circuit is in the V1 position. THAT tube makes a huge difference in tone when you roll various types. I like the Sylvania GB 5751; but, that’s me.
Click to expand...
OMG....a fellow 'tube roller'...V1 in my 71 Marshall Smallbox 50, man that position is sensitive to tube changes....yeah i do play bass with this amp occasionally.
 
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#985
agedhorse said:
You don't think the same compression and limiting hasn't been used on vinyl? It's probably more common with vinyl, to keep the stylus in contact with the groove. There is only so much modulation available on vinyl, less than what is available on a CD.



SMPS can be regulated, unregulated and designed with whatever impedance and compliance the designer chooses.
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I takes me half wave power supplies the way I takes me Camels... unfiltered. Bzzzzz :mad:
 
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#986
agedhorse said:
The stylus jumping from acoustic feedback is not what I am talking about. I'm specifically talking about maximum displacement (modulation) with respect to the possible lateral stylus velocity and acceleration. There were limiting algorithms developed specifically to address this and they have some very brick wall characteristics (some early 2 band limiters came out of this). Iirc, the Aphex dominator was one of these standards.
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You know more than i ever will know (or wanna know)........ but lets be honest, the commercial record playback system was always seriously flawed.....crap turntables, crap setups, dirty records, filthy stylus.....only a handful of people took great care of records and only a very few were chasing the very best turntables let alone proper setups.

FM radio was really taking off in the mid 60's and guys like Henry Kloss were designing outstanding speakers aimed at the mass public, killer low cost solid state receivers from Japan brought back by USA soldiers from abroad......turntables and vinyl were not being treated as well.... though certainly Shure and other companies were making excellent consumer cartridges, they were mishandled and easily destroyed.

Vinyl gets no respect i tell ya!
 
#989
bucephylus said:
In the preamp or power amp?

James Demeter drives his Class D power sections with tubes, usually an ECC81/12AT7. You can even get just the power section driven by the ECC81’s:
Invalid Link Removed
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Please re-read what I said, in the quote you included.
Pay particular attention to the part that says "tube, class D, *OUTPUT* stage."
Thank you. Thank you very much. :D
 
#992
Old Garage-Bander said:
Gots to love me some Lo-Fi as well. :sour:
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Some modelers also let you add line frequency ripple (50hz or 60hz), or double frequency, along with adding in the ripple intermodulation distortion that can add the sidebands. Sag is in there too. It's that familiar sound with soft power supplies but with adjustments instead of luck of the draw. Or take them out and see if you like the bass without MI amp artifacts added in. ;)
 
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#993
Old Garage-Bander said:
Please re-read what I said, in the quote you included.
Pay particular attention to the part that says "tube, class D, *OUTPUT* stage."
Thank you. Thank you very much. :D
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Well, I was not clear what you meant; which is why I asked you the question. You seemed to be asking about a tube driving the Class D section. But, perhaps, you were intending to indicate a Class D topology using tubes? Which, though theoretically possible, there are no commercial examples I am aware of. So, maybe, I’m just missing the contextual relevance. Sorry for wasting your time.:cool:;)
 
#994
Chucky Stiletti said:
Believe it or not, cheap Chinese radio manufacturers used to favor those because the 60Hz hum would stay out of the power BW of the audio amplifier that would have it's low cutoff at 100Hz..
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I can't recall ever seeing a half-wave supply in a hi fi power amp, Chinese or not.
 
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#998
JimmyM said:
Geez, I wish I could remember which one it was for sure, but I'm pretty sure it was the VB3 that I tried. I give it respect, too. Wasn't able to do a head-on AB with an SVT but it's a very good amp, I thought.
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I've only played through the VB-2. Really nice for a tube amp...
Yel_wink.gif
 
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