Tube vs. Solid State Preamp
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From: Chris on 3 Apr 2010 13:03 On Apr 2, 12:58 pm, Joerg <inva...(a)invalid.invalid> wrote: > Jim Thompson wrote: > > On Fri, 02 Apr 2010 10:51:59 -0700, Joerg <inva...(a)invalid.invalid> > > wrote: > > >> JosephKK wrote: > >>> On Thu, 1 Apr 2010 09:13:56 -0700 (PDT), Chris <christopher.man...(a)gmail.com> wrote: > > >>>> On Mar 31, 5:16 pm, "George Jefferson" <Geo...(a)Jefferson.com> wrote: > >>>>> "Adrian Tuddenham" <adr...(a)poppyrecords.invalid.invalid> wrote in message > > >>>>>news:1jg8ngr.1g7xp3le9s3eyN%adrian(a)poppyrecords.invalid.invalid... > > >>>>>> Leo <leo2...(a)gmail.com> wrote: > >>>>>> [...] > >>>>>>> This happens so because the transistors are more ideal amplifying > >>>>>>> devices than tubes are...so the signal that comes in is the one that > >>>>>>> comes out, with as little distortion as possible. Since the tubes are > >>>>>>> less ideal, they add different components to the original signal.... > >>>>>>> this have turned out to be more pleasant to the human ear. > >>>>>> I would disagree with this statement. The curvature of the transistor > >>>>>> characteristic is much sharper than many valves and the harmonics > >>>>>> generated are much nastier-sounding. Valve stages with no feedback are > >>>>>> quite common and the distortion they generate with moderate signal > >>>>>> voltages is quite tolerable, but transistor stages with no feedback are > >>>>>> virtually unusable for audio. > >>>>>> Transistor amplifiers can contain more devices in less space for the > >>>>>> same price and that allows them to employ much more feedback than valve > >>>>>> ones, not just overall but within individual stages; this is what gives > >>>>>> the improvement in overall linearity which you have erroneously > >>>>>> attributed to the devices themselves. The down side is that when they > >>>>>> eventually overload, they do so much more sharply and generate higher > >>>>>> harmonics, which sound vile. > >>>>> Most amplifiers are not meant to distort. Distortion is generally a bad > >>>>> thing in 99% of applications excluding intentional use for audio effects. If > >>>>> a solid state amplifier is distorting and not suppose to then it is because > >>>>> the circuit was designed improperly or it is not being used properly. > > >>>>> A tube circuit can never beat a properly designed solid state circuit for > >>>>> distortion free sound. For audio, this is not necessarily good as I > >>>>> mentioned in my original reply. > > >>>>> A tube amp emphases the even harmonics which are octaves of the > >>>>> fundamental(except for one 5th and up to the 8th harmonic). The odd > >>>>> harmonics emphasize a dom7th chord sonority which means that if you play any > >>>>> chords you are effectively playing a collection of dom7th sonorities(almost > >>>>> anyways). This means the distortion will sound harsh no matter what you play > >>>>> as there will be a great amount of dissonance created. Good for metal but > >>>>> not for a warm sound. > > >>>>> Again, in a properly designed solid state amplifier one will not have > >>>>> distortion(well, the THD will be extremely low to effectively be 0) and a > >>>>> tube amp will always have a higher THD(but designed properly it will still > >>>>> be low). The problem with tube amps is that in most basic amplifiers the > >>>>> load line vs the plate characteristics are non-linear over a large range > >>>>> which will introduce a compressive effect which creates distortion. > >>>>> Transistors have a similar effect but much more linear. > > >>>>> People generally prefer tubes because when they do distort they distort > >>>>> "nicely". Again, the point is, in a properly designed system where > >>>>> distortion is meant to be minimized you cannot beat solid state. The problem > >>>>> is that a SS amp may do it's job too well resulting in a dry unmusical > >>>>> sound. The tube amp will color the sound in a good way resulting in a more > >>>>> musically pleasing experience. > > >>>>> If you neglect the musical aspects of amplification SS amp's win hands down > >>>>> in every aspect except possibly power handling(but not so much any more). > >>>>> Again, it depends on the specifics but this is the general case. Tubes are > >>>>> generally better for musical applications in most cases. > > >>>>> The good thing is, we can use both types to get the best of both worlds. > >>>>> When we require absolute accuracy in amplification we use solid state. When > >>>>> we want the musical effect we use tubes. We might, for example, choose to > >>>>> use solid state amplification for a mixing desk's inputs and it's outputs > >>>>> are tube based. Or simply have one final tube for the output(PA or > >>>>> whatever), which offers less control over the individual tracks but requires > >>>>> far less tubes. > > >>>>> An analogy is incandescent and LED's. In fact, this is much more than an > >>>>> analogy as they both operate from the same physics. > >>>> I play guitar and mix sound. All of the tube amps I have tried for > >>>> the guitar have a more pleasing sound by a long shot, it is nice to > >>>> learn about the Fourier structure that you have shared. It quantifies > >>>> and solidifies what my music ear has been hearing this whole time. > >>>> Moreover, the tube amps that I have tried and own have virtually no > >>>> noise coming from them when the guitar is quiet. SS amps are hissing > >>>> like a pissed off snake. > > >>>> Regards, > >>>> Chris Maness > >>> Not one good amplifier hisses like a snake. SS or not. > > >> The not so good ones usually hum. And badly engineered solid-state ones > >> (meaning a lot of them) go *POCK* when someone turns on a GSM cell phone > >> nearby. I am not a tube freak but I've never heard a tube amp do that, > >> even if the design was a bit screwed up. Because it has no BE junctions. > > > But they _do_ rectify... just not as efficiently. > > Very much less efficiently. I remember when I got my ham radio license > as a kid. All the tube stuff in the neighborhood didn't flinch while > pretty much all the transistor stuff fell off the rocker. My first debug > job was an electronic organ, IIRC the Wersi brand. When I saw how they > had "engineered" the thing I was almost ready to cry. It was EMI > pandemonium. Plus the neighbor was a bit leery letting a kid like me > with a $5 made-in-Italy solder iron have at it. But, we got it quiet. I > depleted nearly my whole stash of salvaged 4700pF capacitors and use > probably 10ft of solder. > > -- > Regards, Joerg > > http://www.analogconsultants.com/ > > "gmail" domain blocked because of excessive spam. > Use another domain or send PM. Your a man "kid" after my own heart ;o) Chris
From: Joerg on 3 Apr 2010 15:22 krw(a)att.bizzzzzzzzzzzz wrote: > On Sat, 03 Apr 2010 00:45:27 -0400, "Michael A. Terrell" > <mike.terrell(a)earthlink.net> wrote: > >> Jim Thompson wrote: >>> But they _do_ rectify... just not as efficiently. >> >> I've seen quite a few tube PA amps that picked up CB radio, and >> police radios into the UHF Mobile band. Some small churches freaked out >> when a police call came through the speakers, at full volume during a >> church service. > > Probably not the tube doing the rectification, though. Usually a corroded > wire/contact in a mic was the culprit. Depending on the sermon topic and the nature of that police call it could be a fitting reminder of the consequences of sin :-) But FM rarely gets in. AM radio from low flying aircraft is another matter. Ham radio as well but since they use SSB most of the time that will sound more like Charlie Brown's teacher ... wah-wa-waah ... ouuah-wah-wah-waaah. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Michael A. Terrell on 3 Apr 2010 15:28 "krw(a)att.bizzzzzzzzzzzz" wrote: > > On Sat, 03 Apr 2010 00:45:27 -0400, "Michael A. Terrell" > <mike.terrell(a)earthlink.net> wrote: > > > > >Jim Thompson wrote: > >> > >> But they _do_ rectify... just not as efficiently. > > > > > > I've seen quite a few tube PA amps that picked up CB radio, and > >police radios into the UHF Mobile band. Some small churches freaked out > >when a police call came through the speakers, at full volume during a > >church service. > > Probably not the tube doing the rectification, though. Usually a corroded > wire/contact in a mic was the culprit. No, it was usually on an unused mic input, where someone forgot to screw the shorting cap back on. That was one of the reasons that Switchcraft developed the shorting version of their 2501 series chassis mount connector. -- Lead free solder is Belgium's version of 'Hold my beer and watch this!'
From: Phil Hobbs on 3 Apr 2010 15:44 Paul Keinanen wrote: > On Fri, 02 Apr 2010 10:51:59 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > >> The not so good ones usually hum. And badly engineered solid-state ones >> (meaning a lot of them) go *POCK* when someone turns on a GSM cell phone >> nearby. I am not a tube freak but I've never heard a tube amp do that, >> even if the design was a bit screwed up. Because it has no BE junctions. > > I have hunted down Radio Moscow from several tube guitar amplifiers. > There was a large number of short and medium wave transmitters in the > megawatt class across the border. You really need to move to a better neighbourhood. BTW a Finnish friend of my daughter's (the friend lives in Olu--they met at school in France) says that during the Winter War, the Finnish government essentially put the whole adult population on methamphetamine to increase production, and then cut off the supply cold turkey when the war was over. Is that so? Cheers Phil Hobbs > > Apparently the pick-up coil inductance and the cable stray capacitance > formed a parallel resonant circuit that happened to resonate on one of > the numerous high power transmitter. Often a quick fix was to use a > different cable with different length, which apparently moved the > resonance to a quilter place :-). Adding a resistor and capacitor to > the input jack usually solved the problems completely. > -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: krw on 3 Apr 2010 15:46
On Sat, 03 Apr 2010 12:22:27 -0700, Joerg <invalid(a)invalid.invalid> wrote: >krw(a)att.bizzzzzzzzzzzz wrote: >> On Sat, 03 Apr 2010 00:45:27 -0400, "Michael A. Terrell" >> <mike.terrell(a)earthlink.net> wrote: >> >>> Jim Thompson wrote: >>>> But they _do_ rectify... just not as efficiently. >>> >>> I've seen quite a few tube PA amps that picked up CB radio, and >>> police radios into the UHF Mobile band. Some small churches freaked out >>> when a police call came through the speakers, at full volume during a >>> church service. >> >> Probably not the tube doing the rectification, though. Usually a corroded >> wire/contact in a mic was the culprit. > > >Depending on the sermon topic and the nature of that police call it >could be a fitting reminder of the consequences of sin :-) For communion do you serve coffee and doughnuts? ;-) >But FM rarely gets in. AM radio from low flying aircraft is another >matter. Ham radio as well but since they use SSB most of the time that >will sound more like Charlie Brown's teacher ... wah-wa-waah ... >ouuah-wah-wah-waaah. FM wouldn't be as obvious. Wouldn't FM just put a DC bias on the mic circuit? |