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#1
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Good?
Bad? Snake oil? |
#2
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Ace Rimmer wrote:
Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre |
#3
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Andre wrote:
Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre I read somewhere (wish i could find it now) that it improved dampening. |
#4
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Ace Rimmer wrote:
Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre I read somewhere (wish i could find it now) that it improved dampening. In case of an amplifier without feedback it does indeed but, take into account that the gain in damping is about from 1 to 2 where for example SS amplifiers nowadays have damping-factors between 200 and 800 At the levels employed with single ended tube-amps like 5Watt I don't think you will hear much difference, exept that you end up with 1/4th. of the output power. Andre |
#5
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Hi RATs!
I run my speakers on whatever taps sound the best, in my system, in my house, to my ears. Anything else is not snake oil, it is intellectual sodomy. Happy Ears! Al |
#6
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Andre wrote: Ace Rimmer wrote: Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre I read somewhere (wish i could find it now) that it improved dampening. In case of an amplifier without feedback it does indeed but, take into account that the gain in damping is about from 1 to 2 Both of which figures are rather horrible. where for example SS amplifiers nowadays have damping-factors between 200 and 800 At the levels employed with single ended tube-amps like 5Watt I don't think you will hear much difference, exept that you end up with 1/4th. of the output power. Rubbish. It's 'theoretically' 1/2 the output power before taking into account other real world factors. Probably realistically a loss of 2 ~ 2.5dB in maximum output. Graham |
#7
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Ace Rimmer wrote: Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre I read somewhere (wish i could find it now) that it improved dampening. You mean damping and yes it will increase the damping factor. Proponents of the SET however prefer the 'improvement' of low damping factor, which tends to rather sloppily 'enhance' the bass registers. Graham |
#8
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
"Eeyore" wrote in message ... Ace Rimmer wrote: Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. Andre I read somewhere (wish i could find it now) that it improved dampening. You mean damping and yes it will increase the damping factor. Proponents of the SET however prefer the 'improvement' of low damping factor, which tends to rather sloppily 'enhance' the bass registers. Graham It can make a big difference, and can be useful for system tuning. I have 6 ohm speakers, and in a small room (my old apartment), they need the 4 ohm tap, with its better control over the speakers, which tended to sound boomy on the 8 ohm tap in that environment. In a large room, the 8 ohm tap gives a slight bass boost at resonance, which is just what the speakers need to sound their best, as room enhancement is nowhere near what it is in a small room. It's not a gross difference, but it's definitely the difference between good and amazing sound. It increases the damping factor, because the output impedance (Thevenin series resistance) of the output tube is being stepped down to half the value on the 4 ohm tap than the 8 ohm tap. |
#9
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
maxhifi wrote: "Eeyore" wrote Ace Rimmer wrote: I read somewhere (wish i could find it now) that it improved dampening. You mean damping and yes it will increase the damping factor. Proponents of the SET however prefer the 'improvement' of low damping factor, which tends to rather sloppily 'enhance' the bass registers. Graham It can make a big difference, and can be useful for system tuning. I have 6 ohm speakers, and in a small room (my old apartment), they need the 4 ohm tap, with its better control over the speakers, which tended to sound boomy on the 8 ohm tap in that environment. In a large room, the 8 ohm tap gives a slight bass boost at resonance, which is just what the speakers need to sound their best, as room enhancement is nowhere near what it is in a small room. It's not a gross difference, but it's definitely the difference between good and amazing sound. Yes, I can see the science behind all of the above effects. You can of course get a very similar effect by using traditional EQ instead of the amplifier tap / impedance to determine the bass respnse. It increases the damping factor, because the output impedance (Thevenin series resistance) of the output tube is being stepped down to half the value on the 4 ohm tap than the 8 ohm tap. Exactly so. This will give better 'control' of the cone at LF. Going the high source-Z route results in less control of the bass and more of a 'farty' sound since speaker resonance is allowed to continue longer. Grahamm |
#10
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp
Ace Rimmer said:
Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. I read somewhere (wish i could find it now) that it improved dampening. It depends if your amp is a triode or beam tetrode/penthode amp. Triodes are a bit more forgiving in mismatching, both in power and distortion Penthodes are a bit more picky. Usually, one needs to get the closest match possible, but if you have no choicem choose the first lower tap available. If for instance you have 6 ohms speakers, attach them to the 4 ohms tap. I can explain why if you like, but for now I'll leave it at this. One thing: NEVER use a tube amp without any loads connected. -- "Due knot trussed yore spell chequer two fined awl miss steaks." |
#11
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp - NEW INSIGHT !
Sander deWaal wrote:
Ace Rimmer said: Andre wrote: Ace Rimmer wrote: Good? You get less power Bad? Won't hurt the amplifier or speaker Snake oil? If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. And suddenly I realized that the changes in sound are, however small, real and can be scientifically proved. And this modification is _free_ So that's the opposite of Snake-oil. ( which appearently comes for $72 for a 10ml bottle, ) Andre |
#12
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp - NEW INSIGHT !
"@(none)" ""andre\"@(none)" said:
If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. And suddenly I realized that the changes in sound are, however small, real and can be scientifically proved. And this modification is _free_ So that's the opposite of Snake-oil. ( which appearently comes for $72 for a 10ml bottle, ) Using the correct load on the incorrect tap will result in at least less power, and in most cases, more distortion. The exception is the triode amp, where a higher Z load connected to a lower Z tap will result in both lower power AND lower distortion. And a fraction better damping of the speaker. -- "Due knot trussed yore spell chequer two fined awl miss steaks." |
#13
Posted to rec.audio.tubes
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Running 8ohm speakers on 4ohm tap of tube amp - NEW INSIGHT !
none wrote: If it's done for any other reason then that there is no 8-Ohm output or 4 Ohm speaker available,.. it's snake oil, yeah. And suddenly I realized that the changes in sound are, however small, real and can be scientifically proved. So which one's 'better' ??? Graham |
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