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Ace Rimmer Ace Rimmer is offline
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Default Running 8ohm speakers on 4ohm tap of tube amp

Good?
Bad?
Snake oil?
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Andre Andre is offline
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Default 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

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Ace Rimmer Ace Rimmer is offline
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Default 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.
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Andre Andre is offline
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Default 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

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[email protected] tubegarden@aol.com is offline
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Default 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



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Eeyore Eeyore is offline
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Default 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

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Eeyore Eeyore is offline
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Default 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


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maxhifi maxhifi is offline
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Default 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.


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Eeyore Eeyore is offline
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Default 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


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Sander deWaal Sander deWaal is offline
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Default 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."


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@(none) @(none) is offline
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Default 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
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Sander deWaal Sander deWaal is offline
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Default 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."
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Eeyore Eeyore is offline
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Default 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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