Running 8ohm speakers on 4ohm tap of tube amp

[Ace Rimmer]

Good?
Bad?
Snake oil?

[Andre]

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

[Ace Rimmer]

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.

[Andre]

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

[[email protected]]

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

[Eeyore]

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

[Eeyore]

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

[maxhifi]

"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.

[Eeyore]

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

[Sander deWaal]

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."

[@(none)]

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

[Sander deWaal]

"@(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."

[Eeyore]

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

[@(none)]

Eeyore wrote:
>
> 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
>

My new insight is not about the effect of (title)
but on calling it snake-oil.

druegkloeete

To be honest,... I don't hear it.
So I came to my first statement.

Thinking it over, I came to the
second statement, pure theoretically !

Now I only wanted to not call it "snake oil"
cause snake-oil is veeeeeeeery expensive
and "Running 8ohm speakers on 4ohm tap of tube amp" is free

Andre

[Sander deWaal]

"@(none)" <""andre\"@(none)"> said:


>druegkloeete


Heheheh! Ik zal de enige zijn die hem begrijpt ;-)

Ik probeer alleen een newbie te behoeden voor het opblazen van zijn
uitgangstrafo, of het per ongeluk laten doorslaan van een buis wegens
vonkoverslag door een te lichte belasting.

Wil je echt lol maken, ga dan naar rec.audio.opinion.

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[Ruud Broens]

"Sander deWaal" > wrote in message
...
: "@(none)" <""andre\"@(none)"> said:
:
:
: >druegkloeete
:
:
: Heheheh! Ik zal de enige zijn die hem begrijpt ;-)

....Howso ?
:
: Ik probeer alleen een newbie te behoeden voor het opblazen van zijn
: uitgangstrafo, of het per ongeluk laten doorslaan van een buis wegens
: vonkoverslag door een te lichte belasting.
:
: Wil je echt lol maken, ga dan naar rec.audio.opinion.
:
: --
: "Due knot trussed yore spell chequer two fined awl miss steaks."

"Gepaste knoop verankerde yore werktijdruit twee de
gezuiverde lapjes vlees van elsjuffrouw"

hehe

btw, spicing up a diode based softlimiter works fine,
the knee is really different for different types :-)
R.

[Sander deWaal]

"Ruud Broens" > said:


>: >druegkloeete


>: Heheheh! Ik zal de enige zijn die hem begrijpt ;-)


> ....Howso ?


I didn't expect you to lurk here every day ;-)


>: "Due knot trussed yore spell chequer two fined awl miss steaks."


>"Gepaste knoop verankerde yore werktijdruit twee de
>gezuiverde lapjes vlees van elsjuffrouw"

>hehe


Babelfish rulez!


>btw, spicing up a diode based softlimiter works fine,
>the knee is really different for different types :-)
>R.


Try using a 6H6 and report back ;-)

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[Ruud Broens]

"Sander deWaal" > wrote in message
...
: "Ruud Broens" > said:
:
:
: >: >druegkloeete
:
:
: >: Heheheh! Ik zal de enige zijn die hem begrijpt ;-)
:
:
: > ....Howso ?
:
:
: I didn't expect you to lurk here every day ;-)
:
:
: >: "Due knot trussed yore spell chequer two fined awl miss steaks."
:
:
: >"Gepaste knoop verankerde yore werktijdruit twee de
: >gezuiverde lapjes vlees van elsjuffrouw"
:
: >hehe
:
:
: Babelfish rulez!
: -)))
:
: >btw, spicing up a diode based softlimiter works fine,
: >the knee is really different for different types :-)
: >R.
:
:
: Try using a 6H6 and report back ;-)
:
: --
no candu, can't use tubes for evrything in this application.
just ss will do
(maybe l8er, though, with PABC80's diodes)
Rudy

[Sander deWaal]

"Ruud Broens" > said:


>: >btw, spicing up a diode based softlimiter works fine,
>: >the knee is really different for different types :-)


>: Try using a 6H6 and report back ;-)

-
>no candu, can't use tubes for evrything in this application.
>just ss will do
> (maybe l8er, though, with PABC80's diodes)


A soft-clipping limiter gets very interesting when there's still some
conduction at Va = 0......... ;-)

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[@(none)]

Ruud Broens wrote:
> "Sander deWaal" > wrote in message
> ...
> : "Ruud Broens" > said:
> :
> :
> : >: >druegkloeete
> :
> :
> : >: Heheheh! Ik zal de enige zijn die hem begrijpt ;-)

Dan heb ik bij deze verraden waar ik (zo ongeveer) woon.

> : > ....Howso ?

Jij ook ?

> : Try using a 6H6 and report back ;-)
> :
> : --
> no candu, can't use tubes for evrything in this application.
> just ss will do
> (maybe l8er, though, with PABC80's diodes)
> Rudy

In case of, wil ik wel een aantal EABC80's doneren.

How complicated should your limiter be and for what
purpose.

Andre

[Ruud Broens]

"@(none)" <""andre\"@(none)"> wrote in message
...
: Ruud Broens wrote:
: > "Sander deWaal" > wrote in message
: > ...
: > : "Ruud Broens" > said:
: > :
: > :
: > : >: >druegkloeete
: > :
: > :
: > : >: Heheheh! Ik zal de enige zijn die hem begrijpt ;-)
:
: Dan heb ik bij deze verraden waar ik (zo ongeveer) woon.
:
: > : > ....Howso ?
:
: Jij ook ?
:
: > : Try using a 6H6 and report back ;-)
: > :
: > : --
: > no candu, can't use tubes for evrything in this application.
: > just ss will do
: > (maybe l8er, though, with PABC80's diodes)
: > Rudy
:
: In case of, wil ik wel een aantal EABC80's doneren.
:
: How complicated should your limiter be and for what
: purpose.
:
: Andre

there are limits to what a limiter cando or shodo
but add some mojo
it candu, sweetly so,

instrument comp.
R.

[Eeyore]

Sander deWaal wrote:

> "Ruud Broens" > said:
>
> >: >btw, spicing up a diode based softlimiter works fine,
> >: >the knee is really different for different types :-)
>
> >: Try using a 6H6 and report back ;-)
>
> -
> >no candu, can't use tubes for evrything in this application.
> >just ss will do
> > (maybe l8er, though, with PABC80's diodes)
>
> A soft-clipping limiter gets very interesting when there's still some
> conduction at Va = 0......... ;-)

Resistive output opto couplers makes the best limiters IMHO. e.g.
http://www.waltzingbear.com/Schematics/Urei/LA_2.htm
http://www.tangible-technology.com/optical/LA4_article.htm

Graham

[Ruud Broens]

"Eeyore" > wrote in message
...
:
:
: Sander deWaal wrote:
:
: > "Ruud Broens" > said:

: > >no candu, can't use tubes for evrything in this application.
: > >just ss will do
: > > (maybe l8er, though, with PABC80's diodes)
: >
: > A soft-clipping limiter gets very interesting when there's still some
: > conduction at Va = 0......... ;-)
:
: Resistive output opto couplers makes the best limiters IMHO. e.g.
: http://www.waltzingbear.com/Schematics/Urei/LA_2.htm
: http://www.tangible-technology.com/optical/LA4_article.htm
:
: Graham

what ? not a dsp program for a liquidmix ?? ;-)
see
http://www.focusrite.com/index.php?pageName=productReview&productName=liquid_mix
and get a sdk in a hurry

heh
R.
(amazing product, that)