opaqueice;292390 Wrote:
> Maybe this diagram will help:
>
> [image:
> http://upload.wikimedia.org/wikipedia/commons/8/88/Source_and_load_circuit_Z.png]
>
> Z_S is the output impedance of the amplifier. Setting Z_S to zero
> doesn't cause any problem - on the contrary, it's desirable (so long a
Wireless, I did not use the built-in attenuators in the TP, because I am
running balanced ics and the built-in attenuators only work w/RCA.
--
Shredder
Shredder's Profile: http://forums.slimdevices.com/member.php?userid=11
Phil Leigh;292171 Wrote:
>
> surely the speaker is wired in parallel across the amp output?
Maybe this diagram will help:
[image:
http://upload.wikimedia.org/wikipedia/commons/8/88/Source_and_load_circuit_Z.png]
Z_S is the output impedance of the amplifier. Setting Z_S to zero
doesn't cause
As to why impedance _matching_ (in the proper sense of the term) of amps
and speakers is usually NOT desirable: basically the reason is that the
efficiency is very poor.
Let's suppose you have a power amplifier with an output Z of 0.1 ohms,
and you want to get maximal power out of it. It might se
O is correct - when we speak of the impedance of a source, we are
talking about what is effectively a series resistance "in" the source.
For a power amp driving speakers, you want it as low as possible. See
diagrams here: http://www.kpsec.freeuk.com/imped.htm. Also, highly
recommend reading: The A
I always thought that Musical Fidelity does a good job explaining the
benefit of reserve power in their amps - they focus on dynamic range
and performance with musical transients, rather than a sustained db
level performance.
'_Here_is_one_such_explanation_from_them_'
(http://www.musicalfidelity.
opaqueice;292163 Wrote:
> Actually, I -am- confused about Phil's post.
>
>
>
> In your examples you treated the amp as a voltage source and the output
> impedance as if it were in -parallel- with the load. But (regardless of
> the class) I thought output impedance is defined as the part of th
Actually, I -am- confused about Phil's post.
Phil Leigh;292086 Wrote:
>
> As an example, if your power amp can swing 40V from its PSU rails, has
> an impedance of 2 ohms and is running into an 8 ohm speaker, the max
> voltage the amp could deliver to the speaker would be:
> 40*(8/8+2) = 32 volt
wireless200 wrote:
> Shredder;292146 Wrote:
>> [...]Perhaps relevant to your original question, I run my TP directly
>> into my power. Without attenuators, my amps had way way too much gain.
>> Added Endler stepped attenuators and am now happy as a clam.
>>
>> Good luck.
>
> Shred, why didn't you
I've come to understand that less 'rated power' can -in principle-
confer an advantage.
Every active component has a dynamic range and that includes power
amps. This means a lower rated amp -can- have an advantage conferred to
it against a bigger amp whose dynamic range stays mostly unused even a
Shredder;292146 Wrote:
> [...]Perhaps relevant to your original question, I run my TP directly
> into my power. Without attenuators, my amps had way way too much gain.
> Added Endler stepped attenuators and am now happy as a clam.
>
> Good luck.
Shred, why didn't you adjust the jumpers inside t
wireless200;292136 Wrote:
> I think that's where you're getting confused.
Confused about what?
--
opaqueice
opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234
View this thread: http://forums.slimd
Wireless, not sure you need all that power for the Aerials. FWIW, I have
Aerial Model 9s-pretty similar to the 7bs except with more bass. When I
first got them, I powered them with a 150 watt Classe intergrated.
Sounded teriffic. However, I had been told by numerous sources that the
9s would only
opaqueice;292064 Wrote:
> Actually the wikipedia article is fine - he just needed to read (and
> understand) past the first two sentences. Maybe that was too much to
> expect.
Actually understanding the article - standard fare in any circuits 101
class - isn't the issue. The article doesn't sa
Thanks Phil and others I think I've got a better understanding of what's
going on there.
Actually I understand the Wiki article just fine. I derived the
theorem in 2nd year EE and have an MSEE. It's covered in every
Circuits 101 class. Actually I think opaq is a little confused about
what it s
David - power transfer is irrelevant in the context of audio (generally
speaking). It is very important in power stations and radio
transmitters.
Amplifiers and pre-amps have active devices in them - transistors and
valves - that amplify the voltages. Power transfer is only relevant
where we are t
Don't try and compare line level situations with speaker load
situations, as there is more to take into account in the case of
speakers.
In the line level situation, which you asked about initially, the
connection is made using voltage bridging (AKA impedence bridging).
Maximum power transfer is
wireless200;292047 Wrote:
> The Mcintosh mc402 gives 2, 4, and 8 terminals as "output load
> impedance." Musical Fidelity Kw550 specs a 50 ohm "output load loop
> impedance."
You're misunderstanding those numbers completely. Those are not the
output impedances of the amps.
The MF has a r
wireless200;292026 Wrote:
> Well I think NewBuyer had it right: you want maximum voltage across the
> target but I wanted to hear Sean's explanation.
>
>
> I want to use the TP as a pre-amp and avoid buying a separate pre-amp.
> That's why I'm asking these questions. Although it's good inform
wireless200;292047 Wrote:
> The Mcintosh mc402 gives 2, 4, and 8 terminals as "output load
> impedance."
Yes: that's the required LOAD impedance, ie. the input impedance of the
device you're driving (the speakers). The output impedance of the
amplifier itself (the SOURCE impedance) will be signif
opaqueice;292032 Wrote:
> Eh? What kind of SS amp has an ouput impedance of 4 ohms? Mostly
> they're well under .1 ohms (usually expressed in terms of the damping
> factor).
>
> An amplifier with an output impedance close to the impedance of the
> speaker it's connected to will audibly distort
I'd recommend that you get the amp/speakers you want and hook up the TP
directly to the amp and give it a listen. If you don't like what you
hear, then add a pre-amp. I wouldn't budget for one right out of the
box.
Having said that, I ended up using one because I like the way it
sounds. I'm us
Take the highly regarded Brystons as an example. Their pre-amps have an
output impedence of 110 ohms, and their power amps an input impedence
of 50k ohms. 100 ohms or so is pretty much a standard value for
pre-amps, and matches the output of the TP.
Therefore this is a technical non-issue in your
wireless200;292026 Wrote:
>
> TP (100 ohms) into Amp (10k ohms) vs Amp output (~4 ohms) into speakers
> (~4 ohms). In one case the impedance is not matched in the other it is.
> I assume this is because the speaker is a physical transducer and you'd
> need maximum power transfer but again I'd l
opaqueice;291976 Wrote:
> I think Sean was probably referring to the "doesn't bode well" part of
> your post when he said it was wrong. Read the second paragraph of the
> wiki article you linked to.
>
Well I think NewBuyer had it right: you want maximum voltage across the
target but I wanted to
wireless200;291953 Wrote:
> Obviously, the theorem is not wrong
> http://en.wikipedia.org/wiki/Maximum_power_theorem
I think Sean was probably referring to the "doesn't bode well" part of
your post when he said it was wrong. Read the second paragraph of the
wiki article you linked to and you'l
seanadams;291893 Wrote:
> That's wrong - below radio frequencies, you want a low source impedance
> and a high load impedance. 100R into 10K is a good (and typical)
> arrangement for audio.
Obviously, the theorem is not wrong
http://en.wikipedia.org/wiki/Maximum_power_theorem
but I'll take your
wireless200;291846 Wrote:
> Matching impedances result in maximum power transfer so this doesn't
> bode so well, does it?
That's wrong - below radio frequencies, you want a low source impedance
and a high load impedance. 100R into 10K is a good (and typical)
arrangement for audio.
--
seanadam
wireless200;291846 Wrote:
> Hmmm, that's interesting... the TP has a 100 ohm output impedance and
> the McIntosh has a 10k ohm input impedance (20k ohm balanced). What
> does this mean as far as sound quality. Matching impedances result in
> maximum power transfer so this doesn't bode so well,
Hmmm, that's interesting... the TP has a 100 ohm output impedance and
the McIntosh has a 10k ohm input impedance (20k ohm balanced). What
does this mean as far as sound quality. Matching impedances result in
maximum power transfer so this doesn't bode so well, does it? I don't
know exactly.
--
100ohms, from http://www.slimdevices.com/pi_transporter.html
--
radish
radish's Profile: http://forums.slimdevices.com/member.php?userid=77
View this thread: http://forums.slimdevices.com/showthread.php?t=46347
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