cliveb;368120 Wrote:
(In theory it is possible to construct resistor networks which will
reduce source impedance, but in practice when you solve the
simultaneous equations you end up with a requirement for negative
resistances).
Way back when, at work we used to use negative impedence
I love you guys...
--
JadeMonkee
2x squeezebox classics {1x wired, 1x wifi} | squeezecentre v7.2.1 |
'readynas duo' (http://www.readynas.com/forum/viewforum.php?f=22) {
raidiator 4.14 | 1gb hynix hymd512m646cfp8-j | 2x 1tb samsung hd103uj }
| d-link dir-655
Hi Pat,
Yes you are right, the Burson website is incorrect and whoever made the
site is wrongly describing what their product even does! Their product
doesn't match impedances as in making them equal, but they
misleadingly call it matching on their website. And then, they
further complicate it
NewBuyer;369048 Wrote:
Is an external buffer essentially a separate output-stage-in-a-box?
You could think of it like that, but the catch is, that it doesn't
remove, or alter the previous devices output stage.
NewBuyer;369048 Wrote:
Is it really a voltage amplifier / preamp without a volume
NewBuyer;369048 Wrote:
My own naive questions: Is an external buffer essentially a separate
output-stage-in-a-box? Is it really a voltage amplifier / preamp
without a volume control? Does the buffer's high input Z and 6db gain,
allow the previous device's output stage to run in a more
seanadams;368466 Wrote:
Haha, by all means go on. :)
I needed a day away to get my lithium level adjusted. Those guys pushed
me over the edge.
Pat
--
ar-t
http://www.analogresearch-technology.net
ar-t's Profile:
I used to build audio output stages with discrete components. Most of it
came down to finding matched pairs of transistors which was already hard
in the 80's when I was at it and I wonder if you can buy them today. I
sometimes went through a shop's complete stock, measuring each
transistor hoping
DeVerm wrote:
I used to build audio output stages with discrete components. Most of it
came down to finding matched pairs of transistors which was already hard
in the 80's when I was at it and I wonder if you can buy them today.
I don't know if you can. I do know that I would buy a bag of
pfarrell;369079 Wrote:
I don't know if you can. I do know that I would buy a bag of transistors
and sit down and measure the beta of each, and match them myself. It was
cheaper to do that then buy them in matched pairs.
That's exactly what I did but I managed to do it in the shop and only
jeffmeh;367975 Wrote:
In the case of an impedance mismatch, what are the comparative
advantages of a buffer over a passive attenuator? I assume that the
buffer will be much more expensive.
An impedance mismatch is usually a case of a high impedance driving a
low impedance. Adding passive
Thanks Dave and Clive. Buffer to boost, attenuator to attenuate I
missed the obvious notion that the impedance mismatch is not always a
case of a source with output that is too hot for the target input.
--
jeffmeh
jeffmeh;368171 Wrote:
Thanks Dave and Clive. Buffer to boost, attenuator to attenuate I
missed the obvious notion that the impedance mismatch is not always a
case of a source with output that is too hot for the target input.
Impedance is almost never at issue in this case. Maybe I can
seanadams;368286 Wrote:
Impedance is almost never at issue in this case. Maybe I can clear up
some of the confusion:
** Line-level interconnection (ie analog RCA or XLR cables): You should
have a low impedance output (eg 100#937;) driving a high impedance
input (eg 10,000#937;).* The
The supposed purpose of the product is to somehow resolve impedance
mismatches, which makes no sense to begin with. The marketing material
goes only as far as the following hand-waving: Impedance matching is a
complex technical issue in audio design. and then proceeds to bemoan
the failure of
seanadams;368317 Wrote:
The supposed purpose of the product is to somehow resolve impedance
mismatches, which makes no sense to begin with. The marketing material
goes only as far as the following hand-waving: Impedance matching is a
complex technical issue in audio design. and then proceeds
seanadams;368286 Wrote:
So what happens in each case if you get it wrong?
Line levels: if the receiving device has a low input impedance (in
which case it is probably defective) or if the transmitting device has
a high impedance, what happens is that the signal becomes attenuated
snip
Thanks all for the great explanations. Can anyone point to a good
layman's definition of impedance? I am math-oriented, but I am not an
electrical engineer, and the definitions I can find on the web seem to
assume much pre-existing electrical engineering knowledge. Many
thanks.
--
jeffmeh
jeffmeh;368425 Wrote:
Thanks all for the great explanations. Can anyone point to a good
layman's definition of impedance? I am math-oriented, but I am not an
electrical engineer, and the definitions I can find on the web seem to
assume much pre-existing electrical engineering knowledge.
seanadams;368286 Wrote:
...Back to the original subject of this thread... taking the above into
account, can anyone suggest a practical scenario that would benefit
from this product? I can't. If a line level source device is too weak
to accurately drive a 10K input, then it is quite simply
NewBuyer;368442 Wrote:
Hi Sean,
One practical scenario (among others) that benefits from this product,
in my experience, is when using 'Scott Endler's 4k \shotgun\
attenuators' (http://mysite.verizon.net/vze4c5pt/id2.html), which
attach directly to the power amplifier.
When driving
seanadams;368317 Wrote:
The supposed purpose of the product is to somehow resolve impedance
mismatches, which makes no sense to begin with. The marketing material
goes only as far as the following hand-waving: Impedance matching is a
complex technical issue in audio design. and then proceeds
ar-t;368456 Wrote:
This is one of the most disingenuous marketing ploys that I have ever
seen. I guess that I now have 3 myths to dispel.
(Sean, if this violates the spirit of your forum, just tell me and I
will shut up...)
Haha, by all means go on. :)
I think the most important
So, an Audio Buffer is a preamp without a volume control, right ?
Did I get it properly ?
In such a case, if you already have a preamp (or an integrated amp)
what could possibly be the advantage of putting a second preamp in the
circuit ?
--
Themis
SB3 - North Star dac 192 - Denon 3808 -
Themis wrote:
So, an Audio Buffer is a preamp without a volume control, right ?
Did I get it properly ?
Not quite.
As usual, wikipedia has a useful entry:
http://en.wikipedia.org/wiki/Buffer_amplifier
In such a case, if you already have a preamp (or an integrated amp)
what could possibly
In the case of an impedance mismatch, what are the comparative
advantages of a buffer over a passive attenuator? I assume that the
buffer will be much more expensive.
--
jeffmeh
jeffmeh's Profile:
Surely if two pieces of equipment don't interface properly at least one
of them is useless.
--
JezA
JezA's Profile: http://forums.slimdevices.com/member.php?userid=21219
View this thread:
jeffmeh;367975 Wrote:
In the case of an impedance mismatch, what are the comparative
advantages of a buffer over a passive attenuator?
They're really opposites. A buffer provides current gain, while a
passive attenuator provides a loss.
You could argue that the problem is that there are no
I'll admit, I don't get it. Every line-level source should have a low
(eg 100R) output Z, no?
Can anyone give an example of actual products that would benefit from
this? Perhaps old tube gear...
--
seanadams
seanadams's
These days, I decided to try to understand how (and why) an audio
buffer works, if it works.
I tried to get some information reading various articles here and
there. I found mostly commercial information, I admit. It seems nearly
impossible to get technical data about this kind of device.
For
Well, if you have a source with a very high output impedance, driving a
preamp with a very low input impedance, you can run into issues with
frequency response, and occasionally, limiting or clipping. Passive
preamps are one type of component that frequently requires careful
selection of sources
My understanding is that a good buffer (like the Burson) reduced the
potentially degrading effects of interconnect cables on the transmitted
autio signal, and additionally presents a stronger and less distorted
signal to the input stage of the following component.
Having the buffer as a separate
31 matches
Mail list logo
