amplifier power

Archived from groups: rec.audio.tech (More info?)

My current Sony amp is on its last legs with "PROTECT" in the display
a regular occurance. My question relates to the 100w + 100w specified
in stereo mode. I rarely have the volume knob past 1/4 travel and
wonder if I need this amount of power for the replacement.

I am interested in moving to a smaller form factor receiver - the
panasonic SA-XR15 - which is specified as 40W per channel. Does this
mean to get the same volume effect in my house I will need to increase
the control to near its maximum? If this is the case what will be the
impact on the Rx itself? Will it have any detrimental effect?

Thanks

Simon

Archived from groups: rec.audio.tech (More info?)

"Simon" <scousep@tesco.net> wrote in message
news:a9fc8de5.0404300932.1820cf93@posting.google.com...
> My current Sony amp is on its last legs with "PROTECT" in the display
> a regular occurance. My question relates to the 100w + 100w specified
> in stereo mode. I rarely have the volume knob past 1/4 travel and
> wonder if I need this amount of power for the replacement.
>
> I am interested in moving to a smaller form factor receiver - the
> panasonic SA-XR15 - which is specified as 40W per channel. Does this
> mean to get the same volume effect in my house I will need to increase
> the control to near its maximum? If this is the case what will be the
> impact on the Rx itself? Will it have any detrimental effect?
>
> Thanks
>
> Simon
Yes, It is a good idea to get another brand. I repaired a Sony that was
locked in protect mode. It had two dead short output transistors a resistor
with the side blown off and a swollen cap. Replacing these got it back. I
had a handycam that died, top end walkmen mechanical cassette drive failures
and other Sony products that failed early and without abuse. Other brands I
owned always lasted much longer. it's a shame because Sony makes products
with the performance and features I wanted.

Well I must be thick headed, because I bought another Sony walkman. It is
the cassette player with TV and weather bands. When I tap it while listening
to AM, I get a scratchy noise in my headphones. Yep, something loose inside.
At leat this one is only $30.
John

Archived from groups: rec.audio.tech (More info?)

In <a9fc8de5.0404300932.1820cf93@posting.google.com>, on 04/30/04
at 10:32 AM, scousep@tesco.net (Simon) said:

>My current Sony amp is on its last legs with "PROTECT" in the display
>a regular occurance. My question relates to the 100w + 100w specified
>in stereo mode. I rarely have the volume knob past 1/4 travel and
>wonder if I need this amount of power for the replacement.

>I am interested in moving to a smaller form factor receiver - the
>panasonic SA-XR15 - which is specified as 40W per channel. Does this
>mean to get the same volume effect in my house I will need to increase
>the control to near its maximum? If this is the case what will be the
>impact on the Rx itself? Will it have any detrimental effect?

There is no standard that relates rotation of the volume control and
how loud things are in the room or the power of the unit. I do notice
that the lower quality units tend to require less rotation before they
become "loud". To a certain market segment this is a good feature. Many
have related to me that, "it was a powerful unit because I only had to
crack the volume control before it blew me out of the room". These
customers will complain about higher quality, more powerful units that
require more volume control rotation for the same sound level --
claiming the unit is not as powerful.

If your protect light is comming on because you are playing too loud,
the 40W unit will not work for you. I don't know what "1/4 travel"
means for your unit. Some units don't get much louder beyond 1/2. It
also depends on what you are playing. Compact Disc players tend to be
somewhat loud and Phono's are not so loud. Some Compact Discs are
recorded louder than others.

As long as the unit has adequate ventilation and you are operating the
unit within it's design limits, there is very little down side for
running the new unit closer to its limit than you are the Sony. (there
is a complex relationship between operating conditions and long term
reliability.)

-----------------------------------------------------------
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Archived from groups: rec.audio.tech (More info?)

In <a9fc8de5.0405020121.3cf8c0b5@posting.google.com>, on 05/02/04
at 02:21 AM, scousep@tesco.net (Simon) said:

[ ... ]

> Good advice about
>disconnecting the speakers, I assumed it would cause damage if I ran
>it this way.

Vacuum tube gear designed prior to the 1960's had problems when
operating without speakers, modern gear does not have these problems.
The math necessary to design a unit without the stability problem was
not available to undergraduate engineers prior to the late 1950's. If
the engineer learned his or her trade without this math, their designs
*MAY* have trouble when no speakers are connected. Using the new math,
engineers can guarantee that this problem will not exist. Prior to the
math, it was hit or miss.

This math came along with the first group of young engineers who were
familiar with transistors. It was this accident of timing that caused
the tube designs of the day to be unstable while early transistor
designs were stable.

I am very careful to always connect a "load" (speakers or a resistor)
to old, classic tube designs. I have never had a problem with newer,
stable tube or transistor designs operating into an open circuit (no
connection to the speaker terminals). (and this experience spans
thousands of units).

-----------------------------------------------------------
spam: uce@ftc.gov
wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13> (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

Archived from groups: rec.audio.tech (More info?)

>
>My current Sony amp is on its last legs with "PROTECT" in the display
>a regular occurance. My question relates to the 100w + 100w specified
>in stereo mode. I rarely have the volume knob past 1/4 travel and
>wonder if I need this amount of power for the replacement.
>
>I am interested in moving to a smaller form factor receiver - the
>panasonic SA-XR15 - which is specified as 40W per channel. Does this
>mean to get the same volume effect in my house I will need to increase
>the control to near its maximum? If this is the case what will be the
>impact on the Rx itself? Will it have any detrimental effect?
>
>Thanks
>
>Simon
>

The difference between 40 Watts and 100 Watts is only slightly over 3dB
(assuming same loas and specs given into same load.

Depending on the amplifier design, you may not hear any difference.

I have a 200W/channel amp and a high current 45 W/channel amp. The 45 Watt amp
sounds better and can drive my speakkers to neighbor annoying levels very
easily.



Richard H. Kuschel
"I canna change the law of physics."-----Scotty