Update on SPDIF to analogue

"Rick" wrote in message
...





Thanks for that info Jim, whilst I'm here, that little Lindy unit comes
with a 5v 500mA wall wart power supply, although if I could I'd rather
have it powered from a spare USB socket on the TV and was wondering about
knocking up a lead [according Wicki, USB voltage output should deliver
from 500–900 mA (general)] so is it wise to assume that the TV's USB
sockets will comfortably deliver sufficient current? as unsurprisingly
that kind of spec isn't given in the manual.



I made up a lead which worked perfectly with the Lindy powered from the TV's
USB socket and whilst I was about it I thought I'd check the current
consumption, which I was quite surprised to find revealed that the unit only
draws a meager 78 mA , so well pleased, although I'm surprised that with
such low power requirements the makers didn't provide an alternative USB
power lead with the unit.

In article , Rick wrote:


I made up a lead which worked perfectly with the Lindy powered from the
TV's USB socket and whilst I was about it I thought I'd check the
current consumption, which I was quite surprised to find revealed that
the unit only draws a meager 78 mA , so well pleased, although I'm
surprised that with such low power requirements the makers didn't
provide an alternative USB power lead with the unit.

I'm not surprised by the result. It is a reflection of the way mass
manufacture operates. The PSU chosen may well be one already being made in
large quantities, so have a price as low - or lower - than an alternative
with a lower output current rating. There are also other factors. Two
examples:

1) The current rating on the PSU may also be the 'safe max' value whereas
the device being powered may need lower ripple, so is operated well below
the max of the PSU.

2) There may be a turn on surge which a lower rated PSU can't handle.

FWIW The power amp I use in my hifi systems only draws a tiny wall current
in normal use. But it eats up to over 100A for a short time when you switch
it on. 8-] Our old TV set used to drop a frame and roll once when the amp
was switched on next door. The lights also flicker. This is an extreme
case, though. Your device is probably less demanding. :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 02/12/2012 16:21, Rick wrote:


"Jim" wrote in message
...
On 01/12/2012 16:26, Rick wrote:


snip
Thanks for that info Jim, whilst I'm here, that little
Lindy unit comes with a 5v 500mA wall wart power
supply, although if I could I'd rather have it powered
from a spare USB socket on the TV and was wondering
about knocking up a lead [according Wicki, USB voltage
output should deliver from 500–900 mA (general)] so is
it wise to assume that the TV's USB sockets will
comfortably deliver sufficient current? as
unsurprisingly that kind of spec isn't given in the
manual.

My Samsung TV displays a warning message if USB
power exceeds the port limit. One of its two USB
ports has a higher rating than the other = intended
for a disc drive rather than a wireless dongle.


Thanks for the info, I can give it a try and see what
happens, the Samsung UE32ES5500 has two USB ports and
I'm using one to run a SSD to record programmes, a
downside I've discovered is that they use Sony .srf
files, which I haven't yet found a way of playing and
converting to other formats on my computer, as I can
with the .trp files that are used on my Technomate HD
satellite receiver.

You might find an answer he
http://forum.samygo.tv/viewtopic.php...art=200#p34737

On Monday, December 3, 2012 10:01:49 AM UTC, Jim Lesurf wrote:

FWIW The power amp I use in my hifi systems only draws a tiny wall current
in normal use. But it eats up to over 100A for a short time when you switch
it on. 8-] Our old TV set used to drop a frame and roll once when the amp
was switched on next door. The lights also flicker.

Ah. Your hi-fi amp clearly must have the Linkohertzheim Class-K arc welder flanging stabiliser circuits installed.

In article ,
wrote:
On Monday, December 3, 2012 10:01:49 AM UTC, Jim Lesurf wrote:

FWIW The power amp I use in my hifi systems only draws a tiny wall
current in normal use. But it eats up to over 100A for a short time
when you switch it on. 8-] Our old TV set used to drop a frame and
roll once when the amp was switched on next door. The lights also
flicker.

Ah. Your hi-fi amp clearly must have the Linkohertzheim Class-K arc
welder flanging stabiliser circuits installed.

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and short
bursts of about 60A into lower loads. But more relevant here is ye olde
fashioned PSU design with a big transformer and low esr capacitors.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Tuesday, 4 December 2012 09:58:32 UTC, Jim Lesurf wrote:

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and short
bursts of about 60A into lower loads. But more relevant here is ye olde
fashioned PSU design with a big transformer and low esr capacitors.

Do you go in for bass-heavy music?

wrote:
On Tuesday, 4 December 2012 09:58:32 UTC, Jim Lesurf wrote:

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and short
bursts of about 60A into lower loads. But more relevant here is ye olde
fashioned PSU design with a big transformer and low esr capacitors.

Do you go in for bass-heavy music?

The thing is, when the violinist knocks the music stand over it's nice
to actually feel the thump when it hits the floor.

Bill

In article ,
wrote:
On Tuesday, 4 December 2012 09:58:32 UTC, Jim Lesurf wrote:

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and
short bursts of about 60A into lower loads. But more relevant here is
ye olde fashioned PSU design with a big transformer and low esr
capacitors.

Do you go in for bass-heavy music?

Nope. I rarely use it at anything like that level. However the amp was
designed in an era when hifi speakers were going south in terms of both
efficiency and input impedance. The problem facing the designer of a hifi
power amp is not knowing what speakers the user will choose, and what music
they will want to play... or how deaf they wish to become. :-) At the
time one of the speakers that reviewers raved about was a 'magnaplanar'
design with an input impedance of about 1 Ohm. And current limiters can
seriously upset music in such cases.

The other side of this is that a design that can sustain high currents and
voltages is essentially 'cruising along' in most normal use. So doesn't
have a performance that varies with use due to things like changes in
temperature. Can also be very durable.

I use the amps with Quad ESLs[1], and rarely drive them to much more than
moderate levels. However worth noting these go down to about 2Ohms at low
frequency. And have a little-known tendency for the low-frequency impedance
to vary with the signal level.

Slainte,

Jim

[1] Not the orginals from 1957, but the later versions from the ESL63 basic
design.

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , Bill Wright
wrote:
wrote:
On Tuesday, 4 December 2012 09:58:32 UTC, Jim Lesurf wrote:

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and
short bursts of about 60A into lower loads. But more relevant here is
ye olde fashioned PSU design with a big transformer and low esr
capacitors.

Do you go in for bass-heavy music?

The thing is, when the violinist knocks the music stand over it's nice
to actually feel the thump when it hits the floor.

Actually, there is something in that. :-) For example, with piano music it
can be a part of the sound to hear the floor 'thump' as the force of the
fingers hitting the keys transfers to the floor. And transients start of
with a polarity offset which means some LF component. Also if you listen to
a concert from somewhere like the RAH there is quite a lot of LF
'background' that is a part of the audible atmosphere.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"Jim Lesurf" wrote in message
...
In article , Bill Wright
wrote:
wrote:
On Tuesday, 4 December 2012 09:58:32 UTC, Jim Lesurf wrote:

Well, it will sustain over 30Amps per channel into 2 Ohm loads, and
short bursts of about 60A into lower loads. But more relevant here is
ye olde fashioned PSU design with a big transformer and low esr
capacitors.

Do you go in for bass-heavy music?

The thing is, when the violinist knocks the music stand over it's nice
to actually feel the thump when it hits the floor.

Actually, there is something in that. :-) For example, with piano music it
can be a part of the sound to hear the floor 'thump' as the force of the
fingers hitting the keys transfers to the floor. And transients start of
with a polarity offset which means some LF component. Also if you listen
to
a concert from somewhere like the RAH there is quite a lot of LF
'background' that is a part of the audible atmosphere.


Trust you don't live in a semi with paper thin walls :-)