THD claims of audio signal generators

On Tue, 10 Jan 2006 02:25:09 +0000, Pooh Bear
<rabbitsfriendsandrelations@hotmail.com> wrote:

Bret Ludwig wrote:

dpierce@cartchunk.org wrote:
snip

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked to deliver
2000 watts? But only for a very miniscule time, and average putting
out, say, 500 mW?

A 36dB transient ? You are joking yes ?
No, he's simply thrashing about in defence of a lost argument - as
usual.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:42gpi5F1is00oU1@individual.net...
** = exactly why you do not get 36 dB peaks above average on commercial
music recordings.
Hell, you are very unlikely to find peaks more than 10dB above average on
most disks these days.

MrT.
 
"Bret Ludwig" <bretldwig@yahoo.com> wrote in message
news:1136858527.925850.113600@o13g2000cwo.googlegroups.com
dpierce@cartchunk.org wrote:
snip

Further, NO one here ever made such a claim, save you.
The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound
MUCH
better than ANY 20 watt tube amplifier when both are
being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35
watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked
to deliver 2000 watts?
You fry the speaker.

Get real!
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:42gpi5F1is00oU1@individual.net
"John Larkin"

Any recording medium saturates at a reasonable, but not
extreme, level above average program level, CDs run out
of bits, vinyl runs out of groove width, mag tape
saturates, even live FM is deviation limited.

** = exactly why you do not get 36 dB peaks above
average on commercial music recordings.
Its even pretty hard to find 36 dB peaks in live performances.

Every once in a while someone drops, or unplugs, or heavily bumps a mic at
one of the preformances I record. This is *always* the biggest peak in the
recording. IOW, the whole recording chain has enough dynamic range to handle
*anything* that actually happens along the lines of music.
 
<dpierce@cartchunk.org> wrote in message
news:1136906345.197482.314530@z14g2000cwz.googlegroups.com...
Arny Krueger wrote:
"Bret Ludwig" <bretldwig@yahoo.com> wrote in message
news:1136858527.925850.113600@o13g2000cwo.googlegroups.com
dpierce@cartchunk.org wrote:

That means a 50 watt SS amplifier will do better at 35
watts than a 20 watt tube amplifier trying to do 35 watts,.
I wholly agree. However what happens when both are asked
to deliver 2000 watts?

You fry the speaker.

And, in the case of his little 20 watt tube amplifier, even if there was
that much energy in the power supply and the plate resistance were
damned near 0, the output transformers would have long since
saturated.
I believe the tubie argument is that between being able to put out say 80
watt peaks and the euphonic nature of tube clipping, the 20 watt amp could
be asked to deliver 2000 watt peaks every few milliseconds, and the
listeners would be pleased.

Get real!

He can't: his argument falls apart, and he can't have that, can he?
I think that "Bret Ludwig" is just another alias for a Luddite troll that's
been around here for years. So, not even the poster is real.
 
In <43be1e25$0$10672$afc38c87@news.optusnet.com.au>, on 01/06/06
at 06:37 PM, "Mr.T" <MrT@home> said:

Since the cartridge you use has it's trackability limits, and the
cutter lathes also have their limits, there is still a finite limit to
what you will ever get from a vinyl disk.
[ ... ]

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.

-----------------------------------------------------------
spam: spam@uce.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]
-----------------------------------------------------------
 
I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag. They used feedback gingerly and
empirically. The transistor guys were fresh out of school, had Root
Locus, and would pour on the feedback. The little detail about SID was
mostly overlooked till about 1980.

-----------------------------------------------------------
spam: spam@uce.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]
-----------------------------------------------------------
 
"Barry Mann" <zzzz@zzzz.zzz> wrote in message
news:43c8b234$2$avgroveq$mr2ice@wcnews.cyberonic.com...
In <43be1e25$0$10672$afc38c87@news.optusnet.com.au>, on 01/06/06
at 06:37 PM, "Mr.T" <MrT@home> said:

Since the cartridge you use has it's trackability limits, and the
cutter lathes also have their limits, there is still a finite limit to
what you will ever get from a vinyl disk.

[ ... ]

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.
Only the very poorly designed ones. But I'm uncertain why you are worried
about the amplifier distortion levels caused by a "scratch or some dirt".
The whole transient itself is distortion. One reason why I always hated
vinyl.

MrT.
 
In <43c9a20b$0$2255$afc38c87@news.optusnet.com.au>, on 01/15/06
at 12:14 PM, "Mr.T" <MrT@home> said:




"Barry Mann" <zzzz@zzzz.zzz> wrote in message
news:43c8b234$2$avgroveq$mr2ice@wcnews.cyberonic.com...
In <43be1e25$0$10672$afc38c87@news.optusnet.com.au>, on 01/06/06
at 06:37 PM, "Mr.T" <MrT@home> said:

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.

Only the very poorly designed ones. But I'm uncertain why you are
worried about the amplifier distortion levels caused by a "scratch or
some dirt". The whole transient itself is distortion. One reason why I
always hated vinyl.
If the preamp bumbles for a while, the event lasts longer than it needs
to.

In some respects you can have a similar situation with CD players. A
relatively minor (from a data recovery or error concealment point of
view) bald spot on the disc can cause the transport to bumble around so
long while attempting to reacquire the track that it runs out of data
and the audio must mute. Had the transport been able to coast through
the bald spot, there would have been no audible problem.

My point being that a design shortcoming causes more audible damage
than necessary.

I agree that tic, pop, wow, and tracing distortion are a bummer.

-----------------------------------------------------------
spam: spam@uce.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]
-----------------------------------------------------------
 
"Barry Mann" <zzzz@zzzz.zzz> wrote in message
news:43c8c7dc$3$avgroveq$mr2ice@wcnews.cyberonic.com...
I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag.
I learned root locus stability analysis in the mid-60s.

This page references a text from that time:

http://www.cbu.edu/~rprice/lectures/rootlocus.html

Coughanowr's book came out in 1965. Coughanowr received his PhD in 1956, so
any precident-setting paper was probably published in the preceeding 15 or
so years.
 
In <jv6dnbCi9vJUMFfenZ2dnUVZ_tGdnZ2d@comcast.com>, on 01/15/06
at 03:17 PM, "Arny Krueger" <arnyk@hotpop.com> said:

"Barry Mann" <zzzz@zzzz.zzz> wrote in message
news:43c8c7dc$3$avgroveq$mr2ice@wcnews.cyberonic.com...
I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag.

I learned root locus stability analysis in the mid-60s.

This page references a text from that time:

http://www.cbu.edu/~rprice/lectures/rootlocus.html

Coughanowr's book came out in 1965. Coughanowr received his PhD in
1956, so any precident-setting paper was probably published in the
preceeding 15 or so years.
I think that it was Bode and crew at Bell Labs during the 1940's that
developed the ground work. I can remember a Knight Kit tube amplifier
of about 1960 that was advertised as being unconditionally stable.
Then, it was a unique product. A few years later I learned exactly what
that meant, but at the time I did appreciate that I did not need to
fuss about accidentally unloading the output.

-----------------------------------------------------------
spam: spam@uce.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]
-----------------------------------------------------------
 

Welcome to EDABoard.com

Sponsor

Back
Top