'Headroom' is a measure of the badness of an amplifier. The bigger the number, the worse the amplifier.

[MAB]

He can have that.

It's much stranger that the 70th member on ASR waits five years to post 19 times in two days guns blazing and then disappears.

I'll leave the internet for today..

Without a doubt.

 

[voodooless]

I'll leave the internet for today..

See you in 5…

 

[mhardy6647]

He can have that.

It's much stranger that the 70th member on ASR waits five years to post 19 times in two days guns blazing and then disappears.

I'll leave the internet for today..

Interestingly, I happened to notice that @Kal Rubinson is member number 67*
Now I am wonderin' who was in between the two (i.e., Kal and Zaph')?



_____________
* Seriously, just happened to see it when editing a typo in a post. It's not like I am stalkin' him or nothin'

 

[mhardy6647]

I am not at all proud to say that I figured out how to find out.

yestaken

www.audiosciencereview.com

one post

Funtez

www.audiosciencereview.com

zero posts

 

[MAB]

That number is the forum's calculation of age.

I notice the age-calculator's headroom changes throughout the calendar year for each member who lists a birthday, which is about as relevant as this thread's OP.

 

[voodooless]

It's much stranger that the 70th member on ASR

How do you know that he’s nr. 70? I think that number in the profile is just the age.. according to the Wayback machine, ASR already had 88 members on April 18th 2016.

 

[JaMaSt]

Surely not the Zaphod, Zaphod Beeblebrox .

You would think someone with the name "Zaphod" would appreciate the additional headroom....

 

[Mikig]

How do you know that he’s nr. 70? I think that number in the profile is just the age.. according to the Wayback machine, ASR already had 88 members on April 18th 2016.

unfortunately age!!
I don't think I'm user 47!!!

 

[mhardy6647]

How do you know that he’s nr. 70? I think that number in the profile is just the age.. according to the Wayback machine, ASR already had 88 members on April 18th 2016.

oh. well now I feel silly*

It's easy to find out a member's number!
"at" them (e.g., @voodooless) and then look at the BB code that's generated when the post is parsed. Click on "Preview" on the top right in the editor.
Hover over the link created by using "@" and look at the link generated. The member number's part of the URL.

Hold my beer and watch this.

______________
* OK, I've felt silly for a long time. Part of my raffish charm.

 

[mhardy6647]

@Zaphod is member number 6018.

 

[JeffGB]

I'm afraid I am now in the position of defending the OP, to a point. All these comparisons of more or less "dynamic" power are usually comparing apples to oranges.
Let's take two identical amplifiers. The very same circuit and devices. One has a huge regulated power supply and one has a smaller power supply but both provide +55 volts when the amplifiers are idle. If we measure the "dynamic power" they will both be exactly the same. There is no free lunch so if the voltage with the smaller supply is +55 at idle, it can't change to a higher voltage (I am ignoring special class H etc that change the power supply voltage at higher power). The difference is in the continuous power. The smaller, unregulated power supply's voltage will sag and reduce the power at low frequencies when current draw is higher and lasts longer. The amplifier with the bigger supply that is fully regulated will stay at +55 and provide more continuous power at low frequencies because the voltage won't sag.

The confusion comes because people are comparing two amplifiers continuous ratings and the dynamic power of one is higher. Unless the circuit of one amplifier is different, you will find the idle voltage of the amp with the higher dynamic power is higher. The power supply in this case is "inferior" and can't provide it's rated power continuously at low frequencies but the small supply can provide the full power at higher frequencies or on short pulses.

 

[McFly]

I tend to agree with you. The amplifier with a cost saving undersized power supply will reach the same "peak" as the amplifier with the larger power supply due to both the designs slamming into the voltage rails (the power limit of the design topology), the amplifier with the larger power supply can hold continuous power for longer than the one with the small supply - however it will look like the amp with the small supply with have more "headroom"

"headroom" is looking a bit like "undersized power supply relative to the circuits theoretical maximum, (assuming infinite heatsinking on both the amplifier and power supply)"

But of course there is always more to it.

 

[MCH]

oh. well now I feel silly*

It's easy to find out a member's number!
"at" them (e.g., @voodooless) and then look at the BB code that's generated when the post is parsed. Click on "Preview" on the top right in the editor.
Hover over the link created by using "@" and look at the link generated. The member number's part of the URL.

Hold my beer and watch this.

View attachment 349240
______________
* OK, I've felt silly for a long time. Part of my raffish charm.

Member #1 doesn't post often

ok, no more personal comments :-|

 

[mhardy6647]

Member #1 doesn't post often

View attachment 349249

ok, no more personal comments :-|

One will find this on almost all forum/bulletin board sites, IME. User #1 is sort of the person behind the curtain (administrator account) when the site is set up; it's not uncommon for user #2 to be the actual honcho.

Or am I getting too personal?

@amirm

amirm

www.audiosciencereview.com

 

[popej]

"headroom" is looking a bit like "undersized power supply relative to the circuits theoretical maximum

If headroom is comparable to crest factor of a music signal, then you can say that you have optimized your budget correctly.

 

[Zaphod]

But you're only repeating "headroom is a measure of how bad an amplifier is" in every single post. Also not very technical or reasoned?

I am arguing from a position of logic.

A stiff power supply in an otherwise identical amplifier to one with a 'soft' power supply will always measure and probably sound better.

 

[Zaphod]

I wish I could remember the source, but tests were done in the 1970s or '80s with three amplifiers of identical circuit but different power supplies. They all provided 100 watts into 8 ohms continuous, but were configured as follows:-

A) Conventional Sagging Supply, providing 100 watts continuous, but 150 watts on 'short-term' peaks.
B) Stabilised supply providing 100 watts continuous, but no extra on peaks.
C) Stabilised supply providing 150 watts continuous but no extra on peaks.

Blind listening tests were carried on with a panel of 'experienced' listeners and amplifiers were rated as to preference. Volume was set to whatever the panel felt comfortable with, so not level matched. Output level was monitored, but there was no attempt to avoid clipping on peaks. This is in line with how people normally listen to music.

Not surprisingly, Amplifier C came out best, but amplifier A came out as clearly preferable to amplifier B thus indicating that peak power, i.e. headroom, was more important than continuous output power.

The testing was reported in either HiFi News or Wireless World (might even have been both) but I can't now find a reference.

Allowing headroom is ALWAYS a Good Thing, whether just for peaks or continuously, and I take a somewhat dim view of an amplifier with little headroom that may just be adequate but would fail if listening to high dynamic range music.

S.

Amplifier A MIGHT sound better than amplifier B. That would depend on a huge number of factors. However, that was not what I was referring to. Amplifier C is the preferred one.

 

[JustJones]

I remember when I had a stiff power supply.

 

[Lambda]

A stiff power supply in an otherwise identical amplifier to one with a 'soft' power supply will always measure and probably sound better.

Better in what way?
What makes you think so?

 

[eddantes]

Come to think of it -- ohm (volts per ampere) is the SI unit of measurement for resistance. The measure of conductance (the inverse of resistance) is (was ) commonly expressed in units of mhos ( which is, of course, ohms backwards).

So... if headroom measures amplifier badness, perhaps we should consider measuring amplifier goodness in units of moordaeh?
I mean, possibly not -- it sounds like one of those words that, if said thrice in succession, would summon demons.


OK, my work is done here.