Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Oct Sat 23, 2021 5:39 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 44 posts ]  Go to page Previous  1, 2, 3  Next
Author Message
 Post subject: Re: Who are they kidding?
PostPosted: Jul Mon 05, 2021 10:43 pm 
Member

Joined: Aug Tue 24, 2010 8:56 pm
Posts: 6195
Location: Northeast Florida
dberman51 wrote:
"...sounds louder by nature" is due to difference in clipping behavior.

-David


Yes, second harmonics....this is what I"ve been saying

_________________
William


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Mon 05, 2021 10:55 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 4789
Location: Boston, MA USA
No, the soft clipping of a tube-type amplifier allows the average audio level to increase significantly, as much as 10 dB, while the peaks are gently compressed. It's the same idea as radio stations using compressors to increase their loudness.

Second harmonic distortion is what happens during linear operation, and in any quality amplifier will be at least 40 dB down, hence irrelevant.

-David


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Mon 05, 2021 11:14 pm 
Member

Joined: Aug Tue 24, 2010 8:56 pm
Posts: 6195
Location: Northeast Florida
dberman51 wrote:
No, the soft clipping of a tube-type amplifier allows the average audio level to increase significantly, as much as 10 dB, while the peaks are gently compressed. It's the same idea as radio stations using compressors to increase their loudness.

Second harmonic distortion is what happens during linear operation, and in any quality amplifier will be at least 40 dB down, hence irrelevant.

-David


Then where does the warm sound of a tube amplifier come from? This certainly isn't only observed at loud listening levels

_________________
William


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Tue 06, 2021 12:01 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
Quote:
Then where does the warm sound of a tube amplifier come from?

The filaments. Well over 100 degrees F :-D

"The Warm Sound" may or may not be there. Or perhaps it's Transient Intermodulation Distortion in the EARLY solid state units, before anyone knew it was there.

Regardless, for all intents and purposes, THE ROOM is the single biggest contributor to how any amp and speaker sounds, once you get into the pro level anyway. There's no use splitting hairs over tubes vs transistors... each has their following.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Tue 13, 2021 6:09 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 10751
Location: Beaver Falls, PA. USA
The soft clipping and more pleasing distortion of tube amplifiers are probably the biggest differences. We have all heard the grungy sound of a solid state amp turned up into clipping, but some people think that is what "loud" sounds like. Besides the room, the type and placement of the speakers makes a big difference in the quality of the sound.

The wattage wars of the late 1960s and early 1970s led to the establishment of the true RMS rating for amplifier output, which was much more honest.

_________________
Tim KA3JRT


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Tue 13, 2021 7:01 pm 
Member
User avatar

Joined: Mar Sun 22, 2020 5:56 am
Posts: 1992
Location: Arvada, CO, 80004
So, if a tube amplifier outputs 50 watts, that is mighty hefty fur a tube amp, and expensive. But a solid state amp can output the same at half the cost. Some systems I have seen go for 500W for gyms. But my Newcomb record player can fill a gym for prom, fairly easy with a singe 6BQ5 tube, which gets watts in the single digits. So, with solid state, is all that power needed from clipping hard?

_________________
Electronics are filled with smoke. It’s my job to put the smoke back in when they fail.
Cheers,
Jay


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Tue 13, 2021 8:03 pm 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
“Need” is such a nebulous concept. The huge power amps came into being due to a marketing and horsepower race.

Any amp rated for .0xxxx thd @ xxxxxWRMS does not need extra power to meet that spec

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Tue 13, 2021 8:54 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 4789
Location: Boston, MA USA
Yes, a solid-state amplifier would require about 30-40 watts to sound as loud as a 4-watt tube amplifier driving the same speaker in the same space. This is because the solid-state amplifier must absolutely not be allowed to go into clipping, ever, while the tube amplifier can be driven significantly beyond its linear region without sounding terrible.

Of course if the intention is to maximize audio quality by avoiding distortion at all, that means the tube and solid-state amplifiers must both be run within their linear regions, and in this case watts is watts.

-David


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Wed 14, 2021 12:09 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
Quote:
Yes, a solid-state amplifier would require about 30-40 watts to sound as loud as a 4-watt tube amplifier driving the same speaker in the same space.

eh? I have to disagree on this one, as per my previous post. That's simply not the case, assuming you read the RATINGS of your solid state amplifier properly. IF it's rated for 10 watts RMS ... RMS I SAY ... at .1% THD, then that's what it is. It's not going to start getting "worse" as it gets close to the maximum output, namely 10 watts RMS.

It it possible that it might, if poorly designed, go into some kind of soft or hard clipping on absolute peaks, but that would violate the specifications. The same holds true fot the tube amp, btw, although it may sound different due to the differences in dynamics between a tube and solid state design.

So if it's in spec, it is what it says. No need to derate it.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Wed 14, 2021 12:33 am 
Member
User avatar

Joined: Jul Mon 08, 2013 2:48 pm
Posts: 797
As Barry said above: at a rated distorsion factor a watt is a watt, period. "Subjective Power" is (once again) a stupid audiophile term which can't be quantified or measured. How many times have I heard that a tube amplifier is X times (replace "X" by any number between 2 and 10) more "powerful" than an equivalent power solid state amplifier. This is pure nonsense.

And why on earth would you use a Hi-Fi amplifier in overdriven condition ? If your speakers (or listening habits) need more drive use an adequate (more powerful) amp to stay below clipping level.
Or If you really like (even) harmonic distorsion added to your program source just buy an APHEX Aural Exciter.

Of course, all the above could be different for guitar amps which are supposed to be used (mostly) in overdriven (saturated) condition. But even here, if you stay below the saturation point (clean mode) a watt is still a watt, no matter how it is produced (tube or solid-state). The loudspeaker don't know the difference either.


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Thu 15, 2021 2:27 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 4789
Location: Boston, MA USA
Properly designed tube amplifiers are intended to be able to be over-driven without anything bad happening. In PA and motion-picture service where peak-to-average audio levels are extreme, driving a tube amplifier beyond the linear region is normal. In high-fidelity service you have a choice: 1) get a more powerful, and much more costly amplifier, or 2) live with a little bit of muddiness on the highest of audio peaks. With 2) you can make a very loud sound with modest amplifier power.

With solid-state amplifiers you do not have this choice. Hard clipping is extremely nasty and must be avoided.

In the earlier days of sound movies, even the largest theater had a vacuum tube amplifier of about 40 watts.

-David


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Thu 15, 2021 3:23 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
dberman51 wrote:
Properly designed tube amplifiers are intended to be able to be over-driven without anything bad happening. In PA and motion-picture service where peak-to-average audio levels are extreme, driving a tube amplifier beyond the linear region is normal. In high-fidelity service you have a choice: 1) get a more powerful, and much more costly amplifier, or 2) live with a little bit of muddiness on the highest of audio peaks. With 2) you can make a very loud sound with modest amplifier power. With solid-state amplifiers you do not have this choice. Hard clipping is extremely nasty and must be avoided. In the earlier days of sound movies, even the largest theater had a vacuum tube amplifier of about 40 watts.
-David

What exactly is the point you are trying to make? If you need to drive an amplifier into clipping, whether it be a tube or solid state amplifier, then you probably need to get a more powerful amplifier. Compared spec for spec, they are virtually identical....read the posts above. One does not "drive a tube amplifier beyond the linear region" in "NORMAL" use, unless you are a guitar player. For HiFi, what you're trying to say does not apply since not even audiophiles drive their amps into clipping :)

If you're trying to say that tubes and transistors behave differently once into clipping range, sure. So what. Again, unless you're talking about guitar amps, if you need more power, buy more power.

I give up.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Thu 15, 2021 6:16 am 
Member

Joined: Aug Wed 24, 2011 4:35 am
Posts: 5778
Location: Sunnyvale CA
Barry H Bennett wrote:
“Need” is such a nebulous concept. The huge power amps came into being due to a marketing and horsepower race.

Any amp rated for .0xxxx thd @ xxxxxWRMS does not need extra power to meet that spec


To an extent, but I think you are selling hifi people short. High-power amps came about because you *could*, and in the process, allowed much less efficient and much more *accurate* speakers. In the days of tube amps, 50 watts was about it, that demanded that to get any sort of dynamic range that you needed very efficient speakers, which are highly compromised in terms of accuracy. Having 100+ watts available allowed more accurate but less efficient speakers to be used. OR, chicken and egg time, the AR-3 came along at 85 DB/watt. Very quickly, you got speakers that more-or-less demanded 200+ watts (Ohm A and F).

There was a second wave of massive power amps in the 80s with CDs, trying to take at least some advantage of the vastly superior dynamic range possible. That's when 500+ watts became common. There is nearly no performance cost of such beasts, you can get negligible distortion at almost any power level. Of course it is hopeless to cover a 16-bit dynamic range in a home setting.

BTW, I *have* heard a 1.25 KW *tube* amp, it had some limitations (like impossible power requirements and incredible heat, and a fair bit of distortion - not to mention the *cost*!!!), but the damping factor had an astonishing effect in controlling the bass, no bloopy tube amp bass on this one - easily as good as a mid power transistor or hybrid.

I won't comment on the clipping, er, discussion, other than to say you can drive properly designed transistor power amps into clipping with nearly no other negative effects, in fact, that is one of the design goals. Where early transistor amps got into trouble with clipping was that it very frequently sent them into oscillation/instability that would then blow or burn something else in seconds, just because they *could* oscillate at high frequencies where tube amps have already rolled off. That should be designed out.

Brett


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Fri 16, 2021 8:59 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 5264
Location: Rochester NY USA
I set up a "Tube Sound vs. Transistor" display at the AWA museum last Fall just in time to shut down until this summer... Got a Dyna 70 and a Yamaha 80 watt receiver from storage and built a box to sequence A-B switching. The Dyna did not quite meet spec (new 7199s and EL34s were not in the budget!); the Yamaha exceed its impressive specs. I matched levels by ear with pink noise (digital meter was all over the place...) and could hear a slight difference no matter what. My hearing has deteriorated over the last year (heavy use of power tools!) so I'm not the one to judge but so far no one has said that either sounded better on music.

Attachment:
Amps.gif
Amps.gif [ 213.78 KiB | Viewed 616 times ]

_________________
My web page: https://bit.ly/2rxq4qx


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Jul Thu 22, 2021 7:49 pm 
Member
User avatar

Joined: Oct Wed 14, 2009 6:36 am
Posts: 6561
Location: New York USA
dberman51 wrote:
Properly designed tube amplifiers are intended to be able to be over-driven without anything bad happening. In PA and motion-picture service where peak-to-average audio levels are extreme, driving a tube amplifier beyond the linear region is normal. In high-fidelity service you have a choice: 1) get a more powerful, and much more costly amplifier, or 2) live with a little bit of muddiness on the highest of audio peaks. With 2) you can make a very loud sound with modest amplifier power.

With solid-state amplifiers you do not have this choice. Hard clipping is extremely nasty and must be avoided.

In the earlier days of sound movies, even the largest theater had a vacuum tube amplifier of about 40 watts.

-David


The real problem is that transistors are not linear and need a LOT of negative feedback to get "good" specs. If they have 20 dB of negative feedback, as soon as they clip the negative feedback stops and the input stages suddenly have 20 dB higher level. This is what causes the "hard clipping distortion".
My old Bogen, Stromberg Carlson and other old Public-address amplifiers have almost no negative feedback, so if they are over-driven they may get a bit of second-harmonic distortion. The ear thinks there must be another octave below that, so the ear thinks the sound has more bass or sounds "warmer". One musician said my 60-watt Bogen LX-60 tube PA sounded better than his 1000 watt system.


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Aug Sat 21, 2021 3:09 am 
Member
User avatar

Joined: Dec Sun 25, 2016 5:53 am
Posts: 344
Tubologic wrote:
hwhall wrote:
There was a lot of that sort of thing; odd ways of reporting the output so that the numbers were larger. I think the King of Misrepresentations was Instantaneous Peak Power (IPP).


Sorry to disagree: there's also the subjective power, a term oten used by Audiophools. The only problem is that there's no know test equipment or procedure to measure it.

It could be measured by using a Subjective Voltmeter and applying Ohm's law. However...

_________________
1970's Avionics Tech, USN Attack Squadron 147, "ARGONAUTS" A-7E A/C


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Aug Sat 21, 2021 10:40 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
"Peak Music Power" was one of my favorites. I always wondered if that was the same amount of power as peak voice power....

The only way to measure these things is to put an "audiophile" in a cryogenically treated room, preferably with the cryo system still operating, and there's your subjective voltmeter. Measured in dB.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Aug Sat 21, 2021 6:43 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 13303
Location: Fernandina Beach, FL
Barry H Bennett wrote:
"Peak Music Power" was one of my favorites. I always wondered if that was the same amount of power as peak voice power....

The only way to measure these things is to put an "audiophile" in a cryogenically treated room, preferably with the cryo system still operating, and there's your subjective voltmeter. Measured in dB.

Hear, hear!!! :lol: :lol:

_________________
Don


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Aug Sat 21, 2021 6:54 pm 
Member

Joined: Dec Fri 08, 2017 5:40 pm
Posts: 394
Location: 44141
Instantaneous peak power was the high figure back in the '60's until the FTC stepped in.

_________________
Bruce Hagen


Top
 Profile  
 
 Post subject: Re: Who are they kidding?
PostPosted: Aug Sat 21, 2021 6:57 pm 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11097
Location: Sunbury, Ohio 43074
Bruce88 wrote:
Instantaneous peak power was the high figure back in the '60's until the FTC stepped in.

Was that into 8 ohms, 4 ohms, or infinite ohms? :mrgreen: 1,000,000,000 Watts of instantaneous peak power into an air gap. FEEL the POWER :mrgreen:

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
Post New Topic Post Reply  [ 44 posts ]  Go to page Previous  1, 2, 3  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 9 guests



Search for:
Jump to:  


































Privacy Policy :: Powered by phpBB