Power . How much do we need...

Frantz, another variable that seems to have a major impact on the sound of the amp is the quality and ability of the transformer used. In my experience, a more powerful amp that utilizes a poor transformer is not necessarily better in its ability to produce bass than a less powerful amp with a better transformer. I think ideally one needs a good power output and a great transformer. IMHO, I would rather have less power output and a great transformer than more power and a poor transformer.:)
 
I ran an amplifier test recently in this regard. I used a 300, 400 and 500 watt amplifier. I could make the 300 sound different with increasing levels. The 400 barely. And the 500 not at all (Mark Levinson 53). The distortion was subtle and nothing what we consider amplifier clipping to be.

Such observation is content sensitive. Clearly music demands vary. I can see someone listening to classical music not needing as much power to reproduce violins than my listening to something dynamic with drums and such.
 

According to this calculator, that would get you 101 db spl at your listening position.

http://myhometheater.homestead.com/splcalculator.html

Currently, I'm also driving my speakers with 32 watts. In my set up, that gets me 98 db spl at my listening position.

I turned things up much louder than I normally listen, and was seeing a max of 95 dbs on the JL Audio app(great free app) on my Ipad.

I've had 700 watts/ch SS monos in my set up. 32 watts/ch of tube power works fine for me.
 
Roger

Without getting too technical .. What one listen in an amp is the power supply signal modulated by music. The Power Transformer is an important element of the power supply it is the final gate through which power flows... A substantial power transformer allow the power supply to deliver more current and or volt without restraint .. Yet the maximum capacity of the output devices is the determinant factor of the amount of power the amp is capable of delivering. You could put a 10 KVA on a SET amp if the output tubes (and of course the output transformer in the case of the vast majority that is NON -OTL ) amp is only capable of 30 watts, that is what you will get 30 watts with the output driven to clipping , thus distortion... Same thing with SS you would have a transformer capable of 10,000 watts, a farad of Capacitors but output transistors/devices capable of only 50 watts and that would be what you would get ...
I am not minimizing the contribution of a good Power Supply hence good transformer by thee way...

@Steve

I have heard both the Lamm 18 watts and 32 watts and in both cases they were very good. If you remember I first mentioned the Lamm 18 watts some years ago in a an AVS Forum post, way before you had thought about them .. These amps are as good as SET can be and amongst the finest amps I have heard and they do drive the Alexandria rather well... I kind of expected that ... I do think however that certain music will tax them to the point of unhappy clipping.. Nothing to do with the Lamm themselves simply of power delivery in the speakers. Anything above 100 dB will have them hit their limit and for a good portion of what I listen to, 32 watts even in a 95 dB speaker and at 4 meters would too often be proven insufficient ... They may be exactly what satisfy you and likely many here; some of us into power music (of any sort) would need more ... watts.. As I have said in another post or thread ... At least 300 watts/ch regardless of speakers is what I consider satisfying both for my engineer mind and my musical soul...
 
Roger

Without getting too technical .. What one listen in an amp is the power supply signal modulated by music. The Power Transformer is an important element of the power supply it is the final gate through which power flows... A substantial power transformer allow the power supply to deliver more current and or volt without restraint .. Yet the maximum capacity of the output devices is the determinant factor of the amount of power the amp is capable of delivering. You could put a 10 KVA on a SET amp if the output tubes (and of course the output transformer in the case of the vast majority that is NON -OTL ) amp is only capable of 30 watts, that is what you will get 30 watts with the output driven to clipping , thus distortion... Same thing with SS you would have a transformer capable of 10,000 watts, a farad of Capacitors but output transistors/devices capable of only 50 watts and that would be what you would get ...
I am not minimizing the contribution of a good Power Supply hence good transformer by thee way...

@Steve

I have heard both the Lamm 18 watts and 32 watts and in both cases they were very good. If you remember I first mentioned the Lamm 18 watts some years ago in a an AVS Forum post, way before you had thought about them .. These amps are as good as SET can be and amongst the finest amps I have heard and they do drive the Alexandria rather well... I kind of expected that ... I do think however that certain music will tax them to the point of unhappy clipping.. Nothing to do with the Lamm themselves simply of power delivery in the speakers. Anything above 100 dB will have them hit their limit and for a good portion of what I listen to, 32 watts even in a 95 dB speaker and at 4 meters would too often be proven insufficient ... They may be exactly what satisfy you and likely many here; some of us into power music (of any sort) would need more ... watts.. As I have said in another post or thread ... At least 300 watts/ch regardless of speakers is what I consider satisfying both for my engineer mind and my musical soul...


Frantz

I have always said that in this hobby one man's passion is another man's poison
 
Frantz

I have always said that in this hobby one man's passion is another man's poison

Not in this case: Not a poison.. I would have preferred it with more power .. As they are, they remain immensely satisfying and amongst the best amps one could use in a system ...
 
Frantz,
also a critical part of that question is energy power reserve-storage, and this can vary greatly between amplifier builds, 50watt amp can have much more power reserve-storage than a 300watt amp.
Question is how much power reserve-storage is required to ensure full dynamic swells-depth-large crescendos-etc.
You cannot discuss one without the other in my experience.

Cheers
Orb
 
I guess my question is "do you think you can't crank up the power with an SET". As I stated I have not been able to make my amp clip ( I could with the ML 2.1 but only at very high SPL)
Actually, Steve, my guess is that they were clipping, but because they are very well engineered you did not actually hear anything happen, there was no obvious problem or distortion when they clipped. This is something I've brought up before with Tim, a well designed amp should be able to clip every now and again and it will be unnoticeable. Why? Because the clipping is extremely transitory, just a few milli sec's, and your ears decided that anything that was audible was so minor it didn't register.

More conventional, less well engineered amps, however, do a combination of clipping and compressing, the power supply is in deep trouble, and it takes the amp a considerable period of time in comparison to recover, plenty long enough to be audible.

Frank
 
I have never had a low powered amp. A beautiful midrange can be had with power, my VAC 140's are very liquid and 3D. My solid state amps with 1200 watts a side maybe not as beguiling but my octal based preamp get's me close enough. When I really want to feel energy and my neighbor is not at home it's nice to crank it up and listen to the music soar. That'a a aspect that tips the scales for me.
Roger, I'm curious to know, when you wind it up this way can you go all the way to your maximum listening level without the character of the sound changing? Forgetting about rock for the moment, how would this go for an orchestral recording, say?

Frank
 
Why? Because the clipping is extremely transitory, just a few milli sec's, and your ears decided that anything that was audible was so minor it didn't register.

And in those few milliseconds the transient peaks are compressed. Is it something we actively take note of? Probably not. But it is more audible than many things audiophiles worry over.

Tim
 
Such observation is content sensitive. Clearly music demands vary. I can see someone listening to classical music not needing as much power to reproduce violins than my listening to something dynamic with drums and such.
Funny thing is that classical for me is the biggest issue, in the case of an operatic soprano hitting a big note and holding it. This is very close to having a test instrument generating a high power sine wave, the very thing they warn you on test disks not to run at high volume, and I have certainly heard the results: the sound starts cracking as the protection circuitry cuts in, and once or twice the amplifier module shut down completely, it was thermally overloading ...

Frank
 
Actually, Steve, my guess is that they were clipping, but because they are very well engineered you did not actually hear anything happen, there was no obvious problem or distortion when they clipped. This is something I've brought up before with Tim, a well designed amp should be able to clip every now and again and it will be unnoticeable. Why? Because the clipping is extremely transitory, just a few milli sec's, and your ears decided that anything that was audible was so minor it didn't register.

More conventional, less well engineered amps, however, do a combination of clipping and compressing, the power supply is in deep trouble, and it takes the amp a considerable period of time in comparison to recover, plenty long enough to be audible.

Frank

There is always discussion about clipping effects, as usually we have to do as you say - just guess if an amplifier is clipping. However, since digital sources have a maximum level it is very easy to calibrate your system for power at 8 ohms - take a -40 dB 1kHz tone and measure the output at your usual and maximum level in volt. Peak power at maximum source level equates 1250 x V x V.

I always calibrate my system when putting a new equipment in my system, and have found that peak powers in my system are 99% of the time much lower than I could expect - and the 1% are due to sessions to impress friends ...

Owners of McInstosh amplifiers, that often have peak power meters, are usually disappointed because the needles move so little, specially if using efficient speakers. :)

Considering that a -40dB test tone has 1% of the amplitude of the maximum level (0dB) and P= VxV/R you get

volt watt over 8 ohm
0.01 0.125
0.02 0.5
0.05 3.125
0.1 12.5
0.2 50
0.5 312.5
1 1250

Do not try to calibrate using a 0dB test tone - you will probably damage the speakers and your hearing! :rolleyes:
 
I always calibrate my system when putting a new equipment in my system, and have found that peak powers in my system are 99% of the time much lower than I could expect - and the 1% are due to sessions to impress friends ...

Owners of McInstosh amplifiers, that often have peak power meters, are usually disappointed because the needles move so little, specially if using efficient speakers. :)
This is so true, the vast majority of the time, for most people, the amp is idling, using only a tidy bit of its theoretical capability. People here question how my HT can do as well as I say, but that's because it's working virtually all the time in its power band, if it had meters the needles would be flickering madly all the way up the dial most of the time ...

Frank
 
One aspect that can change the usual perspective about power and subwoofers is that most audiophiles who are using them use the main speakers full range, without inserting the high pass crossover filters that could color the main sound (and need one more expensive interconnect cable... ) . Using the sub in this way should not affect the power performance of the system. However when using a well matched subwoofer the sound is fuller, more spacious and usually we listen at lower levels for similar loudness sensation. This could explain why we feel that using subwoofers releases the power needs of the main amplifier, even if not filtered.
 
Steve, I'm sure you still get bass, but less slam...however, the question is whether your system has the same headroom and when the onset of distortion begins to occur. The Lamm's are working much harder when the JL's are out of the system.
BTW, I just put a REL sub into my system and I can relate to the fact that it is NOT that easy to get the sub to dial in...close is pretty easy...on the money....well, that's another story:D I hope it won't take me 3 months:(

DaveyF, it took me as well close to three months to properly set up the DD18 with the G's, taking into account that I did use the Velodyne's propietary software/mic to equalize the thing!
 
DaveyF, it took me as well close to three months to properly set up the DD18 with the G's, taking into account that I did use the Velodyne's propietary software/mic to equalize the thing!

Fernando, I only managed to listen to the system for a few hours yesterday with the new Sub. I know I still have work to do, but the initial impression is that the Sub brings some well needed foundation to the system but at a price of a "frisson" of loss in the high frequency/mid clarity department. The GH's are so very, very fast and so accurate in the area of string reproduction, that I have to wonder if anything in the way of a sub would leave them totally unscathed. IF I cannot do away with this "frisson" of loss, then I will most likely live with that on my ss system and relegate the tube amp for ultra purity sessions with no sub.
Anyhow, I will write a report on the T5 as soon as I have enough mileage on it to really be sure of its contribution or lack thereof.
 
Hi DaveyF,

Keep working at it!...i ran DD18 with the Gs for years, and it took a long time to get it right...partly because i did not know how to use the Velodyne as well as i do now. i suspect you can get rid of the frisson. if you can adjust the rolloff...do so. it may or may not help, but in my room, it did. i am sure you will find it rewarding to no end!

good luck!
 

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