A lot less than certain commercial interests would like.
If you want to feel perfectly safe, then run right out and buy a new, far,far larger amp. In the pro audio world one finds some of the real beasts.
Very few mainstream speaker manufacturers make really difficult to drive speakers any more because handling the returns is so expensive.
You may find it ironic that speakers that are very close to being purely resistive loads ("good example") are usually among the most difficult to drive.
Model ? what does it mean ?
often i have no clue of the TS parameters of the woofer used
I would not know where to start really.
no i cannot be sure of this. The pcbs look very very similar but schematics are not available. Strange ... in the past i understand manufacturers used to provide also schematics.
no. This is related to amp design. I have no clue.
I understand that outside class A an amp has no choice to sound good for this xover distortion. Am i right ?
Thanks a lot for the advice. But i have a question.
Lets say that i set the bias following the service manual indications and the amp stays cold. Is it a bad amp ? clearly the bias level must be very low like the limit of class A.
To end, class AB amps have no hope to sound very fine ? Only class A can ?
The question is honest of course. I am trying to learn something.
Thanks again, gino
nope
class AB can sound finer than a poor class A , we just cant come to such simple conclusions. can the finest class A beat most class AB, probably for low power <20W peak. so not my idea for "impressive" sounding using modern speakers. I respectively suspect, a little of the right kind of distortion is pleasing to some, maybe you ?
I sense too much fear of analyzing amps requirements from any speaker designs? you could start by measuring DC impedance and estimating T/s from similar drivers and simulating = modeling the charts.
class AB can sound finer than a poor class A , we just cant come to such simple conclusions. can the finest class A beat most class AB, probably for low power <20W peak. so not my idea for "impressive" sounding using modern speakers. I respectively suspect, a little of the right kind of distortion is pleasing to some, maybe you ?
I sense too much fear of analyzing amps requirements from any speaker designs? you could start by measuring DC impedance and estimating T/s from similar drivers and simulating = modeling the charts.
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I don't know where this is coming from, but it is not true.
I have built an amp from a cookbook. Best decision ever.
http://www.diyaudio.com/forums/solid-state/96192-post-your-solid-state-pics-here-407.html
All good amps, and good amps are now pretty easy to obtain, are sonically indistinguishable if operated intelligently.
If you want to "hear" differences between amps, do sighted evaluations, in which case they will typically all sound different.
Can you tell me what the scales read?So my feelings are right ? i am sure that not only the rating but also the quality of mains transformers and ps caps in many commercial amps, and even not cheap ones, is very poor
Because quality comes expensive.
Maybe the amps you normally test are all very high quality.
I remember one magazine performing the power cube test.
This is the different behavior of 3 amps at the test
http://www.bostonaudiosociety.org/images/meetings/audiograph_result1.gif
does this reflect on sound ? i guess so especially in presence of difficult speakers. I would like better the amp on the left.
I can see 0 to 30 in steps of 5 up the vertical scale. 30 what?
I can 1, 2, 4, 8ohms along the Z horizontal sacle. I assume this is resistive test loading.
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Hi ! actually very few amps and usually expensive (i.e. with big power supplies) show a good performance at this test.
I understand that good sound is not only about electrical performance
i have indeed looked at them ... but they start from 200W up ... i just need maybe 50W/8 ohm ? ... that become 100W/4 ohm ?
(this is an obsessione i know)so it is indeed a problem. Good. A confirmation of my feelings. Some speakers are very difficult to drive properly.
Yes this is strange. But i trust you completely.
I will try to avoid this kind of speakers.
Regards, gino
Ok I got the message and i can honestly tell you that i do not like hot amps at idle. It is just stronger than me. While i can stand that under pressure they get hot just see them laying there and become hot to the touch is out of question.
I understand that this will prevent me to get the very top sound ... but i am willing to leave with that. An amp that gets warm at idle that i can bear easily
it could be that in the end i like some kind of nice distortion in sound. A sound a little tubey ...
It is not only fear but lack of knowledge and also testing equipment.
I can tell you one thing.
Some month ago i was obsessed with noise from power supplies.
I was thinking that to measure noise from a power supply was an easy task.
Then i found a very interesting video on youtube
https://www.youtube.com/watch?v=pKXPqApOYfk
when i see what kind of monster equipment is needed i decided to look just at specs ... when i can find them of course.
I gave up completely to the idea because i surely cannot afford that kind of equipment.
Another amusing story.
I was following a discussion about power supplies mods for digital devices.
A guy was stating of the huge improvements in noise (i was talking about noise in the range of uV) that his mods had brought to the unit.
Then i asked what kind of test he was performing.
He said a listening test
Regards, gino
Hi ! thanks a lot for the advice.
Your amp is very beautifully built indeed. Sincere congratulations.
Honestly ... my dream would be to start for nothing and design and build an amp by myself.
2nd option, more doable, to select a very good schematic and design a pcb and build it.
3rd option, to start from a commercial amp basically good and improve it with better parts, debottlenecking, better connection and wiring and so on.
But i need time and space.
But the project is still on-going. Now i am in the learning phase.
Thanks again, gino
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Classic example of someone who reads what they want to read no matter what is written.
I said hard-to-drive speakers are rarely a problem because it leads to financial losses for the speaker manufacturer and his dealers. Too many easy-to-drive alternatives.
Only a confirmation based on misinterpreting what was written.
These days, very rarely. I would say that at least 90% of the time I read where someone says on an audio forum that their speakers are "Hard to drive" and their efficiency and impedance curve can be obtained, the speakers turn out to range from easy to drive to about average.
It is thus pretty safe to interpret "My speakers are hard to drive" as meaning "I have money burning a hole in my pocket and my emotions tell me to buy a fancy new power amp". That interpretation will be correct > 90% of the time.
Hi and this is a good news. The press gave me a different idea.
Maybe it is a marketing strategy to leave the people unsatisfied.
Thanks again. gino
Hi and thanks a lot indeed.
I will read it very carefully. This is indeed a change in the NP thinking.
I read the article about single ended class A as the best approach for amp design.
Thanks again, gino
Hi !
it is explained here
http://www.bostonaudiosociety.org/meetings/2014/14-11_meeting.htm
bye, gino
Hi ... ok. I should have said that has been a problem in the past and much less with more recent speakers
Again i want an amp able to drive properly many speakers, also old ones.
A lot of nice old speakers in the 2nd hand market. Speakers with excellent drivers like Dynaudio or ScanSpeak that new cost a fortune.
Is it no nice to have an amp good for all speakers ?
I think i have got the message this time
About DIY i would love to build something but i fear to end with an hugly thing.
I get absolutely no pleasure from building something that then turns out ugly.
I could not stand that. But a kit could be a really good start.
The only commercial amps that i like are usually very very expensive.
Like Pass Labs for instance. High quality comes at a price and it is not for every one.
Thanks a lot again.
Kind regards, gino
When you are reading audio magazines, forums and blogs, its often hard to tell where the advertising ends and the actual technical content begins.
Maybe? For sure!
Hi ... ok. I should have said that has been a problem in the past and much less with more recent speakers
Again i want an amp able to drive properly many speakers, also old ones.
A lot of nice old speakers in the 2nd hand market. Speakers with excellent drivers like Dynaudio or ScanSpeak that new cost a fortune.
Is it no nice to have an amp good for all speakers ?
What is an old speaker? Speaker manufacturers figured out that hard to drive speakers cause them to lose money no later than the early 1990s.
There aren't a lot of speakers from earlier than then 1990 that I would like to have. Speaker technology moves more slowly but it has moved quite a bit since then.
BTW the leading areas of improvement of speaker technology since 1990 are:
(1) General lowering of costs due to pacific rim production leading to improved price/performance.
(2) Improved crossover design focusing on controlling directivity and avoiding deep nulls on and off axis.
(3) Active speakers have become more advantageous as they benefit more from on-board DSPs.
(4) Woofer and subwoofer drivers and drivers in general with greater linear Xmax.
I think i have got the message this time
About DIY i would love to build something but i fear to end with an hugly thing.
I get absolutely no pleasure from building something that then turns out ugly.
I could not stand that. But a kit could be a really good start.
The only commercial amps that i like are usually very very expensive.
Like Pass Labs for instance. High quality comes at a price and it is not for every one.
Thanks a lot again.
Audio is not as hard as many make it out to be. It takes care, but the prevailing strategy seems to be scare.
I see. Actually it easy for me to get intrigued by words of some reviews.
Some writers are quite good at that.
I will keep this on mind for sure. Thanks a lot for the valuable advice.
Active speakers are less fun i think. And actually they are extremely unpopular
among audiophiles
People love to play with things.I see active speakers more for professional. They connect the mix directly to them and play music. Too hassle free for a real audiophile.
Love is both pain and pleasure.
Seriously i prefer passive speakers in general.
Thanks again, gino
Thanks. Once upon a time, I was thinking myself about the same idea
of developing my own amp, but in the mean time, I realized the cost/benefit
ratio would just not be justified, both in terms of cost and time. Loudspeakers
are a different story. Good luck!
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