Hi-fi is an funny field. You think you have a grasp of it, and then there are new layers to explore. Making speakers is a good example where "normal" engineering targets are abandoned and replaced by an understanding of human psychoacoustic capabilities and limitations. In loudspeaker design linearity is not just linearity. In audio design we work in a field were we can hear the unmeasurable, milliohms change in GND impedance can musically make or break a design, whilst not showing up how ever careful we may conduct our measurements. It is a wonderful world, were I feel that despite "good" results we have barely scratched the surface of a big ocean of knowledge waiting to get explored. I agree universities most often only teach the rough fundamentals, Then must the talented, skilled and dedicated take and develop basics to a deeper level of understanding.
What's a lack of depth? How do we communicate that? In meters?
Universities aren't interested because there's nothing interesting in an audio amplifier!
We study analogue circuit design...
No, measurement IS crucial and if you can't measure it then saying 'oh well we just can't measure it' is just a get out clause like a theist saying god moves in mysterious ways!
I think if you have read into psychoacoustics and psychology then you would understand a lot of the ways people are able to hear something that's not there. It happens often.
At the end of the day I love music, it's my life and I want to listen to it well. So I think what's the best way to do this? Random stabs in the dark with illogical techniques like huge speakers and a 1W amplifier with crazy distortion or take the logical scientific approach which for me lets me forget about the tech and focus on the music when I listen to music.
What is your system, and how much efforts did your invest in creating it?
Studies and experience are very different subjects.
Also, there are no reasons to consider the Follower as an amplifier. In fact, it is a model of definite stage, nothing more.
There are no reasons to fight against Ciuffolli, he has not patented anything.
This kind of stage (actually very useful stage, for those who has experience) is not more and not less than the emitter follower (common collector) stage. If one could mention, historically, nobody find reasons to fight against CC stage, and nobody tends to name it as a complete "amplifier".
I see the only reason to discuss the two stages (traditional emitter follower and "ciuffolli" follower), in trying to fix different sound signature from the different stages. And, as for me, the difference exists, in favour of "ciuffolli".
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Yes and it's totally useless!
My system is an active 2 way with sub. The two amplifiers (two per channel) are built into the speaker enclosures and directly drive the drive units. The passive crossover is the worst invention for audio ever in the history of audio - is causes so many problems it's untrue and it's so easily solved with an opamp and a few Rs and Cs.
The amplifiers I use are small. They use the LME49830 and output FETs, I measured 0.0008% THD1 at 30W 80KHz bandwidth however this figure is totally overkill. Each amplifier can output 150W so can cope with the huge dynamic range of music, this very easy reason is why low power amps are no good.
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Another simplified assumption ...
"You thought about it once, you should think about it again..."
You should apply for a currency trader position in a large institution in the City.
With your opinions you might bring down a bank.
I understand your system now. Disappointed, it should have 0.00001% at 1KHz fully power into 4R. You chose the wrong chip......
You have just ignored one of the smartest peoples in this forum, particularly VladimirK. A great pity. Interesting how careful experience is ignored when people chase ideologies and follow fads, the duopoly of marketing.....
Hugh
With your opinions you might bring down a bank.
I understand your system now. Disappointed, it should have 0.00001% at 1KHz fully power into 4R. You chose the wrong chip......
You have just ignored one of the smartest peoples in this forum, particularly VladimirK. A great pity. Interesting how careful experience is ignored when people chase ideologies and follow fads, the duopoly of marketing.....
Hugh
I admitted the distortion figure was overkill!? What's wrong with the 49830?
My ideology is logic my fad science and reason. I'm quite the contrary to the marketing rubbish how many active speakers do you see?
and ignorance is bliss....................Hugh you might have an uphill battle here.
People keep telling me I don't know something here but they won't (or can't) tell me what it is.
The reasons I don't like this power follower are the fact it's just unnecessary, if you need to improve an output stage a compound output stage is great. The power follower is single rail, Class A (low power/inefficient) and crude amplifier that really is not goign in any great direction to great sound. It's purpose is something for 'audiophiles' to fuss over.
I have worked in the HiFi industry for a year so understand what goes on. I'm currently studying electronic engineering in one of the best unis in the world. I study electronics in great depth with some of the best lecturers in world for electronic engineering - I'm not stupid.
No one says you are stupid. However, you are infatuated with your own ability and confidence. You need a bit of experience.......
I don't want to waste your time or mine with insults. I recognise your mind is made up. You cannot ignore the increasing numbers of clever people who disagree with you.
I'm done. Have a nice day.
Hugh
I don't want to waste your time or mine with insults. I recognise your mind is made up. You cannot ignore the increasing numbers of clever people who disagree with you.
I'm done. Have a nice day.
Hugh
Boscoe, being ignorant and limited does not bring you forward, and will not give you any answers to what you seek or don't seek.
I have now been in the industry for more than two decades, and frankly to my experience everything matters, you can ruin a good circuit with a poor PCB layout. you advocate active speakers like frequency response is all that matters. This kind of thinking leads to R&D in the direction of how can we make something similar, just cheaper. I may give you sound, but you entirely missed the point and with that the ability for your system to conway the emotions music is really about. With your thinking and limited horizon of potential, I would never even consider to hire you as an engineer for my company. Have respect, be open minded and over the years You too will learn that there's much more to performance than measured specifications.
I have now been in the industry for more than two decades, and frankly to my experience everything matters, you can ruin a good circuit with a poor PCB layout. you advocate active speakers like frequency response is all that matters. This kind of thinking leads to R&D in the direction of how can we make something similar, just cheaper. I may give you sound, but you entirely missed the point and with that the ability for your system to conway the emotions music is really about. With your thinking and limited horizon of potential, I would never even consider to hire you as an engineer for my company. Have respect, be open minded and over the years You too will learn that there's much more to performance than measured specifications.
Oh dear, I'm not doing well am I! What company do you own?
I totally agree layout is just as important as circuit design.
I never mentioned frequency response, I don't think the guys in solid state really understand speaker drivers.
No lumps of metal, plastic and wood cannot offer emotions - they are inanimate. You make the emotions from what you hear, I find active speakers can transfer music better.
"With your thinking and limited horizon of potential,"
I am flabbergasted with this comment. I mean just, you have no right, you epically have no idea who I am.
I started my electronics in this forum about 5 years ago and so I was 'brought up' on this sought of electronics. It took an open mind and a passion for my music to read/understand electronics and the functions of speakers to then change my thinking from the drivel that is valve amplifiers and such to a much more efficient and overall better active system.
Me close minded the anything? - no. Close mind to rubbish - yes.
Go ahead, and your way will lead you to YOU after 20 years passed ... Seems that listening of really top level system one day will change your mind.
Boscoe, I think you may misunderstand the role of the power follower. It is not intended as an amp add on, rather it is a current booster for a preamp with enough voltage swing. Adding on to a power amplifier would be counterproductive as you said.
As for amplifiers making very little difference in sound, I was in your camp until I tried different amps without making any other changes. I had a commercial amp that was fairly traditional lots of GNFB. A Leach amp opened up the breadth and depth of the soundstage and I found that I couldn't pull myself away from listening. I hadn't been able to sit still for a whole cd in ages. That's not something that shows up in traditional measurements. We must be measuring the wrong things if amplifiers that measure worse sound better.
Speakers and room interaction probably make the biggest difference, and if your drivers are unable to resolve differences elsewhere in the chain it is easy to believe that there are none. I went a long way down the path before discovering a difference in amplifiers. Keep an open mind. Sure, there is snake oil, but there is a lot of good information coming from folks like Hugh, John and Many others. Try some different things. You may surprise yourself. Class A may be counter to your production needs, but try it, even in powered speakers.
As for amplifiers making very little difference in sound, I was in your camp until I tried different amps without making any other changes. I had a commercial amp that was fairly traditional lots of GNFB. A Leach amp opened up the breadth and depth of the soundstage and I found that I couldn't pull myself away from listening. I hadn't been able to sit still for a whole cd in ages. That's not something that shows up in traditional measurements. We must be measuring the wrong things if amplifiers that measure worse sound better.
Speakers and room interaction probably make the biggest difference, and if your drivers are unable to resolve differences elsewhere in the chain it is easy to believe that there are none. I went a long way down the path before discovering a difference in amplifiers. Keep an open mind. Sure, there is snake oil, but there is a lot of good information coming from folks like Hugh, John and Many others. Try some different things. You may surprise yourself. Class A may be counter to your production needs, but try it, even in powered speakers.
Thanks Bob I understand it's function and I understand what your saying however I think I'll stick with what I got!
It's just for me it seems this amp follower thing is totally barmy!
The particular implementation published by Andrea is very far from being useful as a real amp, and this could be a reason of existing of contoversial opinions about the stage idea. But the idea itself is very useful, if one cares to make definite adjustments and extensions. For those who does not like "solid-state sound", and believe in superiority of tubes, I could propose the experiment:
1) in the original Andrea's schematics, first of all replace the indicated output cap, by the paralleled 1uF polystyrene, 33uF polypropilene, 16x1000uF Nichikon KZ, 3x10000uF ordinary caps (connected via 0,033 Ohms resistors (three 0,1 in parallel) ; the last three caps are intended to suport the bass only
2) replace the active IRF150 mosfet by triple darlington BJT (for bass improvement)
3) avoid the input cap and input bias resistors, buy using single ended preamp-driver, with suitable voltage at the driver output; this stage could be based on tubes or j-fets, without input cap
4) use shunt-type power supply for the preamp-driver
Believe, if carefully implemented, these measures will change minds of many people about superiority of tubes over SS, at 10W audiophile domain.
Also rock music lovers could be satisfied, if idle current of the output stage is not less than 3A. Some local rock artists came to me with "difficult" rock music CDs, and found nothing to critisize, fast intensive music is well resolved and involving (in this aspect the bridged version without output cap is a bit better, the music was really very fast and "mad" for me). Speakers are PMC EB1i, but in fact they do not need Bryston amps for fast music, as many believes.
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