[DVV]

I just noticed we never really spent any time talking about filter capacitors as a very significant way of affecting the sound. Using the same circuit, but different caps, one will get a different sound - that has been proved many a time.

Between no-name products, via recognized sources of medium quality, to high and ultra high quality caps, effects will follow in a similar way, though not in a linear fashon.

Any preferences here? Dan?

Cheers,
DVV

[Dan Banquer]

Actually I don't really have preferences here. I will predominantly use standard Electrolytic caps in parallel with small value film caps for the power supply. The RFI/EMI filter I use at the AC input wipes out the HF content before it hits the transformer.
Regulation and grounding technique go a long way here and switching different brands has not lead to sonic improvement or any difference that I can hear or measure.
In the audio signal circuits; (not power supply decoupling) I will use either film or npo ceramic.

[DVV]

Actually I don't really have preferences here. I will predominantly use standard Electrolytic caps in parallel with small value film caps for the power supply. The RFI/EMI filter I use at the AC input wipes out the HF content before it hits the transformer.
Regulation and grounding technique go a long way here and switching different brands has not lead to sonic improvement or any difference that I can hear or measure.
In the audio signal circuits; (not power supply decoupling) I will use either film or npo ceramic.

Yes, since you use full electronic regulation, the quality of the capacitor is not as critical as when using caps only.

For standard fare, I generally tend to use Nichicon, and for top quality fare only Siemens Sikorel series. Darn expensive, but really the best I ever came across.

Cheers,
DVV

[audiojerry]

Is the purpose of filter caps to eliminate any frequencies above 60hz? Wouldn't that require very high value caps, which would necessitate electrlytics?
Is this all happening before it reaches the power supply?

[Dan Banquer]

Hi Jerry;
        Large electrolytic caps do very well filtering low frequency components.  I have found many specified for 120 Hz, which is the frequency that most diode rectifiers are set to do. That specification is called E.S.R. This is the abbreviation for equivalent Series Resistance. Due to the series inductance that they have they are typically not very good at higher frequencies. Paralleling electrolytic caps with small value films or ceramics helps the higher frequency filtering. This all happens in the power supply.
Hope this helps.

[DVV]

Hi Jerry, all,

Hi Jerry;
        Large electrolytic caps do very well filtering low frequency components.  I have found many specified for 120 Hz, which is the frequency that most diode rectifiers are set to do. That specification is called E.S.R. This is the abbreviation for equivalent Series Resistance. Due to the series inductance that they have they are typically not very good at higher frequencies. Paralleling electrolytic caps with small value films or ceramics helps the higher frequency filtering. This all happens in the power supply.
Hope this helps.

Dan just about described it, so I'd just like to add a bit. Beside filtering, which is (or should be) their primary function, caps also act as 'batteries", i.e. energy storage supplies. When an amp requires more current to be able to respond to a transient, it draws this current first from the electrolytic capacitors. Thus, they act both a filter and energy storage elements.

As Dan said, they are good for filtering below 1 kHz in general, but above say 5-6 kHz, they start to turn sour and filter only just so-so. It's because of this that we generally parallel them with smaller value caps, which don't filter low frequencies well at all, but do much better at higher frequencies.

A good rule of the thumb here is dividing by 100. Say your primary electrolytic is 10,000uF; the next in parallel should be 1% of that, or 100uF, and following that, 0.1 uF for the really high frequencies. With this, you get good low and high frequency filtering.

However, this does nopt even beging to compare with a dedicated line filter for anything over 2 kHz, and especially over 100 kHz. Our enemy is not just the 50/60 Hz signal, but also the very high frequency ultrasonics signals, well above the 1 MHz range. The worst of it lies in the 1...80 kHz range (electric motor noise, computers, etc).

Cheers,
DVV

[audiojerry]

Thanks, I didn't know that the filter caps also served as the power reserve caps. For example, Odyssey mono amps use 240,000 uF of capacitance. Maybe I'm mistaken, but I do not recall seeing any smaller value caps in parallel with the large bank of electrolytics. Are these both filter and storage caps?

[Raj]

Hi Dejan, dan and Hugh,

where do you all see technology regarding amps going within the next 5,10 and 25 years?

I myself have a class a/b amp, which is biased to give only a couple of watts of power into class a, however I do enjoy the extra resolution that this offers, and stilll believe that although it is very power consuming nothing can touch it in terms of resolution,accuracy and sheer musicality. Listenening in class b seems like a trade off, extra power at the expense of tonal and soundstage accuracy, and although there are some good class a/b amps out there (kits or otherwise), I feel that class b will always be behind no matter how 'well' it's done. If only the technology that is used in the top class krell's intelligent bias techneques (allowing high volume class a outputs and also without the inherent idling heat problems without volume), to us diyers!

With the advent of digital amps and class d intelligent biasing, will it become harder for diyers to make amps that compare? Although even class d is a trade off from class a.

All this said there always the enjoyment of music to consider, and in a world that strives to change with the times, demand influences design. Take tubes for example, there's still demand, and even with the advent of semiconductor technology they're still going strong.



Also surface mount technology is becoming more and more  popular (with manufacturers anyway), how do you think this will affect the diy hi-fi trade?

Do you think we have designers out there that only produce equipment using certain components cause of consumer demand, is this stopping us from moving forwards?

I'm a strong believer that the lowest distortion is the key to good sounding amps, this is also a matter of taste, if you like your music  to sound 'euphoric' etc, you may disagree.

One big dissappointment is there really isn't a massive supply of high quality recordings to make the most out of really world class amps (maybe a good argument for 'euphoric' sounding amps!), certainly cd's have many a brash sounding disc. At present were stuck in a amp and source 'time warp', hybrid amps, class a amps, class a/b amps, class d amps, vinyl, cd, sacd and dvd-a and probably some more! What's going to happen?


Thanks
Raj

[Dan Banquer]

I don't have crystal ball Raj, but the trends I have seen over the past ten years have not made me optimistic. We now posses incredible technology in the recording studio and yet it is generally poorly implemented. (See my article at www.zero-distortion.com  Current Trends in the Recording Format Arena) I am also of the opinion that progress in loudspeakers over the past ten years has been mostly in the area of marketing. Without the above two moving forward, little if any improvements in amplifiers will be of importance on a mass scale. When you consider that I design and sell power amps and pre amps, I think the above is quite a mouthfull.  BTW I'm not the only audio designer who feels that way, I am just more verbal about it.
Surface mount technology is good for mounting a lot of parts in a small space, for audio band that doesn't mean much for fidelity. Switching amplifiers are much more efficent and generally cheaper but linearity and output impedance are very real problems for most of these devices.
Remember the old saying "there's no such thing as a free lunch" This applies to engineering as well as politics.

[Raj]

DAn, Dejan and Hugh

Thanks for the reply Dan,

Do you let consumer demand influence your designs, or do you feel free to offer whatever you choose. What's your design philosophy, do you consider things like power consumption in terms of global effects etc, or do you go for the best sound possible?
Is class a still the landmark to judge performace against?
I prefer no compromise designs and components (within reasonable limits of course),  it's hard to see thru the fog of hype though.
Do you feel that msot designers give replies that the public want to hear?


Thansk Raj

[Dan Banquer]

I deliberately do not let the latest fads influence my designs. That's why you don't see the equipment I manufacture for sale in the used audio equipment directories, except when a critic decides he needs some fast cash. I attempt to do as neutral a design as possible. This is not popular and I don't give a d**n. My design influences come from a number of sources but one major one is instrumentation. If you were to ask my basic design philosophy I would say I just make tools for the analysis of recorded music, no more and no less.
Class A in the strictest sense of the word really does not exist in solid state audio. It's really hard biased AB design.
And finally yes, many designers tell people what they want to hear. There is plenty of evidence of that on Audio Asylum as far as I am concerned.
The reason you won't see thru the fog and hype is that practically no one is doing the testing that needs to be done to find out, and then explaining this to consumers. In short; if you hang around here you'll learn a bit from people such as myself, Dejan, and Hugh, and if I forgot anyone else I apologize.

[DVV]

Thanks, I didn't know that the filter caps also served as the power reserve caps. For example, Odyssey mono amps use 240,000 uF of capacitance. Maybe I'm mistaken, but I do not recall seeing any smaller value caps in parallel with the large bank of electrolytics. Are these both filter and storage caps?

Indeed they are Jerry. You see, filtering function aside (it's a given, the only REAL way to change it is to add more capacitance), what we are really after is energy. Not volts, not amperes, but energy. Energy storage is a product of voltage and capacitance, and you can use a very simple formula to determine what you have:

1/2C x V sq.

where one half C is capacitance in either the plus or minus line (assuming dual power supplies, those with +, 0 and -) in Farads, and V sq. is the voltage on that line squared.

If we assume your monobloks have split power supplies, and if we assume these power supplies to be say +/- 50V, the energy you have stored is:

0.12 x (50x50) =  0.12 x 2,500 = 300 joules.

Experience shows that we need 1-2 joules per every 10W of dissipated power; 1 joule if it's an easy load, 2 joules if it's an evil load. From this, it follows that you have about 1,500 watts' worth of energy into evil loads, which is WAY more than is required to fry just about any speaker I can think of if unleashed. 3,000 watts' worth into easy loads.

To put this into perspective, if you switched your amp off, and if it has no bleeders (resistors put across capacitors to help them discharge), and you put your finger across those caps from the contact side, your wife would have to sweep you off the floor with a vacuum cleaner. Literally.

Or you could use this energy to arc weld another Brooklyn bridge.

Cheers,
DVV

[DVV]

Hi Dejan, dan and Hugh,

where do you all see technology regarding amps going within the next 5,10 and 25 years?

...
Raj

I think we will be moving towards the digital domain, with the objective that our entire audio will be in the digital domain, and ultimately, just one chip in our future PCs.

Personally, I think this is a process which cannot be stopped, but at the same time, it's not necessarily a good thing. We are once again hurling into new technologies while we have not yet truly mastered the old - a story we see all the time, now in vinyl vs CD arena. It took the CD to make us realize that vinyl was actually better than we gave it credit for.

I believe we will still have, use and develop classic solid state for many years yet.

Cheers,
DVV

[DVV]

I deliberately do not let the latest fads influence my designs. That's why you don't see the equipment I manufacture for sale in the used audio equipment directories, except when a critic decides he needs some fast cash. I attempt to do as neutral a design as possible. This is not popular and I don't give a d**n. My design influences come from a number of sources but one major one is instrumentation. If you were to ask my basic design philosophy I would say I just make tools for the analysis of recorded music, no more and no less.
Class A in the strictest sense of the word really does not exist in solid state audio. It's really hard biased AB design.
And finally yes, many designers tell people what they want to hear. There is plenty of evidence of that on Audio Asylum as far as I am concerned.
The reason you won't see thru the fog and hype is that practically no one is doing the testing that needs to be done to find out, and then explaining this to consumers. In short; if you hang around here you'll learn a bit from people such as myself, Dejan, and Hugh, and if I forgot anyone else I apologize.

I can only agree with what Dan said above. Yes, progress IS being made, new ideas are being proposed, and some of them at least are well worth investigating - memory distortion, for example.

Yes, many if not most designers are telling the consumers what they want the consumers to hear, or what they think the consumers want to hear. I know for a fact neither Dan nor Hugh here are anywhere near that territory, that much is rather obvious from their posts. Between the three of us, you have three approaches, each as individual as the man behind it, yet in many ways almost identical in some fundamental aspects. We are not fad driven, we don't give a hoot about the latest trends in customer fleecing, we eschew tubes in favor of silicon bipolar devices, we talk to each other and exchange info we believe is worth the other guys' time - yet we stay individuals. Brothers in arms, you might say.

But most of all, all three are committed, personally committed, to what we believe to be high quality sound reproduction. Dan put it well - essentially, we want to make precision instruments for evaluating music. And we are not willing to make a few extra bucks by starying from that goal (I purposely omit the word "cause", as I don't see any of us as a cruisader, just people with formed opinions they can and will defend).

That this is indeed so is easily tested - ask any question you like, and you will get an answer in as plain language as we can make it. We have nothing to hide, and not one of us claims to be the best out there, much less the only option.

Cheers,
DVV

[Raj]

Hi Dejan,

What did you really want to achieve in this particular topic?

Has it been achieved?

Are we not drawing somewhere near a conclusion, Dan's report on cd recording and also his statement about the state of speaker design, point to the fact they're designs aren't being allowed to shine to their respective potential.

I've built a kit amp and pre (white noise), it's awesome,on decent recordings the sound really is good, but I do feel some dissapointment, why? Because the medium I use for my source isn't being recorded well enough, not the fault of the equipment but the fault of BIG BROTHER, who just wants to make his millions. Anyone whose main source of income is audio, is likely to rip someone off at one time or another, I've yet to meet anyone whose convinced me otherwise. You're lucky Dejan, you understand electronics, you know what you're really buying, the rest of us get caught up in hype., I've got the equipment but where's the quality recordings to take advantage of it? I don't want to pay lashings just for 'audiophile' discs, some of it isn't the music I want. I go out buy a disc in a genre I like, only to find that the recording distorted!

Thanks guys for your time

Raj

[Dan Banquer]

Raj;
      I have found good recordings in many mediums, classical is generally very good, jazz is second, and most of contemporary pop music is pretty bad. Take my advice here as an ex musician; get past the recording and go for the music. It takes some work, but you seem an intelligent sort and I think you will figure it out.

[Raj]

Hi Dan,

I like many types of music, depends on the mood I'm in. I like moody jazz, Miles Davis, do you know of any good recordings by him or other Jazz musicians?


Thanks
Raj

[hairofthedawg]

My impression of the purpose of this topic is that it was intended to enlighten us and I wholeheartedly thank the askers and answerers of questions in this thread.  I don't know that this purpose will ever be achieved as technology will undoubtedly evolve creating more questions and answers.

As far as hype, when I bought my stuff I got a pretty good deal at least as far as comparing it to the list price on Symphonic Line's website but still wondered whether it was as good as it's reputation and my hopes.  I still don't know, but have a lot better idea after reading this and other threads.
I still think I paid to much for something that is a hobby, but I've learned that my system is using quality components and also now realize that part of what I paid for is the time it took to design, tweak and assemble this mix.  It must be a really nice feeling when a designer finally say "I've got it"!  I'm not sure they ever do, but if they get close to that point, it's got to feel good.

I agree about the quality of recording, but I mainly listen to classic rock and don't expect all that much.  I'm slowly migrating toward better quality recordings, but you're right, it can be expensive and I don't always like the selections available.  My reference recording is the New Radicals' "Maybe you've been brainwashed too", so you can read into that what you will.  I've rambled enough and am need of a fix so

cheers,

Dick

[DVV]

Hi Dejan,

What did you really want to achieve in this particular topic?

Some enlightment of the readers, if possible.

Has it been achieved?

I don't know - you tell me. If you now understand some things a bit better than before, then I would say the point has been made.

Are we not drawing somewhere near a conclusion, Dan's report on cd recording and also his statement about the state of speaker design, point to the fact they're designs aren't being allowed to shine to their respective potential.

The conclusion will come when somebody can justly say - here's a perfect amplifier. And that will take some time yet.

I've built a kit amp and pre (white noise), it's awesome,on decent recordings the sound really is good, but I do feel some dissapointment, why? Because the medium I use for my source isn't being recorded well enough, not the fault of the equipment but the fault of BIG BROTHER, who just wants to make his millions. Anyone whose main source of income is audio, is likely to rip someone off at one time or another, I've yet to meet anyone whose convinced me otherwise. You're lucky Dejan, you understand electronics, you know what you're really buying, the rest of us get caught up in hype., I've got the equipment but where's the quality recordings to take advantage of it? I don't want to pay lashings just for 'audiophile' discs, some of it isn't the music I want. I go out buy a disc in a genre I like, only to find that the recording distorted!

One of the objectives of this topic was to share some of that knowledge, precisely because I feel too many people are being handed too much hype and too little facts.

I cannot judge how well, if at all, this has been achieved. That's up those reading all this exchange of views.

Cheers,
DVV

[AKSA]

Y'know,

As I sit here listening to Bob Dylan - horrifically recorded I might add, but nostalgic and very pleasant to this fifty year old - and I read the contributions to date on this topic, I muse that perhaps we are all on crusades, trying to educate, elucidate, to build a better mousetrap, and all of us so determined not to follow the crowd that we expect the journey to far outstrip the destination.

Dan's point about instrumentation is well taken.  Instrumentation technology has brought audio the current source, the current mirror, the cascode, to name but three topologies of yore.

Dejan appears to me to be a gifted writer, with a love of audio and people, who is happy to spend a lot of time educating, explaining, and demonstrating his experience.  Alas, too few such people are as honest and well founded as he;  too many reviewers are driven by acquisitive self-interest, producing ingenuous hype which explains nothing but helps the novice part with his cash........

One of the extraordinary things about audio design is that there appears to be a 'house' sound.  Listen to all the Cary, Wavelength or AR products, and say I'm wrong.  There is really so little known about the psycho-acoustic landscape that it is still possible for all the products from a designer's stable to bear strong similarities and musical presentation.  I'll bet this is true also of Dan's amps, though I've not heard them.  You could probably pick it for its clarity and neutrality;  the overall sound will be unique.  Certainly in all my products there are similarities, and I believe it has to do with musical perception.  I go for the emotional communication;  something I'm obsessive about.  I was quite astonished recently to learn that one of my amps produced 0.007% THD into 8R at 10W;  I'd not made that particular measurement and always designed on sonics (with a little help from CRO and DMM!) and was surprised it was so low!

It is difficult to consider a thread like this one having a goal and a defined end point;  I prefer to think of this thread as a serial, rather like 'The Bill'.

Cheers,

Hugh