two reasons come to mind. One, as you suggest, is that less in the signal path is better. Two, base and treble controls really only work at one frequency each so they are not a very good adjustment. One assumes if you are the designer of a high end amp you tune it properly and tone controls just muck up the plan. You might recall graphic equalizers were popular years ago so you could really play around.
Kind of like asking for salt and pepper in a high end restaurant.
You could always get a decent parametric equalizer and see how it sounds in your system. All of them have bypass capability so you can quickly A-B the sound with and without the equalizer in the chain...
Adjusting treble and bass can do more harm than good since nature of recording deficiency (if any) is more complex than just treble and bass.
It shows in market demand - no tone controls in most high end systems but tone controls in every low end system - they need them to fix lack of transparency and neutrality.
Low end speaker is a good example - limited low end with pronounced hump at mid-bass. On recordings with a lot of midbass it will sound better with less bass but on recordings with low bass it needs more bass from an amp.
I don't have any desire to adjust tone (or balance) but remember doing it constantly with low end system.
Accuphase, Mcintosh, and Van Alstine offer them in many
of their preamps, FWIW.
You are correct with regard to the signal path. And tone controls can affect things such as imaging, soundstage, etc as much other things (distortion, purity, etc).
I also want to suggest to you that there are other ways to affect the sound in your system, other than adding or removing components. In fact, some of the best ways include room treatments, speaker position, and listening position. Experiment with those things - a lot - and you may be surprised how much better your system can sound.
It took me a good many years until I found out why "higher end" gear didn't have tone controls. I always assumed that many factors denoted a need to adjust the sound. I then discovered that having built a system with care and a great deal of synergy, I now hear far more of the music. There are underlying passages I had never even noticed and instrumental lines that had hitherto eluded my ears. Ergo, there was no longer any need for adjustment and certainly zero need for things like balance and tone controls.
But that's just me.
I forgot to add to my above post - the music opened up and became spacious, the bass was deep and concise and the treble clear and distinct. I also discovered mid-range as well. Where the music was pretty much a wall of sound and tone controls only muddied that overall impression, with quality came clarity.
I have read from a few sources that Jim Bonjourno's
Ambrosia Preamp has tone controls the work very well. I've never heard it, but I've never read that about ANYTHING else. Maybe someone can confirm.
The most simple answer is that a good system really doesn't need tone controls.
"Rooms need tone controls"
Room treatments improve clarity and imaging.
Tone controls destroy clarity and imaging.
I understand your thoughts Kijanki. Room treatments to dampen peaks in room frequency and go along way to help give us a flatter response. Agreed, but in some rooms, the only way to flatten response would be some type of frequency control... Obviously subwoofers are very low frequency, but many these days are electronically altered. I do and have used room treatments and agree its the way to go, but as I wrote earlier. I understand that Jim Bonjourno's Ambrosia preamp does a very good job with tone controls... I believe that it is possible for an eq to be built that would do a good job without destroying a sound stage, small increments that very evenly add frequency to channels equally, why do tweeters with a high end rise or a roll off still image? Or a mid with a dip or a peak? Frequency alone does not destroy imaging.
Again, I don't use them, but don't find them an enemy either.
The less in the signal path the purer the sound.I play some of my low gain cds with my passive linestage removed so that the cdp goes into my 300b set amps direct.
The system sounds incredible and open this way.A warning however as this can be very dangerous and not all systems can handle it,so I recommend trying this only with extreme caution.
Today's technology permits more precise specific corrections than yesteryear's crude "Bass and Treble Dials".
Capacitors used in analog tone controls have tolerance of few percent producing different phase shifts between channels. Same goes for limited track to track matching of the tone potentiometer. Capacitors, in addition, have dielectric absorption - introducing distortion. Good caps can be very expensive. Cheap Mylar cap is often the reason for the tweeter glare in many low cost speakers.
Yes, accurate filtering is possible in DSP processing, but signal has to be digitized to start with and then converted back to analog again (two conversions). In addition it doesn't solve many problems. For instance some of my Jazz CDs have acoustic bass coming a little strong (nature of the recording). How can I reduce it (or should I?) without changing sound of lower piano registers. On the other side of the frequency spectrum - how can I make cymbals to sound stronger without changing timbre of voice or not making violins "screechy". Harmonic structure of many instruments is incredibly complex and I don't want to touch it. Less is more.
It doesn't necessarily need to be converted to analog, therefore it's possible not to introduce any new conversions, except for pulse conversion. Perhaps such equalization is best left to room correction, rather than re-engineering existing recordings? Future technologies might be able to identify and correct for individual instruments, but I have no idea when that might happen, if it happens at all.
I have in my home electrolytics, poly carbs, poly props(metalized and pure film), paper in oil, poly styrene and teflons. I have played a bunch. I measure everyone to less than 1% tolerance. I don't have any mylars and generally agree about the sound of those, but I must say, I have had a russian set of mylars that were outstanding, so who's to say. Ok, only a few pio, ps & teflon.
I stand by my comment, really only an opinion that a good tone control circuit (eq) could be built with very good end results. More bands for flexibility would be nice.
That would be really interesting to insert such device in a chain spdif-in spidif-out but I would still stay out of correcting.
It looks like you know your caps. Outstanding Mylars? - no way (Dielectric Constant = 3). It is probably Teflon inside - who would trust Russians? (LOL) Production wise selecting caps below 1% would not be a practical solution while caps like that are very expensive (and still would make imaging a little worse). Circuit would most likely include additional buffer stage that would not make clarity any better either. Potentiometer itself has track to track mismatching about 3dB. Even expensive pots have mismatch of 1dB - still very audible tone change between channels destroying image.
The cheapest amp in Best Buy has all sorts of tone controls - often equalizer, loudness corrector, spatializer, rumble filters, noise filters, balance control etc. It is lacking one minor thing - a good sound. Same goes for many Home Theater systems - a lot of speakers but none of them good sounding.
I think the Luxman integrateds are high end and high performing units with tone controls. So if some one really wants that and can afford them those would be an option.
Here are the Russian mylars Polyethylene-Terephtalate)K73
They took alot of burn in, but after a couple hundred hours were quite good.
Thanks, I haven't seen it before. Looks very interesting.
You're right - it is Mylar (I checked Wikipedia). Must be different construction or something else. Hey, if it works it works.
For 95% of my listening I use the tone defeat feature of my NAD 375BEE, but I also like live recordings particulary of the Grateful Dead.
Those shows are a mixed bag in terms of the recording levels and the tone controls help immensely.