.... on audio buffers , market lies and over ......
this following picture shows the schematic of a priced audio buffer (that i won't mention) from an highly regarded english brand.
I wont talk any bad of this brand because they made excellent devices in audiophile world, but like every brand has its scheleters inside the wardrobe......or some trick to sell sometings less marketable.
...here we are!
this is the LT Spice schematic i did for a simulation....
This device is "for sale" as the perfect and universal recipe (panacea) to improve any CdPlayer on the Earth, connecting a couple of RCA cable from the analog output to its input and another couple of cables delivering signal to the amplifier :) .
These lords(audio gurus) that sells this device, want to improve a signal with a buffer between the audio source and amplifier with a distance of few centimeters between the two devices ........... mostly a well build audio cable is the best solution to keep preserved and untouched the audio signal!
Yes.....this audio gear has sense....but not for the use they advertise it !! It would be usefull to drive an headset or to drive very long distance audio cable (tens and tens of meters) to feed the amplifier (but hardly happen a situation like this !! One time in a million!!!)
The fact is that every well build CdPlayer has its own buffer designed inside to pilot very well even 2 or 3 meters of cable ( who want the cd player at the other corner of his room??)
...so why add another one buffer ???
....and......
....for sure average CdPlayers are improvable and for sure they're affected by some signal deterioration along the path .
In more accurate CdPlayer you can do few things to improve them , but the customization to reach the best result has no limit in the audio chain.
Then, what is the greatest problem in CdPlayers? The answer is the LPF circuit in the output, that is designed mostly with Operational Amplifier (opamps) .
Opamps has very good performance and they're very easy to use moreover they helps to use less components, and helps to simplify any electrical design...then engineers and company are very happy with them.....but??........but marketing leads and impose to use cheap operational amplifier such as NJM4560 - 4558 - 4570 ...... they are always the same in more than 80% of audio devices .... not the worst but neither any particoular good or accurate for audio.
Yes, then......they are guilty to spoil the audio signal!!
The best way is to gives a cut at this spoiling is finding another way to reduce the loss and take care of the signal in every little step since the source af analog signal....then the whole path , from the source (DAC) to RCA connector !!!! This is the only and the only way to keep safe the signal that need to be filtered and need to grow in amplitude without any loss in the informations.
Addictional devices along the audio chain could be only a great risk, and useless if not in very particoular case ....in more than 80% of cases only a loss in signal quality and purity!
Has to be said that normally amplifier has an imput impedance from some teens of Kohm to 100Kohm and sometime more, and for the source is enoght to be a little less than amplifier input to drive it correctly ... e.g. 3/4 of amplifier input could be a great combitation .
This buffer gives some teens of Ohm wich is perfectly suitable to drive an headset (as yet said) but with a considerable loss of audio quality ......I work to keep safe all the components of the sound wich you can call upper and lower harmonics....to keep safe the richness of details , channel separation,coherence of sound, 3D presentation and more.....but not this gear ..this gear in the more lucky case can only stole information.
The first way to improve CDPlayer leaving the same design is to swap the Opamp and find the best one on the market (Analog devices, Burr Brown etc) .
should be very helpfull change capacitors using low ESR and using many MKP or MKT capacitors everywhere taking confidence with their sound and growing the skills to "play" with them in every design to turn the sound indeed as you desire!!!
When you grown more and more skillfull you won't stay without change even a little the circuitry , at least , why not take off muting transistor ???...or simplify the signal path ??!!! ;)
The other way to improve enormously the sound of an average cdplayer is to realize a dedicated design of LPF starting from its own DAC output and then on!
The best way are with tubes the other way is dicrete components (mosfet or jfet or bypolar)
With these last two solution you can reach great result but where is the trick comparing this work of mine with the schematic shown before?????....
....well I take a very small LOSSLESS signal directly from the DAC and I design a dedicated active filter of output(using tubes or mosfet ....) to keep the signal the most undistorted and coherent is possible!
Many DACs has an internal opamp that gives a Voltage output signal for a simplier work for tweakers and designers; other DACs are current OUT wich is the best to work with 'cause it gives most possibilities to achieve the best results for the most skilled designers , but it's even the hardest to work with if you don't have confidence ;)
But market want to please even not skilled (and sometime naive) people, and then???Then has reason to exist our "MISTERIOUS BUFFER" for people that need to believe obsinately in something, but not in their senses.
No polemics, but only for the sake of truth I want to say that the schematic of the "misterious device" shown before is tricky and useless for advertised use and even if some people decide to fix it inside the case (hope you cach my irony! :) ) it require to be connected after the opamp ,even without change a simple resistor of previous setup ,leaving the same mess inside, not any difference by before , but probably adding something even more wrong!
.... just because it is a buffer with no amplification on the signal , so this is not a substitute of the LPF, but an addictional buffer that can only add loss at the signal, if we're talking of short distance cable driving........ and only in some bad designed player can achieve an improvement..... just cutting some awfull shrill temperament but not giving anything, even close, to audiophile sound!
Then for all the people that fall on their knees only watching at a couple of lightened tubes inside their players I want to warn that , first thing is a dedicated design .....tubes could be the best improvement I've ever experienced in CDP LPF section..................... but in this odd case they can only warm a bit the case and ruin the sound!!!!
To conclude, there's not panacea or any audio magic gears suitable for all audio chain , and in this case like in many others a minimalist but not easy way is the best solution ever!!!
Enjoy the music!!!!!!!
PS
Next post will be on laser pick up, construction frame, vibration, RF signal, jitter error and some more
No comments:
Post a Comment