It plays with 150R, it was a little low, It could benefit from 200R, ill take some THD tests...
At first I was like what is this? sounded thin and high frequency missing, then after a few minutes you get used to it. It is a very relaxed sound and it has quite definition, just maybe lacking the impulse.
At first I was like what is this? sounded thin and high frequency missing, then after a few minutes you get used to it. It is a very relaxed sound and it has quite definition, just maybe lacking the impulse.
Haha I took measurements and the noise is somewhere between -150 to 130db haha and the signal at max is so low, -120db !!!
I was listening with 10db range, so yeah, once again the passive IV is not my type of sound/ better leave it for others. It was entertaining to hear what the dac sounds like in the top level registers only, OK.
I would need maybe a 2k resistor to get some dynamic range then maybe THD will be high.
I only needed 200R i/V for driving headphones to good levels!.
I was listening with 10db range, so yeah, once again the passive IV is not my type of sound/ better leave it for others. It was entertaining to hear what the dac sounds like in the top level registers only, OK.
I would need maybe a 2k resistor to get some dynamic range then maybe THD will be high.
I only needed 200R i/V for driving headphones to good levels!.
I find that the opamp even if on paper they are able to drive headphones, there is something missing a lot there.
I listened with a modern dac and it blew up, opamp dirrectly is now out of possibilities.
I listen directly to akm dac through 200uf film caps... directly to white cathode follower. Through headphones it is way more enjoyable than my new pcm58...
I listened with a modern dac and it blew up, opamp dirrectly is now out of possibilities.
I listen directly to akm dac through 200uf film caps... directly to white cathode follower. Through headphones it is way more enjoyable than my new pcm58...
It is all something you can only do through trial and error to see what sort of levels you need. Looks like tit might be a workable option though.
oops I mean it bloomed out 😉 the sound of the opamp is constricted.
I'll change the 100R to 15R, maybe this is impeding the sound.
For level I need only a few uV , I measured it.
I'll change the 100R to 15R, maybe this is impeding the sound.
For level I need only a few uV , I measured it.
I did the modifications, the 10K removed some POP on start up that now is a little.
I think it was a change in the right decision/direction!... 1.6K feedback resistor... 15R output Z resistor fixed, and 10K to ground removed, as well as the cap.
I should stop modifying this dac and keep it AS-IS because I have another version already heavily modified, the filter is changed, regulator and most of the power supply...
I think it was a change in the right decision/direction!... 1.6K feedback resistor... 15R output Z resistor fixed, and 10K to ground removed, as well as the cap.
I should stop modifying this dac and keep it AS-IS because I have another version already heavily modified, the filter is changed, regulator and most of the power supply...
I was looking at the wrong channel haha, we will never know how good the resistor IV was!
As of today reference pcm58 dac: 97.7db 2nd THD , 0Vdb
at -60vdb : 2n -66db . 3d: -63 db
That is very very good... (the other channel can't get be adjusted as much, -103.4db, , and -51db)
at 20khz, there is a little bit of thd -85db at 28khz, , -88.3db 2nd...
Multiple signals dynamic range seems to diminish in the order of 70db, usually they are in the 90db to 100db.
With 150R, seriously I wanted to know as much as anyone how the THD was, I could no reach same levels:
-90db (noise floor is) at -20.64db, I could not see much the THD from the noise, at this level the dac is at 100% power.
at -80db (-20 to which I substracted the max volume) it was getting into the noise of my analyzer, I could no see any THD, so it was better than 50db, my resolution is around -140-130
All digital garbage is still there but it lost exactly 20.64db of amplification, it was obvious on the graphics. I assumed a reduction or difference in dynamics, none. This is very strange because they both sound very different!!! Visual check on Mono=identical...
Actually the I/V resistor is better... maybe 200R is ideal, 150 on the lowest side. Reality is stranger than fiction.
at -60vdb : 2n -66db . 3d: -63 db
That is very very good... (the other channel can't get be adjusted as much, -103.4db, , and -51db)
at 20khz, there is a little bit of thd -85db at 28khz, , -88.3db 2nd...
Multiple signals dynamic range seems to diminish in the order of 70db, usually they are in the 90db to 100db.
With 150R, seriously I wanted to know as much as anyone how the THD was, I could no reach same levels:
-90db (noise floor is) at -20.64db, I could not see much the THD from the noise, at this level the dac is at 100% power.
at -80db (-20 to which I substracted the max volume) it was getting into the noise of my analyzer, I could no see any THD, so it was better than 50db, my resolution is around -140-130
All digital garbage is still there but it lost exactly 20.64db of amplification, it was obvious on the graphics. I assumed a reduction or difference in dynamics, none. This is very strange because they both sound very different!!! Visual check on Mono=identical...
Actually the I/V resistor is better... maybe 200R is ideal, 150 on the lowest side. Reality is stranger than fiction.
When you make changes to something you really need to listen for a long period I find, and to be sure if there are real differences. Even if they sound 'different' it can then be hard to say if one is better than the other or not.
Sounds like you are having fun anyway 🙂
Sounds like you are having fun anyway 🙂
A lot! I learned especially about DAC design, I read everything I could find.
It is very interesting that one can characterize the sound of the dac simply by its type of architecture / pipeline processes.
The types of capacitors and transistor technology changed dramatically the sound character of the chips.
Breakdown voltages of transistors used, CMOS etc.
DEM are used as well for capacitor switching , CS4397... which has an attractive sound special.
PCM63 and others more recent use // or segmented dacs to reduce errors by simplification of the R2R units.
The SMLS dacs use all the channels of the Sabre and sums it up. And it technically works like little ants pushing a bigger rock/picture.
Could this segmentation and capacitor low pass output explain the preference for the latest ad1862? (https://ispg.ucsd.edu/wordpress/wp-...h-Resolution-Digital-to-Analog-Conversion.pdf)
I checked a lot screenshots of real music samples going into spectroscopes, and usually you need 40-50db and another 40db of noise floor and it can be considered 'perfect'. As the music itself is seldom jumping out of this range.
The new types of regulators and new surrounding chips now common for hifi designs were not available back in the days of first dacs...
After all the end goal is to transcribe human emotions. What does it the most? a photo chamber black and white or looking at a high resolution screen? It is highly psychological.
It is very interesting that one can characterize the sound of the dac simply by its type of architecture / pipeline processes.
The types of capacitors and transistor technology changed dramatically the sound character of the chips.
Breakdown voltages of transistors used, CMOS etc.
DEM are used as well for capacitor switching , CS4397... which has an attractive sound special.
PCM63 and others more recent use // or segmented dacs to reduce errors by simplification of the R2R units.
The SMLS dacs use all the channels of the Sabre and sums it up. And it technically works like little ants pushing a bigger rock/picture.
Could this segmentation and capacitor low pass output explain the preference for the latest ad1862? (https://ispg.ucsd.edu/wordpress/wp-...h-Resolution-Digital-to-Analog-Conversion.pdf)
I checked a lot screenshots of real music samples going into spectroscopes, and usually you need 40-50db and another 40db of noise floor and it can be considered 'perfect'. As the music itself is seldom jumping out of this range.
The new types of regulators and new surrounding chips now common for hifi designs were not available back in the days of first dacs...
After all the end goal is to transcribe human emotions. What does it the most? a photo chamber black and white or looking at a high resolution screen? It is highly psychological.
I replaced opamps again! On some songs that I know very well it was lacking what I am used to hear.
The i/v is less imperfect than the opamp...
I found the ad8597 very fatiguing after the resistor i/v ... so back again the vintages NE5532...
Tomorrow I am experimenting with my totally modified dac... I can't wait for either nothing... or disaster or deception , it could be a mix.
The i/v is less imperfect than the opamp...
I found the ad8597 very fatiguing after the resistor i/v ... so back again the vintages NE5532...
Tomorrow I am experimenting with my totally modified dac... I can't wait for either nothing... or disaster or deception , it could be a mix.
This can be an issue with opamp swapping in I/V and filter situations:
I checked that, everything is liquid!
ad8597 used to be my favorite on the CS4397, a fabulous dac which one can listen all day due to the thin sound, black background.
ad8597 used to be my favorite on the CS4397, a fabulous dac which one can listen all day due to the thin sound, black background.
It's good! I can't see any anomalies with my equipment.
Mooly I will receive the regulators from NewClassD today and get to spin that (**) dac which was a () () (**) (***) to modify, I was going almost crazy!
Mooly I will receive the regulators from NewClassD today and get to spin that (**) dac which was a () () (**) (***) to modify, I was going almost crazy!
I just did a last listening test vs AK4396.. it is not a bad dac, I listened to Magical Flute, it is laid back, gives some realism, quite detailed, etc. As soon as it gets more complex the AK lose it's smoothness and just makes some noises.
But the pcm58 just grabs you in with everything so blunt and no signs of stress when suddenly there is a fast crescendo with many instruments jumping in, it has the edge on accuracy to hear all German pronunciations clearly, it gives maybe 30% more detail around sounds. It just grabs your ear but not in a hifi sense, you just have a lot of information which is quite simplified in the AK dac...
But the pcm58 just grabs you in with everything so blunt and no signs of stress when suddenly there is a fast crescendo with many instruments jumping in, it has the edge on accuracy to hear all German pronunciations clearly, it gives maybe 30% more detail around sounds. It just grabs your ear but not in a hifi sense, you just have a lot of information which is quite simplified in the AK dac...
I listened to its a beautiful life, it has quite dynamics and gives a vibe of the system, there are 2 background voices at the end as well as not so easy to render main voice.
In the AK : everything is more blended and very Boom Boom, The voice has a lot of weight and it sounds exciting, the bass line is smooth and everything has detail...
In the PCM58, I noted the lack of aggressiveness, the sound effects are more pronounced and casted in their own, it hits a lot harder and is more musical.
The boom boom is replaced by a layer of distinct beats and sounds all layered and separated, sounds more extended in the high frequency and less boomy!
On good material, both dacs are incredible in terms of atmosphere but the PCM is just incredible... listening to good electronic music, streets of rage, scorpions wings of change. it is just perfect, I have nothing to add.
In the AK : everything is more blended and very Boom Boom, The voice has a lot of weight and it sounds exciting, the bass line is smooth and everything has detail...
In the PCM58, I noted the lack of aggressiveness, the sound effects are more pronounced and casted in their own, it hits a lot harder and is more musical.
The boom boom is replaced by a layer of distinct beats and sounds all layered and separated, sounds more extended in the high frequency and less boomy!
On good material, both dacs are incredible in terms of atmosphere but the PCM is just incredible... listening to good electronic music, streets of rage, scorpions wings of change. it is just perfect, I have nothing to add.