Detail Versus Musicality etc
I pretty much agree with Nuuk on this point. A good example is the difference between a CDR copy and the original CD, on first listen I actually thought the copy was better than the original, it seemed to be tighter and clearer with more detail.
After further listening I came to the conclusion that the copy loses a lot of the fullness, scale and ambience info - is fact it's basically lower resolution. The copy sounds more "digital". Interestingly, a CDR played through the Arcam sounds rather like the CD723 playing the original!!!
As another example: I used to be the dissapointed owner of a BMW 3 series. The CD changer in this car was virtually unused because it possessed a remarkable ability to present plenty of "detail" whilst being completely tuneless.
At the opposite extreme I confess to having owned a Linn system, this was very tuneful whilst presenting minimal detail. New or difficult music was easy to follow, however complex music lacked the interesting bits that keep you listening time after time. I nicknamed it the "nursery rhyme effect".
Nuuk - the CD2 does in fact use NE5534s or a 5532. However I don't agree this is a better part than the OPA627. In some systems I can believe NE553X could balance out imbalances elsewhere. I found a similar situation with Siemens stacked film polyester caps sounding better than Sonicaps in a coupling application, the more limited frequency extremes of the Siemens gave a better overall system sound until I improved some other areas (actually I stopped using Proac R2.5 clones with their overblown bass).
Back to the CD723 - the muting transistors will not be going back in the pcb!
Dave
I pretty much agree with Nuuk on this point. A good example is the difference between a CDR copy and the original CD, on first listen I actually thought the copy was better than the original, it seemed to be tighter and clearer with more detail.
After further listening I came to the conclusion that the copy loses a lot of the fullness, scale and ambience info - is fact it's basically lower resolution. The copy sounds more "digital". Interestingly, a CDR played through the Arcam sounds rather like the CD723 playing the original!!!
As another example: I used to be the dissapointed owner of a BMW 3 series. The CD changer in this car was virtually unused because it possessed a remarkable ability to present plenty of "detail" whilst being completely tuneless.
At the opposite extreme I confess to having owned a Linn system, this was very tuneful whilst presenting minimal detail. New or difficult music was easy to follow, however complex music lacked the interesting bits that keep you listening time after time. I nicknamed it the "nursery rhyme effect".
Nuuk - the CD2 does in fact use NE5534s or a 5532. However I don't agree this is a better part than the OPA627. In some systems I can believe NE553X could balance out imbalances elsewhere. I found a similar situation with Siemens stacked film polyester caps sounding better than Sonicaps in a coupling application, the more limited frequency extremes of the Siemens gave a better overall system sound until I improved some other areas (actually I stopped using Proac R2.5 clones with their overblown bass).
Back to the CD723 - the muting transistors will not be going back in the pcb!
Dave
Well, I think this is what successful hi-fi is all about. It's a bit like making something to eat and we need the right balance of ingedients.
Some may say that Christmas cake tastes better than plain bread but you wouldn't make a sandwich with cheese and Christmas cake (I hope)! 😉
That doesn't make bread better than Christmas cake or vice versa!
Just something I was thinking about:
Thorsten explained the conduction angle for the diodes, and said that (in this case 😉) the bigger the better. Because it causes less harmonics on the supply line.
Maybe that's an explanation for the gainclone's beloved sound, despite it's 100uF per rail.
Thorsten explained the conduction angle for the diodes, and said that (in this case 😉) the bigger the better. Because it causes less harmonics on the supply line.
Maybe that's an explanation for the gainclone's beloved sound, despite it's 100uF per rail.
Yes - a big thanks to KYW for the huge effort he has put into this thread. I have certainly learnt a lot here - especially about the power supplies.
Thanks to Dave too, for the excellent reports on progress so far, and everyone else who contributed.
I have heard comments that suggest that this will be one of the great reference threads for CDP mods. Even our debates (or arguements) on where to start (CDP, mechanism, DAC, etc) should be useful to some.
Thanks to Dave too, for the excellent reports on progress so far, and everyone else who contributed.
I have heard comments that suggest that this will be one of the great reference threads for CDP mods. Even our debates (or arguements) on where to start (CDP, mechanism, DAC, etc) should be useful to some.
c'est le ton qui fait la musique
Fin wrote:
I was surprised by the elegant communication. Even the inevitable intrusions which only degrade or disrupt a thread so often, were very rare, and subsequently dealt with definitely or just ignored.
A very good example, i think, of what another (old, but revived) thread which i just noticed, is all about.
Thanks, Fin, Dave, Bricolo and last but not least KYW, alias Thorsten, a patient guru... Chapeau.
best regards,
Lourens
Fin wrote:
IMHO this was an excellent thread indeed. Though i am a recent and not a very active member, limiting my reading mostly to this ‘digital forum’, i enjoyed it very much. Not only because I learned a lot.
I was surprised by the elegant communication. Even the inevitable intrusions which only degrade or disrupt a thread so often, were very rare, and subsequently dealt with definitely or just ignored.
A very good example, i think, of what another (old, but revived) thread which i just noticed, is all about. Thanks, Fin, Dave, Bricolo and last but not least KYW, alias Thorsten, a patient guru... Chapeau.
best regards,
Lourens
Hi Dave
Did you add the extra transformer, caps and regs for the servo or did you just improve the existing setup?
What specifically did you do to the 5V supply for the main CD processor?
Can you rate the various mods in order of the improvement each made?
Is there someone that have tried to add the OPA660 to a cd723? If so, have you followed Thorsten's suggestion how to implement OPA 660 with 1545 or have you worked out another way?
/Anders
/Anders
I added the extra transformer etc.
Added a separate transformer winding and LM317 with KYW's component values.
This may not be all that valuable to you because it depends on the sequence they are implemented in (see my notes in the next post about the DAC supply). When the CDP gets to a decent level of performance it is easier to hear the differences.
I believe that the DAC supply, op-amp supplies and transport 5V supplies are the most critical. I have not tried any different supplies for the TentClock, however in my Arcam the PSU for the clock made a big difference.
Cheers,
Dave
More Mods and subjective stuff
List of mods (slightly changed from earlier post):
1. Upgrade PSUs
a) +/- 15V for I/V stage
b) +5.4V for DAC (gives 4.9V on DAC after 100R/220uF filter)
c) +12V for Servos
d) +5V for VAM1201 signal processing
e) +5V for clock
2. Modify circuits
a) Fit Tent Clock
b) Adjust for 2mA FSC
c) Change o/p filter from CF to KYW circuit
d) Try AD812
e) Output null circuit to remove o/p caps (or maybe use BG caps and leave the offset (single ended class A?)
f) Removal of muting transistors (and maybe replace by relay)
3. Upgrade components
a) BG NX Hi-Q for Vref
b) Silmic decoupling caps for I/V
c) Silmic decoupling for DAC.
4. Mechanical Mods
Notes (not including those on my earlier post):
Removed output muting transistors (mod 2f). Seemed to reduce the mechanical sound to the music.
Removed the 10n Wima polyprop caps across the output cap (22uF 63V FC). This reduced sibilance a bit whilst giving a significant improvement in coherence and detail. Unexpectedly the bass was improved in tightness and tunefulness.
Remark: This is the first time the CD723 actually sounds “good” and is enjoyable to listen to!
3a Difficult to tell if SQ is better. Maybe a bit more resolution.
Other changes
Removed 1K resistors in series with H/P output (realised the H/P muting transistors were effective through these 1Ks).
Also added 10n Wima MKPs in parallel with FCs used to de-couple the RC4227 (intending to try the AD812 again).
This seems to have made a substantial improvement. Bass is more tuneful, voices have more body and sound more real. Overall smoother sound, the player is rather good now!
Changed output caps from 22uF 63V PanaFC to Solen 3.3uF (Mod 2e). This gave tighter more tuneful bass and general increase in resolution and reduction in grit. Really need to fit some Sonicaps to open up the sound properly.
Revisited 1b. The LM317 is definitely better – more scale and grip (and this player needs all the scale and grip it can get!). The sound is somewhat muted and boring with the on-board 7805.
Thought: PSU quality is critical for DAC, I/V and main processor. Need to improve these PSUs.
3c. Changed DAC PSU decoupling cap from 470uF 25V Pana FC to 100uF 50V Silmic (no 100R series resistor i.e. 5.4V on DAC). This reduced the upper mid hardness. The sound was more natural – faster but smoother – stummed acoustic guitar was less blurred and more musical. Bass became more tuneful.
3b. Encouraged by 3c, I changed the 220u 25V FCs (with 10n Wimas in parallel) for 100uF 50V Silmics. Similar effect – everything improved – creamy vocals, more resonant drums. In hindsight it is obvious FCs are rather lumpy and grainy sounding.
---------------------------------------------------------
Overall I am rather surprised by the magnitude of the improvement brought about by removal of (all 4) of the muting transistors and the superiority of the Silmics versus FCs for (mainly analogue) decoupling.
Question: I have a 5V Jung type superreg. Does anyone reckon this would be a good upgrade over the LM317 to power the DAC?
Cheers,
Dave
List of mods (slightly changed from earlier post):
1. Upgrade PSUs
a) +/- 15V for I/V stage
b) +5.4V for DAC (gives 4.9V on DAC after 100R/220uF filter)
c) +12V for Servos
d) +5V for VAM1201 signal processing
e) +5V for clock
2. Modify circuits
a) Fit Tent Clock
b) Adjust for 2mA FSC
c) Change o/p filter from CF to KYW circuit
d) Try AD812
e) Output null circuit to remove o/p caps (or maybe use BG caps and leave the offset (single ended class A?)
f) Removal of muting transistors (and maybe replace by relay)
3. Upgrade components
a) BG NX Hi-Q for Vref
b) Silmic decoupling caps for I/V
c) Silmic decoupling for DAC.
4. Mechanical Mods
Notes (not including those on my earlier post):
Removed output muting transistors (mod 2f). Seemed to reduce the mechanical sound to the music.
Removed the 10n Wima polyprop caps across the output cap (22uF 63V FC). This reduced sibilance a bit whilst giving a significant improvement in coherence and detail. Unexpectedly the bass was improved in tightness and tunefulness.
Remark: This is the first time the CD723 actually sounds “good” and is enjoyable to listen to!
3a Difficult to tell if SQ is better. Maybe a bit more resolution.
Other changes
Removed 1K resistors in series with H/P output (realised the H/P muting transistors were effective through these 1Ks).
Also added 10n Wima MKPs in parallel with FCs used to de-couple the RC4227 (intending to try the AD812 again).
This seems to have made a substantial improvement. Bass is more tuneful, voices have more body and sound more real. Overall smoother sound, the player is rather good now!
Changed output caps from 22uF 63V PanaFC to Solen 3.3uF (Mod 2e). This gave tighter more tuneful bass and general increase in resolution and reduction in grit. Really need to fit some Sonicaps to open up the sound properly.
Revisited 1b. The LM317 is definitely better – more scale and grip (and this player needs all the scale and grip it can get!). The sound is somewhat muted and boring with the on-board 7805.
Thought: PSU quality is critical for DAC, I/V and main processor. Need to improve these PSUs.
3c. Changed DAC PSU decoupling cap from 470uF 25V Pana FC to 100uF 50V Silmic (no 100R series resistor i.e. 5.4V on DAC). This reduced the upper mid hardness. The sound was more natural – faster but smoother – stummed acoustic guitar was less blurred and more musical. Bass became more tuneful.
3b. Encouraged by 3c, I changed the 220u 25V FCs (with 10n Wimas in parallel) for 100uF 50V Silmics. Similar effect – everything improved – creamy vocals, more resonant drums. In hindsight it is obvious FCs are rather lumpy and grainy sounding.
---------------------------------------------------------
Overall I am rather surprised by the magnitude of the improvement brought about by removal of (all 4) of the muting transistors and the superiority of the Silmics versus FCs for (mainly analogue) decoupling.
Question: I have a 5V Jung type superreg. Does anyone reckon this would be a good upgrade over the LM317 to power the DAC?
Cheers,
Dave
Re: More Mods and subjective stuff
Thanks for reporting your results Dave.
I'm still digesting most of it and trying to apply it to my application.
Did the removal of the muting transistors cause any negative side effects during normal use?
Clicking or popping while switching on or off doesn't matter as you can turn the volume down before hand.
Thanks for reporting your results Dave.
I'm still digesting most of it and trying to apply it to my application.
Did the removal of the muting transistors cause any negative side effects during normal use?
Clicking or popping while switching on or off doesn't matter as you can turn the volume down before hand.
What is the rest of your equipment
What is the rest of your equipment speakers, amplifiers, interconnect and so on. This with audio is very complex. For ex. before I didn’t need a transformer to separate the house electric from the equipment. Today something on the electrical net makes it necessary. I tested a new cd-player and then also needed new interconnect…. Then you have the room….
progg70
What is the rest of your equipment speakers, amplifiers, interconnect and so on. This with audio is very complex. For ex. before I didn’t need a transformer to separate the house electric from the equipment. Today something on the electrical net makes it necessary. I tested a new cd-player and then also needed new interconnect…. Then you have the room….
progg70
Scratch built Grounded Grid pre (with Sonicap output cap and Panasonic Pot)
AKSA 100N (dual mono, shorted input cap) or modified (sort of) AKSA 55 or P3A.
Interconnects - Connectronics Musiflex with Neutrik phonos
Speaker cable - CC Belden 25259 (ala John Risch)
Speakers - Dennis Murphy designed CAOW1 or Proac R2.5 clones.
No other negatives and it actually gets rid of the annoying click between tracks. The only concern is on power up or power down - not a concern for me as it's permanently powered and incase of mains failure the preamp will mute before the pop occurs.
General note: - all my comments are about RELATIVE sound quality i.e. the sound compared to what it was like before. To put this in perspective, last night I compared the CD723 to a Cambridge CD2 and the CD723 still falls quite a long way short of the CD2 performance. OTOH from my memory of comparing a CD2 to a Naim CD5i in a shop, I would not swop the CD723 for the Naim on SQ alone (obviously the Naim wins in every other respect).
Interestingly the slightly bland sound of the CD723 worked really well with the rather solid state sound of my P3A. The CD2/P3A combo actaully sounded worse and gave a rather tiring digital/solid state sort of sound. The CD2/modAKSA55 was by far the best combo. The implication here is that if I only owned the P3a I could come to the conclusion that the CD723 is better than the CD2. Only when playing through the CD2/modAKSA55 together does the superiority of both units become (clearly) apparent.
Dave
Hi
I have finally succeeded in implementing the OPA660 as an I/V stage. First I followed the suggested circuit from T using the OPA660 together with the TDA1545A, but somehow I could not get it to work properly. Then, as I am a lucky one that has my own hifi mentor, I asked him to help me out. After lots of thinking he came out with this circuit:
It is run from a separate PS. The 2K potentiometer should be adjusted so the voltage on pin 2 (not pin 3) equals the voltage at the DAC output pins. In my case it was 3.27 v
Now it sounds open, 3 dimensional and extremely beautiful
/Anders
I have finally succeeded in implementing the OPA660 as an I/V stage. First I followed the suggested circuit from T using the OPA660 together with the TDA1545A, but somehow I could not get it to work properly. Then, as I am a lucky one that has my own hifi mentor, I asked him to help me out. After lots of thinking he came out with this circuit:
An externally hosted image should be here but it was not working when we last tested it.
It is run from a separate PS. The 2K potentiometer should be adjusted so the voltage on pin 2 (not pin 3) equals the voltage at the DAC output pins. In my case it was 3.27 v
Now it sounds open, 3 dimensional and extremely beautiful
/Anders
Konnichiwa,
Hey! Great stuff. Sorry i could not be of more help, but I'm really stretched for time.
Shame the OPA660 will be discontinued soon....
Sayonara
secanbj said:
Hey! Great stuff. Sorry i could not be of more help, but I'm really stretched for time.
Shame the OPA660 will be discontinued soon....
Sayonara
Clock Regulator etc
I changed from the recommended Tent regulator (after fixing the resistor values) to a Trichord clock 4 regulator (similar to Jung superreg) for the Tent XO supply. The Trichord reg is noticeably better.
Unfortunately I don't have a Trichord XO to compare to the Tent, as I think this would be an interesting comparison.
I would really like to try the OPA660 I/V. Does anyone know where to get them (DIL version) in the UK?
Dave
I changed from the recommended Tent regulator (after fixing the resistor values) to a Trichord clock 4 regulator (similar to Jung superreg) for the Tent XO supply. The Trichord reg is noticeably better.
Unfortunately I don't have a Trichord XO to compare to the Tent, as I think this would be an interesting comparison.
I would really like to try the OPA660 I/V. Does anyone know where to get them (DIL version) in the UK?
Dave
Now I've got one too.............
Perserverance has paid off! Finally found something decent for sale at a reasonable price - got a Marantz CD60 on eBay Australia for AUD$72 = 42 Euro = 30 Pounds. So now I have a good basis for comparisson with the Philips CD624.
CD624:- CDM4/19, SAA7310, SAA7321 (Bitstream)
CD60 :- CDM4/19, SAA7310, SAA7220, TDA1541A
Scientifically, this should be an interesting experiment as both machines are almost identical apart from the filter and DAC.
Kuei Yang Wang said:
Perserverance has paid off! Finally found something decent for sale at a reasonable price - got a Marantz CD60 on eBay Australia for AUD$72 = 42 Euro = 30 Pounds. So now I have a good basis for comparisson with the Philips CD624.
CD624:- CDM4/19, SAA7310, SAA7321 (Bitstream)
CD60 :- CDM4/19, SAA7310, SAA7220, TDA1541A
Scientifically, this should be an interesting experiment as both machines are almost identical apart from the filter and DAC.
I'd like to change my 7805 regulator to LM317 as it seems to be a cheap but possibly an efective mod. What things I have to concider if I do this (Do I have to modify the original configuration)? I tried to figure this out by myself reading the data sheet, but I didn't understand much from it.
I also wan't to change the diodes from PS but I can't figure out which diode type is the best. Are there really noticeable differences between good schottky diodes.
My player is Sony DVP NS900
I also wan't to change the diodes from PS but I can't figure out which diode type is the best. Are there really noticeable differences between good schottky diodes.
My player is Sony DVP NS900
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