June 30, 2020

On Image Height

Largely based on a true story again.

Our group of audiophiles continue to have on-line discussions on topics peculiar to our hobby.

This time, the discussion turned to Image Height, which refers to how high up from the ground that the sound sources of the singer and the various musical instruments are perceived to be emanating from within the sound-stage.

This is a performance characteristic that many audiophiles hold very dearly to. Many even take it as a make-or-break item in the capability of a hi-fi system. An image height that is deemed too low may elicit a total write-off of the entire system, all other audio performance criteria be damned!

Usually, the position of "the mouth of the singer" is used as the reference point. As such, solo vocal tracks are commonly used to gauge image height.

The discussion went thus:

A: "What should be the image height from a hi-fi system? How high is considered correct?"

B: "I asked a sifu once, he said it should be the same height as our line of sight. Slightly higher is ok too."

C: "I like my image height to be the rough height of a person's mouth while standing up."

D: "Image height is the result of the interaction between the left and right speakers, this interaction also causes the variation in height. The correct height should be around 5ft /1.5m. If the height is wrong then there is something uneven with the energy distribution within the audio frequency spectrum.

B: "There are actually a variety of height possibilities:

The artist can be performing standing up,

she can be sitting on a tall stool.

or sitting down on a chair.

But one thing I am sure though, no audiophile likes an image height as if the singer is lying on the floor! ๐Ÿ˜"

E: "There is one more position, very comfortable, called the 'Ge-You Slouch' ่‘›ไผ˜่บบ! ๐Ÿ˜"
(note: Ge-You is a popular character actor from China)

A: "No lah! we are talking about the posture of the singer, not the listener lah."

B:"In my opinion, there could be 2 possibilities to the image height phenomenon.

If image height is purely an effect or the result of the interaction between the loudspeakers and the listening space, then our "system tuning" will determine the image height from our system, in our room, for all recordings, since this interaction is independent of the recording itself. That is, we'll get a consistent image height in our listening room.

However, if image height is part of the information encoded in the recording, then we should hear image height variations from a variety of recordings, from different labels, genre, era etc, as the condition or circumstances under which each recording was made would be different.

I don't know which one is correct, but I suspect the truth is somewhere in-between these 2 extremes. I have heard different system and room tuning influencing the perception of image height. I have also experienced hearing varying heights from one same system when playing different recordings. The latter, in my opinion, signifies a highly resolved and highly transparent system."

A:"Is there such a thing as an image height that is too tall?

F: "No lah! Depends on personal taste, who knows, an audiophile may like a front row seat like this....

The End. ๐Ÿ˜‰

June 27, 2020

Our Shiok Sendiri Space!

It was never in doubt that our little blog revival would do well, despite only registering a few post a month, a far, far cry from our past posting records. As our readership rises, with almost non-existent fanfare, we somehow started to get calls from hifi dealers. They noticed! Which is always a good sign of our influence in thoughts.

We have been offered to do reviews of hifi cables & equipment, invited to attend events, request for preview write ups, even offers to pay for advertising. All those things we previously did for the sake of helping to promote the hifi & AV industry. I have so far turned downed all those request & offers. As some of the more keen eyed readers have asked me last week, "I noticed the rebooted HiFi-Unlimited has no advertising panels, unlike previously, what happened?" My reply to this reader would be the same as all those dealers who contacted me. I have agreed with Tan, my long time partner in crime, that this blog would now serve more like our personal space of hifi & AV related expression, yes a personal space for us to SKL(Sin Ka Lan). When we decided on the reboot, we agreed there would be very little room for commercialism here in these pages, unless it's a specific product that we are really curious about, or maybe a very dear hifi cause that is close to our hearts.

Even if we agreed to do "that very specific product review", there are terms & conditions:
1) There must be no deadlines, but we promise not to take much longer than we need to complete the said review.
2) It must be delivered to us for the review & pick up from us after we are finished, we do not collect or send back like before.
3) There will be no guarantees that it will be a favorable review. We will publish our un-censored thoughts about the subject matter, without prior consultation what so ever. In other words, it will be a total surprise!
4) We promise not to ask for review fee or solicit for advertisement or sponsorship of any kind!

Now I want to see how many hifi dealers are up for this challenge!

And then, a funny thing recently happened is that a new reader who was recommended by his friend to read this blog sent me a Whatsapp message, questioning what qualifies me to review equipment and other people's system? My answer is simple, I replied to him to read the articles in this blog from it's very inception, which will take some time, but if he'd do that, he'd understand where we come from, and what we are about. A few days later, I got another message from this same chap, offering me to review his system. I declined but offered to buy him a cuppa instead. We met at a coffee shop spoke for a couple of hours about hifi instead. I have new hifi buddy now....................

Sometimes the weirdest things happens when our readers interact with us. In the mean time, we will just Keep Calm & Shiok Sendiri!

June 21, 2020

SOTA 1989, Accuphase DP-70V CD Player

It was some time during the summer of 2018, I was in Hong Kong, had the weekend there to myself after a few days of work. The idle mind became the devil's workshop. I was't really in to hifi at that stage, being very contended to be away from the scene. But somehow, there was 48 hours of idle time to amuse my self, and began wandering around the electronics retail areas of Mongkok & Sham Shui Po.

There are 3 specific areas of hifi retail in Hong Kong. For the newest and most mighty all hi-end scene, there is always the snooty Admiralty & Central area. For the good mix of mid range & used hi-end stuff, there is always Mongkok area, while you're there check out the great local cafes & street food stall there too! As for Sham Sui Po, there is always a place for antiques, collectors of any sort, and generally old, & unwanted curiosities, hifi included.  

In Sham Sui Po, Ap Liu Street specifically is where my curiosity with Accuphase CD players started! Talk about contrasting lifestyle, shopping for hi-end at low brow, go figure!..................... There are a few shops in Ap Liu Street, specializing in either almost junk or collectible hifi, which are stacked from floor to ceiling. It's quite a place to behold. The shopping experience is not very pleasant to say the least. No auditioning is the rule, a request to audition tells the shop owner you're a time waster, a tire kicker so to speak, he will tell you to go buy from somewhere else. You gotta know your stuff when hifi shopping here, the only thing they will allow is a functional test after you're committed to purchase! 

It's inside one of those dinky little shops along Ap Liu Street that I came across some shiny, Champaign gold, super well built Accuphase amplifiers & CD Players. One that caught my eye was the Accuphase DP-70. If you're unsure....... Yes, Accuphase has 2 DP-70 models, one with a V and one without! I believe the DP-70 came first, followed by the face-lifted model with the V! Both look very similar, except for the button arrangements on the right side of the fascia, and the easiest differentiating feature is the display. The DP-70 sports a red LED display, while the DP-70V comes with a florescent green display, the only one to do so, since the first of all disc players from Accuphase till now! Nearly all Accuphase DP series CD players comes with either red LED or orange florescent displays.

The beauty & simplicity of Accuphase DP-70V CD player with only 4 control buttons on the right side of the front fascia. All other buttons hidden inside the bottom fold able flap.
I was smitten by that Accuphase DP-70 CD player, something about CD player designs from that late 80's till late 90's era always grabs my attention, just like all Bruno Sacco era designed Benz automobiles. However, like I said, I was as far away from the hifi scene as possible, and I didn't like the idea of lugging a 20kg plus box from Hong Kong to Kuala Lumpur. So I let it go and left things to fate.

By spring 2019, having forgotten about the whole episode in Hong Kong, my dear sifu asked me to check out the Accuphase DP-950 & DC-950 transport & DAC combo for him in Akihabara, as I had a weekend to my self in Tokyo! And so I spent the whole day walking around Akihabara hifi stores gawking at Accuphase gears. I wondered what was so good about the Accuphase CD players that got my dear sifu to want to check them out? Yeah! sure, we've heard a few Accuphase CD during our hifi crazy days, I think if you looked in to our home visit pages, you may even spot some systems with Accuphase CD players there. However, at that time, somehow we never given it much thought.  Ya, in case you're wondering, my dear sifu eventually got his dream digital set up. I said dream......... only because it cost more than six figures in price tag! And what a lovely sounding CD transport & DAC combo that is......... right up there, and maybe even better than some of the best CD players I have ever heard!
My unit of the Accuphase DP-70V, some say the early version without the V sound warmer, thus better. I have not compared, so can't confirm how that is! 
As fate would have it, sometime in late 2019, the Good(hifi) Doctor, Oh have one Accuphase DP-70V in his hands to let go. And this time, I took thing more seriously, I went for and audition, yes I can confirm the Accuphase DP-70V sounds very good indeed, but better sounding than my Sony CDP X-7ESD? Hard to say, but the price was tempting, and off went the silver bullet!

Now mine, the State Of The 1989 Art Accuphase DP-70V is 21kgs heavy, built up to Yamato battleship standards and finished in the classic Japanese Champaign gold with glossed wood cheeks. The CD player also come with XLR output besides RCA, among other digital inputs & outputs. In general, I do not buy hifi that does not have XLR connections. Most Accuphase disc players uses Sony transport mechanism, and it's no surprise that this one is using the KSS-190A with the BU-1C or 1D laser head combo. So I already have a standby Sony KSS-190A for either of my CD players should the need arises, how convenient!

On the DAC side is a pair of 20 bit chip set, implemented R to R style, mated with 8 times over sampling filter completes the picture. That's state of the art multi bit chip set implementation, all the way to the 1998 swan song, the Marantz CD-7 which I previously owned.  if I seemed to go round & round back to this golden era of CD players, so be it!

I have a belief that the 1st generation of CD players were designed to overcome technical limitations with focus on functionality & reliability. 2nd generation CD players like the Sony CDP X-7ESD & this Accuphase DP-70V, sports some major technical advancement over their predecessors and were designed with more sound performance improvement in mind. Early CD player developments were bench-marked against the best turn tables of the time, sound wise. From the 90's on wards, CD player developments started to bench-marked against previous top CD players for sound. I think this is where the first mis-steps of Digital players start to deviate from analog bench-marking. It is my speculation about why newer, more technologically advance digital designs start to sound more digitized, more details, lower noise floor but yet at the same time, less natural sounding, compared to the early multi bit CD players, which tends to sound more analog, more life like even!
A look at the front, back & top of the Accuphase DP-70V, note the opened flap at the front bottom panel.
The Accuphase DV-70V follows the sonic signature of the Accuphase sound, very detailed, yet presented in a very organic and slightly rose hued tinted fashion. Compared to my Sony CDP, the Accuphase had very delicately voiced sound, much like the late Ken Ishiwata curated sound of the Marantz CD-7. Some of my buddies have a disdain for Accuphase hifi gear for this very reason. I don't, in fact I find this kinda sound very easily acceptable, and if synergistic with the rest of the system, can be the basis a great sounding system!

I am glad I picked up this gem of a CD player in my lifetime for a fraction of it's original retail price of USD 10,000 a pop! It's a few twist of fate all rolled in to one fine ending. So with this I decided to keep 2 CD players of classic late 80's vintage in my system. 

June 16, 2020

On Tonal Colour

Largely based on a true story.

A bunch of audiophile buddies met online during this stay-at-home period, and the topic turned to Tonal Colour.

That is, the different tonal colours produced by different hi-fi systems - that which gives each system its own distinctive sound/tone/character/presentation when playing the same piece of music from the same recording (the Chinese audiophiles among us refer to it as '้Ÿณ่‰ฒ' or in Cantonese 'yam sek'). Note that we are not talking about the tonal colour of musical instruments here, which allows the listener to recognize what type of musical instrument it is.

I have heard a system's tonal colour described variously as golden hued, warm, cool, icy cold, saturated, light, washed out (and also the dreaded 'neutral', which some take it to imply blandness/emotionless๐Ÿ˜‰, though to me true neutrality is a positive thing) etc..

The discussion went thus:

A: "Is there such a thing as a 'correct' tonal colour, which implies also then that there are wrong ones? Or that tonal colour is a matter of the owner's personal taste, i.e., it is about what I like or dislike?"

B: "I take it as a visceral matter, a matter of the heart. There is no standard, everyone can have a different taste, no right or wrong. Beauty is in the eyes of the beholder."

C: "As long as the portrayal of musical instruments is still distinguishable, then it should be ok, I feel that if an audiophile emphasizes on tuning his system to a tonal colour that he likes, he may stray onto the wrong path. He will get an imbalanced sound. Like, every recording sounds warm, or voluptuous or whatever..."

B: "As long as the system has good balance, tuning the tonal colour is a sprinkling of flavour on top, it is personal taste."

D: "Let's use photos as an analogy. Look at these photos then, their colour balance is equivalent to a hi-fi system's tonal colour.

Which one is right? Which one is wrong? Or there is no right or wrong, just which one you think is the most beautiful in your eyes?"

E: "Looks like A was taken at 7 o'clock in the morning; B at noon time; C at 7pm. I think the colour in every photo is skewed somewhat."

D: "Well, the same photo can be made to look like it was taken at 7am, 12 noon or 7pm. However, the photo must have been taken at one specific time! The 'true picture' can only be revealed if the camera that captured the image and the subsequent production of that image do not involve an iota of alteration.

The camera is analogous to the recording process, the image production is our hi-fi system's replay.

The recording process is in the past tense already, an audiophile can no longer control/influence it but to accept the recording, in whatever media, as it is. What we can control is the choice of our hi-fi equipment and system tuning for the replay. If you want to replay the recording as faithfully as possible, then you'd look to build a system that does not alter (much of) anything - this, to me, is what our hi-fi hobby, as in High Fidelity, means."

F: "I understand now. Whatever the cook serves us, we just eat it, without adding any additional salt, sauce, or MSG, right? LOL!"

D: "What about this photo then? Does anyone think it is 'wrong'?"

E: "The colour is over-saturated leh."

G:"All this intellectual discussion is well and good. I think a system is to serve its master ultimately. So as long as I enjoy what I hear from MY system, then it is good enough for ME, any other hi-fi description is irrelevant!"

All: " Hear! Hear!"

The End. ๐Ÿ˜Š

June 8, 2020

CD Transport Replacement, Sony CDP-X7 ESD

As mentioned in my previous introduction of the Sony CDP-X7 ESD, I had suspected the CD mechanism & laser head was at the end of it's long 29 years service life since new! The symptoms were there, the long disc loading times, some disc unable to detect TOC, or some disc won't either play at the first or last track, and most of all, if I had to skip or reverse a track, it will take a long time to cue, then play. I was looking around for a replacement KSS-190A CD mechanism if I could. I didn't just want to replace the BU-1D laser head only. Yeah...... you can say I like my spare tire!

Found a brand new NOS unit in eBay, to be shipped from Germany, but they wanted some thing like close to 700 Euros and shipping cost have not been factored in yet! I had to turn to my next most trusty source, my sourcing buddy in China. If it's made or available in China, this guy will find it!

And found me a whole KSS-190A unit he did! Bless him..... It's a refurbish unit, come with a test video of the mechanism sent via Wechat too! 2 weeks after that, I got my package from the courier and my replacement project can commence.

Here is a step by step pictorial guide with caption to help someone if any one wants to embark on a similar exercise.   
As mentioned, the Sony is very well built, and like the Marantz CD7 I rescued from the past, one needs to remove the top & bottom cover to access the CD mechanism, and everything inside! The CD mechanism is best accessed from the bottom but some action needs to be approached from the top too! Here you see the Sony up side down, awaiting surgery!

Before the KSS-190A mechanism can be removed, we first need to dislodge the CD puck holder from the top, pull the tray out, then turn the unit back to up side down position.

A close up of the full aluminium die cast CD tray. Very few CD players of today will use this very expensive way to make a CD tray. It's mostly made from plastics of varying quality.

Next the cable loom running thru just beneath the CD transport needs to be unclipped for easy access & removal. Note the 4 springs on each corner of the KSS-190A CD transport! Just like the Philips CD Pro on my previous Marantz CD7! 

The springs do provide the CD transport some degree of suspension from external vibrations.

Now we remove the main ribbon cable for signal, clipped with the white plastic finished locking cover.

Due to age, the handling of this ribbon cable is delicate to say the least!

With the original CD transport out from the Sony, can you spot the new vs the original? Neither could we! What, you think that I would be crazy enough to attend to something like this on my own??? Like I always do, I consulted Wong sifu! 

We couldn't spot the diference between the out going and incoming KSS-190A, until we found this little dot of solder which acts like a shorting plug for transport! The little solder dot needs to be removed before plugging in to the Sony. You'll need a heat controlled solder gun, and very steady hands for this job. Too much heat or too slow hand motion and the ribbon cable melts along with the solder lead! I left this step to capable hands of Wong sifu!

With the ribbon cable prep step done, the replacement CD transport in re-inserted back to it's proper place, be mind full of the cable loom running just over the transport, carefully aligning the cables back in to the white plastic twist clip to hold it in place.

Now it's done, that's how tidy things should be when doing cable management! While working on the CD transport, we also took the opportunity to replace the CD tray drive belts, by removing the little Mabuchi motor and cover assembly on the top right of the picture. Sony's attention to details is that they even cover all moving parts with a stamped steel cover, with the belt & transfer gear vaguely visible on the top right of the picture.

Note the super thick sliding rails on which the BU-1D laser head assembly sits on! The degree of over engineering evident here is astounding! Also note the green coated spring on the bottom left of picture, the other 3 springs are just plain finished, not sure why, but some thing to keep in mind in order to replace in the same position after removal. Also note the transport locking screw just above the green coated spring! be sure to unlock the screw after installation, otherwise the transport won't work during testing, and we found out the hard way!

Speaking of the CD tray belt change, the esteemed Mr Oh supplied me the necessary rubber belts. Bless the man & his treasure chest of audio spares! The small belt is the one you saw on the picture above. The bigger belt is buried much deeper inside the CD transport. 

Now that the CD transport replacement work almost complete, it's time to turn the Sony right side up and run some test. First, the CD tray in/out test, checked & super smooth! 

And now for the CD test, using my favorite CD, Pink Floyd's Dark Side Of The Moon!

Great results, TOC detected, the CD plays well, skip & reverse tracks work fast and paused checked!

With one final naked shot, see the twin XLR output trannies towards the back of the player? Sony never did balance audio signal on any CD player like this anymore! Just too expensive now days...... We proceed to close both the top and bottom covers and call it a day!

Withe replacement a success, it's back to enjoying the music. It took almost 200 hours or so for the refurbished CD transport to run in and start to sound good somehow. May be I am experiencing psycho acoustics  again???

With that I had successfully resurrected another flagship CD player from the dead, and living in today's throw away world, it felt really good to preserve a historic milestone of Sony in it's golden era. Sony today is never the same greatness in commitment to hifi quality again. I sent my dead KSS-190A CD mechanism back to my buddy for refurbishment, waited about 2 months, and finally my original KSS-190A unit came back as my back up transport. I plan to keep this Sony CDP-X7 ESD in service for as long as I could.

I love the sound quality of the Sony. It had a warmish tonal balance, compared to today's high resolution, strictly neutral tonal balance. I would say the Sony does not suffer in terms of resolution, but rather presents it without that fake glare, over detailed feeling of today's player. In contrast the Sony sounds soothing, with an tint of rose hued tonal balance, and what I love the most about it, that bad ass fat bass lines. This player can really rock and plays pop recordings really well....... so well in fact, that when compared to another player from the same golden era costing at least 3 times the price when new, the Sony gives away little in terms of sound quality. The more expensive equipment may sound different, but it's really not much better either! Yes, it's a Sony & it's as good as strolling down memory lane 1988 gets.

June 5, 2020

Nothing Like It Again, Ever! Sony CDP-X7 ESD

Sony CDP-X7 ESD, what a mouthful..... Marantz marketing team is much smarter in terms of  product names.

Here we have a 2nd generation of Sony flagship X7 ES series CD players, launched without much fan fare in 1988. I am not sure of the logic behind the number 7 as flagship naming scheme for Japanese hifi manufacturers, but Sony, and my very own former Marantz CD7 is proof in point. All of Sony's flagship disc players leading up to year 2000, or Y2K Sony SCD1 SACD player, had the familiar X7 ES in various guises for nomenclature as name sake.

In 1988 Sony launched the limited edition of CDP-R1 & DAS-R1, a state of the art 2 box transport & DAC combo to an astonished world. Then towards the later part of the year, when the 2 box flagship combo was at the end of it's run, the CDP-X7ESD came about quietly, with a launch pricing of USD2500 per unit. Sony applied all their digital knowledge from the 2 box flagship in a simplified form, single box solution. Then added a twist in the form of a pair of coupling transformer output for the XLR analog signal, just like some traditional MC phono stage output design! Truly inspiring Sony........
The internal build quality is first rate, this was the time Sony believed in making things last a life time, and giving their best! Just a few years later, with the demise of Akio Morita, founder of Sony, the bean counters ran wild & took control of the company and Sony's fortunes headed south, slowly but surely.

On the technical side, this CDP came with then flagship KSS-190A CD mechanism and BU-1D laser tracking head combo, which are now extremely hard to find, and worth it's weight in gold if you do find one for sale! On the DAC side, a pair of 18 bit Burr Brown PCM53 is used in balance, dual mono configuration, with 8 times oversampling filter giving a claimed 45 bit resolution(honestly, I am not sure how the math works). The balanced XLR output is very special and rare among CD players, and I believe it was never repeated in any other designs, Sony or otherwise. The RCA output was of normal FET circuit design. So to hear this Sony at it's best sound performance, use the XLR output with balanced cables to pre amp is mandated. I know & read many reviews or audiophiles commenting about this player's performance without checking out the XLR output, which would've entirely mis-represent what this Sony is all about, sound wise........

The Sony KSS-190A CD transport, built in the same mold as Philips CD Pro transport.
The KSS-190A, when stripped off it's metal casing reveals that it's even better built than the Philip CD Pro, with thicker tracking alignment rails, encased laser read head, and heavier built CD puck.

The build quality is a reflection of the WWII era Japanese Naval architect philosophy in line with Yamato class battleship standards! Double layer and in some cases triple layers copper chassis with beam & frame design for maximum rigidity was employed, resulting in it's 18kgs of heft. The off centered CD transport is something that later X7 series designs will gradually be moved to centralized position within the chassis. On the left side is 2 potted power supply tranny for analog & digital requirements. Lots of over sized reservoir capacitors post rectifier stage for storage capacity. The capacitors are all dampened for sound tuning. I tried removing and putting on the dampening hard rubber rings again a few times, and the CD player does sound somewhat different with or without them. Those damn things do work, for better or worst!

On the right side of the CD transport is where all the DAC and analog output circuit resides, including those coupling output transformers mentioned earlier for the XLR signal. Talking about the CD transport, how many CD players have acoustically sealed(a rubber band around the chassis opening for the tray dampens the CD tray from vibrations of any kind) die cast metal CD tray sliding in & out? Ahem......

Even the 4 footers at the bottom of the chassis are the real McCoy, made from potted high density ceramic, and each feet does weight a few hundred grams on it's own! None of those nasty empty plastic jobs here. For this model, Sony left nothing to chance, no technical stone un-turned! If there was a better way of doing things, Sony had already applied it here.

While being the technical tour de-force, 30 odd years or so later, I am somewhat surprised about the collectors reception to this CD player, comparing it's present sale value against it peers in the CD player collect able markets. I feel the Sony marketing department is the weakling here, compared to the more international looking Marantz marketing team. Even Philips LHH series CD players fared better in terms of used collectors value. However, for those who are keen to explore Sony's golden era, here is an opportunity at a low entry price of about USD1000 a pop. Worth every penny and I believe it's value proposition can only improve with years, provided if it's still a mint working unit!

The high density ceramic feet! No plastic con jobs here either.

At the time, circa 2018 in my search for a vintage Japanese flagship Denon CD player, this one somehow landed on my lap through a long lost contact. It was in well kept condition, considering it's 29 year constant usage. The top plate & remote looked well worn, but those are minor issues as they can be fixed or restored.Yes, restoration was my game plan the moment I laid eyes on this pretty boy!

The worst part, YES, there is always a worst part! All part & parcel of playing with classics, be it hifi or automotive, always needs some kind of blood, sweat & tears effort, or elbow grease as they say, to make things right. The KSS-190A transport was in it's last legs of service life. Since Sony no longer produces CD players, they have stopped all CD transport production and closed the factory! It would be near impossible to source for a working unit. That was the numero uno hurdle to this restoration project, that I've now decided to under take!

Ah..... no pain, no gain as they say, and my wonderful journey with this Sony CDP-X7 ESD begins!

Stay tuned...........