2018/12/26 created
2023/02/08 updated

Analog disc player

Technics SL-1200GR was selected.
I didn't choose this model for firm reasons. Because there were few competitors and there were no models that were more attractive than this, I decided on this player.

Reasons for Selection

• Direct drive (DD)
  The DD turntable has very short start time. That's convenient for playing a LP record from the middle. The DD turntable also stops quickly by using the electric brake, so it is convenient when you want to pause temporarily during playback.
  It is maintenance free.
• Compact
  The player is compact and not so heavy (11.5 kg) that it doesn't need a special rack to place it.
  (Large, extrusive-designed players don't fit the Gaudi II concept)
• Vibration-proof
  Vibrations are effectively suppressed with its vibration-proof cabinet composed of a resin board and a metal plate.

The competing product was Denon's DP-1300 MKII. Its list price is 200,000 yen, but the actual sale price is about 150,000 yen, which is almost the same as SL-1200GR.
When it comes to DD, only Japanese-made players can be candidates, and most Japanese manufacturers have quit producing AD players, so no other competitions were found.

To tell the truth, I once wanted a belt drive player if I bought a commercial player. However, the belt is a consumable item and start/stop is not quick like DD. DD is useful when you want to temporarily stop playback and resume from the interruption point later. I am familiar with DD Sony TTS - 8000 (the turntable used in PS-104) for many years, I think I cannot be satisfied with belt drive.

DP-1300MKII looks cool for its natural wood finish, but I evaluated SL-1200GR higher than DP-1300 MKII in anti-vibration feature.
The cabinet of DP-1300MKII appears to be made of natural wood, but actually it is a sliced veneer bonded on MDF board. Although MDF certainly has the property of absorbing vibrations, the effect is not satsifactory. I know this from my experience, since I have used MDF many times.
I believe it is better to combine several different materials.

It is also a favorable point that SL-1200GR is more compact than DP-1300 MKII.

Though it was not included in the selection criteria, it was also attractive that the SL-1200GR supports 78 rpm. I don't own any SP records as of December 2018, but I think that I'll obtain some if there are opportunities in the future. In that case, I plan to purchase a cartridge for SP.

Reasons for replacing

Even without buying a new player, there was also the option to continue to use the self-made player PS-104 used in Gaudi even in Gaudi II. I didn't do it because I got dissatisfied with PS-104.
First of all, PS-104 is not vibration-proof enough. I think the cabinet which is made of stacked Lauan plywood boards has a fair performance, but from the current state of the art it is not enough.
Second, there is a problem that the tonearm (Grace G-1040) is not easy to use. Height adjustment can't be done easily, and adjustment of anti-skating mechanism can't be done unless a test record is used. I rarely change the cartridge, but it is obviously better to be able to adjust easily. Moreover, though it is a trouble from around the time I started using it, the arm lifter doesn't work properly. Every time I lift down the stylus on a disc, I get tense.

About a year and a half before I bought the SL-1200GR, I misunderstood that the G-1040 had broken down and decided to urgently buy a commercial AD player. While I couldn't secure much budget, I didn't tolerate a music life without vinyls for a long time, so I decided to buy a player with a high price/performance ratio.
I found a pioneer PLX-1000 when I searched for a player with 100,000 yen or less on the Internet. It seems that it is a product that reproduced the Technics SL-1200. It was about 78,000 yen.
I found some players that seems to be good at a secondhand shop in the neighborhood, but they were all products in the 80's. I didn't buy any of them because they were too old.

I tried the PLX-1000 soon after I bought it.
To my surprise, it was better than PS-104 in sound quality.
I understood the reason at once. It is because the PLX-1000 is more vibration-proof. The player was placed on an old steel rack, and vibrations were easily propagated to the player. The PLX-1000 was affected by the vibrations less than PS-104. So I concluded PLX-1000 is superior to PS-104.
I realized again that the performance of cabinets and insulators is more important than the performance of the pickup itself.

This experience made feel like I should replace PS-104.
Later it turned out that the tonearm of PS-104 was not defective, but decided to switch to another player.

The reason for quitting using the PLX-1000 is that hum appears in the left channel when an MC cartridge is used.
This defect is acknowledged by the manufacturer and it is written on its website that it recommends MM type (meaning that "Don't use MC cartridges").
Besides, there are some minor discontents such as the color of the cabinet (the color is black, my preference is silver), no hinges on the dust cover, etc. I decided to replace it.

Impression

I am generally satisfied. As for sound quality in particular, I am satisfied 100%.
Since it was installed in July 2017, I have played my vinyls almost everyday. I feel every disc sounds better by a notch than before. Discs with wide dynamic range (D-range) can be played without problems.

Some wide D-range discs in my collection are listed below FYI:
(1) Harbie Mann, All Blues/Forest Rain, Harbie Mann Music HMM-1 (1981)
(2) Raymond Lefevre, Stereo Laboratory Series Vol.10 - Strings, Barclay GP-4010 (1975)
(3) Eigo Kawashima, Sake to Namida to Otoko to Onna (Sake and Tear and Man and Woman), Electra L-3503E (1979)
(4) Sonny Clark, Cool Struttin', Blue Note/Music Matters BST81588 (2010)
(1) is the most difficult disc to trace in my vinyl collection. It is a direct-cut disc, so you will hear a tremendously lively sound if the pickup can trace it perfectly. If your pickup can trace this disc, the pickup can trace any other discs. (2) is a bit old record, but the same cutting head (Neumann SX-74) is used as (1). It is the best disc to try out the resolution of the playback system. (3) is 30cm single (rotational speed is 45 rpm). Its groove pitch is so large the groove can be seen with the naked eye and the cutting level is very high. It is the second most difficult disc to trace. (4) is a reissue disc of the famous Jazz record. It doesn't sound so dynamic to my ears, but the measurement indicates the peak level is very high.

Apart from sound quality, I have some dissatisfaction.
First of all, the appearance and operation feeling are cheap. Especially, the tonearm that uses many plastic parts looks cheap.

Regarding the tonearm, I'm not satisfied even in function.

First, the range of the height adjustment is biased toward the higher one. I use Audio Technica AT33PTG/II and Grace Carbon Fiber Headshell, but with this combination, even if the tonearm is set to the lowest position it will still be a little too high. Since new-generation Technics does not manufacture or sell cartridges, the user have to use other manufacturer's products. They should've broadened the adjustment range a little more or lowered the tonearm position a little lower. The PLX-1000 didn't have such a problem.
One of my dear readers gave an advice that the VTA (Vertical Tracking Angle; roughly speaking, the angle between the cantilever and the disc surface) of the cartridge greatly affects the sound quality. I'm going to adjust the VTA correctly by pinching a spacer between the headshell and the cartridge.

Second, the descent speed of the arm lifter is too fast.
Each time it lifts down quickly, I am a little concerned that that quick fall could damage the cartridge. So far, fortunately, no problem has occurred.
When lifting the tonearm up, it moves so quickly the tonearm bounces. It should move slowly a little more. This kind of thing also leads to a cheesy image of this player.

Third, the scale of the anti-skate mechanism is not accurate.
I usually set the stylus pressure to 2.0g, which is the recommended value for AT33PTG/II. When I adjust the anti-skate mechanisim using a test record, it balances when the dial of the anti-skate mechanism indicates 2.5. When it is set to 2.0, the stylus is drawn inward.

One more thing. This is not a complaint but a request. I'd like a remote control. They say this product isn't a mare reproduction of the old SL-1200, but the design was reviewed and improved. I think they should've added the remote control feature in re-designing process. If the remote was available and it's only start/stop of the turntable, you could suspend and resume playback without standing up and walking to the player. This feature is undoubtedly suitable to the DD turntable, which has very short start/stop time. It can be a sales point against other types of turntables. I wish they had consulted me on the product's planning stage (I'm joking :-)).
All the audio components other than the AD player can be operated with a remote. I think manufactures of AD players are stuck to the image that the analog disc and AD player are things retrospective.

I have these small complaints about SL-1200GR, though, I like it since the sound quality is good.
Though I mentioned that it looks cheap, its design matches the looks of my self-made audio rack AR-416 Air. SL-1200GR doesn't look gorgeous but quite neat on AR-416.

By the way, I think the concept of this player is weird in the first place.
I hear the renewed 'Technics' is a high-end audio brand, but the SL-1200 is not a high-end player. It is only to say that they merely depend on the name value of SL-1200, which is the best- and long-seller. According to the manufacturer's advertisement, the current SL-1200 is not a mere reproduction but improved from the previous one to a large extent. So much so,I think they should have developed a brand-new model. With this concept, it is difficult to satisfy users who are looking for high-end players. And, since the price of SL-1200GR is double the old SL-1200 (SL-1200G is four times expensive), I'm sure that users who have been longing for comeback of SL-1200 won't accept the new SL-1200.

 

---

Cartridge

I'll continue to use Audio Technica AT33PTG/II, which I started using with Gaudi, also in Gaudi II.

As of December 2018, I've already used it for four and a half years. I am satisfied with its sound quality and durability.

The headshell in Grace Carbon Fiber Headshell (equivalent of HS-6), The shell leads and the mounting screws are the accessories of AT33PTG/II . The shell leads are PCOCC wires.

 

Reasons for selection

Like the AD player, I didn't choose AT33PTG/II for any special reasons.
I've been thinking about using a low output MC cartridge since my youth. When the price of the microridge replacement stylus of Grace F-14, which I kept using for more than 30 years, reached 130,000 yen, I decided to purchase an MC cartridge at last.
Because there was no model I really wanted, I decided to gather information on the Internet and select the model.
By the way, when the stylus of the F-14 reached its end of life, I purchased Ortofon 2M Red for a temporary use before the purchace of the MC cartridge.

At first, I was interested in products of Ortofon, which has the longest history as a pickup maker. I thought that the MC30 looks good, and I checked it out. Though Ortofon's brand image is high, there is no strong appealing point like Japanese-made cartridges. In addition, it's expensive, so I removed it from my candidate list.

The attraction of Japanese cartridges is that they are made with ultra precision processing technology and the highest level of assembling accuracy. For stylus tip and cantilever in particular, I think Japanese-made parts are the best. Japan's audio industry has produced excellent parts such as Shibata stylus, microridge stylus, ruby ​​cantilever and so on.

I considered ZYX after Ortofon. ZYX is a manufacturer of high-end models, and the cheapest model of a high-end maker is my target. For me who feel that class-B gourmet (popular Japanese foods like takoyaki) is more delicious than foods of a high-class restaurant, a popular audio device sometimes sounds better than a high-end one.
I considered R50 Bloom. However, like the MC30, it was more expensive than I had thought and I couldn't afford it (I remember it was around 90,000 yen).

While googling, I found AT33PTG/II sold at only about 38,000 yen (including tax) at a certain online store. Audio Technica is a reliable manufacturer, and the AT33 series is the leading products among the company's cartridges, so I promptly decided to buy it.

I'm sorry but it turned out to be a story that I bought a bargain priced cartridge after the lengthy explanation on component selection.
It's the same old story for me. For example, I bought on impulse Sony TTS-8000 and Grace G-1040 when I happened to spot them sold at less than half price at a discount shop in Akihabara. They were used in PS-104 later.
Buying G-1040 and making user registration was the beginning of association with Grace (Shinagawa Musen) that lasted more than 30 years. I've been receiving direct mail from Grace since then. One day, I knew they were looking for monitor users of F-14. I applied to it and got F-14 for a half of its list price. It was used in PS-104 too for more than 30 years.
The same thing goes to other audio products I've purchased until now. I don't take a look at and a listen to the product before purchasing it. The only exception is Sony HAP-Z1ES (DAP) currently in use in Gaudi II. Unfortunately, I am not satisfied with it because I noticed some defects that I didn't notice when I took a listening trial. On the other hand, other products I bought at a bargain are more than satisfactory, and I used them for many, many years. It is an ironic story.

What makes me decide most when I buy an audio product is confidence in the manufacturer. I can choose one without hesitation if it's a core product of the most reliable manufacturer. Of course, it is a major criterion that the concept of the product meets my requirements.
As mentioned above, I think the cheapest product of a high-end maker may be also a good choice, but I haven't actually bought such a product yet.

Since I don't read audio magazines, I don't know reviews by professionals, and I don't want to know, either.
I think the Japanese audio magazines have a too strong relationship with audio manufacturers. If there is an audio magazine that does not put any advertisements on it in order to break the relationship with manufacturers, I'd like to subscribe it by all means. Could anyone publish such a magazine?
Exceptionally, I read Seterophile magazine from time to time. In its review articles, the data measured by the reviewer himself are always listed. I feel it favorable that the commentary is mainly focused on the data rather than "personal impressions". Another desirable point is that they evaluate products that are availabe on the market, not samples provided by manufacturers. In addition, it is good that the back numbers can be viewed free of charge on Internet.

Information on Internet is helpful to some extent. Many honest and straightforward opinions are available, and they are helpful.

Impression

When I unpacked the AT33PTG/II, I was amazed at its super precision. At the first glance, I mistook for a moment that the cantilever was missing. The cantilever was so thin and the stylus tip was so small that I could hardly see them. I was worried about the durability at first, but I understood later that this boron cantilever and the mount are so sturdy.

The sound quality of AT33PTG/II is excellent. Clear, transparent, high resolution sound. Yet, it can reproduce a dynamic, richly vibrant sound, not an inactive sound. The sound image is well focused, and the localization is also accurate.
It sounds almost as good as Grace F-14 plus new US-14MR (microridge stylus). Although the F-14 has the best sound quality among the cartridges I have ever heard, the life of the cantilever mount is short. The sound quality begins to deteriorate in about two years, and in about three years the sound quality becomes the same as a cheap cartridge.
My AT33PTG/II has already been used for four and a half years, but its sound quality still remains excellent.

My AT33PTG/II has been used in three players (PS-104, PLX-1000, SL-1200GR), and no difference was found in trace ablity. AT33PTG/II may have high compatibility with the tonearm. However, the combination with PLX-1000 is NG, bacause PLX-1000 induces hum in combination with an MC cartridge.
The recommended stylus force of AT33PTG/II is 2.0g. This relatively high stylus force makes AT33PTG/II more compatible with various kinds of tonearms.

I almost gave a damage to my AT33PTG/II three times so far.
First, when you played an LP (H. V. Karajan/BPO, Richard Strauss: Also Sparach Zarathustra, Speakers Corner Records 2530-402), which was not cleaned enough though it was a brand new, the disc stopped soon (the platter was still rotating and the disc was sliding on it) due to a big friction between the sound groove and the stylus. I stopped the turntable in a hurry, but I was worried that I might have damaged the cartridge.
Secondly, when I was going to secure the tonearm to the armrest, I mistakenly dropped the tonearm and the cartridge bounced on the platter.
Thirdly, one day, I spotted my cat sitting on the turntable and playing with the cartridge. I drove her away in a hurry. I saw her hair was on the tip of the stylus, and I thought the cartridge was broken this time.
I sent the cartridge to Audio Technica and had it checked. Surprisingly, it turned out that no defect was found. I understood AT33PTG/II is so sturdy despite of its fragile appearance, since it never gets broken even if treated roughly this way. For me, my hands are clumsy, it is easy to use.

I'm planning to consider replacing it, when the stylus of the AT33PTG/II reaches the end of its life. But it is likely for me to choose AT33PTG/II once again, unless another more attractive cartridge is found.

 

---

Digital Audio Player (DAP)

I selected Sony HAP-Z1ES.

I bought it in September 2015. I intended to use it in Gaudi II. I have already used it for more than 3 years (as of December 2018).

I'm planning to replace this DAP with PC in the near future, according to the system design (Ver.2.1).
[2021/07/25 added] {I evaluated this player in detail before I sold it. I found out my misunderstanding about the problem I wrote in the following section 'Impression'. See the section}

Reasons for selection

I looked for a DAP (digital audio player) with built-in mass storage that supported almost all formats of music files. I found HAP-Z1ES only, and I bought it.

There were lots of network players available. But they don't function alone. They need a NAS. Such a kind of player is not easy to use. So I didn't choose it.

A few months before deciding to purchase it, I went to an audio shop where I was a regular customer. The shopkeeper recommended this player. I thought its sound quality was very good during a listening trial.
I checked word-of-mouth information on Internet. I knew HAP-Z1ES was very popular and most of the users gave full marks to it.
It is an expensive player for me (the list price: 210,000 yen, bid price: about 170,000 yen), so I hesitated a bit. But its reputation is good, and it is one of Sony's ES series produts, which I've used for many years and been satisfied with. So I decided to buy HAP-Z1ES with confidence.

It is very unusual for me to buy an audio device after auditioning it at an audio shop. Even looking back to my low teens, the only exception is Audio Technica ATH-PRO700 (headphones).

Impression

When I received HAP-Z1ES (called HAP hereafter) and turned it on for the first time, my expectation was shattered at once. I was disappointed.
Noises coming from the built-in HDD and the cooling fan were so loud they could be heard anywhere in the room. I'd never heard of hi-fi audio equipment that generates noise.

Recently there are many A/V equipment and IT equipment with a built-in HDD. I also use PC, digital audio recorder, STB (set top box) of CATV, external HD (USB HD) etc. The most noisy among them is HAP.

I thought my HAP might be a defective unit, I called a Sony service technician and had it checked. However, he concluded that there was no defect.

When the serviceman took off the lid, I also saw the interior of HAP.
Surprisingly, the 1TB HDD is a 2.5-inch drive. The case of HAP is so large that it's easy to accommodate a 3.5-inch silent HDD in it. I don't know why the 2.5-inch drive is used.
I understood the fan is installed to cool the HDD. If the 3.5-inch HDD was used in the first place, this fan would be unnecessary.
The interior is not partitioned into compartments. The digital circuit, the analog circuit and the power supply circuit are arranged in the same space. All mounting screws are made of iron. No order nor torque to tighten the screws is specified in the service manual. No special anti-vibration measures are taken, so it seems that the noises of the HDD and the fans resonate in the case and it made them louder.
As far as the implementation is concerned, I do not think it was designed by a professional audio engineer but an IT engineer.

Until now, I have had four audio devices in Sony ES series (TA-n330ES, ST-s333ESJ, SCD-555ES, TC-k333ESX) other than HAP, which were all satisfactory. But this time I was completely betrayed. I feel like Sony is no longer an audio manufacturer.

I have read through user reviews on Internet, but no one pointed out the noise problem. When I listened to HAP at the audio shop, I didn't notice the noise because it was masked by the background noise inside the shop. I wonder if other HAP users are all using it in a room with high background noise like the audio shop?

I don't feel like evaluating the sound quality of HAP due to the mechanical noise. I observed waveforms of its sine wave output. Some distortion was observed. It seems that the quality of the output signal is not good, either.
I'm not sure about the effectiveness of DSEE, Sony's own real-time upscale function. Sometimes it is effective, and sometimes not, I feel.

If you replace the HDD with an SSD and remove the fan, the mechanical noise will not come out. Sony's service person said that it is impossible for the user to replace the drive by himself because it is strictly protected, but according to word-of-mouth information on Internet, it seems possible.

[2021/07/25 revised] {I evaluated HAP-Z1ES in detail and found out the noise doesn't come from the chassis of HAP-Z1ES but from the audio rack. The output signal that looks like being distorted isn't distorted actually. White noise intrudes into the signal. For details, please refer to this}

I have some other complaints.
Errors occur occasionally when HAP is receiving data from PC via Wi-Fi. Reboot is necessary for recovery.
The appearance of HAP is cheap. I don't require a luxurious appearance, but a classy one. The appearance of HAP looks like an audio device built by an amateur.

 

---

PC Audio

[2021/10/31 added]
HAP-Z1ES has been replaced by PC audio according to the system design (Ver.2.1).
For details, please refer to the supplemental document linked below:
[Introduction of PC Audio]

The PC audio subsystem is composed of the following components:

Component	Manufacturer	Model	Description
PC	OlioSpec	canarino Fils9	Silent PC, 2TB SSD added
Display	Century SHARP	LCD-10000UT AQUOS 4T-C43AM1	10.1" display w/ touch panel, USB3.0 43" 4K LCD TV, HDMI
Keyboard/mouse	Logicool	MK240	Wireless keyboard/mouse combo
Wi-Fi adaptor	Buffalo	WI-U3-866DS	11ac, USB3.0
BD drive	Pioneer	BDR-XU03J	Portable BD drive, USB3.0
DAC	TEAC	UD-301-SP/S	PCM: 192kHz/24bit, DSD: 5.6Mbps, USB2.0
USB cable	ELECOM	U2C-BN10BK	USB2.0, 1m
LINE cable	(DIY)	CB1	Quad-core shielded cable, RCA-RCA
Power strip	ELPA	WBS-T3010B	1m, 3 outlets w/ switch
Music player app	- TEAC	foobar2000 HR Audio Player	For PCM source For DSD source
Ripping app	dBpoweramp	CD Ripper	For CD ripping
Movie player app	CyberLink	PowerDVD 20	Chiefly for replay of DVD/BD
TV app	Digion	Dixim Play	Receive data from STB via Wi-Fi

 

Silent PC OlioSpec canarino Fils9	USB DAC TEAC UD-301-SP/S	PC audio installed in audio rack AR-416

 

---

Crossover Network

Analog Crossover Network

I selected Behringer CX3400. I chose it without a strong reason. I was attracted its low price, as cheap as 12,700 JPY.
I spared it for nearly three years. I decided to use it because my DIY crossover CD-211B A-NET was unstable. I substituted CX3400 for CD-211B.

Since CX3400 is a product,I had expected that all I had to do is place it, connect cables and make a little adjustment. Unlike my expectation, it took me considerable time and labor.
I made measurement and trial listening for CX3400 just as I do for my DIY audio equipment, even though it's a product. It was a wise decision. CX3400 has a few shortcomings. Thanks to the measurement and thorough check, I learned them before I installed CX3400 in Gaudi II system. For details, see the supplemental info 'Review of CX3400'.

Digital Crossover Network

I selected dbx DriveRack VENU360. I bought it on January, 2022.
In addition to the functions as a crossover network, it has various features such as equalizers that are so helpful for tuning of loudspeakers. It should be called a "speaker processor".
I've decided to use a crossover network like VENU360 in the system design of Gaudi II (Ver.2.3). I bought it for the replacement of Behringer CX3400, which is not so good in sound quality.

I compared VENU360 with Mackie SP260. I chose VENU360 because the sampling rate of its ADC and DAC is higher than SP260 (VENU360: 96kHz, SP260: 48kHz).

I expected I could solve all the problems of Gaudi II by employing VENU360, but some of them are still unsolved as of February 2023 (Gaudi Rev.2.12).

Please see my review of VENU360 "Review of DriveRack VENU360".

Balanced/Unbalanced Converter

I bought this converter to convert the balanced output of VENU360 to the unbalanced line signal.
I selected ARTcessories CleanBox Pro.
I searched and found it on Internet. I bought it because the price (8,480 JPY) is reasonable.

CleanBox converts a balanced signal to an unbalanced one by using the differential amplifier. It also has unbalanced to balanced conversion. It has two channels of the converters.
It is compact and light.

The levels of noise and distortion are so low that my instruments can hardly detect them.

---

Power Amplifier

I selected Flying Mole DAD-M100pro as the power amplifier for Woofer.

I bought this amp for the squawkers in 2005. Until that time I'd been using Sony TA-n330ES. I liked TA-n330ES for its good sound quality and reasonable price (lsit price: 49,800 yen), but the size was too large for me, though it was the standard size (width: 44cm).
When I happened to see an advertisement of Flying Mole, I was attracted by a power amplifier called DAD-M1 whose maximum output was 100 W (into 8ohm), the same as TA-n330ES, and size was ultra small (A6 size).
I got information that its professional version, DAD-M100pro, was available at Kimura Musen situated on the 4th floor of the former Radio Kaikan in Akihabara. I bought it through mail order without hesitation.

I used the DAD-M100pro as the squawker amp until I replaced the squawker units of the speaker system SS-309 with horn-loaded type in 2012. Before that, I used the full range LS units for the squawker. The squawker units were switchable from/to midrange to/from full range. I don't remember well now how good the sound quality of TA-n330ES was, but I don't think there was a big difference between TA-n330ES and DAD-M100pro..

Reasons for Selection

As mentioned earlier, I bought this amp because I was interested in its smallness and reasonable price. I don't remember the price exactly, but I think it was about 80,000 yen for two units (two units are necessary since it is a mono amp).

Although the principle of class-D amplifier seems to be devised many years ago, I learned that there is such an amplifier for the first time at this time. It is characterized by much higher power efficiency than Class-A and Class-AB.
The DAD-M100pro uses switching regulators as a power source, and the efficiency is very high (85%) (there are more efficient amplifiers at the moment). I definitely wanted to use the class-D amplifier.

Since the output stage of the Class-D amp is a switching circuit, fluctuations of the DC power supply voltage directly fluctuate the output. In order to solve this problem, the switching regulator is included in the feedback loop in the DAD-M100pro, and this improves the overall regulation. This technology was unique to Flying Mole and patented by the company.

When I changed the squawker of SS-309 to horn type (Fostex H400+D1405), I noticed that noise came from the squawkers. That's because the class-D amplifier outputs noise in high frequency region. I concluded that not only DAD-M100pro but other class-D amplifiers are not suitable for horn -loaded drivers.
When my self-made amplifier MA-215 Arabesque was completed in 2015, I replaced DAD-M100pro with it.

In the system design of Gaudi II, which was completed in 2017, I decided not to use tube amplifiers any more. So, I came up with an idea of replacing the woofer amp MA-201C (tube amp) with the DAD-M100pro. Since the woofer is a cone type, it can be used with the class-D amp. And since the cone type is lower in sensitivity than the horn type (lower by 10dB or more), a powerful amplifier is suitable. Anyway, DAD-M100pro was left unused, I decided to use it as the woofer amp.

Impression

Compared to MA-201C, the way the bass sounded has changed obviously.
I felt the volume of mid bass increased, while the volume of the super low (25Hz to 35Hz) was almost the same. Both the wood and electric basses came to sound more realistic. I thought the driving power of DAD-M100pro was stronger.
Ultra low tone is reinforced by utilizing the resonance of the woofer and the bass reflex duct, so sufficient sound pressure will be obtained without supplying much power. The voice coil impedance will rise dramatically between 35 and 70Hz, and dropped between 70Hz and 110Hz. I suppose MA-201C, of which output impedance was high, was unable to drive the woofer sufficiently in the latter band. This insufficient driving power lowers the sound pressure in that band, and lessens the volume of bass instruments.

I feel that not only the volume of bass but also the quality has improved. For example, when big band Jazz was being played, the sound of the bass used to be heard a bit ambiguously, but it has become possible to recognize the character of the bassist.

I think that not only the replacement of the amplifiers but also shortening the speaker cables contributed the improvement of the sound quality of the bass.
DAD-M100pro is small and light, and it's a mono map, so it can be installed just next to the loudspeakers. I could shorten each woofer cable from 3.6m to 1.8m.
I'm planning to further shorten the cables by attaching the amplifiers to the woofer boxes.

I often hear the theory that a thin speaker cable attenuates basee sound. In fact, it's not true if the impedance of the cable is sufficiently low. I believe it is more effective to make it shorter than thicker. The shorter cable will be less affected by environmental noise and vibration. As of December 2018, the cable I'm using is 0.65mm single core wire (tough-pitch copper wire).

In the system design of Gaudi II, it is supposed to use my original amp for the woofer, but I'm not confident for the moment whether I can design an amplifier superior to DAD-M100pro. In addition to the performance as an amplifier, it is necessary to make the size as small as DAD-M100pro.
I am satisfied with DAD-M100pro, so there is a high possibility of continuing to use as it is.

 

---

Digital Audio Recorder (DAR)

Though the digital audio recorder is not an essential component of the system, I used it in Gaudi II in order to digitize analog sources.
If you digitize them, in case you can't play the analog disc, you can listen to them by using DAP. (most of my favorite albums are LPs). If you convert them to MP3, you can also listen with a portable music player, smartphone, etc.

I purchased KORG MR-2000S-BK in March 2014.
I like both its sound quality and usability, so I continue to use it in Gaudi II.
According to the system design (Ver2.1), a PC will be used as DAP. PC has recording feature too. So when the DAP is replaced with the PC, this DAR will be removed from the system.
[2021/07/31 changed] {MR-2000S will continued to be used, because I confirmed its sound quality is better than that of PCs}

Reasons for selection

As always, I didn't have a firm reason. I wasn't picky. Any DAR that met my criteria,which were supporting DSD5.6M and a product of a reliable manufacturer, was acceptable.
At first, I searched for consumer products, but didn't find anything good. There seem to be few audiophiles who record analogue sources these days. I decided to look for recorders for professional use.

I happened to find KORG MR-2000S-BK sold at a dicounted price of 108,000 yen at an online store. I made a prompt decision and bought it.
MR-2000S supports the DSD5.6M and PCM up to 192kHz/24bit. The built-in 160GB HDD enables recording for quite a long time.
Though it is for business use, it also has unbalanced input/output (RCA jack), so you can easily connect with consumer equipment.

Impression

I think the recording quality is very good.
When data recorded with this recorder are played with another player, the sound quality is excellent.

However, when the same data are played with this recorder, the sound quality is not good at all.
When this DAR is disconnected from the system, the waveform of the output is perfect, so it seems to be a problem of compatibility.
The power supply of the MR-2000S doesn't have a transformer. The ground potential is the Earth. On the other hand, the ground potential of Gaudi and Gaudi II is floating from the ground. This ground potential difference seems to be a factor deteriorating sound quality.
Gaudi II's system design includes measures to avoid problems caused by ground potential differences. It is expected that this problem will be solved in the near future.

[2021/07/31] {I evaluated performance of MR-2000S as a music player, and saved the result in PDF. Please seethis}

---

Optical Disc Player

Gaudi II also supports visual sources. A player that can play DVDs and Blu-ray discs (ie BD players) is included in the system.
Though I'm not considering direct playback of CDs, it is somewhat more convenient if there is a player that can play CDs at hand. Since a CD player is more than enough, I'll use this BD player for CD playback.

I'll continue to use this BD player, Pioneer BDP-330, purchased for 18,000 yen in 2010. I am satisfied with both image and sound qualities.

After the DAP is replaced with PC, this player will become unnecessary. I'm going to remove it from the system then. The fewer the components in the system, the better the overall sound quality.

Impression

Even if I use it as a CD player, I think that sound quality is quite good.

Speaking of Pioneer's multiplayer, I remember the LD player CLD-970 that I used before. I bought it in 1989 or 90 and used it until I bought a DVD player in 2001. I remember that the price was certainly close to 200,000 yen.
CLD-970 was the first player I got as a player that can play CD. However, the sound quality was not so good.
If I could do a listening trial of them right now, I'd definitely feel BDP-330 is better. Though the price is one tenth, the sound quliaty is better thanks to 20 years of technological progress.

I checked the output waveform like I did for the DAP just out of curiosity. This is the waveform when 16 kHz sine wave recorded on CD-R is played back.
Some RF noise is observed. I think this level of noise is acceptable for the BD player, since it isn't a pure audio player.

 

---

Set Top Box (STB)

[2021/10/31 updated] {This section has been rewritten}

The STB (set top box) of CATV is connected to Gaudi II, too. I use Gaudi II when I want to view a TV program with high sound quality.

Since the STB is leased from a CATV station, it's not selected by myself.
Currently I am using Panasonic TZ-LT1500BW. It has dual tuners of terrestrial broadcast, BS, CS and BS4K. It also has recording feature with an external HD.
It can be linked with PC via Wi-Fi.

I used Technicolor BD-V570 until recently, but it was unstable. I had it replaced with TZ-LT1500BW.

I connected 1TB SSD to the STB for recording.

---

TV Set

The television currently in use is, of course, not purchased for Gaudi II. But I've decided to include DVD and Blu-ray discs in the source of Gaudi II, and I'm planning to display liner notes and lyrics on a large screen at the time of music playback. Now the TV is the component of Guadi II system.

As of December 2018, the TV in use is LT-37LH905 of JVC (now JVC Kenwood). I bought it in 2008. It was the television of the highest image and sound qualities at the time. It was about 1.5 times the price of other companies' LCD TVs of the same size, but I absolutely wanted it and bought it.

I have been using it for 10 years already, but I am still satisfied with it. Especially, its excellent sound quality makes me happy. The full range loudspeaker unit used in this TV is Oblicorn Speaker, JVC's proprietary technology. I set the graphic equalizer flat, and it makes the sounds natural. The bass response is so good. And it won't distort even at high volume.
Even when I watch movies and music programs, in most cases, I don't use Gaudi II. Using Gaudi II is limited to sources for which I really want high sound quality.

Though I'm satisfied with this TV set, pale noise came to appear on screen recently. I'm considering replacing it.

[2020/06/14 added] {The TV was replaced with SHARP AQUOS 4T-C43AM1 on July 2019. The table below shows its outline spec}

TV tuner	DTV/BS/CS (2K, dual tuner)
4K tuner	Not equipped
Display size	43 in.
Display resolution	4K (3840 x 2160)
Audio	ONKYO 2.1ch sound system
Video recorder	External HD is required
Inputs	HDMI x 4, USB x 2

 

 

 

---