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Home > Gaudi 2011/04/03 created
2016/07/19 updated

Home-built Audio System Gaudi

(2016/07/16 added) {
Congratulations!Gaudi has been completed at last!!

I stated that I would quit building Gaudi in January 2015, but I retract the statement.
My new midrange power amplifier MA-215 Arabesque has improved the system sound quality more than my expectation. I judged I achieved the goal I had set in my high school day. So I've decided to declare the completion of Gaudi!

Gaudi is a home-built audio system which I designed in 1974, when I was a 17-year-old high school sophomore. At that time, I already had a four-year experience as an audiophile, and I considered the ideal audio system based on my experience and knowledge. It was a tri-amplified system using large size woofers and horn-loaded midrange units and tweeters.
(the initial block diagram of Gaudi)

(2014/07/28 revised) {
As soon as I finished the system design, I began designing and building each component for Gaudi. I planned to complete Gaudi in five years.
However, it was far more difficult to build a high-end system than I had anticipated. I had to learn more about audio technology. My original plan was shattered. Building Gaudi became my lifework.

(2016/07/17 revised) {As of July 2014, I am still building Gaudi. The system design remains unchanged. It is still my ideal system after 40 years has passed, because any major breakthrough in audio technology that makes my mind change hasn't been achieved for the past 40 years.
Now Gaudi is almost completed, and its tonal quality is nearly at the highest level (to my ears).

In September 2015, the midrange amplifier MA-215 Arabesque was completed, and it improved sound quality (SQ) of Gaudi significantly. I've decided to declare my Gaudi system is completed, though it is a bit different from the original system design.
Its SQ is nearly high-end level, but still not satisfactory. I don't think I can improve Gaudi further without changing the system design. So I've started designing Gaudi II (version 2.0).
Until the completion of Gaudi II, I continue to use Gaudi.}
(Today's Gaudi)

Gaudi completed

Gaudi was named after the great architect, Antoni Gaudi (1852-1926). His masterpiece, Sagrada Familia, could not be completed before his death, and his successors have been building it thereafter. It is still under construction.
I don't expect I can complete my audio system by the end of my life. It's just like Sagrada Familia, isn't it? So I named my audio system Gaudi in 1999 (until then it had been nameless).

(2014/06/11 added) The goal of Gaudi sound is 'living sound', a sound that is so lifelike that you feel as if you listen to a real live performance. It is vivid, open, dynamic and energetic. Sounds of musical instruments sing and dance, and make you absorbed in the world of music before you are aware. As soon as music starts, you feel as if the living room changes to a mini concert hall. That's the 'living sound'.
(The goal of Gaudi sound leads directly to the design philosophy. So I described the details in another page)

(2014/06/11 added) It takes an extraordinary long time to build Gaudi, because not only I work so slowly but also I spend much time to search for causes of deterioration of sound quality, consider measures to eliminate them and improve Gaudi by carrying out the measures. I often do those things even though I wrote only major improvements in this homepage. These frequent improvements not only improve the sound quality of Gaudi but also lead to good ideas for designing new and better audio equipment.
This is Tonochi's way to improve the existing audio devices as much as possible and design and build new devices when the existing ones cannot be improved any more. That's why I haven't built so many devices for the long development period.

Now, let me explain the details of Gaudi step by step.


Looking back 1974, I recall how I designed Gaudi...

The configuration of an audio system largely depends upon the type of the loudspeaker. First of all, I began with consideration on the type of the loudspeaker.

I decided the target specs: frequency range: 30Hz-40kHz, and sensitivity: 95dB/W(1m). That specs enables reproduction of the lowest sound of any musical instruments; and it covers the bandwidth of analog records.
Wide bandwidth does not always lead to high sound quality, though, I thought all the sounds recorded on a disc should be reproduced. I want to avoid cutting off very low and high frequencies due to limitation of the audio system.
Low sensitivity speakers are heavy load for amplifiers, and low sensitivity will increase the electric current that passes through cables and terminals. I believed high sensitivity had directly to do with high sound quality. [read more]

System Design

As a result of the consideration, I decided to build a three-way multi-amplifier system and make amplifiers and loudspeakers specially designed for the system.
First of all, I fixed the spec of the loudspeaker: multi-enclosure speaker system with large woofers, horn midranges and horn tweeters.
Next, I fixed spec of the amplifiers according to the spec of the loudspeakers. I planned to make a total of five amplifiers: a preamp, a channel divider (network), a power amp for the woofers (woofer amp), a power amp for the midranges (midrange amp) and a power amp for the tweeters (tweeter amp).
In addition, I planned to make an analog player. [read more]
(Block diagram)

History of Gaudi

When I designed Gaudi, I was only a high school boy, and I couldn't afford to build the multi-amp system in a short period. So I decided to build a single-amp system by reusing components I had for the first step, then upgrade it to the multi-amp system step by step in five years.
However, my plan was delayed and delayed. (2016/07/18 revised) { Though 38 years have passed since then (as of 2012), it is not completed yet. Now building Gaudi is my lifework. 41 years later from the beginning (September 2015), Gaudi was completed eventually. }

In 1974
The system design of Gaudi was fixed. It was nameless at that time.
In a multi-amp system, the preamp and power amp are necessarily separated. Until then I only had integrated amps, so I decided to make a preamp and a power amp.
I made the tube power amp MA-201, the very first work under NOBODY brand. Subsequently I made the tube preamp PA-202. [details]
(Block diagram)

In 1976
I made a poly-speaker system using four units of Fostex FE103 per channel.
I bought an FM tuner and a cassette tape deck. Now I was able to make an off-air recording. [details]
(Block diagram)

In 1980
I gave up the preamp PA-202, which was helplessly defective, and made a new tube preamp PA-203.

In 1982
After finishing my graduation thesis in university, I started making four components in a row: an analog player PS-104, a tweeter amp MA-205, a network CD-206 and loudspeakers SS-307. When I completed SS-307, I was a freshman at a company and just finished the training for the new recruits.
Finally, three-way multi-amplifier system was established, though I couldn't afford horn-loaded midrange and used a full-range driver Fostex FE106 Sigma as the midrange. [details]
(Block diagram)

In 1992
My family moved to a 3-bedroom condominium. Gaudi was installed in the living room.

In 1999
I made a new tube power amp MA-208, which replaced MA-205. That's because I had been dissatisfied with the sound quality of MA-205.

In 2001
I abandoned the loudspeaker SS-307 because of its bad looks. Instead, I made SS-309, which inherited the basic design of SS-307 and had far better looks.

In 2003
I had a house built, which had good acoustics. Gaudi was installed in the living room.
A tube preamp PA-210 Simplicity was completed, which I had been building since 2001. It replaced PA-203.

In 2004
I made an OP amp based network CD-211 A-NET, which replaced CD-206.

In 2005
I replaced the midrange amp Sony TA-n330ES with Flying Mole DAD-M100Pro-HT.

In 2006
I bought two units of Fostex 6N-FE103 several years before to use them as the midrange of SS-307. But they turned out to be a dead stock because I found they were not good as the midrange.
I thought they were too good to be thrown away. I decided to make enclosures for them. I numbered them SS-312.
The tube power amp MA-205 was dramatically improved. Combining MA-205 and SS-312, I built a 2nd system for use in the study room. The CD player was KENWOOD DPC-X517 (It was broken in 2011. TASCAM DR-1 has been used as a player since then).
(Block diagram)

In 2011
Gaudi's basics are still unchanged though many small improvements were made. [details]
(Block diagram)

In 2012-13 (2014/07/28 changed)
SS-309's midrange unit has been replaced with horn-loaded drivers. Gaudi is almost completed. There's only one step to go to achieve the goal I planned in 1974. [details]
(Block diagram)

In 2014

(2014/07/29 added)
Gaudi reached its 40th anniversary this year. Gaudi will be completed when the power amplifier MA-215 is completed, which I am designing now. Though there are many issues to be solved before I finish the design, I am so eager to complete MA-215 and Gaudi within this year. [details]

In 2015

(2015/01/06 added) (2016/07/18 revised)
I stopped building Gaudi. I decided to design and build a new system Gaudi II. I'll continue to use Gaudi till Gaudi II is completed. Gaudi was completed at last! The midrange power amplifier MA-215 Arabesque was completed and it improved sound quality of Gaudi considerably. All the amplifiers in Gaudi are my works now. So I decided the completion of Gaudi. I'll continue to use Gaudi till Gaudi II is in use. [details]

Today (2016)

(2016/07/18 added)
完成したGaudiでひたすら音楽を楽しむ。一方、測定データをもとにGaudiの長所・短所を分析中。結果はこのホームページに発表予定。分析結果をGaudi IIの設計に活用する予定。
I enjoy music with Gaudi every day. On the other hand, I am analyzing measurements of Gaudi and clarifying its good and bad points. I am going to write the result in this homepage in the near future. And I am going to design Gaudi II based on the analysis. [details]

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How to Use Gaudi


As Gaudi is a multi-amplifier system, the level of each band has to be adjusted. You may think it's an easy task only to turn the knobs. In fact it is very difficult.
There are several ways to adjust the multi-amp system. To make a long story short, the best way is adjusting little by little while listening to various kinds of sounds of various kinds of music and sensing frequency balance. I played many records and CDs that I am familiar with one and all. It takes a month or two one thing and another. [read more]

Listening & BGM Modes

(2016/07/19 added) {This feature, switching Listening Mode (multiamp) to/from BGM Mode (monoamp), has been removed since March 2015 in order to simplify the circuit of the network CD-211B A-NET and improve sound quality. So the following description is not applicable to the current Gaudi system.}

(2012/12/09 revised) {This feature, switching Listening Mode (multi-amp) to/from BGM Mode (mono-amp), has been changed as a result of upgrade of the loudspeaker SS-309 and customize of the network CD-211 in November, 2012. The new feature is switching a tri-amplified system to/from a bi-amplified system.

Currently, Gaudi can be used as either multiamptri-amplified or single-amp bi-amplified system. When I want to listen to music in the best sound quality, I choose the multiamp tri-amplified system. I call this configuration Listening Mode. When I want to listen with ease or to save energy, I choose the single-amp bi-amplified system. I call this configuration BGM (background music) Mode. [read more]

Things learned from Gaudi

I have learned a lot of things from Gaudi, which I have been developing for 39 years (as of 2013). These are somewhat different from things written in audio magazines, or can't be found in the magazines. The lessons learned from Gaudi are precious properties for me.
Especially, I would like to feature the following five lessons:

Importance of system design

I was an only high school boy and not proficient in technologies, when I designed Gaudi. The fact, however, was not disadvantage but rather advantage for me. I was not particular about each elemental technology. I pursued performance of the system as a whole. If I had been an experienced engineer those days, I might have been particular about circuit design or some mechanisms; I might have failed to pursue system performance, as the old sayings go, "cannot see the forest for the tree," "too clever by half." [read more]

Charms of vinyl records

On early days of Gaudi, my music source was mainly vinyl records. What's it today? Any digital media? No. It's still vinyl records. Of course, I have collections of CDs and SACDs, but they are no match for vinyl records, which contain 'full-of-life sound.'
Many people love vinyl records like me. Among them, some say they don't care if big noises are mixed with music, and some believe sound quality of the vinyl is superior for no rational reason. But I believe the excellent sound quality of the vinyl has scientific basis. [read more]

Merits of tube amplifiers

In my opinion, the biggest advantage of the tube amp is its high cost/performance ratio. Even low-priced products and handmade amps built with cheap parts have as high sound quality as high-end manufactured amps. [read more]

Superiority of multi-amplifier system

To describe the superiority of multi-amplifier system in one sentence, it is a pure sound quality oriented system with the least number of weak points.
The smallest number of parts are used between the output of the amplifier and the voice coil of the loudspeaker, so almost 100% of the power is conducted to the voice coil. In other words, power loss is minimum.
As a result, the sound quality of the system so excellent that it can reproduce any kind of sounds from Japanese taiko drum's powerful sound (it is almost like wind pressure) to a delicate sound like rustling of leaves in woods. [read more]

Significance of home-built audio systems

The top advantage of building an audio system oneself is that there is no limitation for system design. Either a mono-amp or multi-amp system can be chosen.
As a matter of fact, the multi-amp system is so difficult to build, unless it is handmade. Manufactured loudspeakers and amplifiers are not designed for multi-amp systems, and if you dare build a multi-amp system using the products, many problems will occur such as high cost, lack of space to install and necessity to customize the loudspeakers. If you yourself design and build each component, you can build a multi-amp system with a limited budget and install it to a limited space. [read more]

Secrets of Gaudi Sound

(2014/08/02 added)
The highest grade parts are not used in Gaudi, though the horn-loaded midrange drivers are expensive exceptionally. No state-of-the-art technology is employed. No elaborate process, no innovative circuitry nor mechanism is employed. Most parts and components used in Gaudi are old. The oldest one is the power amplifier for the woofers (MA-201C) that has been used since 1974. Many other old components like the analog disc player made in 1982 (PS-104) are used. Many off-brand, cheap parts are used. The speaker cables are made of thin wire that is only slightly thicker than human hair.
Nevertheless, why does Gaudi offer superb sound quality comparable to hi-end audio systems? [read more]

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Gaudi in Future

(2016/07/19 added) {
All the descriptions in this section are tentative. I'm going to design Gaudi II after scrutinizing Gaudi's good and bad points. Later, I am going to create another page and describe Gaudi II in it.

I am satisfied with the sounds of Gaudi, which are dynamic and vivid. But Gaudi is still under development and the original goal I set in 1974 is not achieved yet. I'll continue to develop it till it's completed.
By the way, I, who is an old-fashioned man, have been interested in recent technologies lately, because they might reduce cost of audio systems significantly. For example, PCBs with surface-mounted components on them. Any individual couldn't obtain such boards before. Today, an individual can design circuits and PCBs by using CAD and order the PCBs to a manufacturer. Surface-mount components are available on Internet. These facts are stimulating my eagerness.
I started the system design of Gaudi II, the next audio system that will succeed Gaudi.
(Block Diagram)

(2015/01/06 added) {
The concept of Gaudi II described above was my idea in June 2012. At that time, I believed a fully digital system was the best. In addition, I wanted to utilize my expert knowledge I had acquired through my 30-year-long experience as a computer engineer.
Later, I learned that digital audio technologies are not as mature as analog audio technologies and analog audio systems would continue to excel digital audio systems without a remarkable breakthrough. On the other hand, my physical strength is deteriorating and I've been struggling to build only one power amplifier recently. Now it's so difficult for me to build a fully digital system for myself.
I am going to complete the detailed system design of Gaudi II based on the concept of Gaudi in this year, and to begin designing new equipment according to the system design.
Current block diagram of Gaudi II)}

(2015/04/01 added) {
I'm planning to design Gaudi II simpler than Gaudi. The main differences between them are as follows:
(1) All the devices will be newly built or purchased except the loudspeakers (SS-309A).
(2) The number of amplifiers will be reduced from 7 to 3.
(3) The current 4 musical sources (vinyl, SACD/CD, the digital recorder and the PC) will be reduced to only one source (a digital player).
(4) Vinyl discs won't be replayed directly but recorded in DSD format (DSDIFF 5,6M) and replayed with the digital player.
(5) All the amplifiers will be battery-powered except the woofer amp.
(6) All the amplifiers will be of IC (op amps) based design. Tubes won't be used.

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