Sansui Amplifiers 山水擴大機的歷史

不知為何，山水在國內外的鐵粉超多，有山水老資料庫，也有山水零件販售網，連二手拆下來的部件、PCB都賣，也很保值。相較於其他品牌，好像沒有一個品牌有那麼多人對"品牌"本身那麼瘋狂的，我的意思是，也許有人喜歡SONY某某機型、Pionner某某機型，但卻不像山水迷那樣，是對於這個品牌很執著信任，忠誠度非常高。

找了一些資料，根據已有的年份表再加以延伸
數個資料來源認為山水大約在1980~1990是黃金時期，1984年品質低谷，採用塑膠面板；後續90年代則力圖振作，但遇到日幣對美元升值、決策方向錯誤，也沒有新招可出，最後在2000年左右無力回天。

The History of Sansui Amplifiers.

HP 3456A DMM

6.5digit desktop DMM, with LM399*1 as Voltage Ref.

SOLID STATE TRIODE series AMT “WARM STONE”

SOLID STATE TRIODE series AMT “WARM STONE”

Kampf V.A.

INTRODUCTION

Tube sounding almost initially became a kind of standard guitar sound, and it is so to this

day. The most frequently used in guitar amplifiers, low power dual triodes such as EСС83

(12AX7). Despite the undoubted musical merits of this triode, it does have some drawbacks

common to all vacuum tubes (fragility, low efficiency, limited resources, deterioration of character-

istics over time, etc.), therefore has long led development engineers to think about creating

devices which will replace the tubes, but devoid of the above-mentioned drawbacks.

Back in the 70 years of the twentieth century in the music industry have been carried out first

attempts to use low-power semiconductor tube replacements. In some models of company

Mesa-Boogie, for example, in the first stage instead of the usual triode 12AX7 was used the

components of the company Fetron. It should be noted that the Fetron's components was

intended primarily for telephone exchanges, where they had been used since the late 60's

in order to save electricity. Substitutes of tubes from FETRON were built in a cascоde

schematic, which provided the ability to operate at high voltages, but they have a pentode

output characteristics, which is clearly visible in the graphs the output current-voltage char-

acteristics [1, 2], therefore, a direct replacement for triode devices with pentode's CVC led

to significant differences in the sound. This circumstance, of course, played a considerable

role in that how cold enough the musical community met such innovation in guitar amplifiers

and, as time has shown, substitutes of tubes from FETRON not taken root in the world of

music.

Some time ago the other companies have also implemented a significant try to the “tube

heights”. Unfortunately, the manufacturers have not accompanied its products with sufficient

technical documentation, so we have no right to speak about conformity of triode current-voltage

characteristics (CVC), or other aspects of the triode vacuum behavior emulation, especially

when dealing with high signal levels. We’re just stating a fact of issue some semiconductor

tubes, leaving to the music community itself the right to form an opinion about the sound

properties of these devices.

AMT Electronics has its own tradition of building tube replacements. In 2007, the company's

engineers used their version of the cascode switching-on JFET and NPN bipolar transistor

in the SS-20 preamp, allowing to accelerate the signal without limitation to several hundred

volts with a minimum of noise floor. Then, were introduced circuits into the cascades that

simulate the grid limitation, and the shape of the signal became very close to that of the sig-

nal on the 12AX7. In 2007, on the basis of article [4] the company started the development

of low-voltage cascades that emulate the behavior of triode at the restrictions. Despite the

use of field-effect transistors with a pentode characteristics, engineers managed to get the

waveforms of signals which are similar to restrictions of a vacuum triode and in 2008, the

world saw the first series of preamps LegendAmps (LA). In 2011, as a result of hard work

on the modernization of low-voltage cascades, a series LA2 were born, which continues the

tradition of using field-effect transistors in guitar preamps.

By 2012, the AMT engineers had accumulated a lot of experience in the development of

semiconductor stages, which are in one way or another substituting the vacuum triodes,

and in early 2012 the company AMT began intensive work on creating a complete functional

semiconductor analogs of popular tubes used in guitar amplifiers.

In this article, we introduce the reader to the main points that characterize the sound of the

vacuum triode in guitar amplifiers and their implementation in the solid-state triode

AMT WARM STONE. Description of high-power solid-state penthodes and tetrodes

expected in the near future in a separate article.

Basic principle operation of the semiconductor triode.

1. "Triode character" of sound of the vacuum triode in the linear region is largely

determined by the shape of the output characteristics, namely, by the strong dependence

of the anode current Ia from anode voltage Ua at a fixed potential of the control grid Ug =
const (pic. 1).

In triode the change of anode potential A U

under the influence of the signal on the grid G U

led to a change in electric field A E

between the anode and the cathode, which is summed

up with a field of the control grid GE

in such a manner that prevents the change of the grid

field under the influence of G U

(Pic. 2), that determines the presence of the inner negative

feedback connection in the triode - parallel to NFB by voltage [4].

Saving BiJou Tune Amp

Bijou

https://web.archive.org/web/20110909022955/http://www.cavalliaudio.com:80/diy/bijou/main.php?page=ampschematic

Trioderizer 將FET三極管化

Structurally, vacuum tube can be categorized into triode, pentode, etc. The famous tubes, like power tube WE 300B and signal tube ECC88, are triode tubes. The curve of triode, pentode are very different. After transistor is introduced to the world, we realized that FETs are more similar to pentode, instead of triode.

There are exceptions, V-FET that are invented by Japanese have triode-like curves; nevertheless, V-FETs are now obsolete and extremely rare plus expensive. V-FETs are produced in late 1970's, and are soon discontinued due to many reasons. Anyway, part of people love its sound, they think V-FET sounds "tubey", and this is the most attractive reason of getting V-FET---A transistor with vaccum sound and as powerful as common transistor!

A 300B amplifier can generate something like, say, 10 watts or so. But transistor amplifier including V-FET style, can easily generate several hundred watts.

You can call V-FET as a power tube without filament heat, that the truth.

Since V-FETs are now gone, then it comes to the question: Can we make transistors like triode?

The key to the answer might be trioderizer or solid state tube.

韓國朋友來信: 有關JOB4修復

The request of JOB4 repair.

一位韓國朋友透過DIYA來信，說有一台JOB4想請我協助修復，據稱先前在韓國維修已經被搞得一團亂，有燒焦的電阻，維修完之後開聲沒多久就掛掉了。我建議他可以考慮Nuforce STA-200(因為根本就是JOB的複製)，STA-200售價再高也不超過800USD，遠低於JOB4。但對方告知，這台機器對於他與他的父親都非常重要，有其特殊意義。恩...該怎麼辦呢?

我請他傳了幾張內部照片。JOB4的特點是把軸向電容都塞滿在PCB上面，所以其實我看不到維修的痕跡跟燒壞的電阻。從外觀來看，這就是典型的JOB、Goldmund機器，功率晶體採用巧妙的上下安裝，輸入採用A2之類的模組，電容用軸向電容，空間非常節省，設計精妙。不過說實在的STA-200打開也是這副樣子，已經修好幾次然後燒了一堆零件了，除了有特殊情感意義，不然真的沒必要再修了。

持續溝通中。

Russian Amanero-based USB-I2S Converter

這是俄國人做的USB轉I2S方案，一開始我以為這是新的方案，不過發現基本上這是跟Amanero購買授權製作的特殊版本，額外加了FIFO跟隔離等一些功能，並且也對各種DAC具有很高的相容性而不需特別調整開關、跳線帽等等，可以相容常見的現代Sigma-Delta DAC，也支援NOS模式的R2R DAC，也可Dual Mono/Stereo，非常方便。
最新的版本稱為Bolero V3，另外也有一個更多界面的DDC，以Bolero為核心的Transport Charleston。
Charleston的相關規格如下:

具有三種輸入(USB, Opt, Coax)，並且都可在輸出端得到相同理想的I2S。採用UAC 2.0規範，MAC系統不需驅動。

1個USB輸入界面，以Amanero韌體為核心，將輸入訊號寫入FIFO緩衝，進而輸出I2S訊號。最高支援32bit/384KHz。
3個SPDDIF輸入，包含兩個Toslink以及一個75Ω 同軸界面。採用AK4113為接收晶片，並將訊號輸出給Charleston，接著寫入FIFO緩衝並輸出I2S。

資料輸入為非同步協議，FIFO緩衝中的時鐘訊號是由DAC的主時鐘所設定。Charleston的演算法確保輸入訊號與輸出訊號的音量同步，並移除多餘訊號。輸入的資料格式只能是PCM，最高支援到24bit/192KHz。

由於說明手冊都是俄文，看不懂；Charleston V3左下角有一個Mini-USB2端子，應該是用來更新FIFO的驅動與韌體。

http://forum.vegalab.ru/showthread.php?t=80671&page=5

USB-I2S Solutions: Review and Research

1) DIYINHK XMOS 768kHz DXD DSD512 (DSD1024)
https://www.diyinhk.com/shop/audio-kits/116-isolated...o-i2sdsd-pcb.html
2) Amanero CPLD/FPGA Combo384
3) DIYINHK XMOS 384kHz DXD DSD256
https://www.diyinhk.com/shop/audio-kits/138-isolated..dsdspdif-pcb.html
4) WaveIO XMOS isolated
https: //luckit.biz/
5) MiniDSP USB Streamer
https://www.minidsp.com/products/usb-audio-interface/usbstreamer
6) JLsounds I2SoverUSB XMOS isolated
http://jlsounds.com/i2soverusb.html
7) Russian Charleston V3
http://forum.vegalab.ru /showthread.php?t=80671

https://www.danomsk.ru/shop/19-konstruktory-i-elektronnye-moduli/178189-usb-spdif-transport-charleston-do-32-bit-384-0-kgts-energyaudio/

Amanero Isolatior: built-in isolator without adapter?

The XMOS-cored USB to I2S has a lots of implementation, since its design is widely open, we have seen so many variations that includes built-in Galvanic isolator.

That means many USB XMOS converter cards can directly output isolated I2S signals, for example, WaveIO provides both isolated and non-isolated output.

Another beloved USB-I2S solution is Amanero Combo384; unlike XMOS, Amanero is provided as OEM solution, people get fully assembled PCBs from Amanero. Barely no varied version is on the market.

So, there is no Amanero Isolated USB to IIS officially. We have to make it on our own.

Luckily, some HiFi guys have the same idea. Below is the application note of Combo384, the manufacturer published a schematic that provides isolation.

The Isolation solution suggested by the manufacturer:

The Isolation solution designed by a Japanese engineer.

Here we can see the key pinout of combo384, which has a standard 20-pin I/O. The I2S signal are located at pin 1, 3, 5, 7. These are the 4 pins that we focus and have to be isolated.

About the Isolator IC.

Isolator IC inevitably increases, or say, adds jitter to the signal chain. It provides isolation but also jitter that we don't want most. So, this is kind of dilemma, we need isolation but not additive jitter, as jitter is the enemy that hifi guys tries their best to eliminate.

Now, what we can do is to choose the best isolator with lowest additive jitter. IL715 seems to be a good one.

Many DIY projects or application notes suggest TI's ISO and ADI's ADuM series solution.

However, looking at the datasheet, TI's ISO series has about 4~8 times jitter higher than IL715!

I found a open sourced IL715 USB Isolator. You can download it here.

However, what we need is a isolator that are at the last stage of I2S output of Amanero or XMOS.

I saw some DIYers has already make this idea real. The I2S output was "filtered" by isolator, then there is final output to downstream devices or DAC.

I want to make it more delicate. That means the isolator is integrated on the board, and the 20-pin I/O provides signals isolated already. In this way, no isolator adapter is needed; this makes Amanero Combo 384 directly pin-to-pin compatible with official version, no change is needed!

Let's start the work.

Unisolder 5.2

[Unisolder 5.2]

哇，開源到這種狀況，連Layout的原始檔也有了。
金屬加工的問題，Maker社群用很智慧的方式解決了，其實就用FR-4板子來當面板就好了嘛! 這樣設計十分方便，只要用PCB軟體把外型畫一畫，連同主板一起洗版，不就完美解決了面板開孔加工的問題了!
而且，畢竟其本質是PCB，其實也可以順便把一些面板開關、電阻、LED一起放上去，又完美解決了按鈕問題。
話說小弟上次研究了韌體，由於是開源的，所以不是一長串HEX碼。因此，如果要對烙鐵進行個小超頻是可以的，例如JBC C245，官方最大130W，可以簡單透過修改數字，小超頻一下到140W。
C210是功率較小的版本，當然也可以如此，讓C210有接近C245的功率。
行有餘力的話，也可以針對溫度曲線最佳化，像是JBC有一點點的Overshoot(但其實已經很好了)，這是為了加熱速度而付出的trade-off，所以相反的，如果追求精確的溫度控制，我們可以把trade-off反向一點，讓加熱速度稍緩一些，改善Overshoot的狀況。

Ultra Low Noise Amplifier 60dB 80dB 120dB

[ULNA超低噪音放大器]

這種機器的原理是將待測物用電容隔離，然後放大很多倍，例如一萬倍，然後連接示波器、電表、頻譜分析儀等得到數據，然後回推出數據。例如待測物經此機器量測到10mVpp的波紋，那除於一萬倍就是原本的波紋量級了。
原本打算自己做的，不過耗時又比較貴，於是買了DIYer的成品機，功能算多，可調GAIN，也可調量測的頻寬。
一般量測LDO跟基準類的需要不同機器，因為阻抗不同，畢竟那種是計較到pV等級的噪音要求。我的需求是20~20KHZ的量測，Audio等級的就行了，所以選擇此機。
未來將與QA401進行密切合作，有了此機器之後，可以量測20~20KHZ內的零件、放大器噪音，那麼就可以建立自己的資料庫，不須仰賴別人的量測結果了。

I2S FIFO Low Jitter Reclocker

頗有名氣的IAN'S FIFO，經過六七年的開發演進，應該是DIY界對於JITTER、RECLOCK最具盛名的解決方案了。目前預購的是FIFO 2020 Q3版本，法國網站已經有上架了。

FIFO Pi簡而言之有三大功能:
1. 訊號電氣隔離

2. 緩衝訊號並重整出低Jitter訊號
3. 重整時鐘訊號，並且為超低Jitter

PCM支援到768KHZ，DSD支援到DSD1024，都是相當前衛了。
FIFO PI有一個最狂的功能就是內建硬體昇頻，支援16BIT昇為32BIT；等於是PCM 32BIT/768KHZ，這是市場上DAC能支援的最高規格了!

Q3做了很多改進，是目前最新的版本。對於像我不用樹梅派的人來說，其實也可以很好地相容IAN'S FIFO，他都幫你想好了。透過"BRIDGEPI"，使用者可以插入一張常見的XMOS或者AMENERO USB轉I2S-20PIN的轉接卡。那麼透過Bridge-PI，USB轉成I2S的訊號就可以接入PI的GPIO針腳，就可以跟FIFO相容了。
最後，可以選擇TRANSCEIVER或者TRANSPORTPI來輸出LVDS BY HDMI界面或者同軸等。
目前比較新的DAC都有獨立的HDMI I2S接口，因此IAN'S FIFO也可以很好地相容這樣的傳輸介面。

IAN'S FIFO應該是目前最好的DIY USB轉I2S界面了，FIFO Q3報價是135USD，加上BRIDGEPI=29USD、HDMIPI=25USD，那麼對於以電腦當訊源DIY者來說，整套FIFO最低是189USD，加運費大概六千元台幣。

在基本款上面，還有一些可以按照個人喜好升級的地方，像是那兩顆XO，原廠是沒有給到CCHD-975這種等級，這要自行升級；另外最近PULSAR XO聽說評價也不錯，當然也可以相容FIFO Q3的DIP-14腳位。

FifoPi Q3 new improvements

Supports XOs with and without an OE pin
Uses pure 3.3V for clean side DC power input. All LDOs at the clean side had been removed to make it possible to work with a better 3.3V LifePO4 or ultra capacitor power supply solution directly.
With optional u.fl XO input sockets to work with external XOs through coaxial cables.
Supports single XO mode
SMT XO sockets, easy to replace and remove.
With both isolated MUTE and isolated DSD EN outputs to work better with pure DSD DACs or external PCM/DSD DACs (through TransportPi or HdmiPi).
New 300MHz high speed flip-flops to lower the additive jitter of I2S/DSD re-clocking at finial output stage.
Optimized decoupling networks to improve power supply performance.

ElecFi Makers

Voltgen