Not sure if this belongs here, but I don't think it would fit in better anywhere else on AK. MASTERS is a small form factor boutique Hi-Fi product line developed by the very recently deceased Mr. Hirano, owner of Ishino Lab. Mr. Hirano is a former engineer at Sansui, and developed the legendary X-Balanced circuit for Sansui. Mr. Hirano opened Ishino Lab in what looks like 1997 - his historical blog is here going back to 2007. We were all introduced to Mr. Hirano and Ishino Lab by @pete_mac in his seminal "A Sansui engineer's account of Sansui history and a continuation of Sansui's legacy" thread here.
With the recent passing of Mr, Hirano and the shuttering of Ishino Lab, I pursued some of the MASTERS product in the used market. Can you imagine? This is as close to REAL Sansui product made in the modern age. Using Sansui nomenclature, styling cues and most importantly Mr. Harino / Sansui circuitry! I hope others here were and are able to secure some of what is left out there, and share it with the rest of us here.
The first piece I picked up is a wild hybrid power integrated amplifier - the AU-900XG/B Custom. It is an X-Balanced 13 watt MOSFET integrated amplifier with 3 line level inputs and separable power amp. What makes this piece extremely unique is that it can be run on 100v AC and also 12v DC! At first I thought this was a portability feature, but no - it's a fidelity feature - Battery Power Sound!
Mr. Harino writes a thorough article on "Battery Power Sound" and the other specs are here.
" What is an ideal power supply?
Complete DC (no AC components (ripples) remaining.
The rectifier circuit reduces the AC components to a tiny level, but theoretically it does not become perfect DC. Batteries are perfect DC.
The amplifier circuit must instantly supply the required current.
Audio signals are discontinuous, transitional signals, so it is necessary for the circuit to have excellent instantaneous supply capability. Improving the power supply regulation rate can have a certain degree of effect.
Also, a stabilized power supply circuit can improve the first item to a certain extent, but it is sometimes pointed out during interviews that it cannot respond instantaneously.
This seems to be due to a response time problem, as it uses an NFB circuit.
Noise components (especially electromagnetic noise) must not be mixed into the current flowing into the speaker.
In recent years, with the spread of high-frequency switching devices such as converters, inverters, mobile phones, personal computers, and smartphones, the electromagnetic noise that is mixed into the power supply and radiated into the air from these devices has become very harmful. How to prevent this harmful electromagnetic noise from being emitted into the air has become an issue for audio amplifiers.
In particular, measures such as filters for electromagnetic noise mixed in from commercial power sources have been taken, but they are not conclusive.
In any case, the importance of the power supply is more important than the amplification circuit."
I've just powered it up on 100V AC and have had a listen on some moderately sensitive speakers. Definitely signatures of the later Sansui Sound. More time to listen and to build a DC power supply!
Looking right at home with all of it's ancestors!
With the recent passing of Mr, Hirano and the shuttering of Ishino Lab, I pursued some of the MASTERS product in the used market. Can you imagine? This is as close to REAL Sansui product made in the modern age. Using Sansui nomenclature, styling cues and most importantly Mr. Harino / Sansui circuitry! I hope others here were and are able to secure some of what is left out there, and share it with the rest of us here.
The first piece I picked up is a wild hybrid power integrated amplifier - the AU-900XG/B Custom. It is an X-Balanced 13 watt MOSFET integrated amplifier with 3 line level inputs and separable power amp. What makes this piece extremely unique is that it can be run on 100v AC and also 12v DC! At first I thought this was a portability feature, but no - it's a fidelity feature - Battery Power Sound!
Mr. Harino writes a thorough article on "Battery Power Sound" and the other specs are here.
" What is an ideal power supply?
Complete DC (no AC components (ripples) remaining.
The rectifier circuit reduces the AC components to a tiny level, but theoretically it does not become perfect DC. Batteries are perfect DC.
The amplifier circuit must instantly supply the required current.
Audio signals are discontinuous, transitional signals, so it is necessary for the circuit to have excellent instantaneous supply capability. Improving the power supply regulation rate can have a certain degree of effect.
Also, a stabilized power supply circuit can improve the first item to a certain extent, but it is sometimes pointed out during interviews that it cannot respond instantaneously.
This seems to be due to a response time problem, as it uses an NFB circuit.
Noise components (especially electromagnetic noise) must not be mixed into the current flowing into the speaker.
In recent years, with the spread of high-frequency switching devices such as converters, inverters, mobile phones, personal computers, and smartphones, the electromagnetic noise that is mixed into the power supply and radiated into the air from these devices has become very harmful. How to prevent this harmful electromagnetic noise from being emitted into the air has become an issue for audio amplifiers.
In particular, measures such as filters for electromagnetic noise mixed in from commercial power sources have been taken, but they are not conclusive.
In any case, the importance of the power supply is more important than the amplification circuit."
I've just powered it up on 100V AC and have had a listen on some moderately sensitive speakers. Definitely signatures of the later Sansui Sound. More time to listen and to build a DC power supply!
Looking right at home with all of it's ancestors!
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