Ongaku
Ongaku är Audio Notes bästa integrerade förstärkare. Hiroyasu Kondo och Peter Qvortrup utvecklade den ursprungliga versionen. Dagens Ongaku har förfinats avsevärt i jakten på det perfekta ljudet och anses vara en av de absolut bästa förstärkarna i världen. Ongaku bygger på 211 SE rör och levererar 27 watt med originalrör från Telefunken. Transformatorn består av silvertråd på dubbla AN-Perma 50 nickel C-kärna. Övriga komponenter håller samma höga kvalitet - Tantalum resistorer, Black Gate kondensatorer, och utgångstransformatorer av 99,99% ren silver. Filosofin vid design, komponentval och tillverkning är helt enkelt - inga kompromisser. Om är intresserad av en integrerad förstärkare och nöjer dig endast med det bästa - då är Ongaku det du letar efter.
Läs recension här.
Pris:
Ongaku - 845.000 sek
Q/A with Peter Qvotrup
Q: Is it correct to assume all tubes used on the ONGAKU are extremely rare and are of NOS, except for the two Jan Cetron 5R4WGB?
A: All the tubes are new old stock that is true, they are fairly rare, but not exceptionally so, since it would be absurd to use tubes that are so rare that they cannot be replaced, as this would have a terrible effect on the resale value of the amplifier!
Q: Is the UV211 the original GE NOS from the 1920s? My search shows that a pair of these tubes can be bought for about the same price of a pair of new WE 300B. Am I mistaken? What price can this tube actually command in today’s marketplace?
A: Well, our VT4-C/UV211s are from some time in the 1940s, the VT4 dates back to 1919, and had a thoriated tungsten filament and a carbon anode in 1924 or there about.
Q: What are the considerations for choosing the UV211 for the ONGAKU?
A: Whilst there were a number of considerations, it is important to first of all point out that there is a limited choice available when one wants to design a single-ended triode amplifier with over 20 watt power output and here there are really only 3 tubes available, the 211, the 845 and the GM70.
To us the main consideration is always linearity and the three tubes above are really the only that can be used if linearity is the main priority. Second consideration is availability, and here the 845 drops out immediately, as whilst they are available from China in quantity, now old stock versions are getting very hard to find.
So that left the 211/VT4-C as the only viable candidate.
Q: Which design aspect of the ONGAKU are you especially proud of?
A: The sound, I feel that we have broken new ground and “upped the ante”, so to speak on the competition.
Q: Why is 211-based amplification design so rare in today’s market?
A: For several reasons,
a.) It is hard to design a wide band quality output transformer with a high enough impedance to get a combination of good transfer behaviour, low distortion and good low frequency (the transformer in the ONGAKU ended up being 16kOhms primary impedance and is very hard to make).
b.) The high tension is 1500 volts in the power supply and over 1,200 volts on the 211 that is hard to handle in terms of layout and power supply design.
c.) a and b above make these amplifiers quite costly to make and that limits the size of the market.
This entry was posted on Tuesday, March 31st, 2009 at 2:26 pm and is filed under Integrerade Förstärkare, Ongaku. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
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