Post by tonyd on Dec 23, 2018 13:02:40 GMT 12
Why pay $7000 when you can get it here for only US$2115:
Discussed briefly here:
Accuphase A-65 (Fabulous Clone)
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Post by michaelw on Dec 25, 2018 9:38:09 GMT 12Oops, there was a slip up! This listing was withdrawn by the administrator gone ! wonder if it worked as well as my friend's $150 rolex. 
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Post by colinf on Dec 26, 2018 21:05:16 GMT 12
Just trying to find info on the output transistor pair they use, Sanken MJD20 and MLE20. I can’t find any info for them on Sanken's own website, where they don’t exist. MLE and MJD are not conventional Sanken transistor number prefixes either. In fact I can’t find any data sheet on them anywhere.
I can only assume they are counterfeit devices, and thus to be avoided. AMR-iFi R&D
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Post by michaelw on Dec 27, 2018 13:51:01 GMT 12
counterfeit amp built with counterfeit devices
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Accuphase A-65 (Fabulous Clone) Dec 27, 2018 14:05:09 GMT 12
- Edited Dec 28, 2018 1:16:16 GMT 12 by mijoh
Post by mijoh on Dec 27, 2018 14:05:09 GMT 12
They are possibly counterfeit, but there is a seemingly reputable company in California that specialises in discontinued and hard to find items that sells them. Maybe that's why they are not listed on the Sanken website.
 spwindustrial.com/sanken-150w-audio-hp-mosfet-mjd20-and-mle20/
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Post by colinf on Dec 28, 2018 1:56:58 GMT 12
Wow £91.79 (NZ$172.50) a pair at SPW Industrial!
Mable Audio US$15 (NZ$22.24) for the same thing. Even if they are old devices, I still can’t find any data sheet on them. That means the designer needs to work out the specs by measuring them. AMR-iFi R&D
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Accuphase A-65 (Fabulous Clone) Dec 29, 2018 13:55:50 GMT 12
- Edited Dec 30, 2018 3:24:35 GMT 12 by mijoh
Post by mijoh on Dec 29, 2018 13:55:50 GMT 12
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Connoisseur
Accuphase A-65 (Fabulous Clone) Dec 29, 2018 21:54:04 GMT 12
- Edited Dec 29, 2018 22:09:38 GMT 12 by colinf
Post by colinf on Dec 29, 2018 21:54:04 GMT 12
Thanks Mijoh, they look interesting. Perhaps they were Sanken's entry into the world of complementary audio mosfets. Sanken is most known for their LAPT bipolar transistors and perhaps that overshadowed their audio mosfet production.
I wonder what their temperature coefficient curve was like, and their forward transfer admittance (Yfs). They look like a similar device to Toshiba 2SK1530 / 2SJ201, whose Yfs was about 5S, about five times the Hitachi 2SK1058 / 2SJ162. The popular IRFP240 has a Yfs of about 11S. It might be a risk to try the Chinese remake version but could be fun to try. I think I’ll stick to Exicon mosfets though, as their Yfs is very low and thus the mosfet is, to an extent, self-protecting from over-current. They also have negative temperature coefficient which makes biasing easy and also self-regulating. The Toshibas have positive temperature coefficient which makes them less simple to bias correctly. The Hitachi mosfets in my hybrid amp have been operating flawlessly since about 1994! Exicon now make Hitachi-style lateral mosfets, taken over from Renesas. AMR-iFi R&D
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Accuphase A-65 (Fabulous Clone) Dec 30, 2018 12:45:21 GMT 12
- Edited Dec 30, 2018 15:30:32 GMT 12 by mijoh
Post by mijoh on Dec 30, 2018 12:45:21 GMT 12
I think you're wise to stick to the likes of the Exicons. Although these Sankens have a following in Japan and China I can find very little discussion or information about them in audio forums elsewhere. With a price range of $22 - $172 a pair, are they all genuine, or like the subject of this thread, the Accuphase A-65, counterfeit?
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Post by colinf on Dec 31, 2018 1:16:15 GMT 12
Looking up the service manual for the Accuphase A-65 shows the output transistors to be Toshiba 2SK3497 / 2SJ618. They are 180V, 10A, 12S devices and look interesting!
AMR-iFi R&D
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Post by mijoh on Dec 31, 2018 21:05:37 GMT 12
As I recall there was quite a bit of discussion about the 2SK3497 / 2SJ618 combo over on diyAudio.com solid state and Pass Labs forums a few years ago.
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