NOS Hafler (HITACHI) 2SJ49 and 2SK134 Power MOSFET pair

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NOS ORIGINALS. NOT "REPLACEMENT" DEVICES. NOS Hafler (HITACHI) Power MOSFET pair: 1 N-channel; 1 P-channel . Original out-of-production Hitachi parts. Hafler QN112 / QP112 -- as used in the Hafler DH120 / DH200 and DH220. Your bid is for TWO devices -- one pair. Brand new parts purchased directly from Hafler years ago. RARE Hafler (Hitachi) Power Output MOSFETs... BACK IN STOCK! An especially popular Hafler parts category has always been the 1980s-1990s Hitachi -manufactured power output MOSFETs used in Hafler's famous line of amplifiers -- as well as in amplifiers from Tandberg, Perreaux, Hitachi, MOSCODE and Soundcraftsmen . Popular devices... but also now long out-of-production and very difficult to locate at anything resembling a sane price.A quick search online will reveal that my prices are a full 50-75% lower than the pricing from others still offering these original Hitachi parts. And each device I sell is tested and MATCHED on an original Hafler DH-919 MOSFET Tester-Checker.Note: Devices marked with the same lot code sometimes implies similar performance... but not always so. That's why I test and match each device before shipment. The N-channel devices are matched to themselves; the P-channel devices to themselves. Matching the N's to the P's is not electrically required -- nor is it something Hafler ever did. (Looking at a sample Hafler-built Pro5000 board I have before me, the 2SJ56 mosfets are gate-rated "2" and the 2SK176 mosfets are gate-rated "4." In any case, gate number matching the N and P devices is not possible given the quantities of devices available to me. A personal tale of woe regarding modern "replacement" MOSFETs. Your Hafler amplifier circuits were specifically designed around the electrical characteristics of the Hitachi-produced MOSFETs -- not Exicon. In our experience, the use of "Exicon" branded substitute parts resulted in parasitic oscillations, higher distortion readings, and a myriad of circuit instabilities. This is not to say that Exicon parts are "defective" -- only that they are just different enough from the original Hitachi parts to cause some real headaches in Hafler circuits. We finally had to quit using Exicon because t appeared to be no circuit "band-aid" that could be universally applied to every unit. The .1uf capacitors that might arrest circuit oscillations in one DH500 did not arrest them in the next. To eliminate any doubt as to the source of these circuit ills, we could pull the Exicon devices out and replace them with original Hitachi, changing nothing else in the circuit, and the amplifier being tested would immediately become electrically stable. It would have been GREAT if the Exicon parts had worked for us. But they didn't. So we had to sell off our inventory of Exicon and return to using Hitachi only . T will come a day when these authentic Hitachi high-power MOSFETs are no longer availale from me. But that day is clearly not now! So why buy "replacement" devices when the original spec parts are still available... for only a bit more cost than the substitute parts? Spare yourself the frustration, expense, and aggravation I went through of trying to "make" an inexact aftermarket part work in your Hafler circuit.Thanks for looking and good luck! OVERSEAS BIDDERS WELCOMED! We Americans well remember the days when the U.S. Dollar was strong... and we also remember what a thrill it was to see how much a U.S. dollar would buy overseas. Well, that situation has now reversed itself. And, honestly, I'm happy for those of you living outside the USA. Things go in cycles none of us mere mortals controls. So now it's YOUR turn to shop for products at advantageous currency pricing in the U.S. We welcome your business! In fact, we've always WANTED to sell worldwide. (But our respective governments created so many obstacles that we simply could not afford the burdensome time and paperwork to make it work.) But NOW it is possible to generate all the required U.S. Postal Service... read more

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