vfet

I have a box of Siliconix VFETs model VM1013 Power VMOS transistors in a TO-3 package that I acquired back in the mid 80s. I tried searching for the datasheet but could not find it. My search did lead me to this forum which appears to have a great deal of interest in VFETs. I don't know if...

I recently pulled the trigger on this amp, I was looking for a new VFET amp to add to the collection, and I was eventually able to find this one for a reasonable price. Unfortunately, since the local European version is generally too expensive for my pockets, I decided to buy the 100V Japanese...

See below to check out the restoration I just finished on a gorgeous Sony TA-5650 VFET integrated amplifier! I’m starting to post more and more restoration and repair videos to YouTube. Hope you all enjoy!

I was told how valve like these Sony amps were and that description is spot on .

Hello all, I’ve recently come across a Yamaha B-2 in quite nice shape. Everything seems to be working properly as it produces sound (from videos sent to me), and quite good sound at that, as the seller almost had second thoughts. Reading through numerous threads about the B-2 on this forum it...

Greetings all, I purchased a Sony TA-4650 VFET amplifier as a quarantine project and thought I'd start a thread to document my efforts. My Stax headphones go well with warmer, less-fatiguing amps and I left my Pioneer M-22 back in NYC, so this seemed like a good pick-up. Plus, I want to see if...

Many people said it couldn't be done so I saw a challenge. On the Audiofreaks forum I documented (in Dutch) my efforts in getting a dud Sony TA-4650 going again without having to resort to tying to get unobtanium 2SJ18/2SK60 SIT transistors. I decided to use IRFP(9)240 instead. Of course the...

Hello! First post here. I am an American who has been living in Japan for the past 12 years. I bought a Yamaha B-2 a few years ago. It had LEDs and gold plated speaker terminals on the A channel. I paid about $100 for it junk because one channel had no sound. Deoxit fixed that easily! The...

I bought recently this amplifier sold as not working, but with clicking relay according to the seller. I did not test it. Right when it arrived I removed the precious VFET transistors, checked them and they're all still OK, so I put them aside. I started replacing the killer diodes, then...

Since there is no unique source of information on the bias for the Sony TA-8650, with no mention of changes from the 125mV in the original Sony Service manual in any service bulletin, and rumors from a Japanese forum of a required new value of 30/40mV, I decided to do a quick and by no means...

I got my hands on a beautiful TA-8650 that I bought broken a couple of weeks ago and brought back to life. It's the best example I have ever come across, nobody had ever worked on it, and it was in storage for a very long time (in a very dusty place). It came with 3 of 2SK60 gone and a burnt...

Hello, I just completed (or so I thought) the restoration of a Sony TA-5650. I am a novice in electronics, and this is one of my first restorations. I replaced the kilelr diodes, added the voltage doubler mod for the power supply, replaced the transistor that control the DC offset, recapped it...

Hi there, I've just finished refurbishing a Sony TA-4650 VFET amp. First thing I did was remove the VFETs, they all tested fine on the DMM, so I went on replacing the suicide diodes, making the PSU voltage modification in order to center the B+/B- values, and replacing four 1.5K ohm resistors...

After building the 4650 integrated amp up and hearing it sound so good, I had a hankering to see what more power sounded like. I snagged a 5550 power amp on Ebay that was in pretty good shape. Here is a link to the HFE page on the amp with the owner's and service manuals...

I'm glad to be adding something to the forum after having followed so many posts! This is a restoration project for my first-ever audio purchase--a TA-4650 from an enlightened stereo person who brought me into the audiophile world when I was 16. There is a lot of love in this device...

I'm sure this has been asked many times before, but does anyone have a line on real VFETs? Specifically 2sk60 / 2aj18, for a TA-5650. I've got a unit with 2 bad VFETs and I'm on the fence about whether to hang on and try to find replacements, or just part the thing out. eBay seems to be chock...