Burning Amp 2023!

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SONY PUSH-PULL VFET AMP KIT FOR AUCTION

Friend of Burning Amp and Pass amplifier collector extraordinare, Dennis Hui has made a quite generous donation of a Sony VFET amp kit for the auction. Here is Dennis' description:

The parts are for building the 2016 Sony push/pull amp project which uses two vfets (2sk82 + 2sj28) per channel: https://firstwatt.com/pdf/art_diy_sony_vfet.pdf (This amp is differernt from the more recent SE designs using one vfet per channel.)

This is Jim's build guide thread for this push/pull amp: https://www.diyaudio.com/community/threads/sony-vfet-illustrated-build-guide.302380/

What I sent are the parts for building the two amplifier boards (and the metal brackets for mounting them onto a standard flat heatsink). One still needs a chassis and a power supply. (For the build guide, Jim used a 4U/300 deluxe chasis and the power supply used an Antek AS3222 (300VA, 2x22VAC) transformer and CRC on a store PS board)

In the box is an original "Essential Kit" offered by DIYAudio shortly after the publication of that project. The "Essential kit" includes

Around that time a "completion kit" (rest of the parts for the amp boards) was also offered, with Fairchild mosfets and Linear Systems jfets as substitution parts for the front end. I didn't get the completion kit as I fortunately had all the NOS Toshiba parts.

For 'completion' of this BAF kit I included the following parts from my personal stash:

  • 2 pairs of 2SK170BL/2SJ74BL jfets (4 jfets in total, ~8.6mA IDSS)
  • 2x 2SK2013 and 2x 2SJ313 front end mosfets
  • 2x ZTX450 and 2x ZTX550 cascode transistors
  • 2x IRFP240PBF and 2x IRFP9240PBF power mosfets
  • 10x TL431A shunt regulators
  • 4x blue LEDs for the amp PCBs
  • Resistors for the PCBs. The smaller ones are Vishay/Dale CMF/RN 1%. The 0.1R 3W current sensing resistors are Yageo/Vitrohm 1%
  • 4x 500R (Spectrol) and 4x 5K (BI Technologies/TT Electronics) single turn trimmers
  • 4x 1N4004 diodes
  • 8x 220uF and 8x 47uF Elna Silmic capactors.
  • 4x TO220 heatsinks for the front end mosfets.

This should be everything one needs to populate the two amp boards.

I believe the 'essential kit' has the TO-3 mica insulators for the vfets, but I don't know if it includes the TO-247 insulators for the power mosfets.

I consider this a harder project to build than the 2SJ28 SE "Lottery amp" which runs on an external SMPS. It's also a bit more involved than a standard FW build so I wouldn't try it as a first project.

Please let me know if this helps and if there are other things you want clarified.
 
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BEST WESTERN PETALUMA INN

It's very nearly booked, just a very few rooms for Friday and Saturday night.

It is on the South-West corner of E. Washington and McDowell.

Get off 101 at the E. Washington exit and go east. Take an immediate right into the Best Western parking lot, or and immediate left on McDowell and go two blocks to the Community Center.

-Tom-
 
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Aleph5 - Yes the (virtual) doors open at Noon PST. The actual speakers sometime after that - detailed schedule to follow.

For you people attending in person, the forecast for Sunday the 1st in Petaluma is a high of 74 degrees, mostly sunny.

-Tom-
 
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EIGHT DAYS A WEEK

  • T-shirts arrived today.
  • We will have La Esquistita Taco truck on-site on Saturday, Forrest Fire BBQ on Sunday.
  • Is there a volunteer to run a video camera on Saturday and Sunday? Chris has an issue that may prevent him from traveling to BAF.

-Tom-
 
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Vincent(WBS) who is donating the VFET amplifier requests the loan of a pair of speakers to use with a First Watt B1 Korg and or PAS DIY B1 amplifier. Since we will be playing one system at a time we can switch out someone else's speakers to his amplifier. Please post here if you can assist.
 
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Correction, Dennis Hui is the member who is donating an unassembled kit for the auction. I'm just bringing my completed 2016 VFET for people to hear so they know how unbelievably fantastic this amp is and thereby increase BAF's proceeds. I'm looking for the most revealing speakers that will do this.
 
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