WHAT'S BEING OFFERED?
A DIY low-power, single-ended, zero-feedback, class A amplifier using VFET followers biased by a constant current source with multiple front-end options.
Each VFET kit contains everything to build a fully working amplifier:
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Stereo front-end from Nelson (and later optionally DIY from a menu of 4 front-ends from Mark Johnson, to be released as complete kits)
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Stereo partially assembled and tested output-stage follower-channels, including VFETs
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36V Meanwell SMPS (You can DIY a linear supply at a later date if you want)
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A custom chassis designed just for this project
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All the other parts required to complete the amplifier
The 360 NOS Sony VFETs being made available (1 per channel, 2 per amplifier) may be some of the last unused VFETs on the planet. This offering is likely to be the last bulk offering of VFETs by anyone to the public. As such, only 180 stereo amplifiers are available.
For more details please read Nelson's DIY Sony VFET Part 1 thread.
WHY? A THANK YOU TO THE PEOPLE WHO HAVE SUPPORTED THE COMMUNITY OVER THE YEARS.
These kits and chassis are being offered at-cost by Nelson Pass and diyAudio to say thank you for everyone's participation and contributions to the diyAudio community over the last 20 years.
The price has been kept as low as possible while covering overheads. It is expected a small profit will be made, 100% of which will be donated to and split between the American Foundation for Suicide Prevention and the Prostate Cancer Foundation. Additionally, purchasers of the kits can optionally elect to leave a "donation tip" at checkout. Direct donations can and have also be made by people who wished to make a contribution.
You can read more about these charities, how much has been donated so far and how you can donate on our Donations to two great charities page.
RELEASE SCHEDULE
An initial batch of 90 stereo amplifier kits using (and including) P channel VFETs are being released now.
Around two months later a second batch of 90 using N channel VFETs will be released.
UPDATE 2021-04-23: The window to enter for batch 1 has now closed and batch 1 has shipped. Everyone who entered the draw for batch 1 has automatically been entered into the draw for batch 2 (except of course the winners from batch 1). There will be another small window opened for batch 2, but due to the overwhelming response to batch 1, we are not going to send out any emails about when this will occur. If you are super keen, keep your eye on the the lottery discussion thread. News about the second window will be published there a few days before it happens (and nowhere else).
HOW MUCH?
Grab a chair...
- Parts kit (including VFETs): $259
- Chassis: $259
- Parts kit plus chassis (complete kit): $499
Prices exclude shipping (chassis from Italy, parts kit from USA).
Parts kit contains everything you need to finish the amp except chassis, tools and solder.
IS THIS FOR ME?
This is an advanced-beginner-to-intermediate level DIY project, not recommended for first time builders.
It would be ideal for those who have already successfully built an amplifier before (like the Amp Camp Amp) but are looking for a bigger challenge (or not interested in the risks associated with a mains-wired project).
A build guide will be forthcoming.
HOW DO I GET ONE?
There is expected to be more demand for the channels that include VFETs than there are units available. So we're running a lottery.
We’re also putting aside a number of kits for people who are lucky enough to already own a pair of same-sex VFETs. If you’re in that boat don't enter the lottery and see the FAQ at the bottom.
HOW DO I ENTER THE LOTTERY?
One final window is being opened to enter the second round of the lottery, at 9PM UTC on Thursday 29th July 2021. Please read this post for more details.
Here’s how it works.
- On April 7th or just before 8PM UTC (1PM PDT, 4PM EDT) go to diyaudio.com/vfet
- You will be redirected to a thread in the Pass Labs forum after a short delay (1-6 minutes) to spread out our server load. Please wait until you are redirected.
- The thread will be open for 15 minutes and then locked
- Make a single post in this thread to enter the lottery
For the benefit of our members on the other side of the world, a second 15 minute window will be opened to post in the same thread, on April 8th at 8AM UTC.
We're taking a "Hope for the best, plan for the worst" approach. We'll be monitoring the server and if it has any issues, the event will be extended until there's a full 15 minutes without issues. Additionally, if our database connection limit is hit (which prevents the server from overloading), you'll be provided an off-site link to enter.
Winners for the first batch will be contacted privately by PM over the next 24 hours, and invited to purchase. You will have 96 hours to complete the purchase after which your invite will go to another member.
If there are more entries than there are kits available, winners will be chosen at random with the following weighting to say thank you for past contributions:
- Every entrant gets one ticket
- An additional ticket is given for every thread in the Pass Labs forum you have participated in (one ticket per thread; only participation before April 1st 2021 will be counted)
- An additional ticket is given for every year you have been a paid member (before April 1st 2021)
DON'T MISS THE EMAIL
We'll contact winners by PM. You will get an email notice to your forum email address. Please ensure you whitelist our email addresses in your email system:
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Add contact@diyaudio.com, contact@diyaudiostore.com and webmaster@diyaudio.com to your address book / contacts
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Move any emails from these addresses in your "promotions" tab to your "primary" tab
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Mark any emails from these addresses in your spam folder email as "not spam"
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Consider setting up filters to mark emails from these two addresses as "high priority" and "not spam"
WHERE CAN I FIND OUT MORE?
Please read Nelson's DIY Sony VFET Pt 1 announcement thread on diyAudio.
FREQUENTLY ASKED QUESTIONS
Q: I already have VFETs. Can I buy a kit?
A: Yes. We will have a number of kits set aside for people lucky enough to own a pair of authentic P channel, or N channel VFETs already. We will need to verify the authenticity of your VFETs. Please email the helpdesk at contact@diyaudiostore.com for details.
2021-04-11 UPDATE: Chassis and VFET-less kits will be available in batch 3, expected to ship in August 2021. Anyone will be able to pre-order as many chassis or VFET-less kits as they like. The pre-order will take place in May or June 2021. We will send an email to the store mailing list about this when the time comes, or contact the helpdesk and we'll make a special note to email you a reminder when it comes time to pre-order.
Q: Can the chassis (or any other part) be purchased separately?
A: We have made 200 chassis to go with the limited release of 180 semi-assembled VFET stereo amplifier kits Nelson has made available. 20 extra were made for reshipments in case of shipping problems and a few for people who already had VFETs but we underestimated how many people had their own VFETs. If you have your own VFETs please wait to pre-order for batch 3.
Q: I want to spam refresh at 8PM April 7th UTC and I'm worried I might overload the diyAudio server. What should I do?
A: Please don't refresh any page more than once per minute. The best thing to do is load www.diyaudio.com/vfet in your browser, and at some time between 8:00PM and 8:10PM reload the page, and you will be redirected to where you can post.
Q: What happens if the server crashes?
A: If this happens don't stress. The server will be being monitored carefully. In the event the server is overloaded (likely if thousands of people arrive at 8PM) we'll extend the entry window for as long as required for things to return to normal for a full 15 minute stretch. Please don't try to refresh more than once per minute.
Photography courtesy of Thuss + Farrell