Sony VFET Amplifier Part 2

[flowerpot]

The pre-ordering of VFET batch 3 has now completed, and all variations and parts, including the supplemental kit, have now sold out. There won't be a public release or any leftovers. Everyone from every ordering group did have a chance to purchase, but those in the later groups had to be very quick when their email invitation came. Apologies to anyone who missed out.

We've learned a lot from this process, and will try to make future kit sales a bit less stressful, but we hope the way we ended up doing batch 3 did provide a reasonably fair way of distributing these kits in a first come, first served fashion.

not sure how the pre ordering works, when the email came, it was already sold out ?? oh well could be because i was on the plane or something...

 

[gschuck]

Anyone tried the Deluxe 4U Steel chassis from the Store? Would be interested in your feedback.

I used the standard 4U and did the drilling myself. Worked fine and runs warm to the touch but not overly hot.

 

[Studley]

I emailed Gianluca and he told me the Deluxe 4U 300mm heatsink has a coefficient of 0.38.
Given that an ambient temp of more than 30 C is exceptional in the UK that should be fine for me.

 

[Variac]

Works fine in Northern California..

 

[Russellc]

The Deluxe 4U Steel heatsinks are 300 deep not 400.

You can indeed get 400, but IDK if you can get it drilled and tapped, which is the sweet part of the "Deluxe" version...look at drop down box.

Russellc

 

[Variac]

Here is the corrected BOM, the previous one has been deleted..
Sorry for making your lives difficult! Especially secanbj

 

[secanbj]

My life is very easy, thanks to all people in this forum. Especially people like you Variac, who actually give instead of always asking.

/Anders

 

[Brumjam]

Good evening folks. My VFET build has encountered its first issue. One channel has been adjusted ready for the VFET'S to be installed. I've got 1.5v across R5 and R6 with 0.1v at T18 relative to ground.

On the other amp board I adjust P2 to give me the required value of -10.7v at T17. However, with P1 fully anti clockwise I have +16.5v at T16. I need to get this down to +12.5v. Turning the clock fully clockwise only results in a change of +0.15 volts. Does this mean I've got the wrong value pot installed at P1? Anything else I can check? All my resistance readings checked out fine. Thanks, James.

 

[Nelson Pass]

Looks like your problem is bad regulator or bad resistor values.

 

[stijn001]

What was changed?

Here is the corrected BOM, the previous one has been deleted..
Sorry for making your lives difficult! Especially secanbj

 

[gary s]

Variac,

Do you know at this stage when the VFET Supplemental Kit will be available again for purchase for the people in the Batch 3 order?

Thanks for all of your work on this effort so far.

 

[Brumjam]

Looks like your problem is bad regulator or bad resistor values.

Thanks Nelson it looks like Q11 has died.

 

[Variac]

Q5 & Q6 were switched

gary s,

There were enough for about half the people ordering Batch 3 and they are now gone. I'm afraid there will be no more Supplemental kits.
People can use the BOM to order from their most local suppliers.

 

[gary s]

OK, thanks Variac, I can handle that.

 

[Manolo47]

Essential kits.......vfets...

What about the kit with the pc boards, vfets, brackets, etc. is that gone too?
Thanks.

 

[Dennis Hui]

What about the kit with the pc boards, vfets, brackets, etc. is that gone too?
Thanks.

It seems like they're all sold out:

http://www.diyaudio.com/forums/pass-labs/276711-sony-vfet-amplifier-part-2-a-275.html#post4989665

 

[juanitox]

It seems like they're all sold out:

what !? how i missed that ? sad so i will rebuild a choke load SITAMp with the last pair of 2SK82 i have ..

 

[marc brown]

I haven't gotten around to building my VFET kit and won't be able to in the foreseeable future. If anyone missed out on the third round, I'm going to be listing my VFET kit and supplemental kit in Swap and Sell later today. Once it's listed, first PM gets it.


Sent from my iPhone using Tapatalk

 

[grimberg]

Marc,

When more people start reporting how happy they are with their VFET amplifiers you will regret your decision. I would not do it. The kit has unlimited shelf life, just save it.

 

[roncagg]

Prerequisites for building this amp?

I am looking for suggestions for a project to do that would better prepare me for this, as I have only built the B1 buffer, never an amp. I have read this entire thread and love the back and forth, but don't understand much of it at a deep level. I can follow instructions but I don't want to risk these VFETS so I want to practice on something less complicated! Thanks for your suggestions.
Ron