FS: Nelson Pass "VFET2" Front End PCBs

[luvdunhill]

Here's the First Watt article in question:

http://www.firstwatt.com/pdf/art_sony_vfet_pt2.pdf

I have a few of these PCBs left-over that I'd like to offer up to the community. The price is $7.50/channel plus shipping. I'd expect shipping to run between $5 (US) and $15 (international) - but the amount will be payed after they ship for exact charges (so, two PayPal payments).

They are 2 layer, 1.6mm thick, 1oz copper, black with white silkscreen, ENIG plated. I'm including a BOM and supporting files in this post. The relay controls both the feedback resistor and the "second input" available via the Cardas dual RCA input connector. This is optional.

These can also make great preamp or headphone amplifier, but such applications would be community supported efforts, not by me 🙂

 

[luvdunhill]

 

[luvdunhill]

I have four of the previous version of the board that most notably have the wrong BJT pinout and some random other silkscreen mistakes and poorly thought-out interface with the output stage. Those are available for free, just pay shipping.

I now have 10 of the (fixed) version above.

 

[luvdunhill]

8 boards left.

 

[luvdunhill]

^

 

[wengtech]

hello,
have you finished this vfet pt2.fe build?
how does the sound, compared to ba3 front end?

thanks.

 

[syklab]

Hi,
How do we use your module on top of the Vfet2 PCB provided by Nelson/Jason?

 

[luvdunhill]

Hi,

How do we use your module on top of the Vfet2 PCB provided by Nelson/Jason?

You don't 🙂 you can use my PCB for output though. I think this more of an experimenters project than a turnkey one at this point. The FE does make a nice preamp / headphone amp though.

 

[luvdunhill]

hello,
have you finished this vfet pt2.fe build?
how does the sound, compared to ba3 front end?

thanks.

I haven't used the BA3 FE, but I would guess this would sound better, depending on how hard you wanted to push the FETs. Also, no output capacitor on this build, which for some is a positive.

 

[wengtech]

I haven't used the BA3 FE, but I would guess this would sound better, depending on how hard you wanted to push the FETs. Also, no output capacitor on this build, which for some is a positive.

i plan to build BA3amp,
if this front end much better then i might use it for ba3 front end.

but i still confuse about the feedback output connection,
at your schematics, is it connected between the "output" and "vfet2 out" ??

because at the original schematic the feedback is connected to the speaker out.

thanks.

 

[dady]

Dear Luvdunhill I want four boards please.
Best Regards

 

[J2M]

Hi luvdunhill,
I know I have come a little late to this but I would be interested in a couple of these boards if you have any left. Paypal is no problem for me but I do live in the UK of course.
Regards John

 

[luvdunhill]

In this case, OUT connects to the output stage output. This relay controls whether feedback is enabled. The VFET2_OUT is the output of the FE. You can use these connections as you see fit, if you are using another output stage or application.

I am heading out on business, I return tomorrow and will count the remaining boards.

 

[luvdunhill]

I have 8 "fixed" boards and 4 "mistake" boards. Prices are the same $7.50/ea for the "fixed" and free for the later. 1 channel per PCB. Actual shipping costs, per the post above.

 

[J2M]

luvdunhill
Tried to send you a PM but your inbox is full.

 

[J2M]

Money sent via Paypal.
Regards

 

[luvdunhill]

Thank you. They are on their way.

I have 4 "fixed" and two "mistake" boards left. Usual policy - first pay first ship 🙂

 

[needtubes]

Tried to PM, but your box is full.

Can you perhaps say what heatsink you are using on the four TO-92 parts shown in the picture in post #2? I have looked for sinks like these but have not found any.

Thanks!

 

[s610adam]

I'll take you up on two of the fixed boards, thanks for making them available. PM me when you have the space please

 

[luvdunhill]

Tried to PM, but your box is full.

Can you perhaps say what heatsink you are using on the four TO-92 parts shown in the picture in post #2? I have looked for sinks like these but have not found any.

Thanks!

Yes, they are from here:

http://xen-audio.com/v1.5/page19001.html