Here is the concept art for the VFET v2 board dubbed "AL"
I have a couple people besides myself looking for errors on the boards. It looks like based on Botte's work that we will need to widen C1 and C2 a bit.
Comments are welcome.
Click this link below for a larger pic.
AL Concept - My Photo Gallery
Teabag,
This is my first post (hope I'm doing this properly).
Thank you for your efforts, as I'm wanting to build this amp.
Nice artwork on the pcbs.
Upon tracing/checking some of the paths, the R12 and R16 resistors positions appeared be reversed with respect to the original schematic.
Were the other zener diodes on the original schematic (Z2/Z6 and Z1/Z5) deemed unnecessary?
What value are the resistors RSA and RSB going to Q11 and Q12?
Thanks a lot!
Msr. MOJO
In looking at the TL431 data sheet (TI) it seems the output capacitance could be lowered to 6.8uF, which would be stable even in the worst case, and would allow use of the compact Wima film capacitors. Any reason this wouldn't work, such as the larger caps resulting in safer startup conditions?
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I am in the process of measuring my VFETS and the power supply is ready. Can someone help me with the markings of G, D and S on the schematic of the test circuit. I don't want to blow these precious VFETS by connecting them wrong.
Thanks.
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My bad. Got it. On the schematic, the arrow pin is gate and the pin closer to the gate is source and the remaining one is drain. Sorry.
Hello Mr Pass or Mr BrainMod
Any issues with just building output stage and running like an F4?
I have an application that does not require voltage gain.
Any issues with just building output stage and running like an F4?
I have an application that does not require voltage gain.
Golden Ear Shootout CSX1 vs VFET Part II (Al)
We had the shoot out this weekend; keep in mind that the new amp is still in break-in.
The first major comment is that that the panel decided that they could live happily with either amplifier and that they were both exceptional.
Both designs shine at detail and ambiance recovery. CSX1 is more ”tube like” and romantic and the new version with the “Nelson mods” is more focused and dynamic. An additional comment was that the new amp made you feel like you were wearing headphones; in that you could hear all the little details that tend to get lost in a room system.
There is something intangible about both of the VFET amps compared to other non-VFET amps, they have an ease about them that is non-fatiguing. Is it the devise or the designer?
Next up; single pair output version, that will take some time as I will need to build some new chassis.
We had the shoot out this weekend; keep in mind that the new amp is still in break-in.
The first major comment is that that the panel decided that they could live happily with either amplifier and that they were both exceptional.
Both designs shine at detail and ambiance recovery. CSX1 is more ”tube like” and romantic and the new version with the “Nelson mods” is more focused and dynamic. An additional comment was that the new amp made you feel like you were wearing headphones; in that you could hear all the little details that tend to get lost in a room system.
There is something intangible about both of the VFET amps compared to other non-VFET amps, they have an ease about them that is non-fatiguing. Is it the devise or the designer?
Next up; single pair output version, that will take some time as I will need to build some new chassis.
Botte
quote:
There is something intangible about both of the VFET amps compared to other non-VFET amps, they have an ease about them that is non-fatiguing. Is it the devise or the designer?
It is neither one nor the other.... It is the designer AND the device. (IMHO)
quote:
There is something intangible about both of the VFET amps compared to other non-VFET amps, they have an ease about them that is non-fatiguing. Is it the devise or the designer?
It is neither one nor the other.... It is the designer AND the device. (IMHO)
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Thanks for the feedback, it does look like the R12,R16 need to be changed Go R12 on left, R16 on right.
The Zener and diodes are deemed optional by Nelson, and no harm leaving in as an option
RSA. RSB are for possible JFET source degeneration if >8ma IDSS JFETs are used. Otherwise it can be jumpered.
Nice work Tea BagHere is the concept art for the VFET v2 board dubbed "AL"
I have a couple people besides myself looking for errors on the boards. It looks like based on Botte's work that we will need to widen C1 and C2 a bit.
Comments are welcome.
Click this link below for a larger pic.
AL Concept - My Photo Gallery
Botte
Thanks again for the comments. Look forward to your single pair output version and your impressions. Any thoughts of trying mono balanced as has been done with F4?
Best
Bob
Thanks Botte for your impressions here.
I Guess So but you confirm, the expensive part of the idea.
I Guess So but you confirm, the expensive part of the idea.
Teabag,
Will you be arranging for production and taking orders for these "AL" PCBs anytime soon?
I'm definitely interested in buying at least 4 pairs.
Thank you for your considerable efforts in designing them.
Msr. Mojo
Fake 2SK82's be careful...
I have no luck again....😡
Bought 10 pieces (and get some discount) 2SK82 of the ALiExpress Eternal Hong:
Aliexpress.com: Koop Sony 2sk82 v fet van betrouwbare FET-transistoren leveranciers op Eternal HONG's store
They are fakes, relabeled 2SK60's probably.... cause when I compare the curves of published 2SK60's they are exactly the same as in my picture (the blue line).
I measured all 10 V-FETs see pic.(Excel). There is one real 2SK82, V-FET number 7, strange enough...
Opened one up ( V-FET number 6), and there is one 3 mm die inside.😡
(BTW, This V-FET is still fully functional without the top.....🙂 )
Strange enough, Fast Freddy bought 4 pieces from this source that are different printed on top, so these are probably good ones. See post 307:
http://www.diyaudio.com/forums/pass-labs/276711-sony-vfet-amplifier-part-2-a-31.html#post4398123
I think Eternal Hong had a few good ones, and because demand is high, he re-printed some of his 2SK60's.... or bought more from a bad source...
He has sold to 14 buyers.
So no endless '1000 pieces available' source anymore....
Acronman was the real last available reliable resource in the world 🙁
Gone is my dream of building a half '40 years commemorative VFET Amp'. 🙁😡
At least I hope that I prevent others to buy from this resource.
I have no luck again....😡
Bought 10 pieces (and get some discount) 2SK82 of the ALiExpress Eternal Hong:
Aliexpress.com: Koop Sony 2sk82 v fet van betrouwbare FET-transistoren leveranciers op Eternal HONG's store
They are fakes, relabeled 2SK60's probably.... cause when I compare the curves of published 2SK60's they are exactly the same as in my picture (the blue line).
I measured all 10 V-FETs see pic.(Excel). There is one real 2SK82, V-FET number 7, strange enough...
Opened one up ( V-FET number 6), and there is one 3 mm die inside.😡
(BTW, This V-FET is still fully functional without the top.....🙂 )
Strange enough, Fast Freddy bought 4 pieces from this source that are different printed on top, so these are probably good ones. See post 307:
http://www.diyaudio.com/forums/pass-labs/276711-sony-vfet-amplifier-part-2-a-31.html#post4398123
I think Eternal Hong had a few good ones, and because demand is high, he re-printed some of his 2SK60's.... or bought more from a bad source...
He has sold to 14 buyers.
So no endless '1000 pieces available' source anymore....
Acronman was the real last available reliable resource in the world 🙁
Gone is my dream of building a half '40 years commemorative VFET Amp'. 🙁😡
At least I hope that I prevent others to buy from this resource.
Attachments
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