You are welcome. The speakers are a 2-way DIY job with efficiency 94 dB/W (1m). On top... Be driver driving JMLC-profile horn. On bottom... TAD TL1601B in sealed enclosure made by fellow DIYer Mark Kravchenko. A 15" JBL Sub driven by a bridged Bryston fills in nicely below 50 Hz.
Attachments
the Vfets has nothing to do with it , i have a vintage Sony VFet and it doesn't sound at all like this one .
the secret is in the PAPA's touch
Then let's say VFets in the right hands - and what better hands than Papa's!
Now I want to try more single-ended output stage amps with this negative phase second harmonic signature...
Very sad to hear about your ordeal. At least you have updates that seem to indicate that the package is moving along, so that is so comfort amidst the long wait.
Hope you get your parts soon!
Rafa.
Could be Royal Zamunda Express Parcel was covering delivery around your area or something like that.
#37 has landed
#37 has landed. Thank you again for this great opportunity. First the family vacation thing first and then when I get back I’ll start building it. I noticed this thread is getting quite large can anybody give me the post numbers of all the OH THAT IMPORTANT so I don’t make Oops. I didn’t notice early on people were talking about making a matching faceplate power supply/case, is that still a thing Count me in for the pre-order.
#37 has landed. Thank you again for this great opportunity. First the family vacation thing first and then when I get back I’ll start building it. I noticed this thread is getting quite large can anybody give me the post numbers of all the OH THAT IMPORTANT so I don’t make Oops. I didn’t notice early on people were talking about making a matching faceplate power supply/case, is that still a thing Count me in for the pre-order.
Attachments
The only thing I can think of that you must check is that there are a small number of boards out there
with incorrect silkscreen for the polarity of the big cap C1.
See Post #154:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-16.html#post6623731
#168:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-17.html#post6623784
#172:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-18.html#post6623797
with incorrect silkscreen for the polarity of the big cap C1.
See Post #154:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-16.html#post6623731
#168:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-17.html#post6623784
#172:
https://www.diyaudio.com/forums/pass-labs/370689-diy-sony-vfet-builders-thread-18.html#post6623797
Hello everyone number 30 landed some weeks ago a delay i some parts ordered for it delayed the build.
Build took place over five evenings no rush triple check everything
I Upgraded all the parts except those already installed.
The reason for the upgraded parts from the beginning was so i would not suffer upgrade nervosa later .
How does it sound after completing all checks and biasing correctly plugged in and connected to my lowther london tp1 fitted with pm6a silver coil 16 ohm drivers.
The sound was initially very smooth but with some hours on it the sound opened up detail all there not thrown at you nothing out of place the longer the amplifier played the better it got.The depth increased instruments seemed more individual notes were followed very easily extremly pleasant to listen to for long periods.
However the best is yet to come for the upgraded parts i have fitted from experience will take some time to fully bed in may take a few hundred hours.
So the above are my initial thoughts.
All credit must be given to Nelson Pass for the design and his willingness to share with the diy community and all the people who made the lottery happen in these difficult times giving people something to smile about.
I will include a few pictures of the completed amplifier completed amplifier for persual.
music i listen to dub reggea classical jazz pop almost anything as now retired have the time if not the funds Regards spades
Build took place over five evenings no rush triple check everything
I Upgraded all the parts except those already installed.
The reason for the upgraded parts from the beginning was so i would not suffer upgrade nervosa later .
How does it sound after completing all checks and biasing correctly plugged in and connected to my lowther london tp1 fitted with pm6a silver coil 16 ohm drivers.
The sound was initially very smooth but with some hours on it the sound opened up detail all there not thrown at you nothing out of place the longer the amplifier played the better it got.The depth increased instruments seemed more individual notes were followed very easily extremly pleasant to listen to for long periods.
However the best is yet to come for the upgraded parts i have fitted from experience will take some time to fully bed in may take a few hundred hours.
So the above are my initial thoughts.
All credit must be given to Nelson Pass for the design and his willingness to share with the diy community and all the people who made the lottery happen in these difficult times giving people something to smile about.
I will include a few pictures of the completed amplifier completed amplifier for persual.
music i listen to dub reggea classical jazz pop almost anything as now retired have the time if not the funds Regards spades
Attachments
A Linear PSU
This took a little longer to complete than I expected. Sure enough, the actual bias current of the VFET output stage is closer to 1.7 Amps than 1.6. This forced me to redo the control circuit for CapMx, but it was all worthwhile in the end.
The amp has been running with the supply for the last two plus days. Every time I sit down to listen, it sounds amazing. In fact there have been a couple times when I sat with my tablet in hand, intending to do some web research or to send an email, and the music insisted that it was far more interesting to focus on than anything on a silly computer. Can't get much work done while this amp is playing; not that that is a problem.
What was immediately apparent was an improvement in lower bass detail and authority. This lends a more physical presence to every recording that I have listened to. As the supply and amp have warmed up and run together for a while, there has also been an overall improvement in 3-D imaging. Top to bottom, left to right, front to back. All have been expanded and more defined. Each of these aspects saw an incremental improvement, but the whole has become a sound greater than the sum of those parts. Some performances have been truly 'spooky,' as in, "how is the sound coming from there?" The image extends above the tops of my speakers as well as beyond the outer sides.
The VFET amp had great timing before, and it is even better now. There is now a more enhanced sense of flow and rhythm. Both large dynamics and micro dynamics have been similarly improved. Again, whole effect is greater than the sum of parts.
In summary, music as a whole is just more present.
Worth it. Definitely worth it
This took a little longer to complete than I expected. Sure enough, the actual bias current of the VFET output stage is closer to 1.7 Amps than 1.6. This forced me to redo the control circuit for CapMx, but it was all worthwhile in the end.
The amp has been running with the supply for the last two plus days. Every time I sit down to listen, it sounds amazing. In fact there have been a couple times when I sat with my tablet in hand, intending to do some web research or to send an email, and the music insisted that it was far more interesting to focus on than anything on a silly computer. Can't get much work done while this amp is playing; not that that is a problem.
What was immediately apparent was an improvement in lower bass detail and authority. This lends a more physical presence to every recording that I have listened to. As the supply and amp have warmed up and run together for a while, there has also been an overall improvement in 3-D imaging. Top to bottom, left to right, front to back. All have been expanded and more defined. Each of these aspects saw an incremental improvement, but the whole has become a sound greater than the sum of those parts. Some performances have been truly 'spooky,' as in, "how is the sound coming from there?" The image extends above the tops of my speakers as well as beyond the outer sides.
The VFET amp had great timing before, and it is even better now. There is now a more enhanced sense of flow and rhythm. Both large dynamics and micro dynamics have been similarly improved. Again, whole effect is greater than the sum of parts.
In summary, music as a whole is just more present.
Worth it. Definitely worth it
