Zen Mod is right as always
I use a 10mm m3 set screw as the all threaded
bolt use the hex end to tighten into the faceplate.
Also have a mini wrench set to tighten the bolt.
You mount all 4 set screws onto the faceplate first
I use a 10mm m3 set screw as the all threaded
bolt use the hex end to tighten into the faceplate.
Also have a mini wrench set to tighten the bolt.
You mount all 4 set screws onto the faceplate first
VFET #169 Is Born!
Just finished assembling my N-Channel VFET amp. She’s singing away right now, surprisingly powerful sounding paired with my rather inefficient FAST TL speakers. Happy to agree with previous builders that this amp is dead quiet at idle. Wiring it up and chassis fitment took much longer than anticipated, be patient and get creative for final assembly.
Couple of build notes and observations:
I have a 27K ohm resistor installed at R7 to tame the LED brightness.
Even with the relay there is a turn-on thump.
At turn-on, DC offset slowly rises to 1.8v then settles back down to 8-10mV.
Lengthening the relay delay or adding SSR speaker protection will be on my to-do list.
I’m very grateful to be an owner of this special edition VFET amplifier, it will bring lots of enjoyment to my household 🙂
Thanks to everyone involved for getting this amplifier package put together and delivered and especially Mr Nelson Pass for his ultimate generosity.
Just finished assembling my N-Channel VFET amp. She’s singing away right now, surprisingly powerful sounding paired with my rather inefficient FAST TL speakers. Happy to agree with previous builders that this amp is dead quiet at idle. Wiring it up and chassis fitment took much longer than anticipated, be patient and get creative for final assembly.
Couple of build notes and observations:
I have a 27K ohm resistor installed at R7 to tame the LED brightness.
Even with the relay there is a turn-on thump.
At turn-on, DC offset slowly rises to 1.8v then settles back down to 8-10mV.
Lengthening the relay delay or adding SSR speaker protection will be on my to-do list.
I’m very grateful to be an owner of this special edition VFET amplifier, it will bring lots of enjoyment to my household 🙂
Thanks to everyone involved for getting this amplifier package put together and delivered and especially Mr Nelson Pass for his ultimate generosity.
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Beautiful work, Vunce! Congrats!
I love how clean the Faston spade connectors look on your PSU board! Plus, they provide strain relief for the wires vs direct soldering. 🙂
I love how clean the Faston spade connectors look on your PSU board! Plus, they provide strain relief for the wires vs direct soldering. 🙂
VFET #158 Takes Flight
Just finished my VFET and everything checks out 100%. Ready for an evening of wonderful music. Thanks to Nelson for sharing another of his outstanding designs as well as the diyAudio community, especially Jason, Mark and Jim, for your continued support and encouragement!
Just finished my VFET and everything checks out 100%. Ready for an evening of wonderful music. Thanks to Nelson for sharing another of his outstanding designs as well as the diyAudio community, especially Jason, Mark and Jim, for your continued support and encouragement!
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Vunce, WKCox,
Congratulations to both on your successful DIY Sony VFET amplifier builds!
Neat work, and now enjoy the music.... 🙂
Once you have a few hours on them, please share your listening impressions.
Congratulations to both on your successful DIY Sony VFET amplifier builds!
Neat work, and now enjoy the music.... 🙂
Once you have a few hours on them, please share your listening impressions.
VFET 174 is singing.
Finished unit 174 this afternoon. I agree it took some tweaking to get the chassis alignment correct. No problem with the heatsinks, but did deburr the holes in the L bracket. Slight adjustment on P3 to get 14 volts and everything is running fine.
First impression is more detail than my M2x with Cedarburg. Feeding with Korg B1 and driving JBL L96a just fine. Clean bass.
Finished unit 174 this afternoon. I agree it took some tweaking to get the chassis alignment correct. No problem with the heatsinks, but did deburr the holes in the L bracket. Slight adjustment on P3 to get 14 volts and everything is running fine.
First impression is more detail than my M2x with Cedarburg. Feeding with Korg B1 and driving JBL L96a just fine. Clean bass.
I see many people tried to modify the output caps 10,000uF. With my experience, the Mundorf Mlytic, Nichicon KG Goldtune,.... really is not better the original from Nelson too much. If you can find and parallel two the Western 4600uF/30V, you will see the sound much better, even for many people it's better than Rubycon Black Gate FK 10,000uF (very rare and expensive).
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Of course the question could be rethoric . . .
Well, you will still have to slowly format them. That sort of forms an even layer in the electrolytes, reducing the DC-current though them.
Very pronounced in high voltage caps (say 400V) the effect should still exist in a 10.000 uF 75 v cap.
First charge it through 50KΩ for a day or two. If my theory is right, initially the voltage after the resistor will be low and gradually increase. Once stable it is fit for use.Secondly, parallel it with a cap, some say a mica (I have 2n7) others say >100nF, this to even out the inductance. Not a ceramic.they change capacitance with the change in AC.
I'm just loving the sound of this amp!
The Lx-minis (bi-amped by design) used to be driven by a pair of ACAs in parallel and an old Linn Klout. Having retired the Klout, I've also dispensed with the super tweeters. There's enough sparkle without them and a lot more detail throughout. Upgraditis definitely on hold while I play all my favorite albums over and over again.
(There's a wee small voice whispering 'Finish the F4 - you know you want to!' But I'm ignoring it.)
Thanks again to everyone involved. Its a privilege to be able to enjoy this little gem.
The Lx-minis (bi-amped by design) used to be driven by a pair of ACAs in parallel and an old Linn Klout. Having retired the Klout, I've also dispensed with the super tweeters. There's enough sparkle without them and a lot more detail throughout. Upgraditis definitely on hold while I play all my favorite albums over and over again.
(There's a wee small voice whispering 'Finish the F4 - you know you want to!' But I'm ignoring it.)
Thanks again to everyone involved. Its a privilege to be able to enjoy this little gem.
I was feeling kinda down after I didn't get picked, so I went on the hunt for something to lift my spirits. I'm listening to a Yamaha B2 right now. 🙂 I feel much better. 😛
I'm going to pull her down and go through the entire thing, but I had to verify the FETs were okay... so I spun some Diana Krull and am sitting back in my chair. Wow this is a lovely amp 40 years old and in need of help, she's still amazing.
I made my mind up to power it up only to make sure it worked when it arrived. I decided 1/2hr only and then shut it down because I don't trust the old caps and some parts. Well, it's going on 2hrs now. lol No really just 5 more minutes!
I'm going to pull her down and go through the entire thing, but I had to verify the FETs were okay... so I spun some Diana Krull and am sitting back in my chair. Wow this is a lovely amp 40 years old and in need of help, she's still amazing.
I made my mind up to power it up only to make sure it worked when it arrived. I decided 1/2hr only and then shut it down because I don't trust the old caps and some parts. Well, it's going on 2hrs now. lol No really just 5 more minutes!
