With the input transformer music is smooth and natural.
Caps are good too i don't have teflons yet.
Last change was MKP bypass for 10000 uF.
LSK jfet's + autoformer gain stage can be interesting experiment.
I can make try this but not easy because i always work on circuit with schematic
and his components values: jfet's Idss, resistors, trimmers ( caps too?) etc.
Brave souls please guide me
you could try the http://www.diyaudio.com/forums/pass-labs/103050-jfet-boz.html ...😎
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Thanks M_Balou for bring this Papa schematic
i was thinking about front-end like M2 or try Mr. Pass
new circuit variant adaptationfor 2SK82 and his 193V inductor load. In drawer Edcor 600:10K , 600:600 and + vintage
Have a nice day 🙂
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Time to build one? 🙂
I connected the amp to my main speaker's horn (800 Hz & up) today, and I find this is a really good sounding amp even though my prototype's build quality is nothing but awful.
Soundhappy, thank you for your comment about the transformer. I decided to make another quick prototype pair with cap input as a woofer side amp.
Good news 193V is quiet
Next 600:600 under test with twice large core.
Plenty of subtle nuances into acoustic music
Have you finalized the bias and voltage? I'm still trying different values. BTW, my heat sink becomes too hot with 2xSIT @20V 2A, so I will have to redo the heat sink job. 😱
Fantastic yes go for it.
Flea watt amp can shake nice field coil excitation woofer with his own power supply , no necessairy bi-amped solution . Just idea.
Haha this L'Amp is like laboratory.
No i don't finalized but i do try different points up to 2A and 25V | 27 V later.
It's completly new vfet who is weak up now from long sleep ~ 35 years.
I like try more Bias current but i give him time and stay polite at 1.5 A for one month.
My heat sink is hot too. For the moment L profile is in reverse position ,
definitive amp version be up side down that distribute better all heat from bottom to the top.
I do try other resistors technology and brands.
Some thing to learn about passives in real working circuit: caps, resistors, trimmers and input transformers
and ideal sound transparency research ?
I like that so much.
Thanks Plasnu for your useful constructive answers
Special dedication for MaxLorenz taste of plucked strings and jazz
https://www.youtube.com/watch?v=FLaOo1Y_smA
https://www.youtube.com/watch?v=ygUqoaeaaug
https://www.youtube.com/watch?v=CXBkGJeyQug
https://www.youtube.com/watch?v=F3zThkeTwdM
Kindest regards 😀
And this (Japanese site). This blogger says this is a copy of Sony's "confidential" internal documentation.
http://www.diyaudio.com/forums/pass-labs/201655-lamp-simple-sit-amp-255.html#post4726442
http://www.diyaudio.com/forums/pass-labs/201655-lamp-simple-sit-amp-255.html#post4726442
They are never too much of heat sinks 😉
Bravo is well done design concept.
Ther is link to AES paper about Sony vfet's share from Papa Diy
http://www.diyaudio.com/forums/pass...2sk82-e-rank-2sj28-f-rank-13.html#post3859010
Merci bien, soundhappy.
Not that it is my preferred but that it (usually) records and uploads well to youtube to hype the DIY creations 😀
Try // Russian polystyrene caps at input and output. 😎
Bonne chance.
M.
Great Max yes some caps from Russia are cool i like it pio bb by mkp.
I play today Chet Baker albums from Capitol Pacific Jazz records house.
This acoustic material make sense for evaluation of amp " fidelity" parameter.
Old school high quality analog techniques of mixing and studio mastering.
Preamp is modify by me and i do use switch one positon for nice caps and
the other for 600:600 transformer. Get choices bring modularity.
After that i can skip input caps of the vfet amp without the risk hooray 😀
et Vive la musique !
https://www.youtube.com/watch?v=0fmlIb2-yKY
https://www.youtube.com/watch?v=2DR6Hh2uC6o
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I found an interesting video where I could see and know my new hero, Sensei Nishizawa:
https://www.youtube.com/watch?v=ihkRwArnc1k
https://www.youtube.com/watch?v=ihkRwArnc1k
Hello JPS64
Could you write bit more about your future diy amp project ?
This is for what type of drivers speakers and preamplifier you probably have ?
Lots of fakes on the market....take care.
Do you try contact member CWtim01 ?
http://www.diyaudio.com/forums/swap-meet/290687-fs-2sk180-2sk180c.html#post4966477
He have curve traced last genuine rare matched pair probably for L'Amp build with big sit hockey pucks.
Best regards 🙂