The Spice file for the OPS has been published before :
https://www.diyaudio.com/community/...-and-maybe-a-power-whammy.390636/post-7309540
There is no accurate model for the Toshiba TO220 MOSFETs.
So here is one for the 2N5457/60 -- FQP3N30/3P20 version.
But this is work in progress, as only the frontend has been built and tested.
And as always, it is only as accurate as the device models.
Maybe you have better ones for the Fairchild JFETs ?
Thank you for your interest,
Patrick
https://www.diyaudio.com/community/...-and-maybe-a-power-whammy.390636/post-7309540
There is no accurate model for the Toshiba TO220 MOSFETs.
So here is one for the 2N5457/60 -- FQP3N30/3P20 version.
But this is work in progress, as only the frontend has been built and tested.
And as always, it is only as accurate as the device models.
Maybe you have better ones for the Fairchild JFETs ?
Thank you for your interest,
Patrick
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Next one to follow is the F5Pi frontend using 2N5457/5460 + FQP3N30/3P20.
As expected, distortion is quite a bit higher at -77dB H2 and -86dB H3 for 2.8Vrms 1kHz output.
Still comparable to the latest F5m, despite the very low transconductance input JFETs :
https://www.diyaudio.com/community/threads/pass-f5m.406472/post-7534522
The Spice simulation is actually quite accurate on H2 at least.
Patrick
.
As expected, distortion is quite a bit higher at -77dB H2 and -86dB H3 for 2.8Vrms 1kHz output.
Still comparable to the latest F5m, despite the very low transconductance input JFETs :
https://www.diyaudio.com/community/threads/pass-f5m.406472/post-7534522
The Spice simulation is actually quite accurate on H2 at least.
Patrick
.
Attachments
Short update :
Beta Testers have got their PCBs made, and ordered From Mouser / DK.
One tester already have all transistors.
The other has his waiting to clear Customs.
So with some luck, we should hear from them before long.
Then we'll publish frontend and OPS Gerber.
The team in Hong Kong has sorted out our inventory.
We can support 20 Toshiba Q sets with our usual curve traced matching.
We probably have 20 additional sets of Fairchild devices already in the EU.
So there will be enough for all, I think.
Of course you can source your own elsewhere.
Enough offers around.
Merry Christmas to all,
Patrick
Beta Testers have got their PCBs made, and ordered From Mouser / DK.
One tester already have all transistors.
The other has his waiting to clear Customs.
So with some luck, we should hear from them before long.
Then we'll publish frontend and OPS Gerber.
The team in Hong Kong has sorted out our inventory.
We can support 20 Toshiba Q sets with our usual curve traced matching.
We probably have 20 additional sets of Fairchild devices already in the EU.
So there will be enough for all, I think.
Of course you can source your own elsewhere.
Enough offers around.
Merry Christmas to all,
Patrick
Hi all,
A few posts back I mentioned that I wold send the F5Pi to another tester to get impressions from someone who is not involved in the build, and leave it with him for a a while to get the subjective opinions of someone else. The tester here has had lots of amps, both commercial and DIY, and has had good hifi systems for many years. The idea here is not to "sell" the idea, but I know all of us want to know if something sounds good before we build it. Its very hard to know that unless you've heard the DUT - so I thought if I got one or two others to listen to this amp, and posted their impressions, then it might at least give some idea of what others think of it.
Fran
A few posts back I mentioned that I wold send the F5Pi to another tester to get impressions from someone who is not involved in the build, and leave it with him for a a while to get the subjective opinions of someone else. The tester here has had lots of amps, both commercial and DIY, and has had good hifi systems for many years. The idea here is not to "sell" the idea, but I know all of us want to know if something sounds good before we build it. Its very hard to know that unless you've heard the DUT - so I thought if I got one or two others to listen to this amp, and posted their impressions, then it might at least give some idea of what others think of it.
Fran
This Japanese DIYer compared a lot of different devices for his circuit.
http://myaudio.seesaa.net/article/399698446.html#toc_06
His conclusions on the K3497/J618 are quite similar to our reviewer above.
You need to give it time to run in.
And maybe you also need to get used to the sudden increase in details.
You can find common impressions on details with amps using these so-called UHC MOSFET's from Japanese manufacturers a few years back.
Including designs by Akihito Kaneda.
Here another one on UHC-MOS :
http://la4.cocolog-nifty.com/blog/2011/02/uhc-mos-fet-93c.html
Patrick
http://myaudio.seesaa.net/article/399698446.html#toc_06
His conclusions on the K3497/J618 are quite similar to our reviewer above.
You need to give it time to run in.
And maybe you also need to get used to the sudden increase in details.
You can find common impressions on details with amps using these so-called UHC MOSFET's from Japanese manufacturers a few years back.
Including designs by Akihito Kaneda.
Here another one on UHC-MOS :
http://la4.cocolog-nifty.com/blog/2011/02/uhc-mos-fet-93c.html
Patrick
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Oh, one more OT point if I may :
Looking at the above picture, the totally encapsulated toroidal transformer is maybe 150~160mm diameter.
It is claimed to be 1000VA. And I searched Toroidy for similar size.
Toroidy Supreme 100VA is 210x90mm, 500VA is 168x80mm.
So either they are using a toroidy with double the height (~160mm), or with much higher pearmeability material.
And then it says in the photo "handcrafted in Germany".
I wonder if that means that they don't use a winding machine, but thread each turn through the toroid with a bobbin.
How many hours would you need to make one of these by hand ?
And we already knew how much heat their heatsinks can dissipate.
Patrick
Looking at the above picture, the totally encapsulated toroidal transformer is maybe 150~160mm diameter.
It is claimed to be 1000VA. And I searched Toroidy for similar size.
Toroidy Supreme 100VA is 210x90mm, 500VA is 168x80mm.
So either they are using a toroidy with double the height (~160mm), or with much higher pearmeability material.
And then it says in the photo "handcrafted in Germany".
I wonder if that means that they don't use a winding machine, but thread each turn through the toroid with a bobbin.
How many hours would you need to make one of these by hand ?
And we already knew how much heat their heatsinks can dissipate.
Patrick
😱
There’s number of parts, but also density of parts!
That being said, it looks fascinating.
I am criticizing your work at all, I hope you know that.
I still think such a project would be an epic journey for me. Maybe I would not make it all the way to Mount Doom.
I am just fascinated by the fact amplifying can be achieved with a myriad of arrangements, with very few parts or a great many parts.
For the new year a further improved version of the speaker protection circuit of post #46.
https://www.diyaudio.com/community/...tage-perfectly-integrated.406024/post-7532667
Works first time.
The US version of the F5Pi above has a bit of DC drift from cold to warm (~100mV).
This is caused by the JFET pair 2N5457/5460.
So a DC servo daughter board has been designed and will be tested later as add-on.
Optional, without saying.
Patrick
.
https://www.diyaudio.com/community/...tage-perfectly-integrated.406024/post-7532667
Works first time.
The US version of the F5Pi above has a bit of DC drift from cold to warm (~100mV).
This is caused by the JFET pair 2N5457/5460.
So a DC servo daughter board has been designed and will be tested later as add-on.
Optional, without saying.
Patrick
.
Attachments
