The three guys who had the PCBs had some difficulties finding the recommended heatsink (Fischer ICK PLCC28).
They are available at both Newark and Farnell. So I guess it takes care of most of the (DIY) world. At Newark they are about USD1.50 each.
🙂
Patrick
They are available at both Newark and Farnell. So I guess it takes care of most of the (DIY) world. At Newark they are about USD1.50 each.
🙂
Patrick
Any chance to have you post the etch file, for the board? Those things are very neatly done. Just like your small heatsinks😎
🙂
Edit. Cant help adding; you take DIY very seriously, and always to the most extreme level!
🙂
Edit. Cant help adding; you take DIY very seriously, and always to the most extreme level!
I'll let you have 2 PCBs free of charge on the same conditions as the other 3 -- you build and test in an audio application, and report back in 2 months.
Patrick
PS The 2x matched 2SK170 buffer I have built umteen times in various applications, as well as the K170/J74 complimentary version. So it has to be something else this time. Watch this space, there are more interesting stuff to come .....
😉
Patrick
PS The 2x matched 2SK170 buffer I have built umteen times in various applications, as well as the K170/J74 complimentary version. So it has to be something else this time. Watch this space, there are more interesting stuff to come .....
😉
Sorry, but I can't commit to that, being up to my neck in speakerwork right now.. At least, I cant promise to have them tested in an audio circuit in 2 months. An etch file would be fine for a rainy sunday, though😉 LL, might even finish before the other 3 dudes😉 2 weeks gone allready..😀
🙂
🙂
I have still not received the boards. Maybe they went to my neighbor by mistake.
If they don't come in the next few days, I may have to fire up Eagle and draft up my own boards / etch them up.
In the mean time, I'm very interested in the BF862 and the potential for driving low input impedance passive filters. Many of these use 3.3K or thereabouts input and output impedance.
If they don't come in the next few days, I may have to fire up Eagle and draft up my own boards / etch them up.
In the mean time, I'm very interested in the BF862 and the potential for driving low input impedance passive filters. Many of these use 3.3K or thereabouts input and output impedance.
If you don't receive them by Tuesday, send me your postal address again (just to be sure) and you get another 2 from me.
🙂
Patrick
🙂
Patrick
Declaration regarding Use of this Design
Perhaps I should have said this at the beginning. But I want to say this nevertheless.
There have been various suggestions for PCB layouts, GBs, commercial useages, etc., even before the 3 gentlemen have finished their evaluation.
Before I published the circuit and the photos, I had no illusion that this could be easily copied. And unless the interest would be so hugh that there would be a demand for 10,000 buffers, it would not even be worth running a PCB batch because of the small size.
So as far as I am concerned, you can freely DIY as you wish. But if anyone would like to copy the layout for public use, I should at least like to be asked. It is still my design, and I should like to see it done (cloned) properly.
If there would be a GB, I should ask you to voluntarily contribute 1 USD per PCB to a donation to Unicef. And for any commercial applications, I should ask you to donate 2 USD per buffer voluntarily to Unicef.
I am not going to check on you or sue you or whatever. You only need to answer to your own conscience.
😉
Patrick
Perhaps I should have said this at the beginning. But I want to say this nevertheless.
There have been various suggestions for PCB layouts, GBs, commercial useages, etc., even before the 3 gentlemen have finished their evaluation.
Before I published the circuit and the photos, I had no illusion that this could be easily copied. And unless the interest would be so hugh that there would be a demand for 10,000 buffers, it would not even be worth running a PCB batch because of the small size.
So as far as I am concerned, you can freely DIY as you wish. But if anyone would like to copy the layout for public use, I should at least like to be asked. It is still my design, and I should like to see it done (cloned) properly.
If there would be a GB, I should ask you to voluntarily contribute 1 USD per PCB to a donation to Unicef. And for any commercial applications, I should ask you to donate 2 USD per buffer voluntarily to Unicef.
I am not going to check on you or sue you or whatever. You only need to answer to your own conscience.
😉
Patrick
Hi Patrick,
I really enjoyed the thread. Thanks a lot for sharing. 🙂
I also have a very (very very) ignorant question about your buffer.
Maybe the question is OT too, so humblest apologies in advance.
Is there a way to turn your circuit upside-down to obtain a inverting buffer?
Thanks a lot for the answer and apologies for the question.
Massimo
I really enjoyed the thread. Thanks a lot for sharing. 🙂
I also have a very (very very) ignorant question about your buffer.
Maybe the question is OT too, so humblest apologies in advance.
Is there a way to turn your circuit upside-down to obtain a inverting buffer?
Thanks a lot for the answer and apologies for the question.
Massimo
EUVL said:If you don't receive them by Tuesday, send me your postal address again (just to be sure) and you get another 2 from me.
🙂
Patrick
Hi Patrick;
Still no boards here. Instead of sending more to me, please send them to the next interested person.
My apologies, I need to drop off this project. I received some bad news last week and need to devote all my time over the next 2 months to things besides audio.
If they ever do show, up, I'll let you know, I can send them back to you. Bob
> Is there a way to turn your circuit upside-down to obtain a inverting buffer?
If inverting meant geographically, then yes, asssuming you accept the poorer heat sinking.
But I guess this is not what you meant. For an inverting buffer, you can use my discrete opamp, or any other ordinary opamps.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=120445&highlight=
This circuit is basically a follower buffer with a gain of slightly less than 1.
> My apologies, I need to drop off this project.
Sad to hear that. Hope all works out fine.
I shall offer 2 PCBs to the next person who would like to evaluate, with the same committment.
http://www.diyaudio.com/forums/showthread.php?postid=1774659#post1774659
Patrick
If inverting meant geographically, then yes, asssuming you accept the poorer heat sinking.
But I guess this is not what you meant. For an inverting buffer, you can use my discrete opamp, or any other ordinary opamps.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=120445&highlight=
This circuit is basically a follower buffer with a gain of slightly less than 1.
> My apologies, I need to drop off this project.
Sad to hear that. Hope all works out fine.
I shall offer 2 PCBs to the next person who would like to evaluate, with the same committment.
http://www.diyaudio.com/forums/showthread.php?postid=1774659#post1774659
Patrick
Hi
I will try it. Mouser delivered the BF862s yesterday. I was going to make my own board for a project already underway.
Regards
JimS
I will try it. Mouser delivered the BF862s yesterday. I was going to make my own board for a project already underway.
Regards
JimS
Pls send me your postal address again by PM.
I shall put two boards in the post, probably early next week.
Am out of town.
Patrick
I shall put two boards in the post, probably early next week.
Am out of town.
Patrick
EUVL said:> Is there a way to turn your circuit upside-down to obtain a inverting buffer?
For an inverting buffer, you can use my discrete opamp, or any other ordinary opamps.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=120445&highlight=
This circuit is basically a follower buffer with a gain of slightly less than 1.
Thank you very much for your answer.
Massimo
Hi PatrickEUVL said:>
http://www.diyaudio.com/forums/showthread.php?s=&threadid=120445&highlight=
This circuit is basically a follower buffer with a gain of slightly less than 1.
> I shall offer 2 PCBs to the next person who would like to evaluate, with the same committment.
http://www.diyaudio.com/forums/showthread.php?postid=1774659#post1774659
I would build one of those opamps with pleasure. Can I build them using 2SK170BL jfets ?
Can these be made double opamps ? I must replace the LME49720 in my meridian 101b and this looks just like what I need. (Burson V2 are too big) 😉
Regards
Ricardo
If Patrick does not have problem with it I could send you mine as I lack the time to go after the parts and I also fear for soldering my fingers instead of the tiny FETs.
I'm very interested in building this if someone wants to pass their boards along. I've been using the opaEARTH and opaMOON and am about to try some 627s as a buffer in my zerodac.
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