I'm done with the project and i'm sharing what i have. I still have to put it into an enclosure and i may share photos of the finished product later.
I listened to it for several hours and my subjective impressions are very good. It is dead quite on idle, very detailed and it maybe adds a bit of nice H2 warmth to it. Subjective as said... But i am not missing anything and it is a very decent upgrade over the MiniDSP 4x8 i used before.
I guess i could write a book about it now, but my impression is that there is not much interest in this project because poeple are more interested in more modern (cheaper) Jfets and in 4th order filters etc. Although i guess it will work with J112 as well, but mind you the different pinout. However, this little project suits my personal needs perfectly and i'm sharing it with you just as an addition to your toolbox. If you have any questions or suggestions feel free to share your thoughts. I said it earlier, i'm no pro at designing transistor circuitries, nor at using KiCad. This is just what i could make myself at home on my kitchen desk.
I listened to it for several hours and my subjective impressions are very good. It is dead quite on idle, very detailed and it maybe adds a bit of nice H2 warmth to it. Subjective as said... But i am not missing anything and it is a very decent upgrade over the MiniDSP 4x8 i used before.
I guess i could write a book about it now, but my impression is that there is not much interest in this project because poeple are more interested in more modern (cheaper) Jfets and in 4th order filters etc. Although i guess it will work with J112 as well, but mind you the different pinout. However, this little project suits my personal needs perfectly and i'm sharing it with you just as an addition to your toolbox. If you have any questions or suggestions feel free to share your thoughts. I said it earlier, i'm no pro at designing transistor circuitries, nor at using KiCad. This is just what i could make myself at home on my kitchen desk.
Hi speedgeil,i have tried to upload gerbers to JLCPCB but i can't see any preview not at gerber viewer ,whats wrong?
Thanks.
There is still sources for original 2SK170. Even 2sk117 is on stock at Reichelt Germany. Otherwise there is plenty of cheap substitutes like the J112. As a source follower circuit it wouldn't matter much what Jfet you choose. I took the 2SK170 because i still had them around after i finished building all that noise sensitive stuff like phono stages etc.
However, i think any experience shared is an addition to a DIYer's toolbox. And if it serves you for having water slide decals as silk screen in the future, then it served well. 👍
However, i think any experience shared is an addition to a DIYer's toolbox. And if it serves you for having water slide decals as silk screen in the future, then it served well. 👍
Thanks, i already noticed. I made a mistake. Sorry for that, i don't have experience with Chinese PCB makers. Actually, this PCBs was about hand etching. That's why it's single layer (except for two traces that would be substituted with two wires). I make my own PCBs since forever and i still love the process. That's what's DIY is about for me. Making everything myself as far and good as i can and enjoying the process. Chinese PCBs look nice, but they also look like "bought" and not "made".
Here is the corrected files. Have fun!
I guess what you mean is the gerber viewer itself, while the preview is showing correct.
I read about issues like that from people who reported the same, but the actual result was fine. I don't know why this is. Possibly a bug in the Gerber viewer. Possibly something with my file. Interestingly the PSU is showing correct.
Maybe someone with more experience could check that.
To be more clear...i have upload this again to JLCPCB and nothing shown,no as preview not at gerber viewer.
Today i made an additional four channel buffer stage that is stacked to the crossover. I need to have pots at the outputs of the crossover and the power amps that follow the crossover have a quite low input impedance. So not to throw away control over the signal i decided to go this way.
It's 2SK170s again. Unfortunately i did not have the right caps around, but a big bag full with 1uf caps i no longer needed. So i stacked many of them in parallel to get the right values. Some say parallel output caps sound mushy. Personally i never had issues with that. Actually i believe that stacking helps because it will lower ESR.
The pots are Alps RK09 i still had around. One for the high and one for the low pass.
This time i used toner transfer for the silk screen, but i wasn't lucky. You really need lotsa heat to get the toner transferred. I did everything i could, isolated the PCB on the back side, to have the heat stay etc...no chance. The result is readable but actually not good. I also tried acetone toner transfer before, but it was even worse. So far the water slide decal method works best, but it's quite expensive. About a € per PCB.
It's 2SK170s again. Unfortunately i did not have the right caps around, but a big bag full with 1uf caps i no longer needed. So i stacked many of them in parallel to get the right values. Some say parallel output caps sound mushy. Personally i never had issues with that. Actually i believe that stacking helps because it will lower ESR.
The pots are Alps RK09 i still had around. One for the high and one for the low pass.
This time i used toner transfer for the silk screen, but i wasn't lucky. You really need lotsa heat to get the toner transferred. I did everything i could, isolated the PCB on the back side, to have the heat stay etc...no chance. The result is readable but actually not good. I also tried acetone toner transfer before, but it was even worse. So far the water slide decal method works best, but it's quite expensive. About a € per PCB.
This afternoon i made some aluminum spacers for the standoffs on my little lathe. Also the bottom case is ready. With Sketchup i made a stencil for drilling the holes for the RCA connectors, fuse and mains cable.
I usually make the same enclosures all the time. I like the dimensions to be slim and long (400x150x60mm). That form factor always worked good for me for building amps of any sort and it uses the space i have effectively. Also i prefer to have no visible screws on the outside, no switches and no lamps. I'm using switchable mains sockets instead and i'm also hiding power LEDs by drilling a 1mm hole in the front. The power LED sits behind that hole. In the hole i insert a 1mm piece of glass fibre that will be grinded to fit the hole evenly on the front. When the device is powered off, you just have kind of an "aluminum brick". Attached a photo of my DAC in the exact same enclosure
. I like working with my hands, so the surface finish is wet sanded aluminum.
I usually make the same enclosures all the time. I like the dimensions to be slim and long (400x150x60mm). That form factor always worked good for me for building amps of any sort and it uses the space i have effectively. Also i prefer to have no visible screws on the outside, no switches and no lamps. I'm using switchable mains sockets instead and i'm also hiding power LEDs by drilling a 1mm hole in the front. The power LED sits behind that hole. In the hole i insert a 1mm piece of glass fibre that will be grinded to fit the hole evenly on the front. When the device is powered off, you just have kind of an "aluminum brick". Attached a photo of my DAC in the exact same enclosure
. I like working with my hands, so the surface finish is wet sanded aluminum.
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Hi,
I like it 😉
IIrc I first saw such on SONY devices that used such ´tiny´ lights as design element on their frontplates in the 80s.
As a young student a part of my thesis -a modular preamplifier- I built the casing utilizing a piece of slate baseboard/skirting board as front.
Same as you I drilled 1mm holes and filled them with optical fibre.
Since its an old and not particularly well foto its not that easy to see the details ... in life it looked much better.
The tiny light spots appear more decent than larger lights, more understatement, but still providing for easy and clean detection of it´s state of activity.
Turned off the spots disappeared fully.
Besides, the splitting of front plates into two, a inner mountage front and a outer design front, opens up design possibilities for cleaner more professional looking devices and could make servicing easier.
btw. speedgeil, did I mention, that I like Your design? 😉
jauu
Calvin
I like it 😉
IIrc I first saw such on SONY devices that used such ´tiny´ lights as design element on their frontplates in the 80s.
As a young student a part of my thesis -a modular preamplifier- I built the casing utilizing a piece of slate baseboard/skirting board as front.
Same as you I drilled 1mm holes and filled them with optical fibre.
Since its an old and not particularly well foto its not that easy to see the details ... in life it looked much better.
The tiny light spots appear more decent than larger lights, more understatement, but still providing for easy and clean detection of it´s state of activity.
Turned off the spots disappeared fully.
Besides, the splitting of front plates into two, a inner mountage front and a outer design front, opens up design possibilities for cleaner more professional looking devices and could make servicing easier.
btw. speedgeil, did I mention, that I like Your design? 😉
jauu
Calvin
Thank you Calvin.
That photo looks like from the early 90ies. The design reminds me of Stefan Steiner's "Fidelity" brand devices. What were they called? Sardonyx preamp and Topas poweramp? Maybe also it goes into the Sugden design direction. Love it!
I knew someone came up with the idea of using glass fibre for indication before me, dammit 😅!
I'm always looking for genius ideas like this which keep the design simple yet sleek.
You didn't say you like the circuit design, did you?
That photo looks like from the early 90ies. The design reminds me of Stefan Steiner's "Fidelity" brand devices. What were they called? Sardonyx preamp and Topas poweramp? Maybe also it goes into the Sugden design direction. Love it!
I knew someone came up with the idea of using glass fibre for indication before me, dammit 😅!
I'm always looking for genius ideas like this which keep the design simple yet sleek.
You didn't say you like the circuit design, did you?
Today i drilled the holes for the connectors and i tried labeling with toner transfer. Humm... the outcome was acceptable. But i'm getting a better understanding of how to apply the toner. Seems like the approach of applying heat on the whole surface is not the best. I'm getting the best results with high pressure and heat with just the tip of the iron on the transfer paper and little steps.
As final treatment i used Zapon clear coat for protecting the toner from rubbing off.
Next step will be making pot knobs and axles on the lathe. At this point i have to be very accurate, otherwise the pots won't turn well because of mechanical tension. I will either use PTFE for the bushings or maybe gunmetal. I will need to see what's in my treasure boxes.
As final treatment i used Zapon clear coat for protecting the toner from rubbing off.
Next step will be making pot knobs and axles on the lathe. At this point i have to be very accurate, otherwise the pots won't turn well because of mechanical tension. I will either use PTFE for the bushings or maybe gunmetal. I will need to see what's in my treasure boxes.
Today i made the axles for the pots. I also found some PTFE i made bushings of. I grinded the holes of the bushings instead of drilling them, what gave a perfect amount of play. So the pots are now virtually play-free and offer very smooth movement without any friction we would need to talk about.
Then i still had some time left and cut a 20mm aluminum plate for the front. I brushed it with 120mm sandpaper by hand.
Then i still had some time left and cut a 20mm aluminum plate for the front. I brushed it with 120mm sandpaper by hand.