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The Official "Build" thread for the V4 WYN Phono preamplifier

OK, finished until I decide on chassis boxes, connectors, etc.
Because the load resistors for each channel are mirrored, I did the same with the piano key switches to keep the order of the levers consistent.

gktaudio_WP_V4.jpg
 
GKTAUDIO said:
OK, finished until I decide on chassis boxes, connectors, etc.
Because the load resistors for each channel are mirrored, I did the same with the piano key switches to keep the order of the levers consistent.

View attachment 3447920
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Looks great! One last thing to check if you could: What is the height of the two big brown caps above the PS board?

I'm going to mount the DIP switches to the bottom of the board and cut a hole in the bottom of the enclosure to access them versus taking off the enclosure's top. The DIP switches will have different actuators versus the BOM "piano" style so the switch numbers will be easier to read.
 
Sorry - I've put that project away in a box while I catch up on amp repairs for people. You can get that info from the part number through Mouser.
 
GKTAUDIO said:
The tallest cap on the main board is 21.3mm - that's the one at the top left corner of the photo. The blue film caps are a smidge taller than the red electrolytics, at 12.7mm off the board. From the bottom of the board to the top of the tallest cap is 23.05mm, so figure your 5mm standoff and some clearance at the top of the cap gives you maybe 30mm.
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My build just fits into a 1U enclosure.
 
Yes. Since you mirrored the resistors and the switches, I installed them accordingly, and to follow the silkscreen. I mentioned it because you mounted your both your switches pin 1 up and I thought there might be questions about my choice.
 
GKTAUDIO said:
Thanks for getting me to take a better look, @hirscwi. I see the location now.

Re: the "100 Ohm" value I stated, that was me switching between magnifying lenses and no glasses at all while mis-reading the component bag markings. 10Ohms looked to me without glasses like, you guessed it - 100. So, no problem with the BOM in that regard. However, some parts with many location numbers didn't import into the Mouser cart completely, with only about 5 numbers showing up on the bag and the packing list. I'll add this to your useful suggestions:
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Mouser limits the characters in that field. The BoM in excel is complete.
 
GKTAUDIO said:
Yes. Since you mirrored the resistors and the switches, I installed them accordingly, and to follow the silkscreen. I mentioned it because you mounted your both your switches pin 1 up and I thought there might be questions about my choice.
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I did this unintentionally.
 
hirscwi said:
I had to google "trigger thumb". I had "game-keepers thumb" many years ago as a result of skiing in sub-zero temperatures.

At any rate, the finished prototype is off to Wyn.

View attachment 3411831View attachment 3411833
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@hirscwi :
  • What parts did you use for the on/off LED on the PS Board? What parts need to be changed or added to adjust the brightness of the LED?
  • In the photo of the prototype there is a green ground wire attached to the preamp board near the switch connections and wraps around to the board to near the back of the 18VAC jack. Was that ground wire attached to the 18VAC jack or?
  • Just by chance do you have a photo of the connections/wires to the front switches?
Thanks!
 
AvFan said:
@hirscwi :
  • What parts did you use for the on/off LED on the PS Board? What parts need to be changed or added to adjust the brightness of the LED?
  • In the photo of the prototype there is a green ground wire attached to the preamp board near the switch connections and wraps around to the board to near the back of the 18VAC jack. Was that ground wire attached to the 18VAC jack or?
  • Just by chance do you have a photo of the connections/wires to the front switches?
Thanks!
Click to expand...
  • Any LED will work. Best way to adjust brightness is by choosing the mcd output (millicandle). The resistor connected to the LED can vary the brightness a bit by increasing, but it doesn't have a huge effect.
  • The outside if the AC input is connected to GNDA, as per schematic. There's a ground connection on the board, near the AC input and it is connected to GNDA via a 10 ohm resistor. This goes to chassis. The other ground connection goes to a ground post on the rear.
  • I don't have a photo and it probably wouldn't help anyway. Best bet is to follow the schematic. The only one to be careful about is the warp/mono/stereo connection and I believe this is adequately explained in the original thread and diagrammed on the schematic. I also think Wyn provided a detailed description of the switch functions in the original thread.
 
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My partner in building a V4.0 has the actual PCBs and I want to spend some time comparing the PCB to the schematic. My way of learning something new. Is there a way to get a fairly high resolution pdf of the final PCB? I looked at the Gerber files but I don't have that software and don't see a way to generate at pdf or other image of the PCB. Thanks!
 
AvFan said:
My partner in building a V4.0 has the actual PCBs and I want to spend some time comparing the PCB to the schematic. My way of learning something new. Is there a way to get a fairly high resolution pdf of the final PCB? I looked at the Gerber files but I don't have that software and don't see a way to generate at pdf or other image of the PCB. Thanks!
Click to expand...
That would be up to @hirscwi. He did the layout.
 
HalfApt said:
In the Kicad 2D or 3D board rendering, disable "Show thru-hole/SMDSMD parts". That leaves the bare board w/silkscreen. Save the image & pass it around.
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That would be a useful addition to the materials for building this project.:)
 
I have just received v4 boards (and BTW have sent out both v3 and v4 PCBs to people over at DIYaudio in the last 2 days)... I love v3 and I know v4 is different, but I'll be building it ASAP—can't have too many phono pres! Hopefully soon.
 
Sean @HalfApt generously offered to 3D print an extension of the MM/MC pushbutton switch and he sent me his prototype to try out on the switch. I would say his effort is a success!

Looking from above at the extension attached to the switch plunger:
IMG_5741.jpeg

From the side initially the extension was pointed down a bit:
IMG_5742.jpeg

After a little gentle trimming on a couple of tabs as noted below where the extension snaps on to the end of the switch and I was able to get the extension horizontal with the switch.

IMG_5743.jpeg

The extension adds a max of 2"/50mm to the switch so the PCB can be set further back from the back panel and it can be cut to meet the builder's specific needs. I suggest the maximum the PCB can be set back from the back panel is 40mm to allow the switch cap to project past the back panel and accommodate the 3mm of switch travel. YMMV. I wouldn't make this extension any longer as the material does have some flex but should be stabilized by the hole in the back panel. I'm going to glue the extension to the switch during assembly.

Switch w/o pushbutton cap: Mouser 612-PBH4UEENA (limited stock, more in May)
Switch w/cap: Mouser 612-PBH4UEENAG1RBLK (out of stock until May)
Switch Cap: Mouser 612-1R-BK

Sean and I haven't worked out the details yet but we wanted to see if there was any interest from V4.0 builders for the switch extension. I know @mkane and I have a need for two more for our respective builds.

Thanks again, Sean!
 
Well, for a productive person, having useful and specialized tools always inspires them to come up with new reasons to use them. I'm sure you would put one to good use. I've also been considering one, and have plenty of ideas for projects, but have literally no more counter/bench space anywhere in this house or garage.
 
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