NV500 Mic pre BUILD THREAD

[Joe Malone]

UNDER CONSTRUCTION

NOTES & ERRATA
R30 is marked on pcb as 100k but is 10k for current orange HPF led to be correct brightness.
The 2 x BA283AV SMD plug-in modules have been pre-biased so are plug-and-play and swapable.
You can check if bias is correct by measuring the voltage across the 12R 1W resistor you should have 1.3 to 1.4vdc after the module has been on for a few minutes and the red led in between the 2 slots is softly light up showing 24.6vdc has been reached after the long soft start.

Link to NV500 Build map
https://jlmaudio.com/builds/maps/NV500Map.html

Link to FetDI500v3 Build map
https://jlmaudio.com/builds/maps/FetDIMap.html

HPF PCB assembly before fitting and soldering to 4 pads under NV500 PCB

HPF PCB 640 1.jpg

HPF PCB 640 2.jpg

HPF PCB 640 3.jpg

HPF PCB 640 4.jpg

HPF PCB 640 5.jpg

HPF PCB 640 6.jpg

HPF PCB 640 7.jpg

HPF PCB 640 8.jpg

FETDI500v3 assembly before plugging onto NV500 PCB

FETDI500v3 640 1.jpg

FETDI500v3 640 2.jpg

FETDI500v3 640 3.jpg

FETDI500v3 640 4.jpg

FETDI500v3 640 5.jpg

FETDI500v3 640 6.jpg

FETDI500v3 640 7.jpg

FETDI500v3 640 8.jpg

[kevinf]

I put the NV500 together during the week and it works and sounds great from initial testing.

The couple of things I scratched my head over during the build were:

- the green wire—based on the pictures that looked to be connecting the HPF switch to the output trim pot. Is that for chassis grounding purposes? I did that and all seems well.

- the 48V LED. It’s very possible I’ve done something silly, but I only saw one red 3mm LED in the kit, and based on build map I put that between the pin connectors on the NV500 board. So for now I put it on sans 48v kit (mostly using DI for now so can rely on the switch without indicator), and I’ll just throw a 3mm red LED in there later when I have one handy.

[Joe Malone]

I put the NV500 together during the week and it works and sounds great from initial testing.

Great to hear

The couple of things I scratched my head over during the build were:

- the green wire—based on the pictures that looked to be connecting the HPF switch to the output trim pot. Is that for chassis grounding purposes? I did that and all seems well.

Yes I have done a photo to show the green wire setup. As you are the second person to ask. It will be added this weekend to this thread.

- the 48V LED. It’s very possible I’ve done something silly, but I only saw one red 3mm LED in the kit, and based on build map I put that between the pin connectors on the NV500 board. So for now I put it on sans 48v kit (mostly using DI for now so can rely on the switch without indicator), and I’ll just throw a 3mm red LED in there later when I have one handy.

Yes the red led is a packing mistake it should have been 2 high bright leds (I have added one into your latest order which is ready to go)

[kevinf]

I put the NV500 together during the week and it works and sounds great from initial testing.

Great to hear

The couple of things I scratched my head over during the build were:

- the green wire—based on the pictures that looked to be connecting the HPF switch to the output trim pot. Is that for chassis grounding purposes? I did that and all seems well.

Yes I have done a photo to show the green wire setup. As you are the second person to ask. It will be added this weekend to this thread.

- the 48V LED. It’s very possible I’ve done something silly, but I only saw one red 3mm LED in the kit, and based on build map I put that between the pin connectors on the NV500 board. So for now I put it on sans 48v kit (mostly using DI for now so can rely on the switch without indicator), and I’ll just throw a 3mm red LED in there later when I have one handy.

Yes the red led is a packing mistake it should have been 2 high bright leds (I have added one into your latest order which is ready to go)

Brilliant, thanks Joe!

[hasanova]

A pic of the "green ground wire" from HPF switch (outer casing) to the output trim pot (outer casing).

green ground wire NV500 .jpg

[Joe Malone]

A pic of the "green ground wire" from HPF switch (outer casing) to the output trim pot (outer casing).
green ground wire NV500 .jpg

[ballo333]

Hi there

Question
Looking for a tip for how to fit red phantom LED where to bend etc

Thanks

[Joe Malone]

Hi there

Question
Looking for a tip for how to fit red phantom LED where to bend etc

Thanks

With the pcb upside down with all top parts fitted. Hook the front of the red led against the front edge of the pcb. Long leg closest to the side pf the pcb. Where the 2 legs go over the top of the led solder pads use a pair of pointy nose pliers lined up with the back edge of the led pad holes and bend legs 90 degrees downwards. Clip the led legs after the bend to about 5 to 6mm long. Sit the 2 legs in the holes and solder one leg while holding the led level above the pcb. Then solder the second leg. Done.

[ballo333]

Anyone know if the small tag on trim pot should be snipped for faceplate to fit flush?
My guess is yes

Thanks

[Joe Malone]

Anyone know if the small tag on trim pot should be snipped for faceplate to fit flush?
My guess is yes

Thanks

Locate tabs on any pots that bolt to the front panel or bracket always need to be cut off flush or they will not bolt up.

[ballo333]

Hi There

So ive finished the Kit NV500
I seem to have 1 ceramic cap left over 102 cant seem to find anywhere it goes?

IMG_02894153E351-1.jpeg

[Joe Malone]

Hi There

So ive finished the Kit NV500
I seem to have 1 ceramic cap left over 102 cant seem to find anywhere it goes?
IMG_02894153E351-1.jpeg

No 102 = 1nF caps are used in the NV500. So that is a stray which we are not sure how it got in the packing.

Not needed. Spare parts draw part or bin it.

[ballo333]

few questions

Managed to mess something up fried 3 resistors
R29 R30 and the one between them 470R

I double checked all replaced those resistors
R29 R30 10K Right?

Another thing was the blue led that light DI input didnt work maybe caused by that problem?
I did spot what possibly could be a short where screw meets the BLUE led

I did fire the 48 volt light come them faded straight away

One last one the 18 pin connectors checking ive got the correct position
From left 1 to right 18in the photo shown

Thanks

Sean

[ballo333]

IMG_6F5B340BB405-1.jpeg

[ballo333]

So managed to solve the problem
Looks like it was a short that blew the resistors and also the red 48v LED

The 48volt works just not the Blue DI LED

Wondering what LED i should get to replace?

Thanks