[BUILD] All things RackNeve

[ion]

As I wrote earlier, you need to connect your +24V DC supply to the "24V DC" connector in the middle of the board. Observe the polarity - positive lead should go to the square pad.
In case your PSU is too noisy and you see HF spikes in the output spectrum of the preamp, you can make an LC filter, or better yet use a common mode choke instead of a simple inductor, and make a CLC (where L is a common mode choke) PI filter and connect it right after your PSU.
Let's not get ahead of ourselves though and have the preamp working first.

There is no polarity sign / square at the 24v dc point middle of the pcb. Only the double line.
i dont wanna burn it, so how to tell polarity?

i left the 2 switches (impedance/invert i think) pcb off now and connected ends of wire 8+9 for testing wich i suppose is correct

 

[Ilya]

Polarity is the same as in the DC in connectors. You can differentiate the positive lead by the square pad (one of the connectors pads is square, another one is round).

Line in should be 2 and 4 (according to JLM). Mic in is either 7 and 9 or 8 and 10.

 

[ion]

Polarity is the same as in the DC in connectors. You can differentiate the positive lead by the square pad (one of the connectors pads is square, another one is round).

Line in should be 2 and 4 (according to JLM). Mic in is either 7 and 9 or 8 and 10.

Yep xts are wired and out has zoebel.

i have no clue what square pad u refer to. (ok you mean dc plug, i just use a pre wired one for testing but i dont know the polarity on the pcb)


do you mean the 2nd line that indicates right from it is + ob 28vdc means the same for the 24vdc? So the line shows + 1 turn right for +?


i have this wired as grey for + now and wait for your green light to power it

 

[ion]

For some reason the 24vdc point has no polarity sign.

 

[Ilya]

Yes, your gray wire is "+". Square pad is under the PCB, you solder the connector to these pads:


Circled pad is positive

 

[ion]

Yes, your gray wire is "+". Square pad is under the PCB, you solder the connector to these pads:
View attachment 97228

Circled pad is positive

Power led not lighting up.
gets a bit warm around the middle, maybe the semiconductor
and powerbank shows current draw around 3 watts

but sadly no sound



correction, bad electrical noise wich gets louder and more silent with trim and turns on/off with gain positions. Tried to tap from out transformer aswell, everywhere the same


my best bet is that my input xt isnt set up correctly bc i am not able to tap any signal from the 3+5 that go to the gain pcb while the noise is probably my powerbank. So at least nth fried hope.

i ve no clue why the led stays off tho

 

[Ilya]

The LED won't work without +48V present, so never mind it.

If the noise gets louder with gain switch it means amp stages work (at least sort of). Do you have your circuit in the enclosure? If not, the hum may be normal.
Try feeding some signal to the a) input transformer and b) to the input of the gain PCB directly. Let's see if we can get any sound from this unit.

 

[ion]

The LED won't work without +48V present, so never mind it.

If the noise gets louder with gain switch it means amp stages work (at least sort of). Do you have your circuit in the enclosure? If not, the hum may be normal.
Try feeding some signal to the a) input transformer and b) to the input of the gain PCB directly. Let's see if we can get any sound from this unit.

Ok so far i managed:

to kill the aux out of my ipad it distorts from now on....whatever. Seems like i got some bad impedance incident.
its the sound source for testing.... it also hung up had to restart etc.

i managed to find a tap at the legs of the trim pot where i could get the signal. Gain didnt seem to have effect(not sure bco distortion) trim did With both ends of the trim going to heavy distortion

 

[ion]

Ok yes i managed to patch into the gain pcb. Both gain and trim working. Soooooo its really just the input tx wiring it seems yeeeeeeeah! .)

i so needed this after a few diy issues recently. I will unsolder clean and completely clean re wire the marinair input and am sure things will move from there.

thanks so much for staying put and supporting. Will move to the eq next days.
can i hang the led to some other place to light (only for inside my build actually)

 

[Ilya]

Nice progress!
I was going to suggest checking different stages, but it looks like all of them are working. Congratulations!
It's possible to wire the LED right from the 24V supply with a suitable dropping resistor. But let me see if there's a more elegant way to do that using the current circuitry.

And never use consumer equipment as a test source - it's not protected enough. Keep on posting.

 

[ion]

Nice progress!
I was going to suggest checking different stages, but it looks like all of them are working. Congratulations!
It's possible to wire the LED right from the 24V supply with a suitable dropping resistor. But let me see if there's a more elegant way to do that using the current circuitry.

And never use consumer equipment as a test source - it's not protected enough. Keep on posting.

are these seated in correct orientation to the pcb?

 

[Ilya]

The 2-pole switches (with 2 pins in the middle) is very hard to put incorrectly. They look fine.
The single pole switch (with a single pin in the middle) is hard to judge from the photo. The only sure way to check is to put the switch in its first position and make sure that there's continuity between the middle pin and pin 1 of the switch. You put the first pin of the switch so that it coincides with the marking bar on the PCB (and the square pad underneath).

 

[ion]

The 2-pole switches (with 2 pins in the middle) is very hard to put incorrectly. They look fine.
The single pole switch (with a single pin in the middle) is hard to judge from the photo. The only sure way to check is to put the switch in its first position and make sure that there's continuity between the middle pin and pin 1 of the switch. You put the first pin of the switch so that it coincides with the marking bar on the PCB (and the square pad underneath).

Ah cool didn't notice the marking. So markibg bar = 1 ob all switches. Got it

 

[ion]

Have a little "short" between blue wire and the pin right to it. I cant undo it, tried several times with unsolder braid.

Is there supposed to be a link?
Will this lead to problems?

 

[Ilya]

These pads are connected, no problems here.

 

[ion]

Ok now i ve a messy situation:/
I was idiotic to use a bad iron since mine stopped working. The pcb looks worse than it is but that situation around the green cable from down is a nightmare. It seems like the solder points from that and the next in place separated from the pcb.

I desperately need a method to work that out please.

Damn sure hope it's not screwed up for good.

maybe best to bypass them? The yellow one above the green has the issue too. Too much heat. Bad iron.

so i think i ve to bypass (jump) over 205 L, 205 E and W (from RV2). Can you guide me through that please?

 

[ion]

These pads are connected, no problems here.

Tagging you simply because i am facing a wall here. Kinda nervous if the switch pcb is screwed up

 

[Ilya]

First of all, I suggest to solder wires not flat to the PCB, but perpendicular. This way you will not short nearby pads. Look at the pictures in the "Wiring the module" section of the guide to see the illustration of what I mean.
Now, the yellow wire has to be replaced because of the melted insulation.
The green wire is a mess and should be replaced as well. What do you mean by "bypass"? Did you lift any pads on the PCB? If not, the chances are that everything is fine and you need to remove the excess solder with a wick (or/and solder sucker) and redo the soldering with a proper LOW POWER iron.
205L connects to W. 205E doesn't connect to this, it goes to the switch and to the resistor.
Here's the shot from the same point of view as in your photo so you can see what connects where.

 

[ion]

First of all, I suggest to solder wires not flat to the PCB, but perpendicular. This way you will not short nearby pads. Look at the pictures in the "Wiring the module" section of the guide to see the illustration of what I mean.
Now, the yellow wire has to be replaced because of the melted insulation.
The green wire is a mess and should be replaced as well. What do you mean by "bypass"? Did you lift any pads on the PCB? If not, the chances are that everything is fine and you need to remove the excess solder with a wick (or/and solder sucker) and redo the soldering with a proper LOW POWER iron.
205L connects to W. 205E doesn't connect to this, it goes to the switch and to the resistor.
Here's the shot from the same point of view as in your photo so you can see what connects where.
View attachment 97350

The 3 problematic pads are as far as i can see lifted by the damn heat. The silver isnt inside the pcb anymore. So i think i should bypass those pads but not sure where thier next connection is even with the graph and if that even works as way out of the problem!?

Sorry to bother!

 

[Ilya]

Here're the connections:

If I'm seeing this correctly from the photo, you connected the negative LED terminal to the rest of the circuit. Don't do that.