SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011

[Barrylime]

Here's the calibration procedure from Bruno earlier in the thread:

"Some folks that are building these have asked about the HPF setup, so here goes. It's the same for the 9K and 4K boards.
R226 adjusts the "knee" of the HPF. Start with R226 fully counter clockwise, the frequency control fully clockwise, and the HPF engaged. Then send a swept tone through the unit from 20 Hz to 5k Hz, and observe a significant "bump" in response just before it takes a dive at around 400 Hz. Adjust R226 to eliminate this "bump" so that the frequency response is flat until the HPF takes over.
R3 adjusts the overall gain of the HPF section. Send a 5k Hz tone through the unit. Adjust R3 so that the output signal level is the same with the HPF in or out.
Enjoy!
Bruno2000"

And then we need to discuss the workaround to fix the out of phase output.

Thanks! I hope I can figure it out with this! I read about the phase thing, but I think this is rev 4.2, does it still have that issue? I don’t really want to mess with cutting traces and making jumpers if I can simply flick the phase switch on the front to non-reverse is, or use a phase flipper cable at the back.

 

[Barrylime]

this is the situation now:

Unfortunately, the LED bar doesn’t work. The function leds do work. I attached a video with more details. Does anyone know where I might have made a mistake, or what might be the causeI’m confident the leds are the right way around, because I oriented them the same as the 4 leds that are connected to the switches. I used the yellow earth wire to create the adaptor ‘poles’ (dunno what to call them) which I slid the LED pcb onto (with shrink tubing on both ends).

I ‘d really appreciate any tips!

vidoe is too large so here is a link:

 

[Ricardus]

Yeah, if the pot is turned all the way counter clockwise, the HPF filter starts to oscillate, that's correct. So turn it enough so it doesn't oscillate, then you have to do the procedure to flatten out the knee of the filter.

As for why the meters aren't working, that's a good one. I attached the meter board the same way you did. Where did you get the LM3915s?

Do you have two more to try?

 

[JAY X]

Hi!
What level (in dbfs), should be the seeep tone, to adjust the HPF?

Does anyone know the output noise level at any 5 gain levels, (fully ccw, 9 o'clock, 12, 3, fully cw)??. It would be interesting to know, to compare my build.

Jay x

 

[Ricardus]

Hi!
What level (in dbfs), should be the seeep tone, to adjust the HPF?

Just sent it some decent signal. So the meters are reading 0, then follow the procedure.

 

[JAY X]

Hi!

Two questions regarding the schematic. In the PAD section, RL1, the throws O2 & O1, appear to be the NC (Normally closed contacts), ¿Is that correct? So, in this NC position, ¿the PAD is OFF?.

¡Thank you very much!

Jay x


Note:
pad schematic:R67/R68/R181

 

[JAY X]

Hi!

I checked things and everything is ok now!

Jay x

 

[frejo89]

Hi!

Iam about to finish my SSL 9k project very soon. But there are a few questions left concerning the LED's used here - Iam convinced that you can help me out here maybe @bruno2000 is also still a member here?

1. as you can see in my pictures, I designed my ssl 9k without having the vu meter leds. So i just "dropped" the additional pcb for controlling the meter LEDs. Will it work this way or will it cause a problem?

2. Another question concerning the status LEDs for Pad, 48V and so on.. (yep, there are missing right now):
Which Voltage should they stand? Do they need 12V or can I use low current LED (like 2V - 3V) ?

Thank you in Advance

Jonas

 

[Ricardus]

Hi!

1. as you can see in my pictures, I designed my ssl 9k without having the vu meter leds. So i just "dropped" the additional pcb for controlling the meter LEDs. Will it work this way or will it cause a problem?

It will work fine. But you also didn't need to populate this area of the board if you weren't going to be using the meter anyway. See attached pics.

2. Another question concerning the status LEDs for Pad, 48V and so on.. (yep, there are missing right now):
Which Voltage should they stand? Do they need 12V or can I use low current LED (like 2V - 3V) ?

Thank you in Advance

Jonas

Just use regular 3mm LEDs there. There are current limiting resistors on the board to take care of all the issues you are concerned about. I used whatever 3mm LEDs that Mouser had in stock at the time since the ones listed in the BOM were not available anymore.

https://www.mouser.com/ProductDetail/696-SSL-LX3044YD

 

[frejo89]

Thank you ! That helped a lot.

I just focused to late on what I do not need to populate at all.
So i just wasnt shure, whether it will take an effect by just keep the additional PCB away from it

Concerning the LED Volts there had been no further Info out of the BOM i have here, thanks for your answer.

 

[frejo89]

It will work fine. But you also didn't need to populate this area of the board if you weren't going to be using the meter anyway. See attached pics.


Just use regular 3mm LEDs there. There are current limiting resistors on the board to take care of all the issues you are concerned about. I used whatever 3mm LEDs that Mouser had in stock at the time since the ones listed in the BOM were not available anymore.

https://www.mouser.com/ProductDetail/696-SSL-LX3044YD

Hi !
So today I got the chance to put my SSL 9k to a 500er Rack for the first time and it worked

but firstly the Gain pot seemed to have no effect to the output at all.
After detaching the front panel - the poti seemed to work properly but with a few "scratches" and hissing, while turning cw and ccw.

So beside checking the potis attachment - what should I also consider to check? I attached the front panel again with a little shim, to avoid forces that would cause some contact issues - but its not in prime condition yet

The pots are from audio-maintenance - iam not shure, what I can improve beyond that ?

 

[Ricardus]

So when the pot was turned all the way down CCW, there was still sound coming out?

 

[frejo89]

So when the pot was turned all the way down CCW, there was still sound coming out?

exactly that. And with the same gain turned all the way up CW

 

[Ricardus]

Mayne upload some close up hi res photos of the top and bottom of the board.

 

[frejo89]

Mayne upload some close up hi res photos of the top and bottom of the board.

Yes. I appreciate

 

[Ricardus]

Yes. I appreciate

I'll have a look when I get a spare moment at work today.

 

[frejo89]

I'll have a look when I get a spare moment at work today.

no probs

 

[Ricardus]

no probs

I'm not seeing anything that looks incorrect after a quick inspection. I'll look harder again.

I built 14 of these and never had that problem.

DId you read the whole thread to see if anyone else had a similar issue?

 

[frejo89]

I'm not seeing anything that looks incorrect after a quick inspection. I'll look harder again.

I built 14 of these and never had that problem.

DId you read the whole thread to see if anyone else had a similar issue?

not at all yet.
But i first will check the pot itself. I got a new API Housing within the next days. Will check again than

 

[frejo89]

So. Right now the gain works fine. Resoldered the pot- that was the Right thing to do.

But now i recognize another Problem. The low cut pot sounds not like it cuts frequencies where it should do.

By turning cw it Sounds like some kind of sweep eq. It seems to boost the frequencies. I dont get it. Very Strange.
I think that i populated Everything the Right why. So i dont Know