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

[TillM]

Thank you so much for the advice, but is 680ohm and 150ohm not to much, when the resistors before was just 2k2 and 10k7?
Hope you can help me

 

[Whoops]

Thank you so much for the advice, but is 680ohm and 150ohm not to much, when the resistors before was just 2k2 and 10k7?
Hope you can help me

Did you find out how much attenuation the stock pad provides in this unit?
you should, ask around, Bruno should know he design it, or do the math yourself.
Confirm if it's 15dbs, if so increase to 20dbs.

Read the page I sent you:
http://www.uneeda-audio.com/pads/

Pads and in this case U can have a lot of different resistor values, the attenuation will be related to the interaction of the 3 resistors.
Uneeda has 2x 680ohm and 1x 150ohms, thats a reference for a lot of people and a trusted source, as I told you I would do that in a pinch.
JLM Go between uses 2x 470ohms and 1x 120ohms for the same 20dbs of attenuation.


Just replace the 2x10K8 for 2x680r and the 2k2 for 150r, solve your problem and go on recording.

Good work

 

[justinheronmusic]

Hey everyone! Is there still a source for the 4K boards?

 

[Whoops]

Hey everyone! Is there still a source for the 4K boards?

I'm sure if there's enough interest Gustav would do another run. (PCB grinder)

Besides that I guess you only option is the Black Market section

 

[TillM]

Hey everyone! Is there still a source for the 4K boards?

I'm also looking for this, hope some more will look for it.


@whoops
Thank you so much!
Now I understand it, the parts will come today, than I can start.
Thanks for your help

 

[TillM]

Well I'm  finished my 9k5.


The Mat02 was shipped so fast - in one week it arrived ! (big thanks to Frank).
Well ... then the first try ... i was an idiot, i did not use my Sound Skulptur extender.
So, my module in my lunchbox, press the on button and than ... hell nooo ! smoke and a flame ... f**k.
Hope my lunchbox work ... so get my module out and resistor R1 is burned.
I get some new resistors after that.
Next try .. same thing ... but now with extender.
Well ... i look a second time at my meter bridge and cut it of as said in the first post.
Next try ... perfect. Everything worked so far. I let my lunchbox on for one hour, just to check, if R1 bourned a second time.
Looks good so far.
Well two things are in progress, cause i did not check it perfectly.
I soldered a cable that goes out my soundcard into my Lunchbox input.
The Lunchbox output i take in my mic input from my soundcard, is that right so far?
Then i play the sweep tone from the first page, actually I don't here these response bump.
Thats the only probleme i have,
Hope somebody can help me.

Big Thanks to: Frank for the MAT02, Whoops for the advice with the Pad, Bruno for the layout, Gustav for the PCB and everybody in this forum.

https://www.dropbox.com/sc/p6vp9gsrws272qs/AAAHRm82DSZVQK1r-VLmMBW1a
(if the pictures don't work in the thead.

 

[Whoops]

so get my module out and resistor R1 is burned.
I get some new resistors after that.
Next try .. same thing ... but now with extender.
Well ... i look a second time at my meter bridge and cut it of as said in the first post.
Next try ... perfect. Everything worked so far.

I soldered a cable that goes out my soundcard into my Lunchbox input.
The Lunchbox output i take in my mic input from my soundcard, is that right so far?

Then i play the sweep tone from the first page, actually I don't here these response bump.
Thats the only probleme i have,
Hope somebody can help me.

Hello TillM,
I'm really sorry I would like to help you but  I don't really understand what you wrote. It's really confusing.
I'm also not an native English speaker so I know how hard it is for us to explain something in a different language.

You said R1 burned, why did it burn?
it's not burning any more? why? did you change or corrected something?


you soldered a cable from your soundcard to the lunchbox input, why? you can just use aligator clips to inject signal for testing purposes
or did you wanted to say I "Connected" a cable from my soundcard output to lunchbox input?

The Lunchbox output i take in my mic input from my soundcard, is that right so far?

The signal that you have at your lunchbox outputs is "Balanced Line Level" so you don't connect that to your soundcard Mic Input (Mic Preamp) you connect the lunchbox out to a "Line In" on your soundcard. That is a TRS input in most soundcards.

Then i play the sweep tone from the first page, actually I don't here these response bump.
Thats the only probleme i have,
Hope somebody can help me.

Please refrain, try to be more clear, ask for to a friend that is fluent in English to help you out in explaining the problem

 

[TillM]

Hi Whoops,
i'm sorry it was late, I will try to explain it better.

You said R1 burned, why did it burn?
it's not burning any more? why? did you change or corrected something?

R1 has burned, cause there was still the connect on the meter board. I put a razor and scratched the part. Then I change R1 and now it works.

you soldered a cable from your soundcard to the lunchbox input, why? you can just use aligator clips to inject signal for testing purposes or did you wanted to say I "Connected" a cable from my soundcard output to lunchbox input?

Yes
I take a DIY-XLR Cable.
So I can also use my aligator clips from my oscilloscope and put them on my card extender, which I use for the testing.

The signal that you have at your lunchbox outputs is "Balanced Line Level" so you don't connect that to your soundcard Mic Input (Mic Preamp) you connect the lunchbox out to a "Line In" on your soundcard. That is a TRS input in most soundcards.

Thank you.
My Lunchox has only XLR Outputs.
So  the cable I use was XLR-Stereo Jack.  The XLR at the output from my Lunchbox and than the stereo jack in the TRS-Input from my sound card.
I did this already.

Please refrain, try to be more clear, ask for to a friend that is fluent in English to help you out in explaining the problem

I hope it clearer now and you understand it better

 

[Whoops]

Nice, yeah I got it now.

Thanks

 

[TillM]

Could you give me a better explaination for the HPF.
I took the sweep from the first page.
This I took in my DAW.
Then I go from the output from my sound card into my lunchbox input.
From my lunchbox output I go in the TRS from my soundcard.
Now I play the sweep and look at the Trimmer on R226. So far, this is right ?
Now I must adjust the trim pot clockwise.
But I don't trick it out already. Hope you can give me a better explanation.

 

[Whoops]

Could you give me a better explaination for the HPF.
I took the sweep from the first page.
This I took in my DAW.
Then I go from the output from my sound card into my lunchbox input.
From my lunchbox output I go in the TRS from my soundcard.
Now I play the sweep and look at the Trimmer on R226. So far, this is right ?
Now I must adjust the trim pot clockwise.
But I don't trick it out already. Hope you can give me a better explanation.

I never done the SSL9K in these Bruno pcb's with the HP filter included,
the SSL9K projects I did were with Gustav's older pcb's that were designed by SSL Tech, no HP filter there, that was added by Bruno when he designed these boards.

So if you are asking is related to some sort of HP setup or calibration, I really can't help,

I'm sure someone in this thread will be able to chime in

 

[TillM]

@whoops
Thank you a million times for all your help building this pre.

I hope somebody can give me a better advice for the HPF.
Bruno told what to do on page 3 or 4, but I don't hear the response in the sweep.
Do I've to turn up the HPF full or is it just important to turn the switch on ?

 

[Whoops]

@whoops
Thank you a million times for all your help building this pre.

I hope somebody can give me a better advice for the HPF.
Bruno told what to do on page 3 or 4, but I don't hear the response in the sweep.
Do I've to turn up the HPF full or is it just important to turn the switch on ?

if you post what Bruno said, or the Guideline I will try to help you out

 

[TillM]

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

that was the advice for the HPF

 

[Whoops]

Well it's pretty clear

Start with R226 fully counter clockwise
the frequency control fully clockwise,
and the HPF engaged

 

[TillM]

Well it's pretty clear

Start with R226 fully counter clockwise
the frequency control fully clockwise,
and the HPF engaged

Thanks !
Both Preamps are calibrated.
Next problem... after playing some hours my first Preamp gets rapidly low gain. Even when i turn the gain knob to maximum nothing happens.
I already changed mic, mic cable, Swapped ICs, looked for cold solder joints and so on.
I hope somebody can help me.

 

[Whoops]

Thanks !
Both Preamps are calibrated.
Next problem... after playing some hours my first Preamp gets rapidly low gain. Even when i turn the gain knob to maximum nothing happens.
I already changed mic, mic cable, Swapped ICs, looked for cold solder joints and so on.
I hope somebody can help me.

You have to troubleshoot it.
Use a signal/audio  probe. inject sound at the input , probe before an after each component until the sound stops, then you might have found the culprit.

If you don't have an Audio Probe, google is your friend  "DIY Audio probe"

 

[Scimitar]

Some time well spent over the December break - a couple of new SSL 9k5's to join the rest of the family in the TAC rack.

First one failed the "smoke test" - my fault - managed to put one of the 220uF caps in backwards - schoolboy error! No damage done just need to replace the cap! Also waiting for another ssm2212, which I am using in the place of the MAT02's and then it will be time for a bit of testing and alignment.

Looking forward to finding out how these stack up against the other pre's in the rack.

 

[TillM]

You have to troubleshoot it.
Use a signal/audio  probe. inject sound at the input , probe before an after each component until the sound stops, then you might have found the culprit.

If you don't have an Audio Probe, google is your friend  "DIY Audio probe"

Hey Whoops,
I made the test with my Audio Probe.
How to describe it the best.
Well, i follow the shematic and get the signal at in and out.
What I don't know is... at the Input the signal is louder than on the output. As i understand, the output must go louder, when i turn the gain pot, is that right?
But nothing happens when i use my gain pot, the signal stays low.
Thats the problem. When i play my snare, i can see, that my module gets the input (i see it at the waveforms in my daw) but i can fully turn the gain pot on and the sound stays low. Could it be possible, that the gainpot works not right ?

@Scimitar
Nice twins !

 

[Whoops]

Hey Whoops,
I made the test with my Audio Probe.
How to describe it the best.
Well, i follow the shematic and get the signal at in and out.
What I don't know is... at the Input the signal is louder than on the output. As i understand, the output must go louder, when i turn the gain pot, is that right?
But nothing happens when i use my gain pot, the signal stays low.
Thats the problem. When i play my snare, i can see, that my module gets the input (i see it at the waveforms in my daw) but i can fully turn the gain pot on and the sound stays low. Could it be possible, that the gainpot works not right ?

If you used the correct Pot for gain I don't believe it's the gain pot, it's probably something in the circuit that is wrong.
It could be a lot of different things impossible to know at a distance.

Before anything you should:
-Check all Electrolytic caps values and Correct placement.  They are polarized + and - are on the correct holes?
- Check all resistor values
- Check all capacitor values
- Check MAT02 placement, is the orientation correct
- Check all IC's Orientation
- Check all solder joints and check for possible solder bridges
- Measure the voltages across each IC and transistor Pins, do a voltage chart, show us

Do you have a friend with electronics knowledge that could help you?