Would love to see the inside anyway.
SSL 9K Mic Pre
- Thread starter BladeSG
- Start date
Help Support GroupDIY Audio Forum:
Hi all,
Well I just finished up a pair of these and started to run some signal through them. I get nice clean audio but my gain pots seem to be an issue.
The first 3/4 of the pot seems to do nothing, it passes some signal but at the last 1/4 it reaches what i would expect to be max gain.
Its all very clean and seems to sound very nice. But this gain thing is stumping me. I searched all the META's and cant find any info.
By the way Im using the Audio maintenance 2.2k rev log pots and the seem to be working correctly. Any help would be appreciated.
Also PS voltages all look good. Im using two PS boards one for 15v and one 18v.
Thanks,
Eric
Well I just finished up a pair of these and started to run some signal through them. I get nice clean audio but my gain pots seem to be an issue.
The first 3/4 of the pot seems to do nothing, it passes some signal but at the last 1/4 it reaches what i would expect to be max gain.
Its all very clean and seems to sound very nice. But this gain thing is stumping me. I searched all the META's and cant find any info.
By the way Im using the Audio maintenance 2.2k rev log pots and the seem to be working correctly. Any help would be appreciated.
Also PS voltages all look good. Im using two PS boards one for 15v and one 18v.
Thanks,
Eric
kato
Well-known member
Sexi little micro-build Geoff004.
How did you fit 2 channels in there? Got any internal pics?
How did you fit 2 channels in there? Got any internal pics?
mitsos said:
It's a classic one.
Glad it's working now
geoff004
Well-known member
kato said:
I'll try to put a little diagram together.
It seems that my DAC is at fault with the little problems I've got. Levels are nice and even. I don't know if the ticking was the converter too, but it seems to be better.
I don't want to try to take the thing apart again - it's a tight fit all the way around.
geoff004
Well-known member
Ok - here's the inside.
I decided I'd add a little shield (not yet in place but ready for installation) to remove any chance of AC hum. BTW, transformer orientation is everything when it comes to AC hum in this package.
Also, I used some ancient 5534s from an old distribution amp I had laying around - they're getting replaced with some newer, less noisy chips.
The only other change I would make if I were to do it over would be to use a lower profile power switch and put it on the back next to the IEC plug.
I decided I'd add a little shield (not yet in place but ready for installation) to remove any chance of AC hum. BTW, transformer orientation is everything when it comes to AC hum in this package.
Also, I used some ancient 5534s from an old distribution amp I had laying around - they're getting replaced with some newer, less noisy chips.
The only other change I would make if I were to do it over would be to use a lower profile power switch and put it on the back next to the IEC plug.
kato
Well-known member
Brilliant!
You didn't have to take it apart just for me. but thanks. Now put it back together. I don't want to be responsible for a loose connection messing up a working build.
Nice work. I was actually laying in bed last night thinking, "he must've stacked his PCBs..."
Way to pack two channels in an impossibly small space. :thumb:
You didn't have to take it apart just for me.
but thanks. Now put it back together. I don't want to be responsible for a loose connection messing up a working build. Nice work. I was actually laying in bed last night thinking, "he must've stacked his PCBs..."
Way to pack two channels in an impossibly small space. :thumb:
Beautiful!!!
I think I will build also 2 channels in one small box to have as a portable unit.
The Toroidal transf is quite close to the PCB , are they quiet?
Don't you have any induced Hum?
congratulations
I think I will build also 2 channels in one small box to have as a portable unit.
The Toroidal transf is quite close to the PCB , are they quiet?
Don't you have any induced Hum?
congratulations
Well I finished!
Front panal was done by Prodigy laser engraving. I love it!
Sounds great. Very clean and seems warm and clear. I caint wait to use it!!
I still need to clean up the front a little and add the power on lamp. Thats what the hole in the middle is for. I also need to match thne knobs the one on the right is bigger.
Eric
Front panal was done by Prodigy laser engraving. I love it!
Sounds great. Very clean and seems warm and clear. I caint wait to use it!!
I still need to clean up the front a little and add the power on lamp. Thats what the hole in the middle is for. I also need to match thne knobs the one on the right is bigger.
Eric
geoff004
Well-known member
Whoops said:
I'd be lying if I said there was no hum. That said, it's very minimal. There's more hiss than anything. (BTW, these are observations made with the gain turned to 11)
I don't know if it'll be good for doing sensitive solo recordings in quiet spaces, which was my intent for it. I'll have to see how it works with the mics I've got vs. the hiss/hum.
On the other hand, I can tell you I'd have no hesitations about using it on something going in a mix - including acoustic guitars or pianos.
Overall, from the 20 minutes or so I've tried it out I can say it sounds really good. The other 9k I built used LM394s from ebay - this one uses MAT-02s. To me the MAT-02 sounds a little more classic and has a little more noise. The other one is a little cleaner all the way around.
Things I'd do differently:
-use a slightly larger box - this one is 9x7x2. Maybe should have used something like 10x7x2 just for a little more separation and a little more space to work.
-use a lower profile power switch or one incorporated into the IEC and put it on the back. that'd make for shorter AC runs and clean up the internal wiring a little.
-also I'd probably move the toroid to the rear next to the IEC. Then the PSU would be in a better position, again making for shorter wire runs.
-use lower profile switches for phantom. Believe it or not the switches are the hardest thing to get the PCBs around when opening or closing the box.
Whatever - it works and I'm done with it.
On to the next thing....
phatmateo
Well-known member
nice job Eric! I'll be putting mine together as fast as my funds allow. Is that a par-metal case? How much was it total for the engraving and case? I'm just trying to get an idea of the total cost. Thanks!
Yep its a Par-Metal case. Its the 11 inch deep one. I thought I would need the room but in hindsite I would have gone for the 8 inch one it would be big enough. So all in it was around 110$ for the case and the engraving. That includes all shipping costs. I thought it was worth it.
After I clean up the wiring I will show some inside shots.
Eric
After I clean up the wiring I will show some inside shots.
Eric
kato
Well-known member
I have an unused 10VA toroid sitting around.
Would this provide enough current for 1 channel, including balancer board?
Would this provide enough current for 1 channel, including balancer board?
s2udio
Well-known member
Yup ,should be ok, 50va is fine for 4 ,as well as led meter and phantom powerkato said:
4x ssl9k
http://www.groupdiy.com/index.php?topic=32343.0
kato
Well-known member
Thanks chaps!
My gut told me it would do, but the math on opamp current draw is not so straightforward.
Will I be the first person to build a 1 channel 9k?? Is that totally crazy?
I'm sure I will find uses for it...
My gut told me it would do, but the math on opamp current draw is not so straightforward.
Will I be the first person to build a 1 channel 9k?? Is that totally crazy?
I'm sure I will find uses for it...
