SSL 9K Mic Pre

[TheGuitarist]

For four of these i calculate about 240mA power draw give or take, should i be fine with just a 30VA 2X18 toroid or should i go for the 50VA.

I have a 50VA at the moment, but it won't fit in a 1RU case... which is lame... its 41mm high, and i  didnt factor internal dimensions into the 1ru sizing.

 

[s2udio]

Yup 30va is fine

 

[Whoops]

For four of these i calculate about 240mA power draw give or take, should i be fine with just a 30VA 2X18 toroid or should i go for the 50VA.

I have a 50VA at the moment, but it won't fit in a 1RU case... which is lame... its 41mm high, and i  didnt factor internal dimensions into the 1ru sizing.

So basically you could just use 1 PSU PCB with the 7818 and 7918 regulators, to Power 4 channels, or even 8 channels, is that right?

 

[TheGuitarist]

Unless the PSU starts doing funky things when more current is drawn. But off the top of my head, it was  16.4 on the 18+ terminal (with +15 coming off it too)  -5 off the negative (with -15 coming off) and 39mA off phantom power.

The numbers seemed a bit odd for me but hey, its what it was giving me.

As for the chips


SSM2210 was 10mA i think
5334 was 8
tl052 was 7.2?
that1646 i think was 8

so per channel its roughly
57.2 mA draw. Times 4

228.8mA

Now even if things fluctuate, i'd say that 800mA leaves HEAPS for the pre. I thought i'd just check before putting the buy through etc.

 

[Whoops]

so 8 channels would be around 500mA

1 SSL9K PSU could be enough to power the 8 channels, thats amazing

 

[TheGuitarist]

By the way, has anyone done a comparison with the Five Fish SC-1 and the 9k?

 

[stereokillah]

hi,
i've built one dual ssl9k with go between and opamp di from JLM for my firend.

He tell me  after some using hours time the gain volume and after 3db more.

this problem is only on one channel with jlm di or with outside di plug on mic Xlr input.

when he put the 48v on and down, the gain come back to the good value  and down from 3 db after some miniutes.

i would have some feels about this problem before have this unit in my hand .

thanks

 

[JAY X]

Hi All,

¿has anyone experienced shortcircuits with the mic preamp boards? ¿where should i look first to test the boards? I recently sent the 9k psu (with toroidal and mains filter)to a technician and among other faults he found that i may have a shortcircuit in these preamps.

On the other hand i used ne5534ap rated for 15 volts, and tle2082 rated at 18 volts, so with only a single psu board at 15 volts and parallel wiring,  these preamps and balancing out should work ok.

Thank you for your help,

JAY X

 

[dubwarrior]

Hy

Ive got some boards of the SSL 9K Gustav PCB here.

And i got some questiona about it.

Is there any Possibility to add a low cut to this mic pre?

I know that i can ad, PAD, and Phase and phantom power with a JLM kit.

But what about a low cut?

Thanks for your help.

Regards

Rico

 

[briomusic]

dubwarrior, you could definitely experiment with stickin a cap between the mic-pre and balancing board. maybe try 100nf? just mess around with different values until it does what you want. then have a switch shorting the cap so the mic-pre is directly connected to bal board.

 

[dubwarrior]

dubwarrior, you could definitely experiment with stickin a cap between the mic-pre and balancing board. maybe try 100nf? just mess around with different values until it does what you want. then have a switch shorting the cap so the mic-pre is directly connected to bal board.

Thanky you very much briomusic.

i will try it.

Ive serched  a little bit on the net about Low Cut filters, wouldnt be better to ad a cap between the mic-pre and balancing board.and a resistor to ground?

like that?

Regards
Rico

 

[Harpo]

Ive serched  a little bit on the net about Low Cut filters, wouldnt be better to ad a cap between the mic-pre and balancing board.and a resistor to ground?

The 10K resistor to ground is already there (inside the ssm2142, 2x 20K in parallel, connecting to virtual ground).
A 100nF in front will give a hpf at 160Hz, 150nF for 106Hz or 220nF for 72Hz.

 

[uncle]

I'm having troubles with two channels of my 9k preamp.
Can anyone post correct voltages? it will help
thanks

 

[helterbelter]

Okay, I have a lot of SSL modules, and a lot of them use 220 uF bipolar caps for blocking DC voltages. I need to replace these caps here and there, so I was wondering, could I replace it with 2u2 wimas, just like the 9K pre ?!? The Wimas are much easier to get, and a lot cheaper as well !

The reason why I ask here in this thread, is because the 9k pre circuit is pretty similar to the circuit of the summing amps of the 5k console.....

As a matter fact, I'm thinking of buying a few of those summing amps just to convert them into micpres.....  ;D

 

[helterbelter]

Bump for the cap-question !:

Okay, I have a lot of SSL modules, and a lot of them use 220 uF bipolar caps for blocking DC voltages. I need to replace these caps here and there, so I was wondering, could I replace it with 2u2 wimas, just like the 9K pre ?!? The Wimas are much easier to get, and a lot cheaper as well !

The reason why I ask here in this thread, is because the 9k pre circuit is pretty similar to the circuit of the summing amps of the 5k console.....

As a matter fact, I'm thinking of buying a few of those summing amps just to convert them into micpres.....  ;D

 

[TheGuitarist]

Can anyone share their grounding schemes at all please?

 

[Harpo]

Okay, I have a lot of SSL modules, and a lot of them use 220 uF bipolar caps for blocking DC voltages. I need to replace these caps here and there, so I was wondering, could I replace it with 2u2 wimas, just like the 9K pre ?!? The Wimas are much easier to get, and a lot cheaper as well !

The reason why I ask here in this thread, is because the 9k pre circuit is pretty similar to the circuit of the summing amps of the 5k console.....

As a matter fact, I'm thinking of buying a few of those summing amps just to convert them into micpres.....  ;D

For the 9K pre circuit these 2.2uF caps with following 100K to gnd form a 1st order HPF with -3dB cutoff set for 0.72Hz [f=1/(2*PI()*R*C)], for these given values =1/(2*3.414 * 100000 * 0.0000022).
Just do the math to check if it matters when substituting your 220uF caps with single 2.2uF caps (not 100* 2.2uF caps in parallel).

 

[dubwarrior]

i've been instructed to use just a 100nf for the c63, but theres another one thats not on the bom too, its also a 100nf, i think its the one next to the 'gain b' and to the right of the +15 and a bit higher.



i used 63v on the line out elec.

:thumb:  :thumb:

Thanks for this info,

could it be that the layout of this cab is wrong?

It has a lead pitch of 2.5mm and its between +18V and -18V, should`nt it bee between +18V and Ground like th Cx?

regards

 

[mitsos]

It's not unheard of to stick a cap between + and - rails for extra PS decoupling. There is another one between the other two 5534's.

 

[dmp]

I'm just finishing up a pair of these preamps and when I turn the gain pot, the preamp only works when the gain is mostly ccw. Turning it up, the sound cuts out. The pot measures fine with a multimeter.
Sorry for the poor picture. I thought someone might have an idea what I did wrong?
I wired the gain pot with the 39 & 27 ohm resistors and used a 2.2k revlog Omeg pot. Using the new MAT12AHZ from AD.