SSL 9K Mic Pre

[mitsos]

well, I know I'm lazy, and obviously everyone else is too. I took a quick look at the bom, it would help if you didn't have all the resistors in there, they make the list extra long and you are even less likely to get help. Just being honest, it's kinda hard to check one's own BOMs, checking someone else's, and then indirectly being responsible when something doesn't fit is not something people want to do.

You've got some backordered stuff... choose other ones unless you want to wait.

I'm not up to speed on my 5534s, I'm not sure the difference between SA5534 and NA5534 versions.
You have 2 different 2.2uF caps. One is big, 22.5mm lead spacing, the other is 10. measure the holes on your PCBs. In general, check lead spacing for all electrolytic and box-type film caps, and get one that will fit properly. Don't forget 'lytic height, if you're going with a 1U rack mounting.

I saw at least one X7R ceramic cap.  Those have a horrible reputation in audio (though are still used by many, including me). Stick with C0G/NPO for your small caps.  It may not make much difference, but at least you can be sure they won't vary much with temperature changes. Or just order wimas for everything that will fit and don't worry about this. Here's what I ordered (from TAW, I think it's for the SSL9K, but double check).
FKP2 331H63                      10        FKP2 330/63/2.5 LS5
FKP2 471H63                      6            FKP2 470/63/2.5 LS5
MKP2 104J100                      8      MKP2 .1/100/5 LS5
MKP2 104K100                    16      MKP2 .1/100/10 LS5
MKS02 104J63                      3              MKS02 .1/63/5 LS2.5
MKS2 474J63                      15              MKS2 .47/63/5 LS5
MKS4 225K63                      10              MKS4 2.2/63/10 LS15  (I'm pretty sure these were a bit too large, but I did convince them to go in eventually)

Placing parts orders is a pretty important step, if you're going to be making your own gear. Get used to looking at datasheets. People are usually pretty helpful with parts questions, but most people have too much to do to read through entire BOMs.

Also, you picked project with a more complex BOM than some others.  It's got lots of parts and lots of possibility for mistakes. But you'll be fine, just triple check everything.

good luck.

 

[dirtyhanfri]

Thanks.

Yes, I agree, it´s so hard to check an entire BOM, I Thinked about it yesterday...

Well, my main question is about the Caps voltage, 100v is ok? or better 63 for everything? 25

And about the resistors, are carbon film resistors ok? (in neeeno´s BOM there are some specified metal film resistor)

I´ll take your advice and triple check the components measurement for perfect fitting everything.

Thanks for the reply

 

[kante1603]

Really nobody could help me with this BOM for the SSL 9k

Hello,

I know I´m a bit late but maybe this helps as additional information.Have used the BOM which you can find in the first chapter here:

http://wiki.nimbleswitch.com/SSL9k

There are pitches for the caps in it and also which resistors should be matched.
I used WIMAs where ever possible,no carbon resistors and MAT02s.
No known issues.

Also some pretty good hints there for drop-in replacements (balancing ICs) and for the voltage drop (diode-trick).

Sorry for I cannot help you on parts numbers (Mouser) as I am located in germany-I had to source them on my own,too.... :'(


Hoping  to have helped,

best regards,

Udo.

 

[dirtyhanfri]

It´s better later than anything..

Well, thanks for the link, I´m gonna check it.

I made my BOM in Mouser because i thought it would be a good way to have a "universal" BOM, I´m in Spain, and surely I´m gonna get the comps in some local store, but, i beleived that it would be a good way to share it.

Are 100 V caps ok?

I´m gonna buy all metal film resistors, and WIMA fot every caps is possible

Sorry my untrained english. And rethanks for the reply

 

[mitsos]

100V caps are way more than the circuit will ever see. For wimas it's fine, as they don't come much less than 63V, but for the electrolytics you have to check the lead spacing because they may not fit.

Buy 1% metal film resistors and match the ones that need matching.

btw, your untrained english is much better than some native speakers!

 

[dirtyhanfri]

So, 100V is ok for all WIMA (Some of them are specified for 63V in Neeno´s bom, i´ll respect this)

Non WIMA caps should be cheked for correct fitting, if 100V are so big, maybe 63V? 50? 25?

Ok, I´ll get metal film resistors (1%), but, what about matched? what does it mean and how important is it?

Thanks.

P.S. Thanks For The Useful Link Kante1603

 

[kante1603]

Ok, I´ll get metal film resistors (1%), but, what about matched? what does it mean and how important is it?

Thanks.

P.S. Thanks For The Useful Link Kante1603

You´re welcome!

Matching resistors is very important for this as it directly affects the CMRR (maybe you´ve read from members who have "scratchy pots"...well,it could end up like this....).

You can match them by yourself:Simply buy-let´s say 100-of each needed value and compare them with a multimeter-the pairs which are closest to each other will be the ones you have to use.The absolute value of a single resistor is not the most important thing-as I said:Measure them to "the closer the better"!Don´t use carbons here,take 1% metallfilms (they are not really more expensive when you buy huge amounts).

Good luck with your pres,enjoy building them,

Udo.

 

[dirtyhanfri]

Ok, so I´m redoing the BOM with your advices

What about the transformer? I´m planning to build a 2ch. unit in a 1U rack case. Could someone link a transformer i should use?

Thanks

 

[Morelius21]

Hi,

I'm from Barcelona and now i make this preamp. If you live in Barcelona, we can meet and see the bom of preamp. If you prefer, you can write me in my mail.

 

[dirtyhanfri]

Ok, I´ll Send you a Mail Later


(Gracias, luego te escribo un correo)

Thanks.

 

[kante1603]

Ok, so I´m redoing the BOM with your advices

What about the transformer? I´m planning to build a 2ch. unit in a 1U rack case. Could someone link a transformer i should use?

Thanks

Hi again,

don´t have a direct link for a transformer at the moment (i had some laying arround here),but it can be a small one.Somewhere here in the forum I read that 1 channel sucks about 40-60 mAs,so yours will be arround 120 mAs max..Somewhere else I read a member running 8 channels from a 25-30VA Trafo,so a small one will fit.Add on additional lamps,leds and/or relais if used.
I think a 10-15 VA will fit pretty good-and it is small...

More important is to use a torroid one,mounted as far away from the pcbs as possible.This is high gain circuitry,so it can pick up hum from the magnetic field surrounding the trafo.

I don´t know what psu is used in your build,have done mine with jlm for 8 channels including leds and relais-no issues.

Good luck and best regards,

Udo.

 

[dirtyhanfri]

Yes, I´m gonna buy a toroid transformer.

I´ll worry about that when I get the parts, I got the BOM from Morelius (Thanks) and I´m waiting to get some money and make the order, I thinks it´s more clear for me right now.

As soon as I start building I´ll post some pics, and surely some questions too.

Thanks again for your advices.

 

[mac]

Hi guys,
Well I am building two channels and after everything progressing so smoothly - I am finally fed up.

PSU's went together as planned Keiths +18 -18 +48 and Mnats +15 0 -15 all put together without a hitch and checked.
Boards populated - resistors all checked DMM prior to soldering them in

Prior to dropping in the IC's, all my pin 4's +17.8v and pin 7's +17.88 on the NE5534, and pins 4 & 8 on the TL 052 sitting happily at -15 and +15v respectively.
TR5 (MAT02) socket has 17.7v on both collectors with zeros on the other four pins.

All good...so I wire up the inputs and outputs, wire the omeg pot just as per others on here (wiper and pin3 on one side and 27r (deck 1) 39r (deck 2) on pin 1).

OK this is where it all goes south. The unit passes a test tone through but at low levels only. 1.5vac test tone at the input provides .7v (fully CCW) through almost zero to about .5v (fully CW). I have tried rewiring the pot every concievable way and it makes little or no difference.

I read about needing to load the input so I have also plugged in a microphone but levels are very low.

Worse still IC 22 and IC 29 go from this (no NE5534 inserted);
Pin 1 0v
Pin 2 17.77v
Pin 3 12.45v
Pin 4 -17.86v
Pin 5  0v
Pin 6  0v
Pin 7 +17.8v
Pin 8  0v


To this (IC 22 and IC 29 - NE5534 inserted);
Pin 1 +13v
Pin 2 +13.7v
Pin 3 +13v
Pin 4 +11.53
Pin 5 +11.3
Pin 6 +11.5
Pin 7 +12.5
Pin 8 +12.5

How can this even happen? how does the negative rail go from -17v to +12v???



??? ??? :'(Mac

 

[briomusic]

Does this happen with both channels, having only one channel connected at a time?
In that case I think it's most likely PSU failure. As the SSL PSU uses 7818 regulators, I am not surprised, I find them to be extremely unreliable, especially the 791x models, making the negative rail fail on a regular basis. (I had to switch my SSL9k on and off several times every morning to get it to work. now I am using a jlm psu this is a problem of the past)

 

[mac]

Yes, both channels are exactly the same, but I have only been trying one board at a time until I got one running properly. I presumed that whatever my error is, I am meticulous at replicating the error for both channels.
I have changed pots, wiring, all the 5534 and 052 IC's, tried different MAT02's SSM chips, retouched solder pads, individually checked each resistor.....etc etc....

I will fire her up again and monitor the PSU rails to see what happens. I must admit my two multimeters were monitoring AC at the output and resistance on the pots - after feeling confident that my PSU was operating as it should, I havent kept a meter across the PSU.

So you are saying that with just one mic pre board the neg rail is likely to collapse? It hasnt even been getting hot. I shall check this next.

Thanks - all suggestions welcome at this point.....
Mac

 

[audiophreak]

Hi Mac,
          I had similar voltage readings that you posted with IC22 +29 , I had to check my notes, and the readings I was getting are very close to yours, after a very frustrated 3-4 WEEKS of testing ,replacing components and such, found that my MAT02's were bogus / bad  - check my post a few pages back.
  I know there is a way to test them, but I lack the equipment / knowledge to do so. I purchaced the new MAT12s from AD and all was good. 
      Dont know if this is your problem, but thought I might mention it. 

  Good Luck and keep us posted on your  progress
     

 

[mac]

Thanks Audiofreak, Yes I had this concern as well which is why I have an SSM2210 in there now. With the same results.

It isnt the negative rail collapsing, -ve voltages are fine at pin 4 of IC 30, 23 & 24. In fact pin 4's of IC 29 and 22 read -17v if you pull out the two NE5534's - but when you put them back in, all pins are positive as per previous post.

I just went back over C62, C92 R76, C45 to double check orientation etc - all good.

But something is wrong - just cant find it....

mac

 

[briomusic]

  I know there is a way to test them, but I lack the equipment / knowledge to do so. I purchaced the new MAT12s from AD and all was good. 
     

If I'm not mistaken you should be able to check them with a DMM that has an hfe function, just test them one side at a time (have a good look at the datasheet/pinouts first)

 

[mac]

I checked mine before I plugged them in. The SSM's were as per spec but my MAT02s were a bit strange

HFE on first one 465 472
HFE on second IC 750 694 (have spoken to supplier about this one - he is sending a replacement).

I am convinced this is not an IC issue as I have been able to replicate this on two boards changing all - (AND I MEAN ALL) the IC's across both boards.

Through diagnostics I have eliminated the balancing board and the input pot etc as a problem.

So my focus is on the components around the input pair and the first pair of NE5534.
Would dud electro caps cause this?

without IC29 and IC22 I have -17v on both sides of R76. when the IC's are inserted I have -17v on PSU side of R76 and +17v on the IC side of R76.

??? ??? ???

Mac

 

[dubwarrior]

You´re welcome!

Matching resistors is very important for this as it directly affects the CMRR (maybe you´ve read from members who have "scratchy pots"...well,it could end up like this....).

You can match them by yourself:Simply buy-let´s say 100-of each needed value and compare them with a multimeter-the pairs which are closest to each other will be the ones you have to use.The absolute value of a single resistor is not the most important thing-as I said:Measure them to "the closer the better"!Don´t use carbons here,take 1% metallfilms (they are not really more expensive when you buy huge amounts).

Good luck with your pres,enjoy building them,

Udo.

Hy

Would it be possible that anyone could tell me wich resistors should be matched?

Cause i hav`nt done it, so if i get some issues i know where i can start searching some problems ;-)

That would be great

Thanks