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

[bruno2000]

do you have a list for the many transformer footprints you put on the PCB?

Cinemag CM-75101APC
Carnhill VTB9045 (via included adapter plates)
Hairball EA-10468 (Ed Anderson)
Lundahl 1538 (or several other Lundahls with the same footprint)
Jensen JT 110 PC mount
OEP  A262A3C

I think that's it!

Best,
Bruno2000

 

[[silent:arts]]

cool, thanks.
so, the Haufe ST8456 (with available adapter PCB) will work 

 

[bruno2000]

cool, thanks.
so, the Haufe ST8456 (with available adapter PCB) will work 

Sorry, if I'd have known someone wanted these, I would have included them on the board.  Luckily there is an adapter available.
Best,
Bruno2000

 

[[silent:arts]]

well, I have had some requests lately (like: will this work in Brunos 4k), and wanted to make sure it fits

 

[mata_haze]

well, I have had some requests lately (like: will this work in Brunos 4k), and wanted to make sure it fits

GREAT!

 

[bruno2000]

Thanks for doing that !!!

THAT 1646  Mouser http://www.mouser.com/ProductDetail/THAT/1646P08-U/?qs=sGAEpiMZZMsX0CFs5rpLHm2GDr7RggaV
LM3915 DigiKey  http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=LM3915N-1-ND
electrochronic (member here) has MAT-02's
Audio Maintenance usually stocks both needed pots.  Maybe Colin can answer.
Apex Jr. usually has suitable relays for less $$$.
Surplus Sales of Nebraska has some suitable toggle switches, but the require a larger hole in the front panel.
There is enough room on the board for MKP caps (rather than MKS) if you want to go that route, but be careful you order the right size for the 2u2F.
Best,
Bruno2000

edited to add stuff

Wanted to add that Futurlec.com also has the LM3915's the 3mm LED's, and some of the film caps but they take a couple of weeks at least for delivery.
Best,
Bruno2000

 

[bruce0]

Can anyone point me to a schematic for this board?

I just finished 2 9K's (I haven't installed the VU yet, didn't want to obscure the board till I tested them).

One works fine, but the other has a problem... it goes like this:

When I turn on the HPF, the light comes on and I get a buzzy tone (haven't put the scope on it yet), it is LOUD and it varies as I turn the HPF cutoff frequency (it sounds like a sythesizer).  Something is oscillating

Any thoughts....

Also  Any schematic? (I have found a DIY 9k schematic from another project but it doesn't have half the components....  I want to trace the likely suspects.)


bb

 

[Stagefright13]

Speaking of clipping... Ya really don't need a meter for this. It will bury your converters long before it clips.... BUT if running to a compressor or EQ...

BUT I noticed 2 different LED schemes green, yellow, red, Just wondering how I should put the eye candy in. LOL. Is +8 probable max gain before clip or +6? Guessing at those values. Will be cool tho finally something with a LED meter in my lunch boxes. And no transformers for a change. Can't wait. Thanks Bruno you rock!!!!

For the record I am using the meter.

John

 

[maxwall]

Thanks Joe

This is a great project , I am personally doing the 9K's for my 500 lunchbox.

if any one needs parts I have Genuine Analog Devices MAT02EH, TI TL052's and Knobs available.

Your can contact me at

Electrochronic(at)ymail(dot)com

 

[bruno2000]

Can anyone point me to a schematic for this board?

I just finished 2 9K's (I haven't installed the VU yet, didn't want to obscure the board till I tested them).

One works fine, but the other has a problem... it goes like this:

When I turn on the HPF, the light comes on and I get a buzzy tone (haven't put the scope on it yet), it is LOUD and it varies as I turn the HPF cutoff frequency (it sounds like a sythesizer).  Something is oscillating

Any thoughts....

Also  Any schematic? (I have found a DIY 9k schematic from another project but it doesn't have half the components....  I want to trace the likely suspects.)


bb

I'll bet that you have the HPF knee trimmer adjusted incorrectly.  Try rotating the knee adjustment trimmer, and the oscillation should go away.  There's a post a little further back that explains how to set it up.
Best,
Bruno2000

 

[bruno2000]

Speaking of clipping... Ya really don't need a meter for this. It will bury your converters long before it clips.... BUT if running to a compressor or EQ...

BUT I noticed 2 different LED schemes green, yellow, red, Just wondering how I should put the eye candy in. LOL. Is +8 probable max gain before clip or +6? Guessing at those values. Will be cool tho finally something with a LED meter in my lunch boxes. And no transformers for a change. Can't wait. Thanks Bruno you rock!!!!

For the record I am using the meter.

John

Greetings John,
I used one red LED for the +18, but you have about 6 dB more after that one lights before it clips.  BTW, the meter is BEFORE the HPF. so you will see possible LF clipping in the mic pre section.
Best,
Bruno2000

 

[bruce0]

Can anyone point me to a schematic for this board?

I just finished 2 9K's (I haven't installed the VU yet, didn't want to obscure the board till I tested them).

One works fine, but the other has a problem... it goes like this:

When I turn on the HPF, the light comes on and I get a buzzy tone (haven't put the scope on it yet), it is LOUD and it varies as I turn the HPF cutoff frequency (it sounds like a sythesizer).  Something is oscillating

Any thoughts....

Also  Any schematic? (I have found a DIY 9k schematic from another project but it doesn't have half the components....  I want to trace the likely suspects.)


bb

I'll bet that you have the HPF knee trimmer adjusted incorrectly.  Try rotating the knee adjustment trimmer, and the oscillation should go away.  There's a post a little further back that explains how to set it up.
Best,
Bruno2000

Bruno:

Thanks so much.  I will try that.
I don't have them adjusted at all now, I just put the trimmers in and the trimmers were new ... which is to say adjusted to 50%. 

I realize that the schematic is a secret sauce and not being disclosed for proprietary reasons, but the 9K preamp schematics I have found online don't have the HPF.....  so I am at a loss as where to search for bad connections.

Without disclosing too much, and keeping your secrets, do you think you could you tell me which IC's are involved in the HPF... I am concerned I might have a bad one or a mismatch and want to switch them out.

I built these preamps because I needed channels, and I had a big basket of 5534's and various related parts that I could re-use from old equipment (I like re-cycling).  So I also could have a bad op-amp or something (or mismatched opamps) although they are all 5534A's.  I still have more 5534's maybe I could build some more, the one that works sounds pretty nice, and I like the filter on the one that works.

I will run through the adjustment procedure and see if that stops the sythesizer.... (I like the sound of the synthesizer... a nice round buzz... I am going to get a picture of the wave shape before changing it... maybe I will put up a clip <grin>... )....

bb

 

[bruno2000]

Greetings Folks,
After many requests, here's a crude schematic for the 9K.  

http://www.dopplerstudios.com/pictures/SSL 9K-42Sch.pdf

Really sorry for the poor organization of this thread, but will work to put everything on the first page.  I'm also going to post a wav file of a sweep from 1kHz down to 10Hz from our Audio Precision System One to use in the HPF knee alignment.

Here's the sweep file.  (Right click and "save as".)

http://www.dopplerstudios.com/pictures/1kHz-10Hz_Sweep.wav


Since I've posted the circuit, some credits are in order:
To the SSL designer(s) who came up with the mic pre section, and the HPF;
To Brother Keith who did it first, and was my inspiration.
To 3nitty who helped with the circuit:
To Wayne Kirkwood for the output section
To the National Semiconductor LM3915 data sheet for the meter;
To Gustav for making the great boards.
All I did was lay it out.

Best,
Bruno2000

 

[Brolik]

Wanted to add that Futurlec.com also has the LM3915's the 3mm LED's, and some of the film caps but they take a couple of weeks at least for delivery.
Best,
Bruno2000

Thanks! added to the list!

 

[bruce0]

Greetings Folks,
After many requests, here's a crude schematic for the 9K.  

...

Since I've posted the circuit, some credits are in order:
To the SSL designer(s) who came up with the mic pre section, and the HPF;
To Brother Keith who did it first, and was my inspiration.
To 3nitty who helped with the circuit:
To Wayne Kirkwood for the output section
To the National Semiconductor LM3915 data sheet for the meter;
To Gustav for making the great boards.
All I did was lay it out.

Best,
Bruno2000

Bruno:

Thank-you for the schematic, it helps a lot to know where I am.  I am always amazed that so many DIY projects are put forth without schematics, which seems to be sort of against the whole point of being able to do it yourself.  Anyway, many thanks.  (BTW the link went dead, but I got a copy before it did).

Attached are some pictures of my build (I like to re-cycle... so it is not pretty, and everything I do is on location so sturdy matters)  but  I like the preamps.

I got a wicked rail to rail 26V peak to peak oscillation when I turned on the HPF on one unit, but your idea was correct it was an adjustment problem, when I rotated R226 to the right it went away.  And now I am adjusting them (I didn't dare hook it into my converters when it was pushing 26V peak to peak).

Here are some pictures, I have not yet put the LED boards in, I didn't want to obscure any points I might want to touch with a probe.

I wanted to have a bracket so it would be sturdy, I use the api gear in a portable rack (a sort of rolling studio setup).  In order to get the board to fit I had to take a little off the front, but the board has a lot of clearance before any copper so I just filed it down.  It is solid as a rock, but the board doesn't sit level... I need different pots or a lower standoff.

Faceplates are a bit rough - just learning to do that.

 

[bruno2000]

Nice, and built like a tank!
There's a sweep file (.wav) on the first post to use when setting up the HPF.
Best,
Bruno2000

 

[culteousness1]

Hi all!

Sorry for bringing this up again, but I am not sure which relays to choose. Unfortunately I couldn't find a datasheet for those Bruno used.
Could someone please have a look on #9805044 at Farnell/Newark? At least their dimension should fit.

Thanks in advance,
Carsten

 

[bruce0]

Don't know if it helps, but this is what i used, seems to work fine:

Mouser #: 653-G6A-234P-DC12
Mfr. #: G6A-234P-ST-US-DC12
Desc.: Low Signal Relays - PCB STANDARD DPDT 12VDC
http://www.mouser.com/Search/ProductDetail.aspx?R=G6A-234P-ST-US-DC12virtualkey65300000virtualkey653-G6A-234P-DC12

And the data sheet, which gives you the layout of pins (for the whole line, but if you look at the correct part number from above you should have it) along with measurements.

http://www.components.omron.com/components/web/PDFLIB.nsf/0/CC2F2FE0CE23240F85257201007DD586/$file/G6A_0609.pdf

 

[culteousness1]

Thanks for your reply Bruce. Btw nice unit you got there!

I already read in a last post that you were using these relays.
Unfortunately they have a lead time of 180 days at Farnell.

 

[bruce0]

I think you can use any non-latching DPDT 12V relay with the pin outs that match the ones in the Data Sheet I indicated.  I am not sure of that, but that is what I did because I couldn;t get the ones that were spec'd.

I think when they say 2 Form C that really indicates that, but I am new to this.  But the data sheet shows the measurements, and you could find a relay that Farnell does have and go from there.