My New 1U GSSL Design (AKA SB4000) RELEASED!!! - GOTO PAGE 9 FOR ORDERING INFO!

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ruckus328

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After 3 grueling weeks:) I am proud to present the plans for my new 1U GSSL design!  Hopefully you all like what I've come up with.

Out of respect to myself and everyone else, I ask to please keep this thread clean and all comments & questions on topic.

That aside, onto the good stuff!

Below are the pictures of the front panel concept drawings and PCB Board Layout, as well as a summary of what's under the hood.  Fonts on the front panel are only preliminary.  PCB routing is completely done, will be ordering my proto boards this week.  Estimate for production run is 3-5 weeks.  All in all I'm 95% of the way there, so figured this was a good point to present it.

If possible, I'd like to start getting some kind of idea of the level of interest and also a concensus on whether to have front panels made or not.  I am in process of getting them and the boards quoted.  I understand that not everybody may want front panels, but if the majority do, I'm inclined to have them part of the package (at least for the first run).  Since you'll all need to have them made anyways, it seems logical.  If I do go forward with them, color scheme will be as it is in the pictures (black anodize w/ white text), totally professional quality.

Summary of Features:

-Design consists of 3 boards Main Board, Control Board, and PS.  (Layout was done as a single panel)  Board is double sided, 2oz copper, and ground plane on component side.  The board pic below shows all 3 boards, the majority of what you see is the main board, power supply board is on the right, control board is along the bottom.

-Costs and component availability was kept into consideration at every step of the way.  All compoenets are readily available, and are digikey/mouser stocked.

-Connectors were sized with the Phoenix/Tyco style terminal block screw type (which means no crimping or housings to futz with), although you can use any .1" spacing connectors you wish.  Exception to this is the control board wiring which is a single ribbon cable (even better).

-With the topology, this deisgn will fit into the smallest 1U rack that Par Metal makes (8" / 200mm deep) - which means it will fit into any 1U rack out there, which was one of my major goals.  

-Main Board Features: Incorporated Turbo, 2x Super Sidechain, VU Bargraph Circuit for IN/OUT Levels, & true bypass w/ relays.  Main board is .5" wider, and 2.75" longer than the existing version.  Considering everything that has been added, this is a very modest increase.  As you can see in the pics, the board was designed to be installed sideways, and all onboard connectors are located on the board in relation to where they are being wired to (aka, shortest wire runs possible)

-Completely redesigned Power Supply & Power distribution.  All regulation is located on the Power Supply.  Board dimensions are 2" x 4.5".  It features LM3X7 Regulators for the +/-15V rails, and the LM78/7912's for the 12V (**CORRECTION: - I accidental had L12's listed here.  That was incorrect.  The 12V rails are powered off of 1A TO-220 LM7812/7912 regulators - it DOES NOT use the tiny 100mA regulators).  Power supply also has an additional Fixed +12V supply for all LED's, relays, and, and the VU Bargraph, and anything else you wish to add.  There are a couple of addtional ISO12V solder pads for wiring into if you add any additional LED's etc..  All caps on the main board are sized at 35V, so you can up the voltage on the Audio rail up to 18V if you like.

-Front panel - Thresh, Ratio, Attack, Release, HPF, Makeup, and Bargraph are all Board mounted on the control board.  Control Board connects to the main board via a 20 Pin Ribbon Cable, which is mounted on the backside of the board for easy routing.  Control board is the same width as the existing, about 3.5" longer.  The VU Bargraph has its own screw down power connector.  It is a mono VU meter, similar to the chameleon labs setup, and is switchable between L & R / In & OUT with 2 mini pushbuttons (Relay driven).  The benefit of this though, is you can monitor both Gain reduction and levels simultaneously now.  And the beauty of the Bargraph is: if you don't want it - IT SNAPS OFF!  And the bargraph driver circuitry on the main board is all within a silkcreened box so you simply don't install anything in that box if you don't want the feature.  

-High pass filter has Off/60/90/130/Tilt1/Tilt2.

-There is also a stereo external send/return, controlled with its own pushbutton, and is relay driven.  It's source driven, so you can send it either a mono signal or stereo for ducking, etc.

-Pot to adjust Turbo sidechain so both sidechains are equal.  Also another pot to calibrate ratios.  (Corrected, accidentally had written threshold here previously)

-Pushbutton to toggle between 10db GR or 20db GR.

-There is an additional release time added - 900mS.

-Resistor is present to adjust the threshold sensitivity if desired.

-GR Meter is sized for the Sifam meters.  The terminal block for the meter has an additional 2 pins for driving a backlight, and onboard resistor for limiting the current.  There's also the additonal resistor present if using a 100uA meter.

-All wiring terminates to the main board.  This includes the Meter and Power LED.  Personally I didn't like that they terminated to the control board on the existing deisgn, it meant I couldn't remove the control board if I had to without cutting and reattaching wires.  All terminal blocks are grouped together on the bottom board edge except for the "Power IN" and Ribbon Cable which are on the right edge and the "meter" terminal block which is over on the left edge near where the meter is.

-Turbo/Bypass puttons were intended to be illuminated, so addtional terminal block pins are on the board to drive the pushbutton LED's, again on-board resistors to limit current are already there.  If you want to use a non-illuminated pushbutton, you obviously still can.

-DBX202 Support (Pin diameters are correct and Parts are clear around it so there won't be any mounting issues)

-Pots at the Audio VCA's to adjust for equal unity gain between L & R.

-7 Mounting holes total on the main board, 3 along each long edge and one in the middle to prevent flex.  Mounting holes are all isolated from ground and have a large keepout area (0.5" Diameter) around them so you can use a metal washer and not have to worry about shorting.

-Component spacing is gratious compared to the existing layout.  Nobody should have any issues with parts not fitting.  Although there is vertually no wasted board space.  Parts are not bashing into each other anywhere on the board.  Input/Output caps have enough room around them that if you want to experiment with film caps there, you can.  All components with .1" (2.54mm) spacing have oval pads, to allow for maximum clearance while still giving plenty of pad to solder to.  Overall Component holes and solder pads have been increased.

-All IC's & Caps are oriented in only 2 directions!  So Pin 1 or + is either Up, or to the Right, making it virtually impossible to install a part backwards.  And it gets better - All VCA's and Electrolytic Caps are oriented in only 1 direction!  And there's more, all Tantalum Caps feature convenience holes so you can use either .1" or .2" spaced leads.  All different types of parts have a unique footprint, so you can easily identify what type of part is installed there.  Resistors footprints look like resistors, Circles are Electrolytics, ovals are Tantalums, Rectangles are Film Caps, Chamfered corner rectangles are Ceramic Caps, etc. etc etc.

-BOM is extremely detailed and gives full spec and sources for every single item.

-I will have full mechanical drilling templates made available for board hole mounting locations.

Shadowbuss_ISO.jpg


Shadowbuss_PCB_Final.jpg
 

mitsos

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May 4, 2007
Messages
2,886
Very nice... I got dizzy looking at that layout, wow, that's tight... talk about efficient use of space!  I'm in for 1-2 PCBs and maybe front panel, any idea of possible cost?

 

mrclunk

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Nov 29, 2006
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1,089
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London
good work! 
I'll be in for a pcb (and panel depending on price...)

Does this still use the tricky to source Sifam PPM14?
 

diyfanatic

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Oct 15, 2008
Messages
502
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Paris, France
Does this still use the tricky to source Sifam PPM14?
yep but IIRC Ptown seems to manage something...Mike from hairball as well!

http://www.groupdiy.com/index.php?topic=36642.40

edit:find the spec on hairball webshop seems to be perfect match
http://hairballaudio.com/docs/meters/8027-B.pdf

cheers!!!
 

snipsnip

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Jun 17, 2009
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520
Location
Brighton - UK
Very very nice, well done my friend.

I am interested in the boards (dependent on price of course).

I have too much black in my rack, so the metalwork doesnt interest me. Shame, as its very tidy. Are you willing to share the design, or is that too cheeky?  :p
 

ruckus328

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Joined
Apr 14, 2010
Messages
906
Location
Philadelphia, USA
Thanks for all the comments guys!  Sorry it took me all day to respond, got slammed at the day job.

mitsos said:
Very nice... I got dizzy looking at that layout, wow, that's tight... talk about efficient use of space!  I'm in for 1-2 PCBs and maybe front panel, any idea of possible cost?

You should see the routing lol.  Talk about intense.  Although it might seem tight, spacing is actually much better than the existing design.  The purple outlines you see around the parts in the pic are "keepout" areas, so nothing's bashed up against each other, bypass caps sized for .1uF film caps, all Lytic/Tant caps sized for 35V, so plenty of room around parts.

Speaking of bypass caps, that's something else I forgot to mention - all chips have their own dedicated bypass caps on the + & - rails.

Pricing still indetermined, I have a ballpark but I don't want to throw any numbers out until I get definate quotes on everything.  I'll have that sorted out soon.

mrclunk said:
Does this still use the tricky to source Sifam PPM14?

For my stock front panels, the cutout will accomodate both the Jewel meter's that Mouser/Digikey stocks as well as the Sifam PPM14 (Ptown's replacement will fit right in as mentioned).
 

e.oelberg

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Aug 14, 2004
Messages
788
Location
Berlin
looks very nice !! I'd seriously consider a blend function, it's pretty easy to implement and pretty easy to leave it out if you don't need it.
maybe checkout the glue, it's a plugin which comes pretty close to a ssl compressor and test the blend function to get an idea.


nicholas
 

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