SSL 4000 EQ

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Can someone repost the latest BOM for the RS-82E02-Q so I can start a new winter project? ;-) PCB's need a new life :)

Thanks! <3
 
im finishing the 1st build of my 5 EQs soon, and id like to make sure about the the Q adjust correction.

so for proper function of the Q we need to wire the 1st deck of the dual A10k potentiometers' pin 1 and 3 in reverse? (compared to the PCB pins)

thank you!
 
Vac11 said:
Yes, that is correct...

thanks Milan,

then im heating up my desoldering station to remove those pots from the PCB.. :D

btw i bought 50pcs of (mini, blue) dualC50k pots from AliExpress, they look totally OK so far. hopefully they will work OK too.
 
its a bit sad to realize that some extra work is needed to get it racked with the out-of-PCB pots..
my FREQ. pots have 2.54mm pins, so wont fit the PCB. the Q pots must be corrected - so cant be populated on the PCB. GAIN pot is the 3rd deck, so wont fit (easily) the front panel as PCB support.
the switches make 0 support, so the PCBs must be carefully fixed in the rack in some ways.
 
Vac11 said:
Sorry I meant "triple gang" concentric. This style:

omeg_triple_gang+ident_concentric_composite_600.jpg


50KC is value from the "original" schematic (see pdf in attachement), in BOM is 47KC cause these triple gang concentric pots were stock in AML eshop. Value 47K is OK and it will not create any problem in this SSL EQ. The same is 22KB (in BOM) vs. 25KB (in origo shem).

Footprint on the pcb is designed for triple gang concentric pot. But you can use instead of triplegang concentric pot 1x dualgang pot (50KC for frequency) and one singel gang pot (25KB for gain) on this positions... For the Q pot is footprint made for different types of potentiometer legs spacing (Therefore, there is a 9 holes on pcb, but in reality you use only 6 holes).

In "original" schem is:
frequency - dual gang 50K anti log (or reverse log or  negativ log or "C") - 4x per one chanel - you can use 16mm 47KC dual gang from AML
Q - dual gang 10K logaritmic (or audio or "A") - 2x per one chanel - no problem with this pot, you can find it on ebay, or aliexpress,...
Gain adjust - 25K linear (or "B") - 4x per one chanel - you can use 22KB singel gang with center O position from AML

I didnt use concentric pots on my build. I used on one chanel 4x 50KC dual gang pots for frequency, 4x 25KB singel gang pot (or rotary switch with resistor chain) for GAIN +- and dual gang 10KA for Q adjusting (these pots you can find on ebay, or mouser...).

1_2.jpg


2_2.jpg


Hope this helps! (?)

Hello "Vac11" ,
do you share some info about frequency step selectors?
thanks
 
I didnt use frequency selector (or stepped switches if I understand you corectly) in my build. I used standard potentiometers....

M.
 
Vac11 said:
I didnt use frequency selector (or stepped switches if I understand you corectly) in my build. I used standard potentiometers....

M.

i mean that showed on the images in the upper post
it is not made by you ?
 
Oh, ok...it is +- 15dB gain switch...

Its only the lorlin rotary switch with 10 pcs of 2k49 resistors...

For 11 steps (5steps-center position-5steps) you need 10 resistors.

Geniue SSL EQ use 25KB (linear) potentiometer for gain.... So 25K/10 steps = 2K5 per one step.

You connect one cable on resistors chains start, other on resistors chains finish and one last cable on switches pole...

Hope this help you...
 
Hello everyone,

I am looking to download Casey's schema in a correct quality. Can someone help me?

Thank you.

Jordan
 
A friend asked me recently to make couple of those so I redrew the PCBs to fit parts of my choice namely the pots which I got from Aliexpress. A 20-25k center tapped pot is virtually unobtainium but you can find several types of dual gang 50k linear center tapped pots (with 40 steps) which when connected in parallel make a descent 20-25k mono center tapped pot. The 50k reverse log pots are also from Ali.
Other fixes included swapping the Q pots terminals as noted earlier in the thread and make the unit ON when power button is pressed in but relay is not activated (it's in normally closed state).

 

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