3D "AIR" EQ - "Night EQ" PCB's Complete!

[bieckmusic]

Thanks for that Earthsled!

I was able to find a .pdf with the BOM and schematic for the SSL9k.  Also, they're were several forums in the lab, including one topic just dedicated to the power supply.  I have located almost all of the parts and then thought maybe the mnats would be better.  But, I'll stick with the ssl 9k power supply.

Have a great day!
greg

 

[earthsled]

nielsk: I've just worked up a second version of my EQ3D build. This time I used potentiometer/rotary switch resistance values that were very close to the original spec. I thought you'd be interested to know that I too am seeing a "boost" that is disproportionately large compared to the "cut" with this config. For instance, my 650Hz band will boost about 14.5dB while it only cuts about 4dB. This seems very similar to what you were experiencing. Attached are graphs...

 

[Whoops]

nielsk: I've just worked up a second version of my EQ3D build. This time I used potentiometer/rotary switch resistance values that were very close to the original spec. I thought you'd be interested to know that I too am seeing a "boost" that is disproportionately large compared to the "cut" with this config. For instance, my 650Hz band will boost about 14.5dB while it only cuts about 4dB. This seems very similar to what you were experiencing. Attached are graphs...

Did you use this document?

(change the extension of the document from DOC to XLS , as it is an excel file)

 

[earthsled]

I used the "stepped-pot" rotary switch version...
www.hausverwaltung-heger.de/al_leck_trick/3D-EQ_PotTweaking_2.xls
...and modified it for a series-string config. but, essentially, yes.

Using 1% value resistors my switches came out to be...
RV total = 553300 ohms
RV center = 50300 ohms
R series = 5620 ohms

Harpo suggests that the bands of the EQ actually interact with each other...
"Simply speaking, boost will work within parts/rail voltages limits; cut to more than -~5dB will work, if adjectant bands levels are dialed in for cut as well."

Perhaps this response is what the circuit was designed to do?
Anyone have sweeps for the original Nightpro unit???

 

[Whoops]

I started a feeler thread on the Black Market for a new batch of Night Eq PCB from Peter.

If anyone would like some PCBs please visit this thread:

http://www.groupdiy.com/index.php?topic=46244.msg580026#msg580026

 

[Whoops]

Night EQ Project - Docs

SCHEMATIC

 

[Whoops]

Night EQ Project - Docs

PARTS LIST

 

[Whoops]

Night EQ Project - Docs

PARTS LIST 2

 

[Whoops]

Night EQ Project - Docs

PCB Overlay

 

[Whoops]

As for Pots with centre ident you can get them here:

http://www.audiomaintenance.com/acatalog/om-01-066_extended_info.html

 

[bieckmusic]

Hello again friends, 

is this 5534
http://www.mouser.com/ProductDetail/Texas-Instruments/NE5534AP/?qs=sGAEpiMZZMtCHixnSjNA6CumnoLUElGjy%2feFGFMqIic%3d

compatible for the eq3d project.  I'm not sure???  Does anyone have a good source for the 5534s?  I found the JRC 5532's are available inexpensively fortunately!!

thanks   Making progress, got my resistors stuffed on my home etched boards...

best, Greg

 

[earthsled]

I used the JRCs in mine. Mouser has them... 513-NJM5532D and 513-NJM5534D ...I think JRC 5532s were used in the original version, not sure about the 5534s (see attached)...

 

[bieckmusic]

Awesome, thanks!  I just ordered them 

Cool, I've never seen a picture of the original unit.  Thanks for the help!


Greg

 

[Davo]

......

 

[bieckmusic]

It's done, and it sounds AMAZING!!!  Great frequencies...  What a great project, big thanks to Kevin and everyone who contributed to this project.  I had to switch my jumpers and check solder joints but other than that this was a pretty straight forward project.  The most time I spent was researching and ordering parts.  I used an ssl 9k power supply for the project.

Also, this was the first time I ever did a self-etch which was interesting... 

I've attached a photo.  I'm going to make some graphics for the front panel at a later date. 

 

[bieckmusic]

one more picture....

Here's the inside of the project.  I'm going to clean things up later, but it's very quiet and smooth sounding. 

 

[Rellister]

Excellent work bieck
How did you end up series-resistor-wise?
Just BOM values or calculated?

 

[bieckmusic]

Hi Thank You Rellister! 

I used the BOM values for all of the resistors.  I just followed everything as close as I could, including all of the inductors, etc...

All pots neutralized sounds almost perfectly flat, I'd like to scope it to check there might be a slight bass decrease, I can't tell.  All the pots from audio maintenence measured around 50k and 60k at center point so I decided not to mess with swapping resistors values. 




Greg

 

[earthsled]

Hi all --

I'm noticing my peak indicators seem to light up at signal levels well below audible distortion. I'm feeding the EQ a 1K tone at about 0.9V RMS and the LEDs begin to glow. Does this seem like the right level? Could the peak circuit me modified to have a trim-pot adjustment?

Thanks!

 

[Harpo]

make R201 a rheostat to dial in less sensivity. Voltage gain of this inverting stage is R201/R200.