ytsestef

So, I finished my Nite EQ / EQ3D / Airband EQ / whatever it is called the other day, I wanted to share with you :)
It worked flawlessly on first powerup, and that's only because it is a very well-designed project. Props to kevin and peter!
I decided to build it on a 2U chassis and have wires to the front panel pots, because I am not confident enough that I can drill with such precision to mount the PCB directly to the panel. This also helped me keep both channels in a safe distance from the toroid transformer, so it's never bad to minimise the hum. The pots are OMEG 470k rev.logs with center detent (thanks Colin), although I was a bit careless and bought them all with center detent (including the boost-only airband). Oh well... :P I also screwed up in the front panel labeling a bit, the 2.5k band is shelving, I drew a bell curve... grrrr! Way to lazy to repaint it! The case is way too big, but I found it quite cheap so I thought "what the hell". I'm not satisfied with the XLR connectors in the back, next time I'll definitely go for some neutrik or switchcraft ones... BTW, the PSU is the SSL9k one. Omitted the +48V line and was done with it :)

The omegs in the center detent measured quite higher than 56k2, which has to be the sum of the series resistor and the pot for a gain of 1. Most of them were in the ~60k range, so, instead of calibrating each one I just replaced all the series resistors with 3.3k (I was afraid if I went lower the opamps would self-oscillate when the pot was in the max.gain position) and was done with it. Still I can hear no difference in bypass and engaged mode when all pots are in the center, so maybe after all the gain controls aren't THAT sensitive.


And now I need a little help. ;D I'm not sure how to ground this thing. As you can see this case has an bare aluminium plane on the bottom, on which I drilled a hole and put a screw as a grounding point. However, this is only grounding the plane, and not the case. I have already installed another screw on the back of the case (can be seen in the photo, not too good though, it is next to the XLR connectors), but then the plane will be floating. If I connect the plane to chassis (from one screw to the other) will I get a ground loop? If I leave it like this it isn't safe, is it?







Stefanos.


Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #1 on: April 08, 2011, 01:27:24 PM »
Nice job.  I certainly appreciate your hand drawn graphics - the sign of true DIY!   Fancy engraving and screen printing is a crutch   ;D

How do the very high bands (40/30K) differentiate themselves to your ear compared to the typical 16K 'air' bands on other EQs?

Congrats!

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #2 on: April 08, 2011, 02:13:13 PM »
nice man, you are becoming a Sharpie ninja! But what happened to the orange panels?  :)

as far as grounding the case, do you mean the panels are isolated from each other? If it's because of painted side panels, you need to remove some paint from around a few screws so that you have continuity between all panels. Otherwise your case is no longer a "shield". You can do the same with screws and wire, but paint removal is neater and pretty standard practice (actually the holes should have been masked prior to paint, but most generic case makers don't do that).

Good luck!

zmgwg

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #3 on: April 09, 2011, 04:52:31 AM »
are boards or self etch files available somewhere?

ytsestef

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #4 on: April 09, 2011, 06:47:06 AM »
Thanks a lot!

lassoharp: 20k and 40k along with the "sub" band are definitely the best bands this unit has to offer. The bandwidth on each band is VERY wide and I think that partially that's the reason it sounds so good to my ears, maybe phase shifting is minimised thanks to the bandwidth. This thing in the 40k setting behaves much like a baxandall filter, which is more than enough to differentiate it from the other typical 16k 'air' bands on other EQs. Sub band also does wonders, as far as the material is clean and it doesn't have any low-freq rumble.

mitsos: thanks man! I'll try scraping the paint off! White is the new orange ;D

zmgwg: unfortunately peter hasn't released the etch files and AFAIK i bought the last two pcb's. You can always try asking him or have a look at the schematic and make your own pcb. ;) More on the project thread.
Stefanos.

gemini86

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #5 on: April 10, 2011, 03:35:22 PM »
LOVE the hand-drawn look... I just wish my handwriting was more legible.
- Rodney

"...you better call Kenny Loggins, 'cause you're in the danger zone."

snipsnip

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #6 on: April 10, 2011, 04:44:39 PM »
i dont know, im impressed when people use their ingenuity to create something gorgeous....  marker on standard panel just looks lazy to me. look at something like zayances mic body, THATS proper DIY.

abechap024

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #7 on: April 10, 2011, 04:48:49 PM »
i dont know, im impressed when people use their ingenuity to create something gorgeous....  marker on standard panel just looks lazy to me. look at something like zayances mic body, THATS proper DIY.

Oh come now. Marker is not being lazy enough! I leave all my panels blank...that way people really think your crazy when they watch you grab for what they think are random knobs.....
AC Sound - some DIY circuitboards

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #8 on: April 10, 2011, 04:53:17 PM »
Quote
I leave all my panels blank


That's the sign of a real pro - if you have to have a knob labeled - you shouldn't be operating the gear!   ;D :D

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #9 on: April 10, 2011, 05:31:01 PM »
I'm all for the marker. If it's good enough for you, it's good enough for me. :)

Nice job and good advice from Mitso on connecting ground to case.

It's a keeper!


snipsnip

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #10 on: April 11, 2011, 04:46:39 AM »
Quote
I leave all my panels blank

How do you remember which box does what  ;D


mac

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #11 on: April 11, 2011, 05:02:39 AM »

Quote
Quote
I leave all my panels blank

How do you remember which box does what 


Once you spend 100+ hours pouring over the same box...... It's etched into your brain
Barclaycon: The client said 'That sounds great, what are you using on it?'
The engineer's reply was: '30 years of experience'.

snipsnip

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #12 on: April 11, 2011, 05:13:49 AM »
yeah, i was only joking. No offence meant to the OP either. I just like it when people do stuff way cooler than top end off the shelf products. Thats what really excites me, and what I aspire to be able to do myself one day. (Kingstons projects are normally good examples).

Shame the last 2 boards have gone, i figured they all went ages ago so never asked after them. Drats!

ytsestef

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #13 on: April 11, 2011, 05:32:01 AM »
Thanks everyone! Snipsnip, no offence taken. It is a matter of taste. Of course, there is always the money factor, but pulling a lasertran stunt is about as cheap as labeling with a sharpie. I just like my gear to actually look hand-made (since this cannot be heard, thanks to the awesome designs people post around here :) )
Stefanos.

Whoops

Re: "Unison Design" 3D "AIR" EQ / Nite EQ finished!! Pics Inside!
« Reply #14 on: October 31, 2011, 12:09:20 AM »
Love the marker on standard panel just looks gorgeous to me!


 

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