NV73EQ addon

[onlymeeee]

Hey all!  Can't believe where the time goes!  I've been using these eq addons for four years now ! (Wow!)

I recently needed some more so decided to buy a batch of metal and pcbs for anyone that wanted to either upgrade their NV73 or build the full thing from scratch..  I've only ordered 20 extra.. but if there's interest, I can order more and keep them in stock like my other two 500 series products.. 

I wanted to keep the ability to use mustard caps (or remake mustard caps) like an original 1073 and the circuit is the same of course.  There's 4 connections to make to the NV73.  I’ll detail it in a little manual.. 

Anyway..  here she is!    (knobs courtesy of the fantastic Don Audio store.. no relation!)

 

[Floti]

Really cool! How much for the add on?

 

[Winetree]

I've got 2 - NV 73s.
Could be interested in a pair depending on price.

 

[iprovlek]

Very interesting onlymeeee....

Interesting the price?

 

[onlymeeee]

Thanks guys!  Not 100% sure on price..  cheaper than my other ones for sure as there's no extra L-bracket (it uses the one already on the NV73)   

It'll depend on what's best to include in the kit..  ie.  It may be better if I include all the polystyrene caps in the kit as they're getting harder to source nowadays..  pots too perhaps..  I'll have a think today and tally it all up... 

 

[Upacesky]

Those are mic  level only, and intended for tracking use, right? Or can I use the eq somehow with line level?

 

[onlymeeee]

Those are mic  level only, and intended for tracking use, right? Or can I use the eq somehow with line level?

They're line level too
(same way the 1063 did it.. with the same infamous 10468 transformer for both line & mic inputs)

 

[dmp]

Cool - very nice looking.

 

[JoelCoteBergevin]

Whoa this is awesome !

 

[pachi2007]

 

[Bobby Baird]

This looks brilliant David. Interest peaked.

 

[weiss]

Very interesting! Looks great. How does it sound?

 

[onlymeeee]

Thanks again guys..!  The page with details is almost done, just working out exactly what will be most useful to everyone to include in the kit..    pots, caps, metal, PCBs & hardware I guess...    everything else is easily got at Mouser, Audio Maintenance & Don Audio..

Describing sound is always tricky.. but when I had it up against a couple of vintage units, a couple of colleagues (a mastering engineer & a mix engineer) couldn't pick it out against the other 2. 

It was actually much easier to get this EQ section to match up to the vintage units than the mic pre which took a couple of revisions..   
This time around, I started by tracing the vintage units that I wanted it to sound like, and seeing what changes were in it.. ie. famous 47pF cap mod etc..  and also making sure to use similar trace size or layout to the unit...  (not sure in reality if this has an impact but still..!)

 

[weiss]

I will definitely try this one! keep us posted

 

[KDE]

definitely interested in some kits!

 

[onlymeeee]

Thanks again everyone!

I've worked everything out for the kit..  and will upload to the site now!  (Bear with me and refresh etc..)
As I say, I've got less than 20 available..  However if there's more demand, then I can order a large batch and keep them in stock.. 

www.thedonclassics.com/nv73eq_addon_diy.html

So tallying up the cost for someone already with the NV73.... 
For the PCBs, metalwork, polystyrene caps, potentiometers & hardware it's £129..  Then only £50 at Mouser..  Inductors & switches from Audio Maintenance..  knobs from Don Audio..  so it'll be around £250 - £300 for an authentic 1073 EQ  !    (That's the way I thought of it when I first did the addon for myself at least!)

 

[Electrobumps]

I've been using these for 3 years now.  Lucky to get a couple of the boards a few years ago.  They sound great and the bonus 10K freq is a fantastic addition. 

 

[samguaiana]

Any way to go about getting these prebuilt? I would really love a pair and this type of build is well beyond my skills

 

[kosi]

Hi David,
today I started upgrading 2 of my NV73 with the EQ add-on. Very nice and easy build.
I found in the polystyrene bag 2 radial 4700J caps, which don't show up in the BOM.

Where do they go ? EDIT "Found it - C8m (47n) on the bottom pcb. these condenser values kill me...."

One little thing: the links in the manual don't work (404)

I hope, I get them ready this week

 

[kosi]

Here's number 1, works like a charm.
Build was pretty easy, no big problems.
The EQ is fantastic, very straightforward, easy to dial in, and oh boy, you can really alter the sound.

thanks to David for making these !!!