onlymeeee

Dual 1073 style micpre & EQ in 1u
« on: August 31, 2017, 12:40:24 PM »
Hi all..
A while ago now I was having a conversation about the lack of a dual 1073 in 1u form with the same style as the original..  I was saying it was a shame that the original was a little bit wider than 1u or else it would fit great..   This lead to a "well why don't you build me one!" from my friend, and so I did!  This was almost a year ago now (wow how time flies)..  Anyway, I've recently took up the project again as my friend wants me to build a couple more and rather than do the metalwork by hand again, I'm going to get a batch made.  If there's any interest I can get a larger batch made up and make it a DIY project on my site www.thedonclassics.com too.

Anyway here's some pics! (I never got round to screen printing the unit I built, but the batch I get made will of course have screen printing on)


I also wanted to make a couple of extra features that aren't on other clones out there:
Powering system:
It can be powered either with a 24VAC transformer/adapter plug..  I normally chop the cheap 2.1mm connector off and use a good screw in Switchcraft connector..

Or it can also be powered by 51X.  Either the +24V rail or the -24V rail.  I realised I wasn't utilising the -24V rail on my 51X rack that much so decided to make use of it!

Almost no wiring:
It uses PCB mount Grayhill with hollow shafts.  So there's hardly any wiring to do.  The big annoyance of making a 1073 style unit in the original style is the immense amount of wiring, so with the PCB mount switches all that is avoided.. It's all connected with simple IDC ribbon connectors..
The only wiring is the 51X connector.


Easy to build/troubleshoot:
It uses all individual amp cards like the original did.  I've used pins and sockets like discrete opamps.. This is useful in troubleshooting..  if you have a problem with the unit, you can just lift out the card.. swap it with another etc.. fix it..  and put it back in without having to remove everything from the unit.


Full 80dB gain:
The problem with the 12 position switches normally is you can't have all the positions that a 1073 had..  so what I've one, is add a little 3 way toggle switch on the back so that when you're on 70dB gain on the front rotary switch, you can click to the side to get 75dB, and the other side to get 80dB.  Obviously not something you'll use often, but nice to have the option.

DI input:
As it's also a pin and socket card, there's the option of diying any design you like and slotting it in. Personally I've designed a "Rupert Neve-ish" DI based on what I think would suit best an old 1073..  ie. transistors.. BC caps..  mustard caps..





The main PCB has footprints so that it can be built as a 1073, or a 1084.  I'm also planning on designing some other units that can slot in too for future projects.. 


Rocinante

Re: Dual 1073 style micpre & EQ in 1u
« Reply #1 on: August 31, 2017, 04:19:18 PM »
Bravo! Beautiful. I love the pin and socket amp cards. You sir are a talented man.
Magnificent work.
If there's a harder way to do this, I haven't found it yet.

TillM

Re: Dual 1073 style micpre & EQ in 1u
« Reply #2 on: August 31, 2017, 05:45:43 PM »
 :o :o :o :o :o :o
this is soooo awesome !

Re: Dual 1073 style micpre & EQ in 1u
« Reply #3 on: September 01, 2017, 01:42:11 AM »
Wow! 📡

justinheronmusic

Re: Dual 1073 style micpre & EQ in 1u
« Reply #4 on: September 01, 2017, 09:50:19 AM »
I'm into this idea  8)
Justin Heron
Artist / Recording Engineer

okgb

Re: Dual 1073 style micpre & EQ in 1u
« Reply #5 on: September 02, 2017, 03:07:17 PM »
Looks Great!
 although I'm in the process of downsizing
any rough idea of cost for critical components ?  or things you would supply ?
GKB Audio / Greg Boboski

wave

Re: Dual 1073 style micpre & EQ in 1u
« Reply #6 on: September 02, 2017, 03:10:50 PM »
Great engineering!

kante1603

Re: Dual 1073 style micpre & EQ in 1u
« Reply #7 on: September 02, 2017, 05:27:23 PM »
Excellent!
I like the use of 51X supplies!
And the boards look so neat!


Congrats!

Floti

Re: Dual 1073 style micpre & EQ in 1u
« Reply #8 on: September 03, 2017, 05:24:27 PM »
This looks amazing!

Brizco

Re: Dual 1073 style micpre & EQ in 1u
« Reply #9 on: September 04, 2017, 05:22:54 AM »
definitely interrested!


Re: Dual 1073 style micpre & EQ in 1u
« Reply #10 on: September 04, 2017, 11:12:56 AM »
This is one of the finest projects i've ever seen! Could you make a DIY project? I'm really interested in trying to do it.

Again, congrats!


[silent:arts]

Re: Dual 1073 style micpre & EQ in 1u
« Reply #11 on: September 04, 2017, 11:32:04 AM »
A really great idea to use the -24V of your 51X PSU  8)

onlymeeee

Re: Dual 1073 style micpre & EQ in 1u
« Reply #12 on: September 08, 2017, 05:34:40 AM »
Thanks for the kind words everyone!  In that case, I'll definitely order a batch and do a DIY kit option, no problem.
I guess it'll be similar to my other kits.. ie. Metalwork.. PCBs.. and any important hard to get parts.. eg. The hollow shaft Grayhills.. then a Mouser cart for the other parts..

kante1603

Re: Dual 1073 style micpre & EQ in 1u
« Reply #13 on: September 08, 2017, 10:24:38 AM »
This will be a great project,no doubt.
Though I can not see a switch for phantom.Will the inputs be fed externally (I have Neumann Phantom PSUs here,so no biggie for me)?


Just curious,


best regards,


Ido.

onlymeeee

Re: Dual 1073 style micpre & EQ in 1u
« Reply #14 on: September 08, 2017, 05:16:47 PM »
This will be a great project,no doubt.
Though I can not see a switch for phantom.Will the inputs be fed externally (I have Neumann Phantom PSUs here,so no biggie for me)?


Just curious,


best regards,


Ido.

Individual phantom switches are near the output gain pots, each with an LED to indicate phantom on

kante1603

Re: Dual 1073 style micpre & EQ in 1u
« Reply #15 on: September 09, 2017, 01:42:50 AM »
Thanks for the info,it is not visible in the pics from the first post.


Best regards,


Udo.


Edit:Found them....... ::)
« Last Edit: September 20, 2017, 01:52:08 PM by kante1603 »

burdoto

Re: Dual 1073 style micpre & EQ in 1u
« Reply #16 on: September 18, 2017, 06:47:39 PM »
Sweet schnibets, I thought I was the only one to ever tried this. I built a rougher looking project similar to this with all the tedious wiring. Mine took so long I can't imagine making another one.

Yours looks much trustable.

burdoto

Re: Dual 1073 style micpre & EQ in 1u
« Reply #17 on: September 18, 2017, 06:48:47 PM »
And the inside

weiss

Re: Dual 1073 style micpre & EQ in 1u
« Reply #18 on: September 19, 2017, 03:58:53 AM »
Wow! Great work  :o

SubhumanRecords

Re: Dual 1073 style micpre & EQ in 1u
« Reply #19 on: September 20, 2017, 10:56:47 PM »
Was wanting to no if you had or could point me in the right direction on where to get the hollow shaft greyhills.
Thanks..