thinking o fdoing some 1073's. Canadian group buy?

[Gwaggin390]

Jim,
i think i get what you are saying about the switch.
If you search for "stepped attenuators" on the web, you will probably find someone who sells them with the PCB "wafer" premade(with resistors), or as a kit.

I don't know how many decks i've seen them for, but somebody already does make what you speak of. If i remember right, the pcb is only maybe a half inch wider than the switch(all around), and the resistors are very close to the switch.

If your "wafer" idea is just for that one 22 pos. switch i understand.

If it was an "option" for the EZ1073, i would stick with the stock one on Martins board.

 

[madriaanse]

[quote author="NEU!"]Personally, I would be fine with just a separate switch and pot. I know it's not as sexy as the concentric switches on a real 1073, but would be simpler and cheaper to source and design.[/quote]

This makes a lot of sense to me. Grayhill PCB mount 1x12's are cheap ($14) and easy to layout on a PCB.

M.

 

[Tungstengruvsten]

I bought a couple 1084's(audioforge) to put on the back-burner...they arent' too pressing right now as I have lots on the go but it is somehting I would like to have someday...so group buys for trannies/inductors/switches etc within Canada would be great.... I'm sure we could have a few different versions of 1073's etc with common parts...maybe not gain switches all around but transformers and inductors for sure...probably most of the expensive caps as well...

 

[tommypiper]

Bluzi, yes, the time is right. I've been thinking of doing this for years, but I have no experience designing PCBs and my life won't allow me any slack, so somone else will have to.

I agree with Martin, go with PCB mount switches.

IMO, there are only two ways to build this: 1) The way the guys already are doing it (Audioforge) with original boards and p2p wiring between boards, switches, like the originals. This is so seriously labor intensive and prone to difficulties that I will never touch it. 2) The way Martin and Chris have done. Put everything on one board, PCB mount EVERYTHING possible. It's NOT original form or switches, which is fine. If you want original, buy an original or build a clone as in #1. But the beauty is that it's a quick and clean build and easily adaptable to mods, ideas, and testing in its native PCB mode.

I'm personally not too hot on cloning, and I always feel while we're studying these venerable old designs why not find a way to do something different, better, or adapt a few ideas in? Maybe it's just better switching, metering, or whatever. But why bind yourself to just an old idea? Copying is very unimaginitive and you are limiting yourself. Adapting an old design is much more exciting!

I've approached two PCB designers to help me make something like this. Both were too busy. I hope you can pull it off. Someone will sooner or later, as both Chris and Martin have shown!

 

[Bluzzi]

Thanks to all above for your comments.

I'm not hung up on anything yet. In any case the gain switch with 22 steps should be an option to Martin's Grayhill.

For the EQ switches I am considering Grayhills, Lorlins as well as Elmas. But that is because I haven't given that part a lot of thought yet.
Using seperate pots and switches is OK for me as well. In fact I prefer it but wasn't sure if the majority did and I want this project to benefit all of us.

I would like to put as much as possible into the fewest boards. I didn't go for audioforge's boards (and I think what he is doing is tremendous by the way) because I found soldering Martin's board so easy it led to this EZ1073.

By the way Martin is agreeable with all this and it looks good for co-operating to eventually make it easy for his board to mate with mine (and EZ1290 begat EZ1073 and the land rejoiced..).

Now I have some questions for you all in the following messages.

jim

 

[Bluzzi]

If you guys can let me know what you think on the following it would help me a lot.

Question 1:
Are the EQ pots Log, Anti-Log or Linear ones? I couldn't find that info anywhere.


Question 2:
Anybody have a problem if a 2 channel 1073 fits only in a 2RU size case?


Question 3:
The 1073 includes a line input which requires a transformer as well.
How many will want a line input? (realize that its probably going to set you back around $100 more so 2 channels=$200. Just sayin')

Question 4:
Meters would be nice. Should we put in an option for a meter buffer like JLM's?


Thats it for now. Thanks

jim

 

[tommypiper]

1 Probly 10k Linear.
2 No prob. One would expect that with all the switches.
3 Must have line input as a build option. What's the point of having delicious EQ if you can't use it except as a mic pre? These are valuable EQs for mixing. Not everyone may choose to build it in, but should be on the PCB for those who want it.
4 Forget meters on the PCB. No space. No need. Extra mess, money, complication. It's easy enough to add metering without being on the PCB for those who want to build it. Keep it off the PCB.

 

[Bluzzi]

[quote author="tommypiper"]1 Probly 10k Linear.
2 No prob. One would expect that with all the switches.
3 Must have line input as a build option. What's the point of having delicious EQ if you can't use it except as a mic pre? These are valuable EQs for mixing. Not everyone may choose to build it in, but should be on the PCB for those who want it.
4 Forget meters on the PCB. No space. No need. Extra mess, money, complication. It's easy enough to add metering without being on the PCB for those who want to build it. Keep it off the PCB.[/quote]

tommypiper - Thanks for response.

So no one knows for sure about the pots being linear or not. I think linear as usually log is noted but not linear. But there is still the question left.

You're right, keep line in so that we can use EQ section alone.

I meant output for meter buffers. Not meters themselves.


Keep the comments coming.

jim

 

[Gwaggin390]

1)Geoff Tanner would know for sure...www.auroraaudio.net
2)Are you talking about 2 EQ's only in a 2 space? or two EZ1290's AND the eq boards? I wouldn't have imagined 2 1290's and 2 eq's would fit in a single.
3)Line has to be an option. a Mic/line switch is easy.
4)Meter electronics option, on board, would be cool, if easily implemented and not expensive

I'm gonna reiterate, just one last time(honest), to go with just one board,
double sided , and use horizontal PC mount switches/pots.
(for everything but your 22 pos. gain switch option)

 

[Bluzzi]

[quote author="Gwaggin390"]1)Geoff Tanner would know for sure...www.auroraaudio.net[/quote]I don't think I'll bother him for that. (for now) but thanks for the tip (maybe I should ask Rupert!). Someone here must know.

2)Are you talking about 2 EQ's only in a 2 space? or two EZ1290's AND the eq boards? I wouldn't have imagined 2 1290's and 2 eq's would fit in a single.

Right. Neve 1073 is pretty compact. Ours would not be. Just don't want anyone to get wrong idea.

3)Line has to be an option. a Mic/line switch is easy.

No need. Check schematic. The line input kicks in after the second STOP position.

4)Meter electronics option, on board, would be cool, if easily implemented and not expensive

JLM already has buffer. I would just have solder points to hook up to.

I'm gonna reiterate, just one last time(honest), to go with just one board,
double sided , and use horizontal PC mount switches/pots.
(for everything but your 22 pos. gain switch option)

This is the idea but may not be practical. Remind me again when I get to that point. This is not going to happen in weeks but rather months. I'm green at this.

Keep those comments coming people.

jim

 

[Freddy G]

Hey Jim,
I'd love to be in on this!
If you need any help designing a PCB for the Elma switches I'm your man.
I use Elmas in all my DIY so I've got a library of different Elma PCBs. :green:
Freddy

 

[Bluzzi]

[quote author="Freddy G"]Hey Jim,
I'd love to be in on this!
If you need any help designing a PCB for the Elma switches I'm your man.
I use Elmas in all my DIY so I've got a library of different Elma PCBs. :green:
Freddy[/quote]

Freddy - That would be great! I'll be getting a sample 2 gang 24 position from Elma in a few weeks.

Could you activate you private mailbox? You can PM me to keep as much clutter from here.

Thanks

jim

 

[Gwaggin390]

[quote author="Gwaggin390"]1)Geoff Tanner would know for sure...www.auroraaudio.net

don't think I'll bother him for that. (for now) but thanks for the tip (maybe I should ask Rupert!). Someone here must know.

He has a forum on the site for EXACTLY these kind of questions and answers them every day

2)Are you talking about 2 EQ's only in a 2 space? or two EZ1290's AND the eq boards? I wouldn't have imagined 2 1290's and 2 eq's would fit in a single.
Right. Neve 1073 is pretty compact. Ours would not be. Just don't want anyone to get wrong idea.

exactly

3)Line has to be an option. a Mic/line switch is easy.
No need. Check schematic. The line input kicks in after the second STOP position.

Still not sold on that switch idea, no idea why you are so hot for it.
It might make the project a little "sexier" but i'm personally after price/ease of build/common sense of build.

4)Meter electronics option, on board, would be cool, if easily implemented and not expensive
JLM already has buffer. I would just have solder points to hook up to.

Fair enough, i was just thinking that there must be an easy design that could be added to the board floating around out there.
I know it would be an option, but paying for and finding the space for yet another board isn't something i'm interested in.

I'm gonna reiterate, just one last time(honest), to go with just one board,
double sided , and use horizontal PC mount switches/pots.
(for everything but your 22 pos. gain switch option)
This is the idea but may not be practical. Remind me again when I get to that point. This is not going to happen in weeks but rather months. I'm green at this.

Well, we live in a big world Jim, where people see things differently every day, but as you are admitting that you don't have much experience,
(i only have a little) as you try to lay stuff out, sensibly, i'm thinking you will find that it's impractical NOT to do it this way.
But i guess that depends on your definition of "practical"........

Component placement and trace length and sensibilty
DO matter.......

A one main board design, with one edge for switches/thru faceplate mounting is simple and clean. You can't mount switches any closer together on a "switch pcb" than you can on a main pcb,
so you save no space. Double sided allows you the proper routing for any multi deck switches and only one PCB needs to be made so it saves time and money.

Digikey sells CTS, Electroswitch, and Greyhill, all who make horizontal PC mount switches.

You've probably noted in the Blackmarket where there is a redesign for a steamlined single board, switches on the board, Neve 33609 project.
And thats from people (Tat, Igor) who have actual experience doing the design and PCB stuff.
It's really the way to go.

 

[Bluzzi]

Gwaggin390 - I think you misunderstand me.

I haven't begun to think too deeply of the actual PCB design yet. Yes probably if it is all on 1 board then it will be 2 sided to shrink the size.

As far as built in meter buffer I don't think I personally will put it in. To me that is an add on.

If by "stickler" you mean the 22 position switch then I'm a stickler. If you want line in, then it makes sense to keep that switch as per original. What do you have in mind that can replace this switch and still include line level as in original?

I'm taking my time on this. Decisions have to be made at some point and that is why I don't want to jump into it right away. Let it distill. The right design will find its way.

Chris's design is close to what you want and it exists now. You should consider it. Although its not double sided and there are 1 or 2 small errors or omissions in the switch board. I myself 'am still considering it or a modification of it. I'm in communications with Chris and will keep all informed.

The pots by the way are linear as I thought.

You are looking for lower cost and ease of assembly and so 'am I as I'm sure we all are. However I just will not compromise audio quality at the expense of a few $. After all is that not why we want a 1073? If you have suggestions on keeping things cheap and quality intact please let me know.

Remember a 1073 goes for between $2K and $3K and maybe more. This build should cost between $500 to $600 per unit!

I think using Lorlins and alpha pots for the EQ section saves $. Making the EQ section PCB will save time to mount.

The Elma is expensive but is the only 22 position PCB mount switch I found. Please let me know if anything else exists. Otherwise you can still buy a cheaper switch instead. I just can't tell you at this stage how you will connect it to the board.

Hope this makes things clearer.

jim

 

[tommypiper]

Jim, it's not clear. I'm not sure what you're saying. Seems the same ground is being dragged over and over.

Stop talking and just DO IT! :grin:

 

[Bluzzi]

Woa..Tommy. If it was that easy! I don't DO-IT. I'm very careful usually. There are too many options. I'm answering people. What is the problem?

But if you think its that easy...maybe you can do it! :grin:

jim

 

[Gwaggin390]

Hi Jim,

really, as you mentioned, i don't think there is a 22/24 position pc mount switch that fits the bill. Personally i just don't think it's worth it, or necessary.
I'd guess, work aside, that it's far from inexpensive as well?(have you gotten a price?) I didn't use the word "stickler" but if if it applies, thats cool, it's your time, and as an option, it certainly might work out great.
The one question would be, did you ask Martin if an external switch could easily be "cut in" to his board?
I beleive the EQ itself would/could cut in very easily at one point
(well, in and out, 2 points)

That aside, if it's an option, it's not that big a deal, clearly it's important to you, and you are putting your time into it.


I'm still not sure what you are saying about a lot of it though.
Chris' design is for a full 1073 and i already have Martins boards,
no need to make chris'
I'm not sure why you think working "smarter" in the design would compromise "audio quality". Martin's board are an excellent example of what i am suggesting. One can take a schematic, or pcb outline of various cards, and smash them onto one board, and " make it work"
but if you look at Martins card, he did an excellent job of
"working smarter, not harder" to get a close representation of the original cards, having them work together, in a linear fashion, front/first gain stage to rear/final gain stage. A great job.
Now, a lot of the layout was done already by Neve engineers, certainly taking nothing away from Martins work.

When i sat down and first thought about the board, it would have been alot like Martins, a "linear flow" of the cards, hi pass, low shelf, presence/hishelf, recreated on one board, behind the PC mounted switches, with the 2 gain stages, behind the eq/inductor/cap stages. There would not (or perhaps will not, if i do one myself) be any "compromises" to the signal path, there doesn't need to be.
As the originals are single sided, it makes it easier to do a basic recreation of the cards on one side, all on one board, then use the underside to route the things that might interfere with one another, or may have been "wired" originally as opposed to being on a board.

I'd probably have roughed up a pcb design already if the schematics decoded the switches a bit more
(so i didn't actually have to put pen to paper)
i just haven't had the time.

I'm still putzing through my Quad8 mic pre/eq "design" (i use the term loosely)but was thinking of tackling an EZ2074(the eq only part of the 1073) design myself after i finished it.

Also, If there was a VU buffer circuit out there, and it took up maybe a square inch of board space near the back or side edge it would be a no brainer to me. People don't have to stuff it if they don't want and the added cost to the board itself would be minimal
(now i don't know if an easy, "free" design exists.....)

 

[chrisv]

Hi Guys,

I thought I'd pipe in and give my 2c worth. I tried to read the whole thread, but it's quite hard to follow. Anyway, if anyone is actually happy to try building my 1084 design, I'd be more than happy to assist. In fact I'd love to make another, it's probably the best sounding pre that I have (and I have lots). I use it on every single session I do!

A couple of things:

- don't worry about a meter buffer. The original Neve design had them just strapped to the outputs, as I have done. What you could do is just have a switch that disconnects the meter (I only really use it to adjust gain anyway)

- the reason I designed the switch board the way I did was to utilise the cheaper lorlin switches. Plus I thought it would make more sense as I'd run out of room on the main board for right-angled switches.

- Another consideration is that the board itself is very similar to an original 1073/1084 layout. I actually traced the 5 original boards exactly, then worked out how to lay them together on a single board. I'm not sure if this would make a huge difference or not, but I think it's enough to warrant the effort. Double-sided boards worry me because of grounding issues and because they're a damn site harder to fix and solder in the first place.

- The unit is actually (incorrectly) labelled as a 1073. It's actually a 1084, where it has an adjustable HF filter (10, 12 and 16kHz). I can't exactly recall where the mistake was, but I'm pretty sure it was how this was connected.

- The gain switch is actually ripped off another Neve module (the number escapes me??) - it allows you to use the same input transformer for both mic and line levels. I was a bit skeptical at first but it works a treat, no problems at all. It saves the extra cost of an additional line transformer. The gain switch is a real bitch to wire up too. LOTS of work.

- Although the whole thing fits in a 2U case, it's a serious squeeze. I think an external 24V power supply would be much better, this is how Rob from proharmonic does it now.

If people want photos of the original, I'm happy to take some close-ups. As I said, I'd love to have another one!

Cheers

Chris

 

[okgb]

Hey Chris , thanks for coming on board , it's good to make use
of the work you've already done [ it will live on ! ]
And always love the pix ,as real world examples , i'm sure bluzzi
will be with ya in a minute .

reagrds Greg

 

[Bluzzi]

Hi Chris, glad you came in. (I was hoping you would)

At this point I'm having trouble making up my mind on which way to go.
Either to go with 1 board with everything in it (EQ switches including) or a board that adapts to Martin's EZ1290 to make a 1073.

Chris if you want to take it from here and guide us please feel free. Its a big project for me and people seem to be complaining. I have confidence I can do it, its just I have to take my time (got many other things sucking my time).

You do have a finished solution.

Sorry if you found the thread hard to follow. Its my first time taking on a project. I'm just trying to answer everyone.

Please let us know your thoughts.

Thanks

jim