EZ1084EQ NEW BATCH COMING - SEE MY MARCH 27 COMMENT ON PAGE 38

[Gwaggin390]

Jim,
i've never quite been able to understand the resistance to the double sided thing.
You mention Martins board, to the positive and the negative in the same post.
Take a good look at his board, it does keep the original layout and trace size, but really only uses the underside to implement where the "wiring" from board to board would be on the original.
It is an excellent example to follow, and really isn't at all "hard" to do.
It's the smartest most efficient way to go about it. If the underside is really only the "wiring" from board to board, or section to section, it won't really vary from the original much at all, and has to be more efficient, and save board size.


You also might think about asking Max about inductors, maybe he can wind them for this project. Parusha is making pultec boards with options for two kinds of inductors, but i can see where this board will be big enough already.
I bought a quantity of inductors from Max for Pultecs and another project and they ended up being about $30 each including shipping.

Don't be afraid to go double sided, Martin's is, and every place i've priced PCBs their "standard price" seems to be for double sided so it doesn't seem to be an added cost. Also, you don't have to go crazy with the second side, but you may be able to save a bunch of space by being able to run a few traces on the second side, and you may also be able to shorten traces and stay away from potential problems that long traces can bring.

I'm afraid of this entire behemoth project I've taken on! What I'd like to do is leave as much of the original "parts layout" of the modules and fit them on a large board. I guess what I want to achieve is a board that connects all the modules together as well as the switches replacing all the wiring. I'm not knowledgeable enough to want to alter the way it was done. I'd like to also keep trace size to original if possible. Martin's board is a perfect example of this. However if it becomes a real pain to do this we will follow path of least resistance.

 

[Bluzzi]

Gwaggin390

I don't know if you meant me but I wasn't resisting the board being double sided. Just mentioning its a possibility. If the board needs to be double sided it will (it most probably will).

Neither do I mention Martin's board in the negative!
Martin's board is actually the genesis of this project! I really have no idea where you got that from?

By the way the above may seem harsh but don't take it that way. I really don't see where you understood those things. No big deal though. Just sayin'

Is Max the one in the Black Market selling inductors? I will be contacting him, thanks. Last time I checked his prices were almost identical to Carnhill's. Maybe if I contact him we can work something out. Thanks for the tip.

cheers

jim

 

[Ephrem]

Hello,

On BA 205, there is two pots (10k &50k).
are they linear or log pots ?

Same question on Ba 211, the 10 k pot, is it linear or log ?


Regards

Ephrem

 

[Bluzzi]

All should be linear from what I've found.

jim

 

[madriaanse]

Hey guys,

Just wanted to chime in. It should be pretty easy for me to add a line-in to EZ1290, but cost will increase quite a bit because you'd need to add the following parts to the EZ1290 BOM:

a: XLR in $3
b: 31267 - Carnhill VTB9046 $82
c: Mic/Line (DPDT) switch $7
d: Grayhill 71BDF30-01-1-AJN (line level gain control) $17
e: line switch resistors - R1, R7, R9, R24-R28 from EH10023 $3

That's over $110 for a line-in, not counting extra machining and other labor. Is that worth it? Not to me, but if there's sufficient interest I'll add it to EZ1290 V3.0 along with the jumper points for the EQ section.

Keep up the great work!!
:thumb:
Martin

 

[drpat]

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[ChrioN]

I couldn't agree more with drpat. When I see the topic, I think of a line in neve eq section...

 

[Bluzzi]

OK, lets clarify things as they seem a bit fuzzy. The original title was there to get opinions from everyone about which direction was best. I was confused myself as there were so many ways to go (entire 1073, entire 1084, EQ only, EQ only that patches into EZ1290 etc.). My dilemna was I wanted a project for myself but that would also appeal to others in this group.

I originally wanted to make a full 1073 clone then I saw the 1084 EQ section and thought "why not that one" ...and so on. Well to do a full 1073 or 1084 costs a lot because of transformers switches etc. So I thought since I already have 2 EZ1290s almost done why not build an EQ section only.

Its at that point and with inputs here that I decided to go for a 1084 EQ only.Of course one must have a line level input in order to use other than with mike, so YES it must have a line in to work independently of a 1290 etc. Think of my project as (1073 minus EZ1290= EZ1084EQ).

However for people that have an EZ1290 like myself they will probably want to patch it into it so that would be an option for some to at least start using it with their EZ1290 and it becomes albeit a lineless 1073. However the plan is to have line level in as an option if they want.

So yes the project will have line in. I'll be using the Carnhill line in XFR but there is no reason that one cannot substitute if they want something else in there.

Please feel free to ask any questions.

jim

 

[Bluzzi]

[quote author="madriaanse"]Hey guys,

Just wanted to chime in. It should be pretty easy for me to add a line-in to EZ1290, but cost will increase quite a bit because you'd need to add the following parts to the EZ1290 BOM:

a: XLR in $3
b: 31267 - Carnhill VTB9046 $82
c: Mic/Line (DPDT) switch $7
d: Grayhill 71BDF30-01-1-AJN (line level gain control) $17
e: line switch resistors - R1, R7, R9, R24-R28 from EH10023 $3

That's over $110 for a line-in, not counting extra machining and other labor. Is that worth it? Not to me, but if there's sufficient interest I'll add it to EZ1290 V3.0 along with the jumper points for the EQ section.

Keep up the great work!!
:thumb:
Martin[/quote]

Martin hi, great to hear from you!

If you read above, my intention is to design the line in with the EQ but also have patch points that would connect to EZ1290. The reason for that is it does make sense that EQ will be used mostly at line level.

If you design into your board for use alongside mine then that forces people to get the EZ1290 everytime they want the EZ1084EQ. However lets see what others say, they may want to use line in without EQ.

How about a separate line in pcb? I wouldn't mind that, less work for me!
This way I only design EQ and optional line output section (not needed if using EZ1290). See what I mean! So many options, for me its hard to find the 1 solution for all option. Maybe there isn't any.

I think either way if people want 1084 Eq they are going to have to pay for expensive switches, transformers and inductors. I keep repeating to all that this is not an inexpensive project. I myself have not purchased the parts yet! (hey Christmas takes its toll on the wallet!) Nevermind about finding the time to learn Eagle!.

Also using the input transformer for line in sounds interesting. But why did NEVE drop this later on? (I imagine 1063 is before 1073). Chris does use it on his 1073/1084 hybrid clone and has nothing but praises for it.


jim

 

[tommypiper]

Happy holidays, everyone. Nice to hear the Doctor Pat chime in.

I like Martin's offer of putting everything you need for the line in into V.3 of his EZ1290. Martin knows the circuit, we know it will be excellent, we know it will work. That reduces your work load, Jim, and makes things easier for you. That benefits everyone who wants a mic pre along with the EQ. Which will be most people. I see it as a win for everyone.

That means you only have the passive EQ to design. That's much better. Those who want can put the passive EQ board into the circuit of their choice, too. Like a tube circuit. Like an API, etc. It offers the maximum of flexibility for everyone. Thanks, Martin!

You don't want to get bogged down with extra line in design stuff when the active elements are already on Martin's board, etc. It makes no sense to have half the active elements on Martin's board but the line in controls and resistors and active controls on your board.

Jim, also, you don't need to learn Eagle, just work out the EQ on paper and write out a board design by hand or in a simple drawing program, and send it to a pcb house. (Many of them will work with hand drawings for minimal additional charge, like $10.)

You can specify the details of the pcb mount parts sizing (like the Grayhill switches and the inductors) so they will be to scale and will mount on the board -- you won't have to draw those by hand, talk to the pcb houses, they can help you there.

Dave Royer was the first one who told me how to do this. He said just draw it by hand with a felt pen and call around to the PCB houses and they will take it from there. For something on one sided boards with through holes, it's all you'll need.

cheers.

 

[drpat]

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[tommypiper]

Hi Pat. As you say, it will work fine with the 1290 because the control will be there. Anyone who wants to insert the passive EQ into another circuit would presumably also have a level control in that circuit and would design accordingly as needed. The control would be there. No one is running a line amp without level control!

No one is planning an "EQ only" module. It would couple with the 1290. Or potentially with another active line circuit.

I wasn't suggesting a stand-alone EQ only module. Only that Jim could design the EQ as a discrete board which would work seamlessly with the 1290, as Martin has suggested.

EDIT:
I was wrong about him not planning an "EQ only module." Jim explains below. My apologies.

 

[drpat]

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[Bluzzi]

Hi guys, I'll chime in to explain my intentions again.

I do intend to make a "EQ only" module! That means line in and line out is a must. Probably it will have the switch for line in to attenuate or boost. Most using an EQ only would want to patch it into a console or between a mike preamp and their converters. I think it would be best to leave the ability to have some level control in, we never know what someone else is going to be interfacing to.

I do also want to be able to "patch" into Martin's board. Martin and I have discussed this and he would include that patch point into a future pcb.
I also believe that current owners of the EZ1290 (like me) could patch into the pcb it just probably won't be as pretty!

My reasoning behind having no line in control built into the EZ1290 is that it would be redundant if I have it included into the EQ.

Now there may be folks that want to patch in 2 EZ1290s on their stereo mix bus to add flavor (I hear that is popular with some) so a line in on the EZ1290 would make sense for that.

I was planning on having a true relay or plain switch based "bypass" on the EQ section. However if enough people say so I could have a bypass just for the EQ and not the line in so that the EZ1290+EZ1084EQ could be used in the above manner. I'd rather not as it adds more complexity so unless I hear a really good argument I'll stick to hard bypass for the entire circuit.

Or again here is where Martin would be able to give us patch points on his board for a line level insert! Level and impedance would then be our responsibility. I think with that option everyone would be happy!

The only thing I'm still wondering about is the output section. If someone uses Martin's EZ1290 then the EQ only needs line in as his board takes care of output. So in that case I guess its my turn to have an option to leave out the output section including XFR.

And guys I love to hear your comments and value your opinions on this project! I couldn't and wouldn't be doing this without your support.

jim

 

[Bluzzi]

Hi Tommy - Thanks for the tip on using a felt pen. I didn't know the PCB houses would accept that. Its a good option if I can't get anywhere with Eagle. I also could use Illusrator and use that to home etch. Of course thats only if its single sided. Don't know yet.

3nity is supposed to design the board and home etch, and I want to help. So I want to learn Eagle for the sake of this project and future ones too.

jim

 

[drpat]

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[Gwaggin390]

Jim, i've mentioned this before, but you might want to find a Neve 2074 schematic. The 2074 is an EQ only module that is line in and uses the 1073 EQ. It has no gain adjustment. It might be a good reference to have as you draw the "line in, eq only" part of it.
There is also an eq only module(maybe the 2076?) that uses line in, the 1073 eq and does have a gain control.


[quote author="Bluzzi"]Hi guys, I'll chime in to explain my intentions again.

I do intend to make a "EQ only" module! That means line in and line out is a must. Probably it will have the switch for line in to attenuate or boost. Most using an EQ only would want to patch it into a console or between a mike preamp and their converters. I think it would be best to leave the ability to have some level control in, we never know what someone else is going to be interfacing to.

I do also want to be able to "patch" into Martin's board. Martin and I have discussed this and he would include that patch point into a future pcb.
I also believe that current owners of the EZ1290 (like me) could patch into the pcb it just probably won't be as pretty!

My reasoning behind having no line in control built into the EZ1290 is that it would be redundant if I have it included into the EQ.

Now there may be folks that want to patch in 2 EZ1290s on their stereo mix bus to add flavor (I hear that is popular with some) so a line in on the EZ1290 would make sense for that.

I was planning on having a true relay or plain switch based "bypass" on the EQ section. However if enough people say so I could have a bypass just for the EQ and not the line in so that the EZ1290+EZ1084EQ could be used in the above manner. I'd rather not as it adds more complexity so unless I hear a really good argument I'll stick to hard bypass for the entire circuit.

Or again here is where Martin would be able to give us patch points on his board for a line level insert! Level and impedance would then be our responsibility. I think with that option everyone would be happy!

The only thing I'm still wondering about is the output section. If someone uses Martin's EZ1290 then the EQ only needs line in as his board takes care of output. So in that case I guess its my turn to have an option to leave out the output section including XFR.

And guys I love to hear your comments and value your opinions on this project! I couldn't and wouldn't be doing this without your support.

jim[/quote]

 

[Bluzzi]

[quote author="drpat"]Alright Jim, it sounds like you've got your scope of work narrowed down pretty well. I think it would be a good idea to leave the "line in" on the 1290 also.

My reasoning... I'm assuming that the 1290 would interface with the EQ section via unbalanced (sans transformer) means. If this assumption is correct, then your line input (to the EQ) would be unbalanced, unless you sprang for the two additional transformers to do it balanced. I doubt that most people will do that, but if they do, god bless them. With a line input on the 1290, you'd end up with a balanced line input for the EQ section, and would get the "full iron" effect while going through the EQ at line level. This would still keep the price of iron down to the cost of two pieces, with the added benefit of being able to patch it into the mix buss.[/quote]

I was thinking more balanced transformer line in as in original 1073 or 1084. If using the 1290 the signal would be taken after the line in stage and would use its output section. I don't think the XFR would be annoyed by an unbalanced line level in any case.

However you've got me thinking about something else now. I have to look at the schematics again but I think the line in may actually go to one of the amplifier stages in the 1290. If that is the case then that may pose a problem with my original plan! 'Cause then I need to design in another circuit which if used with the 1290 becomes redundant! I'll have to take a look tomorrow when I have more time. I hope I'm wrong.

jim

 

[drpat]

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[drpat]

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