Neve 1290 build completed!!

[mitsos]

Check the datasheet of the input trafo. You should have dual primaries. If you put them in series you have a 1:2 trafo, if in parallel, you have a 1:4 and lower input impedance.

 

[Di_Sousa]

Check the datasheet of the input trafo. You should have dual primaries. If you put them in series you have a 1:2 trafo, if in parallel, you have a 1:4 and lower input impedance.

thanks mitsos,
I dont really know what its a 1:2 and a 1:4.
I know how to solder and build puzzles, thats how I'm slowly building this preamp.

but, from what I understood I can have a switch to exchange from a connection in series (1200 ohms) to the input transformer or to parallel one (300ohms) , is this correct?

the input trafo I'm using is the Carnhill 9045

 

[zachs]

I'm still unclear as to how I get the +24 to all 4 of my boards. The Power Station only has 1 +24v on it, do I just wire up 4 different pairs off the xlr 4 pin power that go to each pcb?

Would it be easy to add a vu meter to these? I guess it's just eye candy, but is a nice aesthetic and can help fill out a front panel.

 

[wolfgang]

Just wire all PSU Connections parallel from the power station.

For the VU: There is an unbalanced out on the bord at point F when i remember correct. Maybe you can use it for driving a VU.

Regards,
Wolfgang

 

[mitsos]

Check the datasheet of the input trafo. You should have dual primaries. If you put them in series you have a 1:2 trafo, if in parallel, you have a 1:4 and lower input impedance.

thanks mitsos,
I dont really know what its a 1:2 and a 1:4.
I know how to solder and build puzzles, thats how I'm slowly building this preamp.

but, from what I understood I can have a switch to exchange from a connection in series (1200 ohms) to the input transformer or to parallel one (300ohms) , is this correct?

the input trafo I'm using is the Carnhill 9045

Yes, correct.

Check this page for some Neve trafo diagrams/wiring info:

http://www.technicalaudio.com/reading/neve_xfmrs/neve_edo7113.html
Look for the 10468, the original Neve Mic input trafo.. the Carnhill is the modern replacement.

You have 2 primaries and two secondaries. You want your secondaries in series. Then you need a switch to swap your primaries like you posted above.

 

[Di_Sousa]

Thanks for the Info.
I will use the Carnhill transformers

 

[Di_Sousa]

Mitsos,
there's some info on selecting the BC184C here:

http://www.groupdiy.com/index.php?topic=8911.0

and

http://www.groupdiy.com/index.php?topic=1698.0

 

[mitsos]

thanks man... I had seen those threads at some point.. I never remember the MPS-A18... I wonder if there is a difference between the On semi and the Fairchild for less than half the price?

Martin, any comments??

 

[Di_Sousa]

did you find the On Semi somewhere?

 

[mitsos]

I couln't find it on On Semi's site.. I'd go with the fairchilds or the mpsa18.. unless there is reason not to do that switch.. I'm gonna get both to try..

 

[Di_Sousa]

nice one.

have to check those mpsa18, haven't seem them before.

I ordered 20 fairchild ones from mouser, but anyway I would like to get some alternative ones to compare

 

[trancedental]

Just putting a BOM together for the EZ1290 build, I have most of the Digikey manufactuers codes found on rswww.co.uk but was just wondering if anyone has done a BOM this side of the pond? ;D as it could be helpful for newbies like myself ??? :

I'll post the BOM later on when time allows!

 

[Di_Sousa]

To be honest none of this BOM's really helped me.
It helped me much more the silk screening on the board when I was ordering components.

But anyway, maybe they can be useful to you.
there's 2 BOM's inside the excel file

you can find them also if you search in the forum, or in the Meta

 

[zachs]

Whoops, are you not in the states? If you are, I can't see how that's possible, it was the easiest sourcing I've ever done.

 

[Di_Sousa]

Whoops, are you not in the states? If you are, I can't see how that's possible, it was the easiest sourcing I've ever done.

Europe , my friend.

 

[zachs]

Heh yea I figured Would be nice if someone over there who's finished one could help you all out. What's the shipping from Digikey? They have 90% of the stuff.

 

[Di_Sousa]

yes,
that's right.

I'm doing my BOM while I'm building it, so as soon as I finish the unit and the BOM I will upload it somewhere.
Don't really know the shipping in Digikey,
for Europeans it's not only the shipping costs, but also the Duty costs + VAT, and those can be quite high if the sender shipped through UPS or Fedex. The best way to receive stuff from the states is through USPS, thats top notch - takes longer but makes everything simpler and cheaper.

Sometime ago I asked some free samples from TI. The were kind enough to send me the chips. Although they made the mistake of working with Fedex,  because of that they asked me to pay 80 dolars on duty fees, Fedex duty Tax, Vat . The value of the chips was 20 dls.
I refused to pay of course, so the parts went to be destroyed.

In Europe I order stuff mainly from Banzai and Farnell.

 

[Di_Sousa]

I ordered all the Capacitors and Resistors from Banzai and had no problems.

Let me have a look at my order ....

 

[Di_Sousa]

http://www.flickr.com/photos/33553017@N08/3118994141/sizes/l/in/photostream/  BOM 1

http://www.flickr.com/photos/33553017@N08/3118994469/sizes/l/ BOM2 (resistors)


I've got a European BOM jpeg put together with all the manufacturers parts numbers from the original Digikey ect BOM
at the above links for the EZ1290, it's missing the following 6 items which I can't find @ farnell
rswww or Banzaieffects?????

c10 Polystyrene Digi-Key 399-4493-1-ND CAP 1500PF 50V 5% CER AXIAL KEMET
c11 Polystyrene Digi-Key 399-4480-1-ND CAP 680PF 50V 5% CER AXIAL KEMET
c3 Polystyrene Digi-Key 399-4511-1-ND CAP 4700PF 50V 5% CER AXIAL KEMET
c5 Polystyrene Digi-Key BC1045CT-ND CAP 330PF 50V CERAMIC C0G 5% VISHAY
C1 Polystyrene Digi-Key 1003PHCT-ND CAP 50V 180PF AXIAL CERAMIC C0G VISHAY
Phantom LED Digi-Key L10021-ND LED RED 1/4" HOLE 5V PANEL CML 5102H1-5V

Also the following resistor values seem to only be available in Carbon Comp / Metal Film @ banzai??

R10 Digi-Key 91QBK-ND 91 OHM 1/4W 5% CARBON FILM N/A ?
R6 Digi-Key 4.3KQBK-ND 4.3K OHM 1/4W 5% CARBON FILM N/A?

From another Forum:


"Styroflex is a registered trademark from BASF.
When used in capacitors, whe are talking about polystyrene"

0.001µF  =  1nF  =  1000pF


C10 - 1,5nf
http://www.banzaieffects.com/Styroflex-1-5nF-pr-21165.html

C11 - 680pf
http://www.banzaieffects.com/Styroflex-680pF-pr-21161.html

C3 - 4,7nf
http://www.banzaieffects.com/product.php?productid=21168

C5 - 330pf
http://www.banzaieffects.com/product.php?productid=21158

C1 - 180pf
http://www.banzaieffects.com/Styroflex-180pF-pr-21155.html


No Benefits in using 5% carbon film at all, let's stick with the higher quality 1% Metal film:

R10 - 91R Metal Film
http://www.banzaieffects.com/product.php?productid=16968

R6 - 4,3K Metal Film
http://www.banzaieffects.com/product.php?productid=17033


Gotta love Banzai




Phantom LED Digi-Key L10021-ND LED RED 1/4" HOLE 5V PANEL CML 5102H1-5V

-don't be too strict with this kind of stuff, this is very specific , it's a matter of taste. You can use any Led you want or not even use one at all.
endless possibilities.

 

[trancedental]

Cheers Whoops! 8)

Have updated the links in the post below

Also available in Excel by PM !!!!! ;D