[Build] Neve 2254 BUILD THREAD

[kazper]

Congrats Kasper, at least someone is pushing forward on the original 2254. How did you mount the boards inside?

cheers
christoph

I'm still working that out, but it will be using angle, square and flat stock aluminum. I don't have all the tools I used to have before I moved last November.

I'll take some pictures and provide some ruff estimates on dimensions and post here when I get to it.

 

[crisotop]

cool - thanks for that, I still wonder how to mount everything in a box...

best,
christoph

 

[kazper]

Hope this helps you out

The joy's of renting a pad, enjoy the beauty of my strung out AV wires in the background..

I'll be installing it like this, with small L brackets used to keep it vertical. (Next update)

Sorry for the blurry photo, it's from my cellphone.

It's going to be rather tuff on fitting all this inside the case. I think that working in a 3U case would be ideal. I'm trying hard to work within the mean's of this case, no matter how hard it has been.

Thats 1/2" (12.5mm) at 1/8"(3-3.2mm) thick aluminum angle with perfect inner corners (some of them have rounded corners). Total length was 3" (75mm) with the first hole (BA283 board) about 20-22mm from the starting edge, followed by 3 more holes every 15.5mm. Distance from the edge is what ever it takes to get you to center of the hole of your connector (3mm on mine).

I plan in making something to help support the PCB's out of nonconductive plastic. Better get good at this as I have to do it again on a EQ.

Kaz

 

[crisotop]

thanks for the insight - looks very neat! I might go for a 3U Panel (weren't the original 2254 3U?) and mount the pcbs vertivally..

please keep us posted kazper, I want to collect as much info as possible before I start my build  8) (which won't be happening before mid-summer).

best,
christoph

 

[crisotop]

I happen to have matched 1n4153 at home - could I use them as 4148 replacement for the diode bridge? they have slightly different usages as far as I'm able to compare the datasheets, but the basic specs look the same?

thanks!
christoph

 

[crisotop]

re the changes to our B185 PCB's

as well as the fore mentiond

Cut the connection from + of 470uF lytic and collector of T4; ad a connection between collector of T4 to powersupply 'F'.

also there is,

R14 should be 1k8
R19 should be 33k
C7 should be 150uf
R22 should be 2k7
R23 should be 2k2
C11 should be 22uF

One additional BA185 find (don't know how critical they are):
C9, 10 should be 1000pF

And I dare to confirm that the changes as seen in this picture from pedro / kazper are correct and needed for original Neve specs:

BA191 differences:
R13, R14 should be 220k
R15 should be 470R
R17 should be 1k
R19 should be 33k
R20 should be 820R
R21 should be 270R
C11 should be 160uF
C12, C13 should be 20uF
C15 should be 5uF

B192 differences:
R6 should be 10k
R9 should be 2k2
R15 should be 220R
R18 should be 22k
C6 should be 680pF
C9 should be 330uF
C10, 11, 12 should be 100uF
C13, 14 should be 22uF

BA283 differences:
C1 should be 22uF
C3, 7 should be 22uF
C6 should be 680pF
C9 should be 330uF



God this thing is quite a lot of work....
christoph

 

[crisotop]

Bumperoo for a lot of found differences between the wonderlandaudio boards and the original Neve schematics.

Also I'd like to save a bit on the limit threshold switch and use a 12-pos lorlin instead of a 24-pos Elma. Now there's a fixed 15k R1 and 2k7 R18 before and after the switch, which makes the conversion from 17 to 12 steps a bit more complicated (at least for me). I tried various substitutions with the help of volkers log. pot-to-switch excel sheet which didn't work out that well. I couldn't even recreate the original values that Neve used for gain make up - anyone knows how exactly how they calculated their resistor values?

thanks!
christoph

 

[Wonderlandaudio]

Long time without being around...
Most differences you´ve mentioned are not mistakes, but different versions on the schematics

 

[Wonderlandaudio]

Although some others are... Better to follow nee schems... I did

 

[Wonderlandaudio]

Bumperoo for a lot of found differences between the wonderlandaudio boards and the original Neve schematics.

Also I'd like to save a bit on the limit threshold switch and use a 12-pos lorlin instead of a 24-pos Elma. Now there's a fixed 15k R1 and 2k7 R18 before and after the switch, which makes the conversion from 17 to 12 steps a bit more complicated (at least for me). I tried various substitutions with the help of volkers log. pot-to-switch excel sheet which didn't work out that well. I couldn't even recreate the original values that Neve used for gain make up - anyone knows how exactly how they calculated their resistor values?

thanks!
christoph

Limit switch gets closer to a linear law than a log one. Total resistance, incl 15K ans 2k7 is around 22k, so you may use a 5K lin pot. If you still want to use a switch, get rid of the 5 lowest positions of the original ( you wont limit that much ) and add the total to the 15K resistor.

The gain makeup is pretty much a 5Klog.

 

[SIXTYNINER]

hi
there is some picture about "nice" finished unit?
cheers
8)

 

[kazper]

Posted the missing documents  for this project  in the Group Email.

Lots of Pictures, The 2254 Service Manual, Schematics, Etc...

 

[synthi]

Thanks! 

 

[SIXTYNINER]

hey
checked
"group" mail
unfortunately found nothing about  ???

Posted the missing documents  for this project  in the Group Email.

Lots of Pictures, The 2254 Service Manual, Schematics, Etc...