should i dare wire/connect my vintage Neve 1272`s myself? or go to pro?

[alexc]

From your pic it looks as if just one small greencap capacitor
has been used to replace a polystyrene cap.

The rest looks OK - some resistors are changed to metal film (small blue ones).
And the RCA big transistor replaces a Motorola one - easy change if needed.

No real problems. If you were able to recap them, you could change the greencap
and big transistor pretty easy.

So, do you have a rack for these ? And a +24VDC 250mA wall wart for testing.
While you are organising that, and I'm sure you will get the know-how to wire the rest.

More pics - say of the whole module, then detail on the pcb connector and the rear
connector so see just what wiring is there.

Between you, your tech and the forum you will get there!

 

[ion]

thanks alexc your comments are always very motivating and helpfull !!!

precise and no blah blah

thank you for that!


i am going to let the PSU to be build by my tech for yround 50,- eur (24v only)
i dont wanna touch the powering stuff.


-i found he motrolas and will order them as by now 2 people told me they would make a difference


- the greencap you mean is the one at "C3" correct? ... so should i get the part that belongs there originaly or is this trivial?

- i have startet to work on the faceplate and havy it color ready, haev ordered the RAL Neve blue spray color, drilled 4 holes to fir the 4 knobs...
i will leave it open like the old BAE 1272`s ...so the PSU will be external and connected through a Pigtail together with the XLR`s to the Amphenols

-i have no 24v wallwart for testing



will do pics now

 

[ion]

well i hope these help to help 

of course these are al from one module only but beside wire color diferences and the 2x470uF instead of the 1000uF i dont see any differences

 

[kazper]

For power supply options  try these:
World kit would cover the transformer fuse etc..
JLM AC/DC Kit Ver 2 will cover your 0-24V and the +48V phantom.
Link: http://www.jlmaudio.com/JLM%20Power%20Supply.htm

Look up the EZ1290 on this forum, as most of the questions your asking are found from reading the information for the build of that unit.

Like most people here you can do it, but this is a pretty pricey project to tackle as a first and you wouldn't be happy messing it up.
The risks as you asked about are simple.
You could kill yourself or someone using it down the road, electricity kills people all the time. Look up ungrounded microphone death's here is one example (http://gizmodo.com/5261328/a-concert-with-death-as-the-encore)
You could ruin a vintage transformer or two from a silly mistake.
You could mess it up enough that it's fairly uneconomical for you to fix it over just buying one new.

Like Marty suggested , maybe you should let this one go to a good tech, maybe he will only charge you 150 now..

Some of the legs could have more solder on them (just a tad to cover the hole and make the connections better) Some of them from the picture don't look like enough solder (By the screw). Bad looking joints by the Neve name upper right of picture, will surely give you problems down the road.

Not to say that the transistors were socketed by Neve, who knows the origin of this PCB, but they look like the transistor mounts. It could be seen by looking at the board and how the solder traces are, and as others had said the 2N3055 looks like it was replaced once upon a time.

In my most humble opinion, it looks like that board has been to hell and back. You would be money ahead to let someone else handle it and make it correct.

 

[ion]

well the kinda raw solderings like upper right corner are my work  : but those unsoldered next to screw was came like that to me... i also jsut noticed it on this picture...

my tech said a +24v PSU + a +48v one made by him would cost me about 50,- in parts and 30,- in labor ... i think i could get a +24v only for 50 than...

yes maybe i should make a deal for 100,- = PSU + wiring with him... i guess that should work out



also i was wondering about grounding.. is there any?

also someone earlier said i could blow a fuse  ;D there isnt any!

 

[1954U1]

Ion..
give them to your tech.
As others already said, its not a good idea to learn how to solder etc with these 
And yes, calm down.. you've the boards, the irons, the tants, the transistors, so all its ok.. at least for now  ;D

I'm envious for the sound you will have.

 

[ion]

k.... will anyway oder the Motorolas i guess.. or are they absolulty trivial and unimprtant soundwise?

 

[alexc]

Yes C3 - probably trivial. Should be a polystyrene 4700pF (or  4.7nF - same thing.) No + or - direction to worry about. To change the transistor, some 'solder wick' will help you remove the solder when you go
to change it. Can only fit one way, 2 solders to undo and redo.

With the external gain potentiometer you asked about before, top = left, bottom= right.
(it could be the other way around - if it is sounds reversed in use, then swap the left and right)

So your tech will make an external psu for +24V and +48V phantom power for mic.
Easiest and safest. Sounds like you have the rack well under way. Probably a good idea
for him to reflow some of those solders as suggested. Takes 5 minutes.

So what you need now is the pinout for the rear connector of the unit.

I don't have the pinout detail myself unfortunately. But I'm sure some one can help out.

For sure it will be (mostly) worth it. Of course, some kind of guitar DI is useful as these units
can sound killer with guitar and bass too.

 

[alexc]

The motorola will make a difference to some, and none to some.
May as well change it if you are concerned with 'brand power'!

Here is a pinout table for the 1272 module rear external connector.
I believe it is correct. It should assist your tech.

Here is the pinout for the 18-pin 1272 rear connnector

Pin # Pin name Connected to
1 A 10468 input transformer primary - winding #1 (+)
2 B 10468 input transformer primary - winding #2 (+)
3 C 10468 input transformer primary - winding #1 (-)
4 D 10468 input transformer primary - winding #2 (-)
5 E B- (0VDC). Also known as signal ground. Common for gain boost resistors.
6 F Connection for gain boost resistor for NV (preamp) stage.
7 H No connection. Used interally to feed B+ to NV stage.
8 J Bottom of preset pot.
9 K Wiper of preset pot.
10 L Input of AM (output) stage.
11 M No connection. Used internally to feed B+ to AM stage.
12 N Connection for gain boost resistor for AM (output) stage.
13 P Unbalanced output (+)
14 R Transformer-balanced output (+)
15 S No connection. Pin 6 from LO1166 output transformer. Useless.
16 T Transformer-balanced output (-)
17 U B+ (+24VDC)
18 V Chassis

 

[ion]

yeah you are right a DI would be nice i am thinking about it.... but on the other hand the 1272 will hang permanently as main insert on my summing mixer wich is in build these days by John Suitcase and i asked John to add 2x DI on the frontpanel of my summing mixer

so the only advantge or disadvantage would be that i run the signal that way as wel through a pair of cinemag transormers at summing output

i think this will work fine as my permanent DI for everything so i thought i skip the extra DI on the preamp



yah i will unload the whole bag at my tech on monday : )

anybody need the little "AUDIO TRAX" ? JLM PSU thing?

he said he wont use it... i dont know if he will use the little AC adaptor wich he said will do the 24v

 

[ion]

oh and THANKS for the pinout

i had/have a graphic of it somewhere or shematic or whatever but i am unable to read it ...wont hurt to give this text to him aswell

 

[kazper]

Ion,

if you do ever want to give the EZ1290's a try, there a simple PCB layout. I'd say entry a moderately simple project for a newbie. Most this stuff works right away if you measure the parts as you place them to make sure they are what you think they are and you look through the schematics and follow it with the PCB. $150-200 worth of tools to get you started. Keep the transformers spaced decently apart, twist as a minimum any wire paired runs or use twisted shielded wire with the shield grounded at one end.

here is a link to the project information: http://www.groupdiy.com/index.php?topic=22828.0

If you ever do compare the two sets and if there close to the same, decide what you want to keep and sell the other.

Kaz

 

[ion]

another mpc head : )


well maybe one day i may do it...


did you compare? your advice has a kinda sarcastic side-tone!? 

 

[Biasrocks]

...
types and the output transistor should be a Motorola, it's what Neve specified ...

Mark,
any link or source to this specification?
thanks
Volker

Hey Volker

From Geoff Tanners "Neve Secrets" forum.

The BA283 output stage in many ways resembles an old Class A tube amplifier circuit but with a 2N3055 instead of a triode or pentode tube. The 2N3055 is an unusual choice for an audio amplifier as it was designed as a 115 watt device for linear dc power supplies. It's not famous for its high frequency response and Neve modules must use Motorola (or obsolete Newmarket transistor equivalent) transistors to ensure an adequate high frequency response.

Also check out this post on Geoff Tanner's forum.

http://www.auroraaudio.net/dcforum/DCForumID1/699.html

Starting around post #9

Mark

 

[ion]

i ordered a 6pack

does anyone need the other 4 or a pair?

2N 3055, Motorola, TO-3 (E0998)

 

[digichild]

i could use 2, how much are they?

 

[MagnetoSound]

Much talk about 'socketed' transistors ...

Are those white plastic parts definitely sockets? Looks to me like they may be stand-offs, or lead-dressing supports and, if so, are not such a bad thing.

Correct me if I'm wrong.

 

[MartyMart]

Much talk about 'socketed' transistors ...

Are those white plastic parts definitely sockets? Looks to me like they may be stand-offs, or lead-dressing supports to me and, if so, are not such a bad thing.

Correct me if I'm wrong.

They are stand offs - but that also is a "kind of" heat sink as it leaves safely more lead exposed and that
dissipates a bit of heat !
MM.

 

[onlymeeee]

i ordered a 6pack

does anyone need the other 4 or a pair?

2N 3055, Motorola, TO-3 (E0998)

I'd be interested in the other 2.

How much? Where you based?

 

[ion]

pm' d about the Motorolas