Preamplifier's universal input board building info/support

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Igor

Well-known member
Joined
Jul 17, 2006
Messages
2,193
Location
Israel
Hi to all, here's another usefull thing...
No need to talk much, just see schematics and pictures.

P1000134.jpg


http://i251.photobucket.com/albums/gg291/diy33609/in_di_assembled.jpg
http://i251.photobucket.com/albums/gg291/diy33609/in_di_pcb.jpg
http://i251.photobucket.com/albums/gg291/diy33609/pre_in_pcb.gif
http://i251.photobucket.com/albums/gg291/diy33609/pre_in_sch.gif

Kit contains:
-PCB, switches, input Jack, transistors, relay.

http://i251.photobucket.com/albums/gg291/diy33609/P1000157.jpg

Ordering:

http://www.groupdiy.com/index.php?topic=29771.0
 
@ Peter: Agreed! :)
@pedroplanet: say, you cloning 1272 and need input board with
pad, phase, phantom and HI-Z DI discrete circuit
before input transformer...here it is.
 
so..........does it works with this project:

http://www.groupdiy.com/index.php?topic=22828&start=0

neve 1073 preamp......

if its ok, how to connet it?

excuse me foe my newbie question........


niko
 
Well it says universal! it fits any front end preamp!
but to answer your question yes it will work!

wiring its very simple you wire the mic where it says mic,  the preamp from where it says pre.
you need to feed this with 24V and 48V where its marked.
look at this image:
pre_in_pcb.gif
 
Here's the measures.

You can use it as drilling template, resolution is 300dpi.

http://i251.photobucket.com/albums/gg291/diy33609/in_pcb.jpg
 
Same purpose, but bit different idea, different schematic. Just compare by schematics etc.
 
Igor,

do you accidentally have a source for the gain knob on the ba-33 amplifier as shown right at the picture?

thanks!
christoph
 
Hi...I assume D3,4,5,6 are 4148 correct??
Do not know what D2 is...914 , is it swapable with another # ? :p
Regarding C3 , what do you meant by "C34,5x11" ??



Edit : 1N914 eg:9843817@Farnell
 
Hi, all diodes are 1n4148 or 1n914.
4.5x11 came from Eagle package, it is measures, don't relate to this.
 
Thanks for the reply,
"22utant" makes me wonder if it should be a tantalum cap?
The one on your pic seem to be polarised lytic...What should I do please ?

Also , I've had short search about 520R , seems hard to find (Banzai , Selectronic...)Would 510R do the trick?
 
would this work with +18 instead of +24? Maybe a voltage drop resistor & a 12 volt relay.... this would open it to use with other preamps that do not use +24V.
Does the JFET DI really need +24, or would it work fine with +18? It seems like an 18 volt swing into a mic pre would be plenty.....
What are the board dimensions?
 
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