Igor

Re: Preamplifier's universal input board building info/support
« Reply #20 on: August 21, 2009, 10:53:50 AM »
22uf 16v will be fine. 1uf input capacitor can be 63-100V, poly, Wima etc.

Yes, DI booster will work on +18 as well, with less output swing. Not sure every 24V relay will work on 18v btw...
Possible to check how many volts do you have on rectifier capacitors on power supply,
if + is more than +29V, it is possible to add +24V separate regulator, LM317 and some parts will do the job.
The board dimensions are 81x54mm.
http://www.ij-audio.com
(new site hopefully will be up in July)


Nele

Re: Preamplifier's universal input board building info/support
« Reply #21 on: October 12, 2009, 11:58:53 AM »
anyone have a type-number of the switches to use? preferably from Farnell or RS..
thanks


noulou

Re: Preamplifier's universal input board building info/support
« Reply #23 on: November 12, 2009, 08:17:13 AM »
I wanted Igor and anyone who wants to build this board know that the relay-driving transistor for the DI is marked upside down on the boards silkscreen.

So if you're planning on putting a pn2222 or 2n3904 NPN in there, put it upside down.

Thanks,
Nikos

Igor

Re: Preamplifier's universal input board building info/support
« Reply #24 on: November 12, 2009, 08:30:08 AM »
OOPS... Anyway, refer to CBE printed on PCB, it is right.
http://www.ij-audio.com
(new site hopefully will be up in July)

Kid Squid

Re: Preamplifier's universal input board building info/support
« Reply #25 on: January 17, 2011, 07:03:09 AM »
Hi Igor,

I'd like to order four of these fantastic boards, with two of the 24 / 48 v PSU Boards please,
Kindest regards,
Steve
It is not the same as 4+12, nor is it the same as 4+8, but 4+12 IS the same as 4+8+12....

http://www.facebook.com/LazyLizardLabs

radiance

Re: Preamplifier's universal input board building info/support
« Reply #26 on: April 06, 2011, 10:34:05 AM »
I'm going to use these for my api 312 build but I realize that the 312 has plenty of gain, so no need for boosting the line signal right?

I might just route the signal coming from the line input jack straight to the input transformer of the 312.

Or am I missing something?


EDIT: Duh...just realize it's a High Z input...

Never mind...
« Last Edit: April 06, 2011, 10:39:20 AM by radiance »
"Knowing that you are dreaming, however, does not automatically guarantee full rationality.
Then again, being awake doesn't ensure good thinking, either." -  Lynne Levitan

letterbeacon

Re: Preamplifier's universal input board building info/support
« Reply #27 on: April 06, 2011, 01:06:16 PM »
Does this DI add any colour to the signal at all?  I want to put it in front of a DIY 1290 but would like to keep the colouration of the Neve without adding to it.

dmp

Re: Preamplifier's universal input board building info/support
« Reply #28 on: April 06, 2011, 01:24:09 PM »
Quote
Does this DI add any colour to the signal at all?  I want to put it in front of a DIY 1290 but would like to keep the colouration of the Neve without adding to it.
How would one answer this question? I used this for my ez1290 project and it sounds great with a Precision Bass, which is all I've used it for, but i haven't done any 'colouration' tests...

3nity

Re: Preamplifier's universal input board building info/support
« Reply #29 on: August 23, 2011, 09:32:39 AM »
Igor.
Can i use both fets here?
schematics says J109 and pcb says J111??
Thanks.
Life is a path, death the destination.


mrcase

Re: Preamplifier's universal input board building info/support
« Reply #30 on: October 07, 2011, 04:49:09 AM »
Hi!

does anybody have a mouser / farnell link to which relay and which input jack fits the pcb?
and which is thte best substitute for the  BC214C??

cheers

3nity

Re: Preamplifier's universal input board building info/support
« Reply #31 on: October 07, 2011, 08:31:28 AM »
Igor is too bussy !
I asked a question a few weeks ago!
Life is a path, death the destination.

mrcase

Re: Preamplifier's universal input board building info/support
« Reply #32 on: October 07, 2011, 09:28:41 AM »
Maybe I`ll try via his shop....

okgb

Re: Preamplifier's universal input board building info/support
« Reply #33 on: October 07, 2011, 12:10:46 PM »
Use a socket to try different transistors and use the old method of putting
a regular d.i. into the mic input to experiment with different combo's
[ it would be like using a countryman d.i.  - fet  - into the mic in ]
GKB Audio / Greg Boboski

madreza

Re: Preamplifier's universal input board building info/support
« Reply #34 on: January 30, 2012, 07:06:33 AM »
Hi Igor,

I've gotta be missing something !!!!

I bought 10 DI's from you and have the same probleme on all 10 :
No Signal
tried feeding them with a 1Khz Sin , checked with Oscillo
I have a signal till the G pin of the J111 .... nothing further than that !
any idea ?
Thx
Knight 1: We are now no longer the Knights who say Ni.
Knight 2: NI.
Other Knights: Shh...
Knight 1: We are now the Knights who say... "Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.

dmp

Re: Preamplifier's universal input board building info/support
« Reply #35 on: January 30, 2012, 09:58:21 AM »
Quote
No Signal
tried feeding them with a 1Khz Sin , checked with Oscillo
I have a signal till the G pin of the J111 .... nothing further than that !
any idea ?
Thx
I'd suggest you check that the bias on the G of the JFET is correct - should be about 12v. If not, you have a resistor wrong or a diode backwards.
If that is correct check that your pinout of the J111is correct for the pcb.
I've built these and they work - so you have a problem somewhere.

madreza

Re: Preamplifier's universal input board building info/support
« Reply #36 on: January 30, 2012, 04:03:26 PM »
thanks dmp
in fact I get 4.8V !
gonna check the resistors value and the diodes
Knight 1: We are now no longer the Knights who say Ni.
Knight 2: NI.
Other Knights: Shh...
Knight 1: We are now the Knights who say... "Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.

madreza

Re: Preamplifier's universal input board building info/support
« Reply #37 on: January 30, 2012, 06:52:08 PM »
Diodes are fine, resistors have the right values !!!!!
Knight 1: We are now no longer the Knights who say Ni.
Knight 2: NI.
Other Knights: Shh...
Knight 1: We are now the Knights who say... "Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.

dmp

Re: Preamplifier's universal input board building info/support
« Reply #38 on: January 31, 2012, 10:02:46 AM »
Then pull the JFET and see if the voltage becomes correct. Problem may lie with your J111. Maybe the pinout is wrong or it is a bad part?
Look up the datasheet for the J111 you bought, verify that the pinout is correct for the PCB.

madreza

Re: Preamplifier's universal input board building info/support
« Reply #39 on: February 07, 2012, 08:15:08 AM »
Thanks DMP for your help

In fact Igor Sent me a K170 instead of a J111
the pinout isn't the same and I didn't check that :D
now it works great !!!!
Knight 1: We are now no longer the Knights who say Ni.
Knight 2: NI.
Other Knights: Shh...
Knight 1: We are now the Knights who say... "Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.


 

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