8 Channel, 3U NEVE 1073 completed

[desol]

Great to hear! What was the problem?

 

[Mr.GrinchSD]

Not really sure I replaced the .01uF cap and 1K5 resistor connected between Pin 8 and 5 on the output transformer. And the 2N3055 and a couple of other resistors on the board but still had a very bad hum but had signal finally!!!.  Then I had to ground the 3 pin on the line output to the board the one that says you can connect or not connect and that made it as quiet as a mouse. But I still dont have the JML go between hooked up I removed it to test everything so im gonna put that  back in tomorrow. . . SO IM NOT QUITE OUTTA THE BALL GAME YET!!!!

 

[desol]

You never really are until everything is measured and sounding good. You should be able to still have it quiet though without the output shield connected. I ran into some ground issues and weirdness with other outboard by having the output shield connected...so i decided to disconnect it(as recommended). Didn't make any difference in noise...it was still quiet. Be sure your switch touches ground(frontpanel). I experimented with an alligator clip clipped to ground and touched various non-critical(energized) stuff to see where and when it went quiet. Keep at it and good luck! Just don't short the output transformer. 

 

[useme2305]

last thing i was about to say before you said "it's working" was that you should check your xlr cords.

 

[Mr.GrinchSD]

ok so you dont think i need the output sheild cable??? What else could it be cause that seemed to fix everything. Ya I definatly dont wanna short the transformer AHAHA. Also when you say make sure you swicth is touching ground (front Panel) are you reffering to the Greyhill switch?? Also what would be non critical energized stuff???

 

[Mr.GrinchSD]

whats a good potentiometer that you guys can reccomend thats not too expensive???

 

[useme2305]

look for a decent conductive plastic potentiometer

 

[MicDaddy]

Get crazy with your DMM in continuity mode.  Make certain all of your Grayhills, trimmers, toggles, XLR in/out, and ALL chassis panels are making good mechanical and electrical connection.  Start with a probe at one switch, touch every other piece of metal that should be shielded with the other probe, listen for chime, then move to the next piece again touching all other shielded pieces.

I didn't do this at first and had some low level hum that was nearly inaudible, along with some oscillations only at the highest gain settings.  The hum was so low we did not observe it when doing audio comparisons with some Vintech X73i.

I found that none of my panel XLRs were making electrical connection between the chassis and each other.  Also my Grayhills were insulated from the panel from the paint, This caused little spitz of static when I'd touch a knob to throw the gain switch.  I had to scrape paint and check with DMM for good continuity. 

The pots I used for trimmers were conductive plastic and ~$8/ea USD.  There's a link for them early on in this thread.

 

[Mr.GrinchSD]

???? AHAHAH I really know so little about all this stuff its a blessing that its even up and running. THANKS FOR ALL THE HELP REALLY. . . . ILL PUT UP SOME PICS WHEN ITS COMPLETE.

Also will a linear potentiometer work casue someone told me no???

 

[desol]

???? AHAHAH I really know so little about all this stuff its a blessing that its even up and running. THANKS FOR ALL THE HELP REALLY. . . . ILL PUT UP SOME PICS WHEN ITS COMPLETE.

Also will a linear potentiometer work casue someone told me no???

It's good advice by micdaddy to be sure you can make 'good' electrical(ground) connections between things...by good it means as close to zero ohms as you can get. It makes things quiet and safe. Continuity is a setting on your meter...it makes a beeping sound between connections when they are made, and should show you the corresponding ohm reading. Search for information on the pot in the build manual.

 

[Mr.GrinchSD]

PLEASE SOME MORE WISE WORDS..

What is the difference between the VTB9049 & the VTB9070 on audio maintenance

 

[desol]

VTB9049 is a gapped transformer(lo1166). 10 second search reveals:

http://recording.org/diy-pro-audio-forum/41460-gapped-ungapped-trafo-how-know-difference-2.html

 

[leitrim_lad]

not sure if im in the right place but im wondering could u help me. i seem to be having a problem with my ez1290. channel 1 keeps cutting out. it kinda cracks with i talk into the mic and then will cut out. weirdly if i tip the case at the front for example it comes back. if i tip it again it goes again.there is kind of a pulsing noise very slightly in channel 2 as well.. id say they could be related. any ideas of what might be the problem? Cheers, Leo

 

[spase]

i think you should check your ground connections.

 

[leitrim_lad]

Cheers ill check that out. They seemed ok to me tho. Would that be causing it to cut out?

 

[Mr.GrinchSD]

Ok so im still having trouble. when to pre is turned on there is a slight buzz in my head phones. And with no mic enguaged if I tap on the front panel hard enough I can hear it quite clearly in my headphones????? Also when turning gain up it sounds good but turning it back down when I hit 50db it has a slight POP this only happens on 50db. ANY IDEAS ON WHAT I SHOULD CHECK???

 

[desol]

Sounds like ground issues to me.

 

[Mr.GrinchSD]

Ok I hope this is the last problem and it can be fixed fairly eazy. Everything is now working fine BUT I have the gain at 50 and the output up all the way and it seems to distort pretty eazy is this normal???? If not what should I check to get this fixed???

 

[MicDaddy]

Distorting with what at the input?  A condenser?  That's a lot of gain for a condenser and I would expect overloads.  With 50dB I can make it overload with a dynamic mic.

Are you positive you're not clipping the A/D?

 

[Mr.GrinchSD]

Ya its a condenser Akg c-414b-uls.  Well its running through a rosetta 200 and the rosettas not clipping for sure... So is that just normal??