Neve style 500 series mic pre 1290 1073

[onlymeeee]

@onlymee: i will also wire it fixed as i'm not able to source the AGQ26024 either (in europe).
What about the opposite side ? doesn't need that to be "switched" on as well ? (datasheet looks like...)
can you re-verify ?

thanks

No need to link the other side, but no probs if you have

 

[janczmok]

Okay, so the last bits for today ( close to finish the whole Unit :

- The Output pot will be connected to P and L => L=wiper, P=Max out what about the GND connection, where do i best get that from ?
- i am lacking Fuse F1, where is it on the PCB ?
- For the "pure" 24V 51X , i don't need to install the small power PCB, do i need to run a wire somewhere else or is everything fine ?

That's all then. Thanks for looking into.

 

[onlymeeee]

Okay, so the last bits for today ( close to finish the whole Unit :

- The Output pot will be connected to P and L => L=wiper, P=Max out what about the GND connection, where do i best get that from ?
- i am lacking Fuse F1, where is it on the PCB ?
- For the "pure" 24V 51X , i don't need to install the small power PCB, do i need to run a wire somewhere else or is everything fine ?

That's all then. Thanks for looking into.

Good work!
Should be better to explain in these..
http://www.thedonclassics.com/nv73topsilk.jpg
http://www.thedonclassics.com/nv73bottomsilk.jpg
http://www.thedonclassics.com/images/24v%20operation.jpg

 

[janczmok]

That perfectly answers the question, thanks !

 

[Brolik]

Hey are these totally sold out? Are you expecting to get more or did I miss it? happy new year!

 

[onlymeeee]

Hey are these totally sold out? Are you expecting to get more or did I miss it? happy new year!

Hi,  10th Jan I'm expecting a new batch of PCBs (metal work's already arrived) so shortly after that, they'll be available again.

 

[onlymeeee]

Hey are these totally sold out? Are you expecting to get more or did I miss it? happy new year!

Hi,   10th Jan I'm expecting a new batch of PCBs (metal work's already arrived) so shortly after that, they'll be available again.

Just to let you know.. PCBs have arrived.. so they're back in stock (paypal button on site now active again)

 

[Brolik]

I don't seem to able to log into Paypal through your checkout interface. I'm able to sign directly into paypal though. Shall I just send you the correct amount of money or is the problem easily fixable on the site?

 

[onlymeeee]

I don't seem to able to log into Paypal through your checkout interface. I'm able to sign directly into paypal though. Shall I just send you the correct amount of money or is the problem easily fixable on the site?

Strange, it's working for me in Firefox, yet not in Internet explorer.  (anyone have any ideas?) What browser are you using? I'll look into it.  If you pm or email me your paypal address, I can send an invoice if you like.  (or has it worked and gone through now)

 

[Brolik]

It was acting up on me in Chrome, which usually handles things pretty well. It worked fine once I tried it in Firefox. One NV73 please! Thanks!

 

[onlymeeee]

really?

so the bottom two (spaced away) pins are the magnet coil in the relay yea?
and the switching switches the two 'common' connections to the opposite adjacent pins... i dont see what this is doing on the board.

i've not used relays before, only transistors so this is helpful.

some people just never stop posting dumbass questions do they!

Hi Kebeb, it's just come to my attention that I drew the link as looking from above the top PCB, not the bottom like the jpg suggests.  So to stop confusion, I'm just saying link both sides now. 
eg.

Did you clock this?

 

[kepeb]

I thought that,
after looking at the traces on the board i couldn't understand how it would work jumpering that side.
double checked with you at the time.
good reason to learn about relays tho huh

 

[crisotop]

just turned my pair on for the first time - quick - "calibrated" them to the suggested 22V. Both sort-of work, I get oscillation with the trimmer full on and the gain set to 45dB or higher. I'm running them on the 24V rail of the 511 rack, anything I should double check?

thanks!
Christoph

 

[onlymeeee]

just turned my pair on for the first time - quick - "calibrated" them to the suggested 22V. Both sort-of work, I get oscillation with the trimmer full on and the gain set to 45dB or higher. I'm running them on the 24V rail of the 511 rack, anything I should double check?

thanks!
Christoph

Maybe post some pics to see if we can spot something..  If it's on both it's probably not short or cold solder joing I'd guess.  Could be a wrong part.

 

[crisotop]

here you go: picture I haven't had the time to double check everything, but since the problem is exactly the same on both builds it seems to be definitely my fault

thanks for the quick support!
Christoph

 

[onlymeeee]

here you go: picture I haven't had the time to double check everything, but since the problem is exactly the same on both builds it seems to be definitely my fault

thanks for the quick support!
Christoph

Nothing is immediately jumping out at me..
Does it still oscillate with the input shorted?
How are your voltages on the transistors?
I'd concentrate on trying to find the fault at 45dB or 50dB as that takes the 2nd BA283AM out of the equation.
How are the gain levels?  Not sure if you have a multimeter with AC voltages on it?  
But if you put in a 50Hz -55dBFS (from DAW say) into the pre.. what level comes back out into DAW at 50dB gain?  Check with multimeter at pin P (between 2 gain stages)
How's freq response? might be a clue.. 20Hz level 2kHz level and 20kHz out of DAW and back in... should give decent idea.  Should be within 0.5dB or thereabouts


Actually...scratch that... well... I'll keep at as good general troubleshooting...
but in your case.. one thing has jumped out at me.. that ouput transformer cap... that looks hugely bigger than one I use... I suspect it could be causing coupling between the 2 transformers...

If you'll excuse the poor pic.. this is more what mine's like...


I'd try and reposition that slightly away from the input transformer and see if that sorts it.  Mayb you'll need to add a bit of wire to extend legs now to see.  But if you've got more then I'd be inclined to just snip it out just to see if it helps the problem.

 

[kepeb]

i'm confused.
are you on 16 or 24v?

i think i may have wired something wrong too then.
you have a jumper in the bigger gap where the resettable fuse is on mine for 24v

i thought i needed all the power components adjacent to the last two pins for 24v

 

[onlymeeee]

i'm confused.
are you on 16 or 24v?

i think i may have wired something wrong too then.
you have a jumper in the bigger gap where the resettable fuse is on mine for 24v

either is fine.

i thought i needed all the power components adjacent to the last two pins for 24v

No worries either.. if anything.. it makes the -16V rail a little nicer for other modules(!)

 

[crisotop]

Mines running on 24V (no DC-DC board installed)

The outzobel cap is a 10nF styroflex - disconnecting makes no difference. When I run the amp as a 0dB line amp it sounds fine. As soon as I turn the gain up, I hear a buzzing noise and oscillation at higher levels. I can crank the gain fully up and turn the fader down until the oscillation dissapears, so I guess it's not a problem of one particular gain stage. I'll investigate further - thanks for the input so far!

Christoph

 

[onlymeeee]

Mines running on 24V (no DC-DC board installed)

The outzobel cap is a 10nF styroflex - disconnecting makes no difference. When I run the amp as a 0dB line amp it sounds fine. As soon as I turn the gain up, I hear a buzzing noise and oscillation at higher levels. I can crank the gain fully up and turn the fader down until the oscillation dissapears, so I guess it's not a problem of one particular gain stage. I'll investigate further - thanks for the input so far!

Christoph

When you say disconnecting do you mean completely removing from the unit? It's it's close proximity between it and the 2 transformers I was thinking that could be effecting it.
Don't worry.. we'll get to the bottom of it! They're only electroncs!  They don't know the meaning of voodoo! There will be a logical reason..!