Neumann V476B

[chriss]

Dear Forum,

the upper mentioned Mic-preamp has an overload-LED built in on the front-panel but this is not connected with the circuit. It's directly connected to the plug on the back-side. So the overload-detection has to be done outside of the unit. Now I found a little pcb wich seems to perform exactly this job. It's called 'U411A'. Anyone ever heard of this? I tried to Behringerize the circuit, since Neumann don't have any schematics left for their Mixer-Modules. 

The schematic I have done is under >>> removed <<<

Could this one be an overload-detection-circuit? And if so, can anyone find mistakes in my schematics? (The pcb is very tiny, so quite difficult to Behringerize).
And, if my guess is right, it might be interesting to V476B-owners.

regards

Chris[/url]

 

[peter purpose]

Chris,
I don't know what you've put on line, but my computer goes into spasm when I hit your link..!!

peter

 

[chriss]

Hi Peter,

you are right, my computer has the same problem, when I click on it. I have no idea what this is.
BUT: If I download it, everything is fine.
I will try to do another file soon.

Chris

 

[asm]

fixed your file.


heres a smaller version so everyone can load it easy:

http://tinypic.com/degrd


and heres the huge orginal one, compressed sized:

http://tinypic.com/degrt


remember to save them and put them on your own server, those will be automatically taken down in a couple days (not by me, its free temp hosting).


enjoy!
:thumb:


t

 

[[silent:arts]]

haven't looked at yours, but here is the original schematic:
http://www.silentarts.de/lab/studiotechnik/neumann/U411A_Schematic.pdf
:green:

 

[synthi]

Thanks Silent arts, you got anything!

I`m interested in those pcbs for my 476b pair, is anyone doing a batch of pcbs for this?

Thanks,

Synthi

 

[chriss]

silent:arts! that's not funny, do you know how many hours i spent over these tiny pcb's with strained eyes....
but honestly: thanks a lot for that, i even found an error with the power-decoupling-cap. i fixed this and changed the numbering of the parts to make the schematics compatible to the original.

and synthie: that's why i reverse-engineered the pcb. i want to do a new pcb so i can fit a friends v476's with this option as well. if you are interested, we could share the cost for pcb-making. by the way: the pcb is 3 x 5 cm. how many 476's do you have?

new schematics:
>>> removed <<<

 

[chriss]

silent:arts!

do you have anything about these units in your collection as well?

V476B Mikrofonvorstufe
U473A Kompressor/Limiter
W492 Entzerrer
U472-2A Pegelanzeiger
U479A Phasenkorrelationsmessgerät

i'd be very pleased since neumann refuse to send anything and audio-sonic, who are the current supporters don't even answer my emails. very professional...

regards

chris

 

[synthi]

Hey chriss,

I have 2 476b and I`m with you for sharing pcb cost

Best Regards,

Synthi

 

[fluxivity]

I'd be interested in several (like 6) of these boards, and a whole lot more if anyone knew where I could get more 476B's

 

[[silent:arts]]

Hi Chriss,

you should have done a search in the LAB before reverse-engineering :wink:

V476B Mikrofonvorstufe Schematic
U473A Kompressor/Limiter Schematic
W492 Entzerrer Schematic
U472-2A Pegelanzeiger Schematic
U479A Phasenkorrelationsmessgerät Datasheet

I would be in for 6 PCBs :green:

 

[synthi]

I was thinking how to hook those overdrive detectors to the 476b, I think the input must be conected to the output 2(unbalanced) from the 476b, and the led out to the led inputs in 476b, right?

Also, Could be these used in other preamps for monitoring overdrive? I was thinking in my Teles V376, U274...

Synthi.

 

[chriss]

thank you, silent arts, i have found most of these on the forum before.
but the u473a is a bit different to the u473 and i have to change the caps in one of mine and wonder, if the pcbs are different too. the u473a has a de-esser on/off-switch instead of the mono/stereo-switch on the normal u473. and i'm interested in the manuals as well...
but thank you anyway!
i will tell when my pcb-layout is finished. i doubt very much that i will do a run of 20 to 30 pieces... but i will surely put the layout online.

regards

chris

 

[[silent:arts]]

[quote author="chriss"]but the u473a is a bit different to the u473 and i have to change the caps in one of mine and wonder, if the pcbs are different too. the u473a has a de-esser on/off-switch instead of the mono/stereo-switch on the normal u473.[/quote]

The PCBs should be the same. the A has the mono/stereo switch outside on the tuchel connector, the u473 has the de-esser switch on the tuchel connector. The schematic looks itself looks the same.