neumann v475 pimping ...

[[silent:arts]]

[quote author="3phase"]isnet the MO12 just a highcut filter?[/quote]
yes
[quote author="3phase"]How you got rid of the low cut these broadcast modules usually have?[/quote]
look at the frequency response - no need to get rid of any low cut

difference between the b and c version:
since they are very "neutral" summing amps I don't think you will hear any difference

 

[3phase]

thanks for the info. maybe i mixed it up with the telefunken summing amps..they have a serious lowcut.

Do you know if all neuman summing amps leave the lows untouched?

What system do you use for your audio measurings?


regards
Sven

 

[[silent:arts]]

[quote author="3phase"]Do you know if all neuman summing amps leave the lows untouched?[/quote]
as far as I know or measured them: yes

[quote author="3phase"]What system do you use for your audio measurings?[/quote]
Neutrik A2 and Audio Precision System Two Cascade Plus

 

[ermens]

what are the specs (type) of the trafo and where to find this (schuricht?)?
looks very smal.
thanks for this suggestion anyway

 

[[silent:arts]]

Farnell PartNr 9531629

 

[ermens]

thank you vm!
hope to not bothering you while asking about your 475project in the future?!
ermens

 

[crisotop]

Thanks to Volker I'm just starting a very similar project with (hopefully) some minor differences.

First of all I'd like to make the first 2-3 input pairs mono-switchable. I thought of simply adding a 4dpt switch per pair, which sends the input signals to different resistors + both busses for the mono path. Secondly it would be nice to have a passive summing outlet as well - could I just split the summed signal before the V475? Do i need the same "shunt" resistor between the summing busses for the V475? If not that might be a problem when using the unit in "passive" mode with a simple signal split.

I will check the cards pinout + needed connections in the next few days in order to double check with the summing specialists at this board...

thanks in advance
Christoph

 

[philkerg]

Congratulations ! Very nice rack !

I have a 475-2 on my shelves waiting for something like that ....

Looking at the schem I couldn't guess where you connected the main volume control ( I suppose the nice stepped attenuator switch is a master output level control ... BTW where did you get this beautiful baby? )

Generally on those modules gain control is a kind of feedback on the input xformer. But on this one I can't see anything like this :-(

What did I miss ?

Thank's
Phil

 

[[silent:arts]]

Phil,
the gain switch on my unit is ended the RG (Feedback patch)
it is an Elma 11 x 4 (thanks Viitalahde)

If this is possible on your unit, you have to look if you have an a, b or c version.

 

[philkerg]

Mmm, don't know if I'm unlucky but mine seem to be a 475-2 .
No A,B or C model. Refering to the schems it's the only one that has no feedback loop ... but I can't guess the gain of this amp :-(
Is it full gain (around 40db I suppose) or is it unity gain ?
Can I make a summing amp with this one or was it just built for some other purpose ?

And maybe another dumb question but how do you calculate the Zshunt value for a 0 ohm input ? (using th classical formula you find Zs = 0 !!!!)

Thank's,
Phil

 

[[silent:arts]]

475-2 = A model
gain is 1:1, expecting the right Rin (5K1)
the only thing you can do is; a summing amp

 

[philkerg]

Thank's Volker,

475-2 = A ?

refering to the schems on kubi's website, I saw a 475-2 A with gain control (pin 12-13 & 18-19 or something ...)
and also a 475-2 (no letter mentionned) with no gain control ....

Did I misunderstud something ?


And on the other hand can you make a passive summer with a unity gain amp ?
How do you compensate the gain loss of the resistor summing network in this situation ?

Thank's
Phil

 

[[silent:arts]]

[quote author="philkerg"]And on the other hand can you make a passive summer with a unity gain amp ?[/quote]
when using a V475 it is not a passive summing mixer :grin:

and you are right, the 475-2 is the V475-2A without Rg - they have the same Datasheet.

if you want to add some Level control just put a passive attenuator at the output.

 

[philkerg]

Thank's again Volker,

Ok I 'll sell this shit :grin:
A unity gain amp is for active summing only ... correct ?

I think I have some other dual 0 ohm amps such as TAB 372-1D. Is it in the same league than the neumann amp ?


And more basic : What are the positive points of a 0 ohm amp vs a regular mic amp for passiv summing ?
I saw somewhere a thread about this but I can't find it now ...

Cheers,
Phil

 

[[silent:arts]]

[quote author="philkerg"]Ok I 'll sell this shit :grin:
A unity gain amp is for active summing only ... correct ?
I think I have some other dual 0 ohm amps such as TAB 372-1D. Is it in the same league than the neumann amp ?[/quote]
for summing I would prefer the V475,
you can do other things with the 372 :green:

 

[crisotop]

I've to schematcis which state an "Rgk" for the V475-2?

Schemo1
Schemo2

regards,
christoph

 

[[silent:arts]]

[quote author="crisotop"]I've to schematcis which state an "Rgk" for the V475-2[/quote]
both are V472 ? :green:
(did you receive your package yet ?)

 

[crisotop]

damnit - should have paid more attention

but the A model Kubi schematic has the Rg?

christoph

 

[[silent:arts]]

yes, your A model has the Rg:
http://www.silentarts.de/lab/Studiotechnik/Neumann/V475-2A_Data.pdf

and it only needs 2 decks for a (stereo) switch, not 4 (like the B model)

 

[philkerg]

I think 475-2 A,B & C models have Rg connections.
Only the basic 475-2 doesen't Grrr

Volker, what did you mean about "doing some other things" with the 372 ?
Was it making a fire for the barbecue :wink: or something more serious ?

I used a 372-1 (the faceplate mono model) for a mic pre, it was not bad at all .... different from a 672. But very interesting in a different way.

Any opinions about 0 ohm amp vs "classical" mic/line preamp for a passiv summer ?