neumann v475 pimping ...

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hello,

would any of you have the schematics of the TAB v375. It's not on kubarth's site. If I understand correctly, the vx75 are supposed to be summing amps but this one looks strange.
Thanks!

Alex.
 
Hi all
great thread here.

I am finishing up my V475-2 (version 'A' i believe) summer and have a few questions:

1. recapping the 6 caps on the v475 - should I use audio grade or power grade types? any exact recommendations are welcome.

2. how can I mount my V475-2 as it has no mount holes? (I see what crisotop did but am having trouble finding something simler.- this is what I have found so far: (but I need mounting from bottom not back of rail)
http://www.mouser.com/ProductDetail/Eagle-Plastic-Devices/561-CG400/?qs=sGAEpiMZZMtzcnMBgC2bs%252bvKDjKRahTzR36de0GJivA%3d
http://www.mouser.com/ProductDetail/Keystone-Electronics/8636/?qs=sGAEpiMZZMtzcnMBgC2bs4YUwRIfgamPG4Dbko%2fHGfs%3d

3. anyone source a case in the states for this type of build (1U case with 3 db25 in the back)?

4. recommended gauge (or any other important info) for audio wiring?

5. recommended wire gauge for power (I have tons of dead computer PSU wires)?

6. I believe I read that this model has a broadcast resistor (filter) which should be removed and replaced with just wire. My V475 PCB does not have any component markings on it. Anyone that has experience with my model that could help would be fantastic. Pic below.

thanks
 

Attachments

  • IMG_0762.JPG
    IMG_0762.JPG
    176.5 KB
Hi, concerning your questions:
1. just take a look at the schematics. things where audio is passing should be replaced using audio grade, the ones for the power section can be of power grade (hope i'm right with my limited knowledge)
2. I have to figure that out too with my own 475-2
3. just take a look at the whitemarket, i think there are several people out there who sell cases and also do custom cases.
4 & 5. i use 22awg most of the time. for power a bit more sometimes, but if you take a look at a 30VA toroid, the wire is not much thicker.
6. that question was answered sometime before in this thread. it's just 12 pages, so you won't loose too much time if you read all of it ;-)
 
Hi there,

A quick question about the V475 2A.....

I see on the Vintage Maker site he says the A model has  what he terms 'low subharmonic tolerance' as opposed to the B and C models, and hence not so suited to electronic bass heavy music. Isn't that just a hipass filter that can be removed?
 
Is anyone that has a summing box based on the V475-2A and does bass heavy material having issues with it not dealing with or letting through enough bottom end?

This seems to suggest that the 2A cards are not good for bass heavy material, although I am not really too put off by a rolloff at the bottom that does -1dB at 30Hz and -5dB at 20Hz, as that is kind of what I would do anyway.. :

http://vintagemaker.net/neumannv475.html

Thoughts, anyone? Anyone that has a 2A running? Pretty please....

 
lol....indeed one could wonder. Like I say, those levels of rolloff don't look like I would be missing out on anything I am likely to want to keep anyway, regardless of what music

I was more concerned with his wording of 'low subharmonic tolerance', and whether it may have anything in it suggesting if you lay into an A card with heavy stuff it would somehow saturate in an unuseful way. Although I struggle to imagine that too....really just got a bit jolted by what he writes on that site.
 
Hi chaps,

I am looking to put a stereo out for passive summing with a pair of mic pres in between the resistor network and the Neumann V475 to give the option. Hence the way I understand it, although I don't need a shunt resistor in front of the V475, as it is active summing, I will need one before the output pair to go to mic pres as passive summing network.

I am going for a 32 channel (5.1K for the stereo legs and 7.15K for mono inputs) and if anyone could help me determine the value of the suitable shunt resistors I would be most grateful indeed.
 
Hey Guys!

Old thread, I know, but I´ll be building one of these babies.  ;D
One thing I think would be nice to integrate would be an active / passive switch. So I would have different flavours for makeup gain.
So I was wondering - Is it really as easy as using a 4pdt switch going in one position to the V475 and in the other position to the passive outputs via  shunt resistors? and what value would I need for the shunt resistors??
thanks as always
Martin
 
Almost off topic, but how would a neumann v475b card fair as the active gain component for a stereo DI?

Mainly to add some flavor to my stereo rack synths.
 
Hi all,


so here´s mine finally.
Massive thanks to Volker for tips and tricks here in the thread,schematics and supplying me with lovely PSU-boards of course!
Basically V475-2C,precision gain switch on small relays,MPRs and anleftover 12-pos. switch.Multipins are original SIEMENS 39 pole.
Writings in german ;D .Have fun.


Udo.
 

Attachments

  • Front 1.jpeg
    Front 1.jpeg
    502.7 KB
Well done Udo! Looks great! Like Meter a lot.
I´m still not ready to start my build but I stumbled across this:
http://www.ebay.com/itm/260636624590?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

wouldn´t that be perfect for my gain pot? what do you guys think?

best
martin
 
mrcase said:
Well done Udo! Looks great! Like Meter a lot.
I´m still not ready to start my build but I stumbled across this:
http://www.ebay.com/itm/260636624590?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

wouldn´t that be perfect for my gain pot? what do you guys think?

best
martin
Hi Martin,


thanks for the kind words.


You mean using the mentioned switched pot for RG (Feedback-Rs)?
Could work technically but I'm not sure about the pot travel behaviour (it seems to be a log pot).
With the pot completely closed (= whiper shorted) you will get -12dB,totally in circuit (100k) I guess you might get some +5dB or so,e.g. I have Volkers recommended 48k7 to get +4dB for the RGs.
To get +6dB you need an open condition for RGs (=infinity).
Also I'm not sure how close the resistors are matched which is quite important.
To get different values you'll have to change the "RE"s,not so nice I'd say.


Volkers values for 11 steps worked very nice for me,I just "added" a 12th position.
Maybe this switch is availabe as naked so without resistors?You could use your own values then.
I think there's a formula to calculate them somewhere,I thought I had seen it in the Neumann V475-2C manual(?),maybe Volker can tell us.....


Cheers,


Udo.
 
Back
Top