Neumann eqs: W495B = PEa?

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synthi

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Joined
Jun 9, 2004
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Hi People,

Those eqs have similar front panels. Do you know if they are the same eq?
I weas thinking the PEa would be a passive version for the 495b?

Thanks,

Synthi.
 
[quote author="synthi"]Hi People,
Those eqs have similar front panels. Do you know if they are the same eq?
I weas thinking the PEa would be a passive version for the 495b?[/quote]

the PEa and the W495b are the same, PEa is just the older name. I'm not sure if it's exactly the same schematic, but they are compatible for exchange in the old Neumann Mixers. the PEa is not passive (I've two of them).

the schematic for the W495b you can find here:
http://www.silentarts.de/lab/studiotechnik/neumenn/W495B_Schematic.pdf
 
in case anyone's still interested:

PEa and w495b do differ significantly in circuit design. they both are xformer in & out. PEa has less active stages, no input buffer, and a passive RLC-stage for the mids, followed directly by the output stage, which is a neumann OA10 discrete op-amp. w495b has more active stages, different design for the shelvings, a (probably gyrator-based? CAPS?) mid section with RC only, followed by a proprietary discrete buffer amp, plus a symmetrical (!) discrete output stage which drives either leg of the output xformer.

that said, it should be likely that both models sound more or less different, too.
 
I`ve found the neumann PEa here:

http://www.irt.de/IRT/publikationen/braunbuch/PE.PDF

I still need to check it but there seem to be identiocal to the W495...

Best Regards!

Synthi
 
Does anybody have experience with fixing the 495b?

I have one in pieces that won't pass audio. When I first gave it power it didn't seem happy. I read a comment by Olly that they are touchy about
hook up and the output section fails. This one came from a non-tech
fellow who got it from who knows where . It must have been tried connected to a non-floating input or maybe wrong power hook up.

I've confirmed the pin outs and checked for shorts. I have yet to organize a good set up for powering up while it's apart .

Lance
 
Did someone ever DIY one of those? (a 495b that is)
It looks like a nice DIY project altough I don't know if there are some hard to get parts involved (the ic HA1-4605/4741 maybe?).
What makes this EQ sound the way it does? special in/output transformers?

I've only build a SSL and a 1176 clone so maybe this is a little to much for a newbe like me. On the other hand, the circuit is not too hard to understand and can be done on prototyping pcb I think...
 
[quote author="kubi"]Yes, the two differ, w495b sounds better IMHO
W495b is Neumann's best EQ. Actually, it's the best EQ ever.
.[/quote]

My Neumann sp75 desk has "oev" eq's (not the duo versions).

anyone know the sonic differences between the w495 and these? I like mine very much-but it crossed my mind to pick up a pair of 495's if they offer a significantly different "flavor".

Erik
 
[quote author="extraware"][quote author="kubi"]Yes, the two differ, w495b sounds better IMHO
W495b is Neumann's best EQ. Actually, it's the best EQ ever.
.[/quote]

My Neumann sp75 desk has "oev" eq's (not the duo versions).

anyone know the sonic differences between the w495 and these? I like mine very much-but it crossed my mind to pick up a pair of 495's if they offer a significantly different "flavor".

Erik[/quote]

yes, I got some OEV 930s coming: they run on AC 15V! No ICs (Spulenkerne) and those same opamps. They are from 1972. Do I have to replace caps? How is your desk Erik? You care to post some pictures? I didn't get them yet (next week), so any info would be great. The seller promised me schematics.... REALLY looking forward.
 
Dear Folks,

I got 4 of those Neumann's OEV eqs. 3 of them are working fine, sort of. But one of them has no audio passing through. The others are working but have very different responses, so no stereo operation allowed, phase goes a bit weird, even when they are flat eq'ed...
I tried to reach Neumann for schematics, they sent me to AudioSonics in german but they don't have anything either. Does anybody has those schematics? I would be really happy if anyone could help...
I'd be glad to pay for them!

Best regards!

Gabriel
 
I sent you a schematic that says PEV 930 (sorry no server available, PM me if you want it too...)
don't know if it is the same.
I have two OEV 930 here did not test them, they run on 15 V -/+ instead of the normal 24V DC for the rest of my stuff, and I just recovered from a hernia.. phew :cool:

hope you can do something with it...
cheers,
Reptil
 
Hi Darius,
sorry I was coming to that, I feel like an octopus right now, following 10 ebays, mixing a song, checking schematics, and drinking coffee while watching Ghost in the shell, stand alone complex season 1 again (for the 6th time), so a bit slow but here they are (check your inbox)
Glad to be of service to you guys, Knotenpunkte im Schaltpläne Land!
cheers,
Reptil
 
Dear Repitle,

You're the greatest! Just received your PEV schematic, waiting anxious for the OEV one.
The guy from Audio Sonic didn't have the schematics but could tell me that it was +-15v. so I already did a PSU and racked them. Man, they sound sweet!

Best regards,

Gabriel
 

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