Neve 10x1 Audience Reaction Mixer?

[ruffrecords]

yes that would be a good way to go. The one you're thinking about buying looks like the 10468 were harvested and they replaced them with whatever 30267 they had in their parts drawer

I think you mean 31267.

Cheers

Ian

 

[ubxf]

yes you are right, i was quoting from the listing and didn't notice the error.
In your experience is the 10468 a must or is the 31267 wired backwards close enough.

 

[ruffrecords]

yes you are right, i was quoting from the listing and didn't notice the error.
In your experience is the 10468 a must or is the 31267 wired backwards close enough.

The 31267 is normally wired 4:1 to make it 10K:600 whereas the 10468 is normally wired 1:2 to give 1K2:4K8. But you can wire the 31267 2:1 so turning it backwards should work. I don't think that was ever done at Neve but that does not mean it would not work. The transformer of course has no concept of input and output.

Cheers

Ian

 

[ruffrecords]

A3559 is the Neve job number. I can try to find out what is was and for whom. However, I have a feeling may may be just a small part of a very big project. Back in the mid 70s Neve built several enormous mixers for NBC for the Olympic Games and an audience reaction mixer was a likely subsection of each of them.

Cheers

Ian

It turns out that A3559 was one of three 32 channel TV consoles made for CBS in 1975. Apparently CBS sere still using a 150 ohm termination to define 0dBm so all the outputs had to be capable of doing this. It was this that spurred the change to using dBu instead of dBm at Neve. Here is a little video from Rupert.



Cheers

Ian

 

[Golgoth]

@ruffrecords Thanks a lot for all the interesting informations about that piece of gear.

I am still debating buying it, 10 vintage Neve preamps in a 1U 19" rack is very very tempting! I don't mind too much about no pad, phase or HPF tbh.. But there is still a bit of work to do to get it where I want it : stereo output.

@ruffrecords What would be your technical advice about this restoration? I am wondering about which output transformers to add to the output stage, I don't want to keep VTB1148s and would like to get that box back to its former glory if that makes sense.. I have read a comment of yours about the VTB2281 being better? What about a vintage one if you have a candidate in mind?

Also, would making it stereo by replacing the output pot with a stereo one and adding another B183 amp card + output iron be a doable job with the actual +24V PSU?

 

[ruffrecords]

@ruffrecords Thanks a lot for all the interesting informations about that piece of gear.

I am still debating buying it, 10 vintage Neve preamps in a 1U 19" rack is very very tempting! I don't mind too much about no pad, phase or HPF tbh.. But there is still a bit of work to do to get it where I want it : stereo output.

From looking at the Reverb listing this is almost certainly a line level preamp. The 31267 transformer is a line in transformer normally wired 10K:600. This also explains why there is no pad or phantom power. In addition, each channel has a simple rotary level control. If you connected the 31267 transformers backwards wred 1:2 you would have a mic pre with 18dB of gain - not a lot of use. So you would need to increase the gain of the BA338 with an external resistor perhaps in the form of a rotary switch or pot.

@ruffrecords What would be your technical advice about this restoration? I am wondering about which output transformers to add to the output stage, I don't want to keep VTB1148s and would like to get that box back to its former glory if that makes sense.. I have read a comment of yours about the VTB2281 being better? What about a vintage one if you have a candidate in mind?

Also, would making it stereo by replacing the output pot with a stereo one and adding another B183 amp card + output iron be a doable job with the actual +24V PSU?

In addition to the changes mentioned above to the preamp you will need to add pan pots and an extra bus amp and output transformer. Also, since the mixer about 45 years old you would probably to do a complete recap. Sounds like a lot of work for an unknown benefit,

Cheers

Ian

 

[Golgoth]

From looking at the Reverb listing this is almost certainly a line level preamp. The 31267 transformer is a line in transformer normally wired 10K:600. This also explains why there is no pad or phantom power. In addition, each channel has a simple rotary level control. If you connected the 31267 transformers backwards wred 1:2 you would have a mic pre with 18dB of gain - not a lot of use. So you would need to increase the gain of the BA338 with an external resistor perhaps in the form of a rotary switch or pot.

In addition to the changes mentioned above to the preamp you will need to add pan pots and an extra bus amp and output transformer. Also, since the mixer about 45 years old you would probably to do a complete recap. Sounds like a lot of work for an unknown benefit,

Cheers

Ian

Thanks for the input Ian.

I am actually quite fine with the box being full of T1452 line irons, I would maybe only swap two for T1444 mic transformers. Hence me being not too worried about not having pad, polarity etc..

I had the adding bus amp + output transformer part in mind, but not too sure about which output transformers to use as I would like to source two vintage ones. I had also mentionned not adding pan pots but hard wiring individual channels to L/R busses not to mess with the front plate for now. That simplifies a lot if the work I guess.

To you tho, and that's the most important part: the actual circuit design would not sound good enough to bother with all these modifications? I was hoping to get the Neve sound from what is already in the design. Input transformer > opamp > bus amp > output transformer..

 

[ruffrecords]

As it stands you will definitely get the classic Neve class A sound. Adding another BA283 will allow you to split the channels into two groups without altering the front panel. The 3A PSU should be plenty power this. The normal output transformer to use with this is the LO1166

Cheers

ian

 

[Golgoth]

As it stands you will definitely get the classic Neve class A sound. Adding another BA283 will allow you to split the channels into two groups without altering the front panel. The 3A PSU should be plenty power this. The normal output transformer to use with this is the LO1166

Cheers

ian

Thanks a lot! I will try to negociate the price with the seller and see if I can source x2 LO1166 for a reasonable amount too!

 

[ruffrecords]

You could ask him which output transformer is in their right now.

Also, looking at the pics on Reverb, it looks like the level knobs can also be pushed in to operate a toggle switch. What does that do?

Cheers

Ian

 

[Golgoth]

You could ask him which output transformer is in their right now.

Also, looking at the pics on Reverb, it looks like the level knobs can also be pushed in to operate a toggle switch. What does that do?

Cheers

Ian

It's a VTB1148 mounted in there, I guess the original output transformer was harvested and replaced.. The buttons are push-pull to mute the unused channels

 

[ruffrecords]

OK. THat all makes sense.

Cheers

Ian

 

[blakeyboy]

That is one strange beast.
2 of the 438's are not there, so it's 8 channel, not 10, and only one of the 438's is original.
It looks like the transformers were robbed out years ago, and they put in what they could gather together.
it looks like the inputs go into the 31267 primaries, so it's wired for line level.
I don't think the 183 board is original.
It's odd to see a class A stage with 438's- most of these mixers had a 489 board with a 438 and a 440 on it,
not this mix. Also- when did you see neve mount a 183 so it's face down? Weird.
I can't see where the 438's mix together- there's a pile of resistors somehwere- most of the little mixers like this were virtual earth.

I have five of the six channel mic mixers, and to give you an idea of what a pain it is to add all the output stages and transformers, the pile of five mixers hasn't moved for twenty years.....

The price is way over what a cobbled together line mixer is worth.
It looks like it's just the price of the parts- ten 31267's bought off ebay wouldn't be cheap now....

 

[FIX]

CBS referred to the 150 ohm reference as "FADER LEVEL" for some odd reason, at API, we did much of the same kinds of stuff that Rupert did, and were grateful for the dBu reference, which made it universal. I seem to remember that the equivalent of the +4 dBu into 150 ohms ended up being something in the order of +8dBm. Most of the broadcast facilities in the US used pretty heavy duty cable, as driving 150 ohms between floors would actually get a drop in level because fo the wire.

I remember when ABC moved from their facility in NY (the headquarters of the three main broadcast networks were within 4 blocks of each other in those days) to the new building, the industry was switching over to stereo, and because of space and the unavailability of the same old wire, they had to run new pairs of wires to do stereo and simply ran out of space. They also needed new studios, control rooms, etc. When they moved, they took the equipment that they wanted, sold the rest and left the wiring for the landlord to deal with... They also walked away from some very custom, cool Neve consoles that were purpose designed for what they needed.

Imagine when you see those rows of racked equipment, that there are big square holes between floors under the racks to the next floor for the wire ways, so removing the racks was impossible. This must have been when someone invented the saws-all!

 

[Golgoth]

@blakeyboy

I bought it after negociating the price with the seller. Got it for way less than the individual parts value (31267s are not cheap indeed, BA438s aren't either, if you find them!). I also managed to find the 2 missing BA438s from an ex-Neve engineer (one of which is an early prototype and was provided with full documentation about what they tried back in the days!).

I wired the 31267s backwards for mic level, and added a second output for more flexibility (stereo tracking, dual mono tracking, summing etc..).

The outputs are now BA183 + LO1166, so the unit is kind of a mix between the 1081 input section and 1073 output section. The individual channels are directly summed into each BA183's input. You're correct indeed that there should be a 489 board on the output instead of a BA183, but as each unit was custom made to order we can't be 100% sure about the fact that they were all identical.

All I can say is that this is an incredibly great sounding unit now!



Cheers,
G

 

[ubxf]

Congrats, it looks like you did bring it back to its former glory. Well done

 

[Golgoth]

@ubxf Thanks a lot!

 

[ruffrecords]

Well done. A great sounding bargain.

Cheers

Ian

 

[Golgoth]

Well done. A great sounding bargain.

Cheers

Ian

Thanks again for your help on this project Ian!

 

[Golgoth]

The only mistake I did was to reinstall the original 10K pots by wanting to keep everything as genuine as possible.

They are linear (as was the original output pot, which I find very strange), fragile and very unreliable. The push to mute functionnality, although pretty useful, has become very sensible and quite often keeps on getting stuck. They also feel terribly soft, I like hard to turn buttons.

I will for sure be replacing them for new A10Ks in the near future.