Neve 1073 schematic wrong!

In studying the 1073 schematic I thought something was wrong!!!
The BA211 pcb has 8 positions for switched pot but on the main schematic it only shows 7?
I’ve got the frequencies as 360hz, 700hz, 1.6khz, 3.2khz, 4.8khz, 7.2khz.
Along with the off position that’s 7, what frequency is the 8th and why is the schematic wrong!!!!!

it seems that the U connection on the BA211 is not used?

BA211

ive got the BA211 on the main 1073 all pack, that link dont work btw.

Should work now!

Thanks tekay, makes more sense now, will change my wiring.

According to the manual the 10kHz position was used on the 1078 channel amp.

If that 8th position is 10k what is the high eq frequency? 12k?

I have built some 1073 Neve type EQs where the MF selection has 8 positions and some have 7. The 8th position in my experience has always been 10k, but that of course can be changed to your liking. The HF shelf is 10k with the values shown on the schematic. You can use the HF section from the 1084 if you want and make that selectable as well (10k, 12k , and 16k I believe). I had some boards made for this very purpose to use with some 1073 builds.

It may seem odd to have 10k for both MF and HF, but remember the HF is a shelf and MF is a peak, so the different behaviors will yield differing results even at the same frequency. Again, these values can all be changed to suit one's preference.

Thanks!

Paul

Yeah I like the idea of having a peak and a shelf.

a bit late to the party, but just wanted to also confirm that the BA211 in the 1073-fullpak.pdf has some errors in it. The one from TeKay has the correct wiring. There's also a third version, which you can find in the Neve_1073_1084_User_Manual_Issue5.pdf (p.28) that has a 220k resistor in parallel. Unfortunately all schematics are missing the inductor values:

T1530
2H - 100nF
1.1H - 47nF
0,45H - 22nF

The T1280 inductor is only connected at the 0.2H tap, the remaining taps aren't used in the 1073.

Well I’m having an absolute nightmare with this!!!
All this misinformation, I don’t seem to be able to get a waveform through the gain stages when just testing them?
But when I then rout them in the chain I get a signal through them??
So far I have managed to get a signal into the b205, the signal is pretty similar to output going into the b205 but way down coming out and this is also when It’s put into the gain stage C to E?

Think I’m gonna need to speak to someone who has actually managed to make a working 1073 with LF, MF, HF and HPF.

All words of wisdom welcomed!!!!

So on the 211 board I may have made a mistake then, I have the 2H to the 100nf, the 1H to 47nf and the 450mh to the 22nf.

The 2.7k should go to the start of the winding?

And the 200mh goes to 10nf - 1n2 right?

Spencerleehorton said:

So on the 211 board I may have made a mistake then, I have the 2H to the 100nf, the 1H to 47nf and the 450mh to the 22nf.

The 2.7k should go to the start of the winding?

And the 200mh goes to 10nf - 1n2 right?

Click to expand...

I've got to admit that I've never worked with real inductors ;D But that sounds about right to me.
What might help you troubleshooting: you should be able to just use an OpAmp instead of the BA284 board.
Connect the inverting-input and output to your EQ circuit and the noninverting input goes to ground. Something like an LM358 might not give great performance, but it can run from a single supply up to 32V.