Neve 2254 rewire

[richiyobs]

A Quick search online...
It should be R16 270ohm
J connection Is for release

 

[Spencerleehorton]

Yes would helps thanks as I’ve had a nightmare with this from the start!!
But hopefully I’ll figure it out!!
I think most of my problems are because that R16 270R isn’t there as the lorlin pot isn’t connected I half bet that when I connect it, it may spring into life!!

 

[richiyobs]

Since your build Is 1:1 with the original design... Can you share any voltages values?
For example CV out and Interstage tfx to sidechain?
So i Will check mine
Best

 

[richiyobs]

the first attachment is from simulation, with also the limiter section
the second one has only the compressor part, it s the version i would build
i did it just for learning purpose... so i could update my diode simple bridge comp, dsb48

best

 

[Spencerleehorton]

Here are my voltages on the ba185 pcb

I’ve tested signal from interstage txf to output and it’s fine.
And meter seems to work on input but not on GR and output?

So I’m thinking it’s the ba185 which is faulty?

 

[Spencerleehorton]

Do I replace the 270R resistor with the other resistors on the attack lorlin or do I leave the 270R resistor in there?
At the moment my attack lorlin has 2.7k, 2.2k, 2k, 1.8k, 1.2k, 1k, 6 steps but 270R isn’t part of the steps? I’m assuming it should be?

 

[richiyobs]

ba185 should be the detector limiter part that is sending signal to meter driver if i m not wrong, but it also has the diode-vca part so signal path.... if you don t have the limiter you ll use only the vca part
and so no Gr on meter, that s why i ll not use ba192 ppm-meter but an alternative solution to monitoring Gr with no limiter section
the only wiring i see from out board to meter is point R in ba283, check that point from R31 going to trimmer and then to meter selector

270R is the faster attack position ... so it s your choice to have it on a lorlin step or leave it on the pcb... for easy of wiring i will use it on lorlin
there s another 2254 version that uses a shorter or longer fixed attack and different values on release maybe it s the 2264 model, don t remember, not so important....

best

 

[Spencerleehorton]

So looking at ba283, F is the signal output for the meter output pot, which feeds the limiter, I’ll feed the signal into F and see if I get the signal through.

As I said before I’ve fed signal into ba185 and only get small signal on output so something is wrong with the ba185 that’s why I’ve posted the voltages.

 

[Spencerleehorton]

I will document all voltages from all pcbs today as this will help find any faults hopefully!!

 

[richiyobs]

What about point U on ba185?
The signal that feeds the limiter sidechain comes from a part of ba192 then to tfx4... There are any trimmers...
I really don t Remember but with all boards schemos and the entire block/wiring diagram It s more Easy to understand all the flow....
I believe that ba192 amp part Is the feedback from output to limiter dtektor...
So if you don t get the proper level the limiter wont work...
Is your limiter working or do you get only compression?

 

[Spencerleehorton]

I don’t get compression or limiting, this is what I’m saying, I’ve tried inputting signal into U on ba185 but get very little signal out on R of ba185 into U on ba283?

I almost need to simulate like what you have done to get ruff voltages to see where it’s going wrong, would help a lot to fault find the ba185.
Trouble is I’m rubbish with sim apps!!

 

[Spencerleehorton]

I’m using bc184C and BC214c and 2N1711 or 2N3053 I have to try if needed.

 

[Spencerleehorton]

I want first to get signal through without compression or limiting

 

[richiyobs]

i can send you my sim.... just replace opamp buffers with tfx model and also any bjt, you can safe time...
in my case i just setted levels with opamps to get both compressor and limiter sidechain works
that s why i was asking you voltages at sidechain input
or if you have time i can share my kicad pcb, it is divided into 2 boards using 500 format template but different pinouts respect to Api just to connect the 2 boards .... simply put tfx instead of opamp...
as i said i only drawn it, last spring time, but never had time to etch and build a proto

 

[Spencerleehorton]

I think it’s possibly blown diodes on this ba185? All signal inputting after it checks out.
Yes if you can send me what you’ve got I can have a play, thank you

 

[richiyobs]

Ok... Just the time to find the right folder on pc

 

[Spencerleehorton]

i have input signal into U on ba185 and i get signal now on output!!
no compression but limiting does seem to sort of work, even though the limit level pot has to be maxed out one way or else its just noise?
seems my input txf is killing the signal some how?
This is really weird?

 

[Spencerleehorton]

weirdness continues but i am getting 4v out now with output maxed and im putting in 5v signal.
threshold control does nothing?
when i adjust attack, release or limit recover it compresses waveform?
limit level control does nothing?
limit switch when i switch it in, loads of noise appears on waveform?
meter seems to work on input, still a bit pinned on GR and nothing much on output?

have simulated all pcbs in LTspice now so have some voltages to compare.
3 transistors on ba192 look weird and 3 on ba191 so will change and see if improves.

 

[Spencerleehorton]

 

[Spencerleehorton]

My question now is do these voltages look about right?
Also I know the zener diode is in a different position on the ba191 which I will move, as per DB54 build, its correct on my boards but I know DB54 build has said the Neve schematic is wrong? Just wanted to verify this?