Neve 2254 build with ba185, ba191, ba192, ba283

[Spencerleehorton]

My inbox is empty now but anyone can email me:

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[Rob Flinn]

reason why , most .. 54 diy projects are " limiterless "  ?  :-[
cheers

So in reality they're not really 2254 projects.    Almost everyone says the limiters are no use.    I find them very useful.    They are great to use on the way in to stop overloading convertors.      People always say you can't push the limiter, but these people haven't studied the circuit.  If you look at the 33609 the limit sidechain is taken after the make up gain & the compression is before it.    If you crank the make up gain you can get the limiter wheezing.

 

[Rob Flinn]

Any ideas on the F to P connection?

On the diagram you posted it is fairly clear that F is the unbalanced connection from the BA283 whohc connects to pin P on the connector on the back of the 2254 case.


You need to remember that all the boards have pins with the same lettering as the overall connector on the back of the 2254.  Look at the attached list to tell you what the rear connector pins do

 

[r2d2]

So in reality they're not really 2254 projects.    Almost everyone says the limiters are no use.    I find them very useful.    They are great to use on the way in to stop overloading convertors.      People always say you can't push the limiter, but these people haven't studied the circuit.  If you look at the 33609 the limit sidechain is taken after the make up gain & the compression is before it.    If you crank the make up gain you can get the limiter wheezing.

i'm more than fully with you !!!
( ...they do not know…..)

i use limiters anywhere i think it can give me something more ,  and  for various different cases…
( …  include bad musicians.. band..)

33609 (when available on rack…) saved my "life" many times …

since own an  original unit require a life bank loan … ,
a serious "54" with limiter  diy project will be a so cool "rainbow" …

cheers

 

[Spencerleehorton]

Well for me the limiter will happen, I just need to wind another txf and then make the other connections and switches.

I had a wire come off C to H so that’s why I wasn’t seeming compression!! Now compression is fine, still no meter level on input and output?
Signals going in at about 620mv my scope is saying but needle doesn’t move until I up the signal to at least 1.3v? So the 100k trimmers for adjusting the input and output level are just set to flat out!!
I can get loads of GR but why such low levels for input and output?
I’ll start to put it in case now and then put some audio through it and see what it sounds like!!
I don’t think I’m quite home and dry yet!!!

 

[Spencerleehorton]

From what I can see my problem lies with prog meter section.
The B feed fr b185 is fine.
So when I switch meter switch to input or output the level is too low this can only be Prog meter.
Will check signal through transistors to output B on b192.
Hopefully I’ll see something here and all will be fine.

 

[Spencerleehorton]

At work today but changes I made to b192 are bcy70 , I used a bc560c, it’s PNP and fairly close in spec, would this be a problem?
I will get a couple of hours in the morning to go over voltages and trace the signal, hopefully I’ll find a transistor is blown or cold solder joint, or possibly an error in where I put a component!!

 

[Spencerleehorton]

Success!!! Was one 2.2k on the first transistor on b192 which I hadn’t put down to gnd!!
Input and output metering works great now and all looks fine and dandy, now to put it all in a case and see what it sounds like!!!

 

[Rob Flinn]

Success!!! Was one 2.2k on the first transistor on b192 which I hadn’t put down to gnd!!
Input and output metering works great now and all looks fine and dandy, now to put it all in a case and see what it sounds like!!!

Well done Spencer.  You will like this compressor they sound really good.

 

[r2d2]

Well done Spencer.  You will like this compressor they sound really good.

+ 1 ( and loud) here
cheers

 

[Spencerleehorton]

ok, well i've put audio through it today and it doesn't sound that great!!, i suspect its the chameleon labs transformers i've used so i'm going to wind my own and then see how it sounds and compare.
Getting a fair bit of not nice distortion, could be a grounding issue? will see, it still isn't in a metal case!!! oops!!!

 

[Rob Flinn]

You shouldn't be getting any nasty distortion from the 2254.

 

[Spencerleehorton]

it seems pin 2 waveform is low and pin 3 waveform ok?, again this might be the bias but i need to find out where the distortion is coming from?
when i bypass the compressor the bottom end comes back in, so something isn't right, its compressing well though!!!

 

[Spencerleehorton]

I think I need to find out why waveform is fine on one side (+) but not on the other (-)?

 

[Spencerleehorton]

Something is either wrong with the 185 or the 283 pcb I think, im getting the same problem i had before from the F output of 283, the waveform is chopped off and now im not seeing the meter work on GR but fine on input and output?
Im still getting compression just not showing on meter?

There is a lot of noise in the signal and i cant see where its coming from?
going to just build the 185 and 283 pcbs and see if i can get no noise and clean waveform on output!!

 

[Spencerleehorton]

Put both pin 1 to 0v, compression is back on meter again!! Dry joint on 10k B output.
Bias pot adjusts waveform symmetry but when at 23v waveform is cut in half, at 18.3v waveform looks good, only thing is at 18.3v the 47R gets too hot and turns brown! 

 

[Spencerleehorton]

just found my mistake!! R6 on 283 i'd put in a 100uf!! rather than a 18k resstor!!!!

works great now and no noise!!!

now im going to put in case and start building channel 2.

 

[Rob Flinn]

just found my mistake!! R6 on 283 i'd put in a 100uf!! rather than a 18k resstor!!!!

works great now and no noise!!!

now im going to put in case and start building channel 2.

We've all done something like that ! haha

 

[Spencerleehorton]

I have to say this compressor sounds amazing!
Really big and fat, audio just sounds plain when it’s in bypass!!
I’m very happy indeed, just need to put together the other channel, wind some transformers and then put together another couple of 1290 then I’m done for diy for a while, need to record stuff!!!

Thanks guys for all your help.

 

[SIXTYNINER]

Made them myself from photos, have done quite a lot of that sort of thing before, I find it quite easy now.

nice job , well done !
have you some link where get  the cards "photos" ?
cheers