Neve 2254 build with ba185, ba191, ba192, ba283

[Spencerleehorton]

Think I’m on track now with this build, would like to add adjustable side chain filter at some stage but best to get this going first!!!

 

[Tekay]

Insert a HPF in front of the BA191 buffer, or use a smaller value for C14 (6dB) .

 

[Spencerleehorton]

What schematic are you following? The original Neve doesn’t have part numbers only values? The audio maintenance version has its own numbers?

C14?

 

[Spencerleehorton]

Pcbs nearly done, just a couple of caps and transistors I’m waiting for!

 

[Spencerleehorton]

from looking at Igors 33609 version it looks like i would have to build a complely different VCA and amplifier sections.
There doesnt seem to be a version which uses the 2254 and only uses the compressor section?

Does anyone have a schematic of just the 2254 compressor please?

I should be able to follow what info I have to cobble something together but im by no means a person who understands this!!

 

[Tekay]

What schematic are you following? The original Neve doesn’t have part numbers only values? The audio maintenance version has its own numbers?

C14?

The buffer amp is a part of the  BA191 board. Input is "C" and output of the buffer is "B"

 

[Spencerleehorton]

Hi Thomas,

thanks for you help btw, so your saying if i want to put a HPF it should go after the threshold control and into C on BA191?

Also i have tried to mod this 2254 schematic to show just the compressor parts.

Could you also confirm it is the 270R resistor which i need to replace on BA191 for a series of resistors, its output is to J and to the last BC107 on original schematic.

 

[Spencerleehorton]

I've also notice that on the garamesh DB54 it uses the 270R, 1.2k, 1.3k, 1.8k, 2k, 2.2k, 2.7k as the stepped attack.
On the Igor version it uses 130R, 200R, 360R, 560R, 820R, 1.2k, 2.2k, 2.7k, 3.6k, 5.6k.

there are similarities within the sidechain of the 33609 and the BA191 but I think im better on sticking to the DB54 version as this is what im using.

 

[r2d2]

2254 is coooool device (i prefer with limiter)
cheers

ps:
please make "room" on your pm box

 

[Spencerleehorton]

Email me:

[email protected]

i'll start wiring up everything next week and powering up boards, just build a new setup desk for testing everything, need to update laptop to 10.13 so i can get scope software to work!! nothings easy!!

 

[Tekay]

Hi Thomas,

thanks for you help btw, so your saying if i want to put a HPF it should go after the threshold control and into C on BA191?

Also i have tried to mod this 2254 schematic to show just the compressor parts.

Could you also confirm it is the 270R resistor which i need to replace on BA191 for a series of resistors, its output is to J and to the last BC107 on original schematic.

The HPF should be infront of the buffer, between the L10468 secondary and buffer "B".
I guess the 270ohm sets the attack time, make sure you use a MBB switch.

 

[Spencerleehorton]

For the attack switch is a lorlin make before break?

Just checked my order of the lorlins and it doesn’t says whether it’s MBB or not, so will just have to check on MM!

 

[Tekay]

For the attack switch is a lorlin make before break?

Just checked my order of the lorlins and it doesn’t says whether it’s MBB or not, so will just have to check on MM!

Lorlin has both, MBB = shorting
The standard for pcb are CK1059 and CK1060

 

[Spencerleehorton]

I’ve just put a connection list together, I’m a way off finding the time to complete this project but will slowly start putting it together outside of a case.
Have my digital scope now sorted and work station for testing.
Hopefully get a bit of time this week to sort connections for input into ba184 and into ba283, then I will try and get ba191 involved.
Still slightly confused about how to implement meter without ba192?

 

[Spencerleehorton]

have just measured my VU meters and they are 1/2mA, tested with 10k resistor and put in series with 5v into v meter, needle goes up full scale, if meter had gone halfway they would have been 1mA meters

 

[Spencerleehorton]

started putting together, just a few connections, still trying to suss it all out!!

 

[Spencerleehorton]

need to find out exactly where all the voltage connections for psu are?

is there a power supply schematic?

it doesnt actually show where B+ is on any of the schematics that i can see?!!!

 

[Rob Flinn]

need to find out exactly where all the voltage connections for psu are?

is there a power supply schematic?

it doesnt actually show where B+ is on any of the schematics that i can see?!!!

Just looking at the diagrams in thsi thread logic tells me that B+ is connected to U

 

[Spencerleehorton]

Do you mean that U with the 10R resistor to the output txf?

 

[Rob Flinn]

Do you mean that U with the 10R resistor to the output txf?

Yes.  If you compare it to any other diagram which uses a BA283 it's exactly the same & has the 1250uF cap across it too.