DB54 - 2254 style compressor {update 22.10.19}

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dirty1_1garry

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Hello!

This thread about DB54 diode bridge compressor.
It's based around Neve 2254 but not a blind clone.

It's available as diy kits for those who are interesting in building their own compressor:
kit  contain BA185, BA191, BA283 boards, board for joining BA cards, face board for switches and 24V psu board.

More info:
https://www.diystudiotoys.com

Some additional info here:
http://wiki.diyrecordingequipment.com/projects/garash-db54-diode-bridge-compressor/

Build info here:
http://bit.ly/2dLli43

Progress:
12.06.16 - topic start
21.09.16 - first run, check Reply #41 for video!
05.10.16 - fully calibrated and works as it should, check Reply #48 for more info.
10.11.16 - samples added! Check reply#71 and #73
25.03.17 - assemble gude added. Check reply#126 and further
12.10.18 - 9 kits left from third batch
22.10.19 - we start to order 4th batch of DB54




----------------------------------------------------
PRIMORDIAL THREAD:

As a couple years ago I was really inspired by original 2254,  I've started to explore its schematic and construction. Now, after about 8 month of lazy processing I've got some results that I hope very soon will be materialises in to the real piece of gear!

During my explore I’ve decided to get best from vintage, save mojo approach as possible, extract some not useful function and add some additional options multiplied by modern approach.

And here is what I’ve got:
- first of all I’ve recreated original BA cards - 185, 191 and 283, I hope that save some vintage “mojo”. Using same 18pin connectors give possibilities of using vintage cards that sometimes can be found on evilbay.
- one mono unit will feat into 1U
- limiter function was deleated, compressor only
- all wires between BA cards was replaced with pcb
- additional variable attack times (original has fixed on 5mS)
- additional faster release times
- meter off switch. Yeah, that's my own freaking function. It stay compressor in action but turn off the gain reduction meter. It let me concentrate on the sound and hearing it with ears not eyes))
- relay bypass

Unit will need three transformers (31267, 10468, 1166), three BA cards - 185, 191 and 283 and outboard power supply.


47634-120516042148.png

47634-120516042215.jpeg
 

dirty1_1garry

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Spencerleehorton said:
You going to use lorlins?
And when are the pcbs available you hope?
Also am I right in thinking the limiter function  can be added?

Regards

Spence.

- Yes, I'm going to use lorlins rotaries for attack, release and ratio. They are good enough for that purposes. For threshold and gain make up there will be potentiometers.
- pcbs will be available after that moment when I will test prototype. All components are on order, so when they will arrive I will move forward
- Are you sure that it's useful?) I asked a couple folks who use 2254 a lot, all folks sad that they never use limit mode so I decide to remove it. But in future that's possible to add it (it will add one more BA cards and one more transformer)
 

Spencerleehorton

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yeah,
just like some of the neve stuff ive built you can omit what you dont want.
Im happy to build and test one if you have any other pcbs going and i dont mind paying, msg me if you wanted, as i can build the transformers as well, i can print out the 283 pcb as i already have that the 185 and 191 i dont think i have but could mock them up easy enough, would just need the front panel pcb and other.

regards

Spence.
 

dirty1_1garry

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Spencerleehorton said:
yeah,
just like some of the neve stuff ive built you can omit what you dont want.
Im happy to build and test one if you have any other pcbs going and i dont mind paying, msg me if you wanted, as i can build the transformers as well, i can print out the 283 pcb as i already have that the 185 and 191 i dont think i have but could mock them up easy enough, would just need the front panel pcb and other.

"as i can build the transformers" - tell us more!)
I should test and after that moment I can supply you with pcbs, that's no problem:)
 

Rocinante

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That looks slick. I too am anxious to see how this turns out and would also like to hear more about Spencer winding his own xfmrs...
How do they compare to say.... carnhill or mariner?
 

dirty1_1garry

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I had a little bit of experience in comparing Neve'sh transformers. I've compared input and output Marinair, Carnhill, Cinemag, EA, Sowter between each others. And that would be cool to hear Spencer ones!)
 

nielsk

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Looks like an innovative assembly approach to what Chandler used to do (2254 with limiter deleted built from BA cards)
I have hand drawn notes on the Chandler interconnect of the BA cards and switches if needed...
 

dirty1_1garry

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Messages
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nielsk said:
Looks like an innovative assembly approach to what Ch*ndler used to do (2254 with limiter deleted built from BA cards)
I have hand drawn notes on the Chandler interconnect of the BA cards and switches if needed...

I have same drawing too :p when I had an experience to repair one. But I did not try to blindly clone it, I've just used that information as a part to build my version of 2254 :)
 

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