2254C build/support thread

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Igor

Well-known member
Joined
Jul 17, 2006
Messages
2,193
Location
Israel
Hi guys!
Here will be posted info for 2254C builders.


Will try to help when have a free time minute ;)

I can't care for any damage if you going to kill somebody with this thingy,
electricity shock, etc.

Short history: after building some 33609 units, came a mind to
use 2254 make-up amp with 33609 sidechain, add instead of limiter
attack control and sidechain 2nd order hi-pass filter.
After all... Sounds really nice, very usefull compressor.

1.jpg


The build manual from Reanimatorstudio:

http://twin-x.com/groupdiy/thumbnails.php?album=409

Photos:
http://i251.photobucket.com/albums/gg291/diy33609/P1000120.jpg
http://i251.photobucket.com/albums/gg291/diy33609/2.jpg
http://i251.photobucket.com/albums/gg291/diy33609/3.jpg
http://i251.photobucket.com/albums/gg291/diy33609/4.jpg
http://i251.photobucket.com/albums/gg291/diy33609/5.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000040.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000043.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000049.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000051.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000118.jpg
http://i251.photobucket.com/albums/gg291/diy33609/P1000115.jpg

Please visit here:
http://www.groupdiy.com/index.php?topic=36955.0
for great info

Schematic for reference:
(right-click, save-as...)

http://i251.photobucket.com/albums/gg291/diy33609/schem-1.gif

Most part numbers are same as on Neve drawings for reference.

Errata: still nothing. If mistakes will be found, look here.

Schem description:

coming soon

Test proc:

coming soon

Internal wiring:

coming soon

PCB parts placement:

http://i251.photobucket.com/albums/gg291/diy33609/pcb_main.gif
http://i251.photobucket.com/albums/gg291/diy33609/pcb_fp_top.gif
http://i251.photobucket.com/albums/gg291/diy33609/pcb_fp_btm.gif

Power supply:

http://i251.photobucket.com/albums/gg291/diy33609/ps.jpg
http://i251.photobucket.com/albums/gg291/diy33609/POWER_SUPP_33609.gif


BOM:

http://i251.photobucket.com/albums/gg291/diy33609/BOM1.gif
http://i251.photobucket.com/albums/gg291/diy33609/BOM2.gif

PCB's and kits ordering:

http://www.groupdiy.com/index.php?topic=29771.0

Cases:
Purusha did an excellent desin, for my taste.
http://www.groupdiy.com/index.php?topic=32647.0
 
Purusha said:
Wow, those red LEDs look really good!!!

Thanks for the front panel drawings Igor. Will put up my offer for the 2U cases in next few days.

Nice work as always  ;)

Are you not planning on offering 1U cases? I think a few people may prefer 1U's, even if building a pair (I know I would).

Matt
 
Sorr said:
What audio transformers are you using?

From Igor's previous posts:

Trunny options are:

Input: 10k:2k4 (31267, TF10016, OEP262**, etc)
Interstage: 1k2:5k (10468, TF10015, OEP262**, etc)
Output: gapped 200:600 Ohm (LO1166, etc).

Yes, schemo says "optional", because I had to draw these trunny's on schematic to layout them on board.

PCB has options for Beclairs, Marinair/StIves, OEP. Output trafo installed out of board. Other types of input/interstage trunny's can be used as well, there's 5 pin Molex connectors for this purpose on PCB. Same as in 33609 project.

From my experience, best subs next to Marinair/Ives are Carenhills and TF10015/6. OEP sucks, otherwise you want ugly distorting box.

Cheers

Matt
 
Hi Igor,

I'm starting to collect parts and have a few BOM questions.

Just a quick question about the BC184's, if memory serves me correctly Neve used BC184C's in certain stages on the B183/B283 boards because they needed high HFE's to curb noise issues. Did you use undesignated BC184's in yours or a B or C version? the BOM or PCB overlay doesn't seem to indicate any specific designation.

RE the Tant caps, one says 10m, one says 47u, am I guessing correctly in that they are both uF (microfarad) values?

Also I'm confused about the ceramic values, the 6 pieces that say 0.1..0.22U? I'm trying to follow the designations but it is fairly confusing... for example I'm looking at the schematic to back trace them and the one value CB6 seems to say CB6/C3/224/100m? Care to decipher that for me, Hah Hah!

Thanks again for this great project.

Cheers

Matt
 
Hi Matta!

Just a quick question about the BC184's, if memory serves me correctly Neve used BC184C's in certain stages on the B183/B283 boards because they needed high HFE's to curb noise issues. Did you use undesignated B184's in yours or a B or C version? the BOM or PCB overlay doesn't seem to indicate any specific designation.

Quick answer: BC184C, possible to use BC109C. Pinout EBC.

RE the Tant caps, one says 10m, one says 47u, am I guessing correctly in that they are both uF (microfarad) values?

Yes, they are in microfarrad. 10uFx(16..25V) and 47uFx(16..25V).

Also I'm confused about the ceramic values, the 6 pieces that say 0.1..0.22U? I'm trying to follow the designations but it is fairly confusing... for example I'm looking at the schematic to back trace them and the one value CB6 seems to say CB6/C3/224/100m?
These are ceramic power supply bypassing capacitors. They just should present, value in range (47nF...0.22uF),
5mm pitch 50V. CB6 is bypass ceramic cap, C3 is 100uF (25...35V) low ESR 'lythic.

Thanx for pointing on this.
Hope now all is clear, if there's another questions, feel free to ask.
 
Igor said:
Thanx for pointing on this.
Hope now all is clear, if there's another questions, feel free to ask.

All clear, and as always, thank you, will bring more issues/confusion to light if they appear. I thought this would be the best place to post so we can keep the threads clean.

Cheers

Matt
 
bradb said:
Can we talk a bit about these trannys?

Trunny's are:
-line (31267 or substitute) qty1
-mic (10468 or substitute) qty1
-gaped output trunny (1066 or sub') qty1.

Brands, sources, costs, sounds?  Especially for those of us in the good ole US of A... ;)

Brad,

All those numbers above are the original Neve tranos made by Marinair/St Ives.

The closest thing these days are the Carnhills and your best bet to get em, unless you arrange a Group Buy (do able, but NOT fun!), is through Colin (Slenderchap). Costs are not cheap (though Colin's prices rock!). I think you are looking at +-100 British Pounds for a set ex shipping/duties.

You can find them on Colin's site here: http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html

The model numbers there would be:

-line VTB9046
-mic VTB9045
-gaped output VTB9049 (though there are other options with fly leads, lower profile frames etc).

RE sound, they are prob as close as you are going to get to the originals, thick, velvet like tones, beefy lows, somewhat muddy mids and a beautiful airy top end (at least my personal experience, YMMV).

I hope that helps, but really think these questions should be asked in the help thread to keep things clean, I'll post my response there as well.

Cheers

Matt
 
Igor...
I am new to the group and haven't had the time to read the entire thread regarding the 2254 build project.
Very interested in obtaining a full kit if available. I have a real 2254E in the studio, but building one would be a real blast. What do I need to do and how much in US dollars? If you could PM the details for payment etc, it would be appreciated. Outstanding job by the way!
Billy Yates
 
SIXTYNINER said:
HEY IGOR,
possible place carnhill transformers as in the original 2254, or your project require
bell transformers?
the stereo kit you supply include pcbs+parts for 2 channels?
(interested to stereo kit with psu pcb)
thanks in advance
6T9R

Yes, it is possible, the boards accept multiple transformers, please read my post above that I quoted from Igor. The info it posted right here  8)

Cheers

Matt

 
ok, looks like $337 for a stereo set of trannys from carnhill..

That's not as bad as I was expecting...  I know Igor gives a big thumbs down for the OEPs, but I seem to remember people liking them in other posts.  Anyone care to comment?
 
Hi Bill,
I am new to the group
Wellcome, this is most friendly place IMHO over the net:)

and haven't had the time to read the entire thread regarding the 2254 build project.
Very interested in obtaining a full kit if available.
Hey, but anyway, please try to read all this unnecessary stuff, just to save your and others time :)

I have a real 2254E in the studio, but building one would be a real blast.
This is a bit different compressor, better to say, very close to 2254 soundpath,
and 33609 sidechain with some upgrades and addings as well. I will be happy to know
your impressions after comparing 2254C to Neve 2254E :)
IMHO, usefull :)

What do I need to do and how much in US dollars?
If you could PM the details for payment etc, it would be appreciated. Outstanding job by the way!
Billy Yates
Thank you!
For orders:
http://www.groupdiy.com/index.php?topic=29771.0


In case you need help with building the unit/troubleshooting, ithis is the thread.


 
What OEP's can be used to substitute the 31267/VTB9046 and 10468/VTB9045?  I've been looking at the usual suspects around here, but the impedances look off compared to the St. Ives/Carnhills. 

$350 for Carnhills hurts.
 

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