substitute

Re: 2254C build/support thread
« Reply #60 on: May 19, 2009, 10:35:59 PM »
Quote
Thanks Igor

I obviously didnt look hard enough!
I found this for 47n from Mouser: 75-MKT1822347254

here is the updated BOM
cheers

http://twin-x.com/groupdiy/displayimage.php?pos=-3173

Thanks so much for posting that jplum!  I have vowed to finish a few other projects before I start this one but it's cool to get organized.   


jplum

Re: 2254C build/support thread
« Reply #61 on: May 21, 2009, 12:26:33 PM »
No problem, glad I can contribute in some small way

Reminder to verify yourself though!, but I pretty much used this parts list as per the XLS file.

I intend to make 3 changes to the BOM XLS, but havent got round to it yet so will document here to remind me!

1. CZ in BOM is incorrect pitch and needs a replacement
2. CPS"1 (1000 uF) Cap in BOM is Radial. Needs to change to Axial as one in BOM is too tall IMHO
3. C"17 change from Radial to Axial

Just waiting on update from Tat re Case and also Igor for any docs to assist in setup

cheers
« Last Edit: May 21, 2009, 04:55:51 PM by jplum »

jplum

Re: 2254C build/support thread
« Reply #62 on: May 21, 2009, 04:53:57 PM »
Apparently Tat has been banned from the forum, why i've no idea but i guess its not my business to ask  :(
He has kindly returned my email almost instantly with update on shipping of my case.
Not sure what happened but i thought i'd let this thread know, as probably you guys are also waiting on news of case

Re: 2254C build/support thread
« Reply #63 on: May 24, 2009, 05:07:33 PM »
Hi Guys,

Well im stuck already, go to stuff my 1st resistor and i cant find it! lol

im looking for R'19 (1M)

I have found R"19 (820)

I dont remember reading any thing odd about this one or have I missed some thing?

any pointers much appreciated,

Pete

Re: 2254C build/support thread
« Reply #64 on: May 24, 2009, 05:18:04 PM »
Found it!

 ;D

I'm assuming the N/A means we dont stuff it?

Pete
« Last Edit: May 24, 2009, 05:19:41 PM by sinestaraudio »

SIXTYNINER

Re: 2254C build/support thread
« Reply #65 on: May 24, 2009, 05:56:15 PM »
hi
something about this project , somebody else have found similar?
original picture for comparisation with rev 1,4 is this :
http://i251.photobucket.com/albums/gg291/diy33609/3.jpg
« Last Edit: May 24, 2009, 06:01:22 PM by SIXTYNINER »
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

bradb

Re: 2254C build/support thread
« Reply #66 on: May 24, 2009, 06:27:10 PM »
I've got a simple question about the psu.

With the lm317, do I need to have an insulator between it's case and the heatsink?  I plan to solder the heat sink to the pcb. 

TomWaterman

Re: 2254C build/support thread
« Reply #67 on: May 24, 2009, 06:36:15 PM »
I'm assuming the N/A means we dont stuff it?

Pete

There were a few N/A parts, but I think just in the filter circuit, Igor recommended leaving them out.

SIXTYNINER:

Not sure about R41 yet, I think it is Igors output TX termination... but haven't studied that bit yet. I just stuffed a the bits I saw I knew were good. I can't see why it would need to be special from here.

C10 was used in combo with R10 I think to make resonant filter in sidechain, however Igor recommends not fitting these to use standard HPF in SC.

The two parts with * next to them are damping networks for the input transformer to improve square wave response (if thats where your picture is pointing), as far as I can tell they are marked with a * as depending upon whatever iron you choose they may either be omitted or altered for best termination.

It also looks like Igor has used MilMax sockets to allow easy in circuit matching of the diodes. I just used the diodes that came with the kit but if it compresses weird I will go back and solder sockets to allow testing/matching.

I know a few guys who match these for Vf and then spray them cold, heat them up and then test again to find matches that are consistent across temp.

I can't seem to locate C13'2 the 47uF tant on the board, but I have not had time to really search.

My kits seem to be short on 680uF, with a few extra 1000uF caps, also short on 1Meg resistors.
-T

Re: 2254C build/support thread
« Reply #68 on: May 24, 2009, 10:25:40 PM »
Quote
I can't seem to locate C13'2 the 47uF tant on the board,

this one is on the front panel boards, next to com_recovery switch.

In my Cap bag i have a flat black sqaure cap, with a red side on one end, marked with cx16j 476M, any ideas on what this one is?

pete

TomWaterman

Re: 2254C build/support thread
« Reply #69 on: May 24, 2009, 11:29:47 PM »
Hey thanks Pete I hadn't done those yet!

What a twat. Easy miss.

The square flat caps are the very same, 47uF solid tants.

-T


Re: 2254C build/support thread
« Reply #70 on: May 24, 2009, 11:46:00 PM »
LOL these are tricky little buggers arent they!

thanks Tom,

Pete

kambo

Re: 2254C build/support thread
« Reply #71 on: May 25, 2009, 03:50:57 PM »
from 33609 :
4.1. APPLY 0DB TO INPUT. COM OFF, LIM OFF, BYPASS IN, MEASURE OUTPUT IS 0 DB,
CONNECT LINK TO CV 3.00V WITH CROCODILE CABLE. ADJUST RV2 TO GET -8 DB AT OUTPUT....

i assume we will have similar procedure like above on 2254c the monster, too :)

those 0 DB -8 DB means dbm (dbv) ... i can read dbm (dbv) on fluke 187...
am i good ?

matta

Re: 2254C build/support thread
« Reply #72 on: May 25, 2009, 05:02:55 PM »
John (Jplum),

Out of interest what made you settle on the WIMA FKP range rather than the MKS? Also your BOM seems to indicate the pitch of the leads for most of the poly caps is 2.5mm, Igor's BOM seems to show 5mm spacing... I don't have a PCB in front of me to confirm, but assume the 2.5mm fit just fine?

Thanks in advance!

Matt
Matt Allison
www.matt-allison.com

Quote
We are not going to start thinking of ways to get an octopus to commit a crime, cause that just has failure written all over it – Earl J Hickey

jplum

Re: 2254C build/support thread
« Reply #73 on: May 26, 2009, 03:57:55 AM »
Hi Matt

<<<what made you settle on the WIMA FKP range rather than the MKS>>>

I made my decision based on tech data sheet that implied typical applications "Audio Eqpt" and availability at the time of building the BOM. Do you consider the MKS range more suitable (or anu other manufacturer/range for that matter) ? I havent PUP'd yet so cant give you any opinion on audio quality etc but it would good to call out potential issues now.

<<< Also your BOM seems to indicate the pitch of the leads for most of the poly caps is 2.5mm >>>
I think the 2.5 in the p/n referes to tolerence. I believe they are 5mm, certainly for my boards they have been fine. The only wrong p/n in the BOM as far as pitch was CZ and I'll update soon

All the best
John

SIXTYNINER

Re: 2254C build/support thread
« Reply #74 on: May 28, 2009, 06:44:35 AM »
hi
follow info can be good for this project?
*
take a look at a 33609 schemo and all will be revealed!  The mic transformer is used in the line input signal chain as a step up.  Here's a brief run down of what happens
1) Signal enters and is dropped 6dB by using a 31267 wired for 2:1
2) The signal passes through a line pad to drop it a further 25dB.  The signal must be padded because the diode bridge cannot handle high levels.  
3) After the diode bridge the signal goes through a transistor buffer and onto a 10468 in 1:2 and is stepped back up by 6dB.  
4) After this the signal is amplified back up to line level by a BA183 card providing back the missing 25dB plus the makeup gain needed to account for compression.
The 33609 manual used to be available on the Neve site, if not send me aa email to ruairioflaherty ((at)) eircom **dot** net and I'll send it on to you.  
*
anycase thanks to mr : Ruairi

peace 6T9R
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

SIXTYNINER

Re: 2254C build/support thread
« Reply #75 on: May 28, 2009, 11:54:45 AM »
from 33609 :
4.1. APPLY 0DB TO INPUT. COM OFF, LIM OFF, BYPASS IN, MEASURE OUTPUT IS 0 DB,
CONNECT LINK TO CV 3.00V WITH CROCODILE CABLE. ADJUST RV2 TO GET -8 DB AT OUTPUT....

i assume we will have similar procedure like above on 2254c the monster, too :)

those 0 DB -8 DB means dbm (dbv) ... i can read dbm (dbv) on fluke 187...
am i good ?

this one can help you?
http://audio.rightmark.org/download.shtml

peace
6T9R
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

Re: 2254C build/support thread
« Reply #76 on: May 30, 2009, 12:37:43 PM »

Hey Guys,

when matching Diodes with Vf for this and other projects, how many decimal places are you matching too?

My test set only goes to two decimal places, is this enough?

Cheers!

Pete

Re: 2254C build/support thread
« Reply #77 on: June 01, 2009, 03:15:18 PM »
well i matched the diodes to two decimal places, hope thats going to be fine.

Igor, would it be ok to use 0-100uA meter for this project? just curious...

Im stuffed and soldered, almost ready to go...

 ;)

syn

Re: 2254C build/support thread
« Reply #78 on: June 02, 2009, 04:49:00 AM »

Igor, would it be ok to use 0-100uA meter for this project? just curious...


Same question,  I have some 0-100uA (1k internal resistance) that I want to use here.

Thnx

jplum

Re: 2254C build/support thread
« Reply #79 on: June 03, 2009, 01:50:37 PM »
Guys

Tat's 2254C case arrived today. Well packed and looks 100% as per the design that was on the thread he started thats no longer around.
Cant wait to start putting it all together now and start the interesting part of testing and listening  :)
Regards


 

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