2254C build/support thread

[ptron]

Ok up to now ive put all caps in " place"
This are my observations / doubts

1.  R34 ( 2x47k) missing ?

2. I got 8 toggle switches in total. (all spdt) i think 2 extras

3.  2 x 1Mohm extra ( R19 i cant find where it goes ehehe)

4. C'4 and C'6 say 80 on the overlay, i got few 100 uF i guess theyre it.

5.  10uF x 6 extras. 4 axial and 2 radial.

6. Other thing about 10uF. There are 3 kinds on the kit, 2 pairs of kemet 10% axial (black ones) and blue smaller ones, those are axial and radial. Any hints on which goes where?

7.  Tr 3 2n3055 and the heatsink, how do i mount that? (i know with the screws) but, anythin else? Do i need to make sure anything while placing it? Also just 2 bolts for this purpose... 4 nuts and washers but only 2 screws

8. And last.. To connect the stereo link toggle, what kind of toggle do i need and how/ where do i connect from / to?

other thing.. i am asuming the overlay on the pcb`s is all right (i have no doubt in my mind). i say this because of transistors J109 and BC 184 / 214.  i got to bend the legs but the body should go as the overlay shows i guess?  (igor said sometimes EBC are different legs.) dont know what make they are or i would look into the datasheet

sorry for redundance.. carnhills would be OP_TR = Part Code: CA-18-VTB9049
                                                    INTR1 = Part Code: CA-18-VTB9045M
                                                    INTR2= CA-18-VTB9046M       

(from audio mainteinance http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html
Thanks a lot!

 

[ptron]

bump

 

[Igor]

Ok up to now ive put all caps in " place"
This are my observations / doubts

1.  R34 ( 2x47k) missing ?

2. I got 8 toggle switches in total. (all spdt) i think 2 extras

3.  2 x 1Mohm extra ( R19 i cant find where it goes ehehe)

4. C'4 and C'6 say 80 on the overlay, i got few 100 uF i guess theyre it.

5.  10uF x 6 extras. 4 axial and 2 radial.

6. Other thing about 10uF. There are 3 kinds on the kit, 2 pairs of kemet 10% axial (black ones) and blue smaller ones, those are axial and radial. Any hints on which goes where?

7.  Tr 3 2n3055 and the heatsink, how do i mount that? (i know with the screws) but, anythin else? Do i need to make sure anything while placing it? Also just 2 bolts for this purpose... 4 nuts and washers but only 2 screws

8. And last.. To connect the stereo link toggle, what kind of toggle do i need and how/ where do i connect from / to?

other thing.. i am asuming the overlay on the pcb`s is all right (i have no doubt in my mind). i say this because of transistors J109 and BC 184 / 214.  i got to bend the legs but the body should go as the overlay shows i guess?  (igor said sometimes EBC are different legs.) dont know what make they are or i would look into the datasheet

sorry for redundance.. carnhills would be OP_TR = Part Code: CA-18-VTB9049
                                                    INTR1 = Part Code: CA-18-VTB9045M
                                                    INTR2= CA-18-VTB9046M       

(from audio mainteinance http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html
Thanks a lot!

Hi, sorry for abandoning the thread.

Missing components: mmm...human factor, happens; if you can source them, I will refund the cost + shipping;
or, just send me the list by mail, will ship ASAP.

Extra components: ok, have a fun and use for other project(s)! Probably, when Sergey arranged the kits, he added some stuff -
with good intentions, of course, not just for reason to complicate your life!

"Original" old drawing, where the BA283 part was copypasted from, shows 80uf, actually, 100uf were used too....
in other words, 100uf is right. Electrolytics have +/-20% tolerance, so, within range in any case

10uf, blue, axial, goes to audio; tantalums are used in time constants (sidechain); that's it!

2N3055 should be raised a bit, thus, 4 nuts and 2 screws on each PCB. If something is missing, again, e-mail, will ship asap or refund the cost.

Stereo link: to LINK points at front panel pcb, near the meters; spdt toggle.

Transformers: seems correct; was already posted some pages back. If need very fast answer, skype/mail.

P.s. R19 = N/A (not installed).

 

[ptron]

hey thanks a lot!!

just a couple of questions now.. sourcing the parts..

1- found some heatsinks for the PS..  is this one good for the job?
Mouser N.º: 588-RA-T2X-38E
Fabricante N.º: RA-T2X-38E
Fabricante: Ohmite
Desc.: Cuerpo de Refrigeración HTSNK TO-220 218 247 BLK ANODIZED
RoHS: En conformidad con la RoHS

2- power supply regulator now.. lm317TS.. i can not find TS termination on mouser but a lot of them... i need the 1.5amp 1.2-37V or 1.2-57V? or neither?

Mouser N.º: 863-LM317TG
Fabricante N.º: LM317TG
Fabricante: ON Semiconductor
Desc.: Reguladores lineales - Estándar 1.5A ADJ 1.2-37V Positive
RoHS: En conformidad con la RoHS

3- tl071p i can see CP, IP, termination. do i want higher db rejection mode or doesnt matter?

Mouser N.º: 595-TL071CP
Fabricante N.º: TL071CP
Fabricante: Texas Instruments
Desc.: Amplificadores Operacionales JFET Input Low Noise
RoHS: En conformidad con la RoHS

4- about 2n3055.. in the .doc instruction manual says i should use thermal paste also. is this needed? if so can i find in mouser? (all my list is on mouser makes sense to source everything there now.)..
also about this .. only screws and bolts for one board.. ill try and find them in mouser again.. im very incompetent looking for bolts there ehehe.

i guess all the rest is good almost there!!

 

[Igor]

For the heatsink: should fit at first glance, but check again with datasheet.
LM317 should be 1.5A, 37V is OK, 57 too.

TL071, ot TL081 etc: used as reference voltage source, +3 or +5V, for compressor adjustment.
You need it for 20 minutes when adjusting the compressor. 99% of generic op-amps in DIP-8 will work here.

2n3055: no need for thermal paste, just screw to heatsink.

Screws: ma bad, human factor; just mail me, will ship asap.

 

[ptron]

hello! thanks a lot! i saw your email and didnt look here afterwards... studio construction works takes it out from you... im nervous hehe my studio will never be the same.. if only just slightly better it will be ok.

anyways. thanks! almost ready to make this order .. about the screws no worrys ill try and source on my own.. shipping from over there to here for just 2 screws man.. will figure it out for sure . if u got a mouser part number or similar screw id be very greatful but ill get to look for that now

again thanks a lot man.
all the best!

 

[Igor]

Actually, all you need, is just buy 4x screws, 4 x nuts, and 12 fasteners, all M3; screws are 12...18mm;
it is common thing in every DIY shop like ACE or even Office Deport..
Here, it goes in packs of 10 and costs about 1 eur for whole bolts story.

Psychedelic trance, BTW! Do you like Legendary Pink Dots?

 

[ptron]

Actually, all you need, is just buy 4x screws, 4 x nuts, and 12 fasteners, all M3; screws are 12...18mm;
it is common thing in every DIY shop like ACE or even Office Deport..
Here, it goes in packs of 10 and costs about 1 eur for whole bolts story.

Psychedelic trance, BTW! Do you like Legendary Pink Dots?

Ehehe pink dots? Is that a legendary trance band?
Im going today see if i find the screws on office depot. Thanks a lot for the infos.. I got to pick up some fiberglass now ! Endless work

All the best! Tat will post the case some time next week and i will start takin some pictures

 

[Igor]

He! Legendary Pink Dots isn't a trance, but good psycho stuff.
I used to drink sometimes at Charlie Bar, Haifa; somehow, when barmen see me, the "Curious Guy" song appears in playlist.
Isn't it Tao? (bugagagaga!!!!!)
"Love Puppets" is another song I very like. Morbid!!! In Addams style!

Cool than, waiting impatiently for photos of working and calibrated unit! The Sontec kits are arranged and posted, BTW.
Some stuff was missing, second package will be on the way shortly.

 

[ptron]

He! Legendary Pink Dots isn't a trance, but good psycho stuff.
I used to drink sometimes at Charlie Bar, Haifa; somehow, when barmen see me, the "Curious Guy" song appears in playlist.
Isn't it Tao? (bugagagaga!!!!!)
"Love Puppets" is another song I very like. Morbid!!! In Addams style!

Cool than, waiting impatiently for photos of working and calibrated unit! The Sontec kits are arranged and posted, BTW.
Some stuff was missing, second package will be on the way shortly.

Thanks a lot!! Sontecs yum! ill look into pink dots! Its great to get inspiration from the past and abroad.

The 2254 ill order whats needed tomorow but toroid is coming still and thecase also hasnt made it yet!
I hope it gets all here very verysoon im 100 times as anxious to see it working ! (or at least flaming some resistors )

 

[ptron]

hello! i got the transformers at last!! whew.. were in customs for a while!.
anyways.. i was just wondering. i got the metal kind .. so they should be pcb mounted i think.
two questions..

1. would i have to put the little bits that were cutout from the front pannel pcb`s?

2. the input and interstage transformers.. in the pcb there is only 4 holes for each side. on the transformer it has 5 pins!! :/ weird

EDIT 3. on the power supply do i have to connect G4 pad and unnamed pad underneath thru G2 ? with link wire?

thanks for your help

 

[ptron]

Bump...
Is it me or this thread is a bit dead?

 

[ptron]

ehehe hi how are yall!! anyways ill keep asking a bit.  who knows!

i got a question.. or a couple still.

in the power supply pcb. igor said something about the pads on both sides and G2 hole. i think i got to join all 3 together? please tell me if im wrong.

the link on the compressor i dont understand cus there is 2 links on pcbs... main pcb labeled LINK and ratio /recovery pcb labeled >LINK

i thought i had to get spst switch to get the 2 links from main pcbs (LINK) and whenever them 2 are together its stereo linked? what are the >LINK for?

well i still dont know about the transformers. theyre definitely the ones i need (i think) i posted the numbers back a few posts ago. in any case, the pcb would be missing 2 holes.. i thought of drilling them eheh silly me. havent done it yet and dont plan to cus thinking twice is very silly idea. maybe i mount them like the normal 9045 and 9046 with molex..

anyways any help will be greatly apreciated
thanks a lot!!

 

[khstudio]

Hey Matt,
I'm having trouble calibrating my unit & was cross referencing the other calibration docs with yours & think there MAY be a mistake in yours but I'm not sure - You said:

Adjust the +CV trimmer on PSU for -20db / (0.0775VAC RMS) at output XLR
Adjust RV3 to reflect 0db on Meter

Shouldn't it say:
Adjust RV3 to reflect -20db on Meter

???

Thanks,
Kevin

Right, as promised here is a point by point calibration procedure based on the bits I got from Kambo, Igor and various other sources (thanks to you all for your insight/info along the way).

Before we start we need to set the BIAS current on the output stage of the BA283, the easiest way to do this is to adjust RV1 to give you a 100mA across R"7, the 47R resistor. Logic/Ohms law dictates that 4.7VDC across the 47R resistor is 100mA, so adjust RV1 to give you 4.7VDC across it... simple and effective, no scope required!

Moving on...

Make sure the settings on the control board are as follows:

MAKE-UP GAIN = 0
THRESHOLD = Fully Clockwise
ATTACK = 8 o'clock
RELEASE = Fully Counter Clockwise
RATIO =  1:2
+10 and HPF switched OUT
Compression IN

We then need to set the +CV voltage, which is done on Igor's PSU so adjust the onboard trimmer on the PSU to give you +3VDC at the +CV out.

With the compressor switched in adjust GAIN trimmer to get unity gain.
Then croc clip the +3VDC C+V voltage from PSU to the LINK on Main Board
Adjust RV2 to get -8db (0.308VAC RMS) at output XLR
Adjust the +CV trimmer on PSU for -20db / (0.0775VAC RMS) at output XLR
Adjust RV3 to reflect 0db on Meter
REMOVE the croc clip to the main board and PSU
Set the Threshold to -2db (1st click on the Threshold switch)
Adjust RV5 for -1db / 0.690 at output
Set the Ratio to 6:1
Set the Threshold to -20db and measure -16db / (0.123VAC RMS)
Adjust RV3 to reflect this accordingly

If all goes well your unit should be fully calibrated!

Happy compressing  ;D

Cheers

Matt

 

[khstudio]

Hey guys... (Girls, if any  :-*)
I'm having trouble getting my unit calibrated & could use all the help I can get:
#1 - Is there a list of the "TEST POINT" Voltages for IGOR's 2254c?
I did find the "33609 schematic with voltages but not sure if it applies... Having IGOR's schematic for THIS project, marked up would be GREAT to have!
#2 - I'm having trouble adjusting the "Unity Gain" on one channel... it's almost there = .667VAC with the "GAIN" trimmer maxed out!!!
Is it possible that the "compression/diode bridge" is clamping down on the raw signal & not letting enough through?
I've followed all the calibration procedures & can't figure it out.
also, I've been VERY careful building & rechecking the entire unit then rechecked it again last night & today... it's all good.

#3 - which should be #1 -
When I first turned the unit on, the 33R resistors feeding the 24v DC to the TL072 for the HPF "SMOKED"!!!
Not sure where I bought them (years ago) but I have a bad batch of "TL072's"... after realizing this I measured one of the same, Brand NEW TL072's from the same batch & it measures a dead "SHORT" between pins 4 & 8 (The Power pins)
So that sucked... I checked & replaced ALL surrounding components along with the TL072's & it seem OK but I'm not sure if it could have damaged anything else?

Thanks, Kevin

 

[khstudio]

Another quick pic... will post Bigger & cleaner pics when I finish.

 

[khstudio]

OK... ALL Fixed & working well.
I'm not sure where my stock of TL072's came from but THEY were the problem!
They're what caused the 33r power resistors to "smoke" & was messing with my calibration.
After swapping several (over 8) TL072's I found 2 that worked... very strange indeed. A few were even NEW (from a few years back) & measured almost a dead short from V+ to V-.

Just thought I'd share... the dumbest things can really cause problems.

IGOR -
What is R60, 18k* for?

 

[duantro]

I'm starting to get it together.I wish I had more time to work on it.
Next to start drilling mounting holes for the standoffs and try to find an IEC receptacle that will fit Parusha's case.

One question- is the 2N3055 supposed to be elevated to allow it to cool or is it to keep from shorting out.
I mounted it flush and am wondering if I should pull it out and reinstall new ones?

 

[ptron]

I'm starting to get it together.I wish I had more time to work on it.
Next to start drilling mounting holes for the standoffs and try to find an IEC receptacle that will fit Parusha's case.

One question- is the 2N3055 supposed to be elevated to allow it to cool or is it to keep from shorting out.
I mounted it flush and am wondering if I should pull it out and reinstall new ones?

i think this is good for the case http://mx.mouser.com/Search/ProductDetail.aspx?R=6200.2300virtualkey69300000virtualkey693-6200.2300

 

[duantro]

I'm starting to get it together.I wish I had more time to work on it.
Next to start drilling mounting holes for the standoffs and try to find an IEC receptacle that will fit Parusha's case.

One question- is the 2N3055 supposed to be elevated to allow it to cool or is it to keep from shorting out.
I mounted it flush and am wondering if I should pull it out and reinstall new ones?

i think this is good for the case http://mx.mouser.com/Search/ProductDetail.aspx?R=6200.2300virtualkey69300000virtualkey693-6200.2300

Thanks Ptron, I was looking at those but wasn't sure about the measurements being exact.

Have you installed your transformers? I'm going to do mine as most others have appeared to do, by side mounting with zip ties on pcb and using the molex connectors. The mounting holes appear to be for marinair, etc.

I'm also wondering about the psu pin 2 connection wire also. Have you sorted this out?
Cheers