New API 525 build thread.

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peter purpose

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This will be the official new design 525 build resource.
I'll add stuff throughout the day.

525Cschsm.jpg

Biggun http://lazpro.com/525Cschbg.jpg

This version can have a Lundahl LL1540 transformer on the front, or a differential input opamp. If using the opamp (A4)......

525a4.jpg


A4 bom http://lazpro.com/525A4BOM.txt

The 2520 overlay and bom.....

laz2520sm.jpg

Biggerer http://lazpro.com/laz2520.jpg

Rs 16 & 17 need] to be 1/2W, the rest 1/4W.
As some BC184C batches seem to be a bit dodgy, use 550C instead.

The switch and meter board.......

swmtr.jpg


The switch resistors need to be miniature types. R9-17 should not protrude through the pcb.
Don't solder in the switch until you offer it into the metalwork, as it sits off the pcb by roughly a mm.

SWMTR bom. http://lazpro.com/SWMTRBOM.txt

The main board...

525main.jpg


Main board bom http://lazpro.com/525MAINBOM.txt
 

zayance

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Anybody found the 1K and 1M pots Log pots needed for this build? They need to be small so not much options from what i see...
Thanks a lot.
 

jsteiger

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zayance said:
Anybody found the 1K and 1M pots Log pots needed for this build? They need to be small so not much options from what i see...
Thanks a lot.
Sorry for being a pimp but I have 1k logs. http://classicapi.com/catalog/index.php?cPath=50_131

FWIW, I have 250pc of 2623-1 due in the 1st week of February. Once those arrive, I will be opening them up for individual purchase again.

Pardon me, Jeff
 

zayance

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jsteiger said:
zayance said:
Anybody found the 1K and 1M pots Log pots needed for this build? They need to be small so not much options from what i see...
Thanks a lot.
Sorry for being a pimp but I have 1k logs. http://classicapi.com/catalog/index.php?cPath=50_131

FWIW, I have 250pc of 2623-1 due in the 1st week of February. Once those arrive, I will be opening them up for individual purchase again.

Pardon me, Jeff

Allright, then the 1K's will be added to my shopping card at your place, they should fit, thanks Jeff
Now let's hunt for the 1M again....


EDIT: I guess these would do as well, forgot about the small alpha's, but won't fit the small Api knobs tough...
http://www.banzaimusic.com/Alpha-12mm/
 

mulletchuck

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Howdy peter.  nothin' against your 2520 design, but i'm assuming that the Gar2520 will work as well?  I'm familiar with building that version of the 2520, and am hoping your pcb uses the same footprint, and thus opens up the doors for the gar1731 and the other DOAs that are pin compatible with the 2520..
 

zayance

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mulletchuck said:
Howdy peter.  nothin' against your 2520 design, but i'm assuming that the Gar2520 will work as well?  I'm familiar with building that version of the 2520, and am hoping your pcb uses the same footprint, and thus opens up the doors for the gar1731 and the other DOAs that are pin compatible with the 2520..

2520 footprints are all the same, only diff could be the pin socket size, but if you get them from Jeff then you're good to go....
 

zayance

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Allright i think i found another solution, i tought these won't fit but....
So for the 1M pot will be using the CT ones found at Digikey as well as Mouser as well as banzai iirc.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=109386570&uq=634622023213144546

The 1M would fit but you need to trim it's little PCB sides and gently bend the pins  (as seen on Pic)., trimmming with pins facing down
and little holes covered to not get all the nasty dusts on the track...

It won't be possible to use CT all the way as you can see it's pretty tight, but also because the Input one won't pass
at all because the body is too big (about 15.5mm), Jeff's Bourns are 12.5mm ( 5.7mm taken from center) so that would fit better

So the setup that would work would be 1K's from Jeff and 1M from CT....both beeing log and both with 1/8"Shaft for the Api knob lovers haha....
On the pics i didn't used the CT washer, but using it will hide the Pot Thread and so make the knob sit flat on panel...

20120115125924.jpg

201201151252501.jpg

20120115125143.jpg

20120115125335.jpg
 

zayance

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For those who would be interested:

http://www.goldmine-elec-products.com/prodinfo.asp?number=A10751
 

901

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Which LED Bar Driver did you guys choose? LM3916? And how to pick RM1 and RM2?

 

zayance

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901 said:
Which LED Bar Driver did you guys choose? LM3916? And how to pick RM1 and RM2?

Answer is in the Datasheet

http://www.ti.com/lit/ds/symlink/lm3916.pdf
 

901

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Sorry, for my stupidity, but I have seen the datasheet. But I am missing the part of the schematic that has the LM and I can only guess what Vref should be.

Would you guys care to explain to me? Pleeeeeease....  :-[
 

peter purpose

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901 said:
Would you guys care to explain to me? Pleeeeeease....  :-[

If I could, I would. I'm dyslexic when it comes to datasheets and formulas.
Schematic is the standard two resistor version from the LM390X datasheet.
 

zayance

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Actually the VCR2N's are also available from Electrochronic, along with some other goodies, a little more expensive than Goldmine elec, but he will ship worlwide, just for info:

https://sites.google.com/site/diypartsstore/catalog/misc-components
 

901

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I´m 90% done with my build. Still waiting for parts to come in (Grayhills and transformers). I have once again some questions:

The RGB LED I got has 4 pins, which I think is very logical for a 3 color common cathode LED. But there are only 3 holes in the PCB. Should I solder the cathode to ground somehow?

At which point in the circuit is this LED inserted? Or in other words, I´d like to know the maximum voltage that is applied to the LED + RLED so that I can calculate RLED.

I guess there are not that big variations on LED voltages (mine is 1.9V / 3.2V / 3.2V). Maybe any of you who have already completed their builds can tell what they chose?

And whle I´m nearing completion I wonder how to set the 4 trim pots. From the schematic I gather they are Gain for the input stage, for the Limit Mode, Release Time Over-ride (?) and Meter Calibration. But how to dial them in properly?

 

peter purpose

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901 said:
I´m 90% done with my build. Still waiting for parts to come in (Grayhills and transformers). I have once again some questions:

1. The RGB LED I got has 4 pins, which I think is very logical for a 3 color common cathode LED. But there are only 3 holes in the PCB. Should I solder the cathode to ground somehow?

2. At which point in the circuit is this LED inserted? Or in other words, I´d like to know the maximum voltage that is applied to the LED + RLED so that I can calculate RLED.

I guess there are not that big variations on LED voltages (mine is 1.9V / 3.2V / 3.2V). Maybe any of you who have already completed their builds can tell what they chose?

3. And whle I´m nearing completion I wonder how to set the 4 trim pots. From the schematic I gather they are Gain for the input stage, for the Limit Mode, Release Time Over-ride (?) and Meter Calibration. But how to dial them in properly?

1. Can't be common cathode if they are seperate. Get a 3 leg.
2. Max V will be plus 16V.
3. http://www.twin-x.com/groupdiy/albums/userpics/525_Page_10.jpg
http://www.twin-x.com/groupdiy/albums/userpics/525_Page_11.jpg
 

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