525 build thread

[peter purpose]

what happens with this attack mod=? faster attack=?
As originally implemented, the attack pot had little effect. The first mod (the extra resistor) only reduces the control voltage to the fet. The last mod should give true attack control.

should i connect the term jumper=?
i build a stereo version with controlls for each channel ..so i connected the mono strap on led pcb.. is this ok=?

Check back in the thread somewhere. There you'll find instructions for stereo operation.


peter

 

[mata_haze]

[quote author="peter purpose"]should i connect the term jumper=?
i build a stereo version with controlls for each channel ..so i connected the mono strap on led pcb.. is this ok=?

Check back in the thread somewhere. There you'll find instructions for stereo operation.
[/quote]


I checked in the previous pages but could not find anything. I have encountered the same issue while wiring for stereo: shall I connect the "mono strap"?

Mattia.

 

[peter purpose]

You're not looking hard enough son. Page 15.

BIGGUN.. http://www.twin-x.com/groupdiy/albums/userpics/525STQU.jpg

while wiring for stereo: shall I connect the "mono strap"?

You connect to those points, but don't strap em.

 

[king-rb]

my 525 is working good no noys and the amp stage is working but
its not reacting to attack, release and macke-up gain and no
change in the signal if im switching comp & limit ...

i found out that in the schematik is a comment "SW1A,B,C
Mechanically interlocked SW2,3&4 are alt action" i think tis is
the reason..

i used switches instead of pushbuttons.. so this means to connect both "side" of the switch togeter that 4 pins are everytime connectet together=?
and where is sw1a =?

thank you very much!

 

[king-rb]

ahh .. found sw1a in the orginal schematik this switch dont exist in the new version right=?

 

[peter purpose]

[quote author="king-rb"]ahh .. found sw1a in the orginal schematik this switch dont exist in the new version right=?[/quote]

Right.
As to your other problems... double check your connections.

 

[king-rb]

thank you.. i will do the connections in the sw1b & sw1c then it should work perfect!

 

[louder]

Hi Peter
as for the 600r resistor across the out tranny,you said some pages ago,to leave it if you want the next piece of gear to terminat the tranny.
i will use the 525 connected to the sound cards,as a insert for mixing,or after a preamp to track.
should i leave it,or should i not?.
once again,thank you so much.
best regards
Pedro

 

[peter purpose]

Stick it in, do the mod and fit the switch. Try em both for preferred flavour.
A standard 525 does not have 600R across the output.

 

[Rob Flinn]

I'm looking at the inter wiring diagram. Particularly the hook up to the rotary switch.

Looking at the hook up diagram it appears that from the ground through R64 should be connected to sw5A position 0. However when I look at the circuit diagram it shows it going to sw5B position 20.

Other than that can someone clarify some of the test procedure:
section 4

E) turn up the step control checking for 2dB steps......
F) adjust the in pot for 0DBm out.

so does one do F) with the step control on zero or 20 ??? Either way not a lot is happening for me here.

Does someone who has got these working have a list of all the corrections/erratas. I compiled my own, trolling through this thread several times, but I suspect there is something I must have missed.

 

[Siegfried Meier]

Does anyone have a BOM with part numbers for Digikey and Mouser?

Thanks,
Sig

 

[peter purpose]

Jayzus Robert..!!
Ground goes through R64 to SW5B pos 20. Ground also goes direct to SW5A pos 0. If you nail R64 between those two switch positions, then take a wire from SW5A pos 0 to ground, you'll be hunky dory.

 

[Rob Flinn]

[quote author="peter purpose"]Jayzus Robert..!!
Ground goes through R64 to SW5B pos 20. Ground also goes direct to SW5A pos 0. If you nail R64 between those two switch positions, then take a wire from SW5A pos 0 to ground, you'll be hunky dory.[/quote]

Thanks Peter, I'll sort it this afternoon when I get back from bashing my drumkit !!

 

[DAN_000]

LM3915 or LM3916 ??

LM3915 is 3dB/led and LM3916 is Vu scale.

If original meter is 200uA I think 3915 is the choice, what you think?

Dan.-

 

[edanderson]

more 2623 type transformers for sale:

http://groupdiy.com/index.php?topic=27318

ed

 

[scottlwilson]

Hi Everyone

I'm going to begin building my 525 pair.....finally. I am wondering if any of you gentlemen could help me with a supplier/part number for the rectangular poly red caps that Peter spec'd for these? Not sure if they're poly or what specific manufacturer/supplier.

Thanks very much for any clues you can provide to the clueless.

cheers

Scott Wilson

 

[kazper]

Red poly cap's are generally Wima brand or a knock off and can be found from Taw electronics or mouser.

Taw will help you and stock a huge assortment. Make sure you specify what lead spacing your after. Mouser has less Wima stock but probably what is needed for a 525.

 

[Rob Flinn]

Having a bit of a problem with one of these. The other 3 I have built are working really nicely.
I'm following the calibration procedure and all is fine up to step F. when I set this to 0dB out the signal starts to creep up slowly, stopping maybe 3-5dB above where it was 30sec later.

When I turn down the gain switch it sort of reads 0dB out for most of the way then does some weird stuff at the lower end. If I turn the switch from zero to 2dB the meter goes from nothing to about 3 leds below top gain reduction. i.e all the meter action is on the top 3 led's when it is compressing. Also when changing the switch postion I get the slow level creep aftr the switch postion is changed , like in the above paragraph.

SO I have checked the resistors on the switch. The meter is on the top led when the switch is at 20dB gain reduction. I have tried 3 of the VCN fet .

Anyone got any ideas, as I have spent a lot of time on this now, & am tearing what little hair I have out now ??

 

[Rob Flinn]

Ok so I found the problem with the signal creeping up & down. It was a fault in the sidechain OP Amp. I swapped it out & now it is behaving nicely although the meter range is still a bit bunched.

 

[Greg]

Last component to source is sockets for the DOAs. I'm not sure what size will fit the board. A little help please? These ones I have in my shop are toooo big, and I'd prefer to not drill the PCB.