[thislittlepiggy]

I'm thinking about doing the passive mod that has been talked about on the forums, but the pictures that I've seen are kind of confusing. First off, can I just use generic radioshack resistors and caps such as these:

1/2 watt 100k resistor
4.7uF 35V cap

Secondly, what do I do with the cables after I detach them from the RCA signal jacks? Do I ground them on the RCA jack?

Finally, can you all double check on what I think the procedure is?

1. desolder cables coming from RCA signal jacks
2. cut two cables and solder the caps onto each one
3. solder one cable onto C12 (L) and one onto C13 (R)
4. solder the cap and one end of the resistor onto the RCA signal jack. Do for both cables. C12 goes to white (L) jack and C13 goes to red (R) jack
5. solder the other end of the resistor onto the RCA ground
6. cut out another piece of wire and solder the ends to the resistor/ground contact point, essentially connecting the two grounds and resistors
7. solder the two cables that were detached in step 1 to any RCA ground(?)

oh and one more question: does directionality of the resistors and caps matter?

here's the post that I'm using as a reference:
Quote:

Originally Posted by tilt /img/forum/go_quote.gif Bypass. (picture taken by Bg4533)

I'm a neophyte at DIY, so try to keep it simple.

 

[d-cee]

Quote:

Originally Posted by thislittlepiggy /img/forum/go_quote.gif 1/2 watt 100k resistor 4.7uF 35V cap

you can use those, but electrolytics won't sound crash hot

Quote:

Originally Posted by thislittlepiggy /img/forum/go_quote.gif Secondly, what do I do with the cables after I detach them from the RCA signal jacks? Do I ground them on the RCA jack?

de-soldering them would probably be the best thing.

Quote:

Originally Posted by thislittlepiggy /img/forum/go_quote.gif Finally, can you all double check on what I think the procedure is? 1. desolder cables coming from RCA signal jacks 2. cut two cables and solder the caps onto each one 3. solder one cable onto C12 (L) and one onto C13 (R) 4. solder the cap and one end of the resistor onto the RCA signal jack. Do for both cables. C12 goes to white (L) jack and C13 goes to red (R) jack 5. solder the other end of the resistor onto the RCA ground 6. cut out another piece of wire and solder the ends to the resistor/ground contact point, essentially connecting the two grounds and resistors 7. solder the two cables that were detached in step 1 to any RCA ground(?) oh and one more question: does directionality of the resistors and caps matter?

looks good except for step 7, see above

direction shouldn't matter for the resistor, but because you're using an electrolytic cap - they're directional - then you will need to solder + into the PCB and the - into the RCA

 

[thislittlepiggy]

thanks for the help again d-cee. what other kinds of caps are there instead of electrolytics?

 

[d-cee]

film caps - polypropylene, polyester, polystyrene, teflon etc.
i used paper in oil caps for mine i think they were 5uF

they're much smaller values and physically larger than electrolytics but in this mod you probably won't need anything more than 10uF

a good guide to caps here: ecp.cc

 

[thislittlepiggy]

are there any advantages to using film caps over electrolytic? I'm kind of intimidated by the size and price of film caps. would a 4.7 uF 50V blackgate N be enough?

 

[kvant]

Quote:

Originally Posted by thislittlepiggy /img/forum/go_quote.gif are there any advantages to using film caps over electrolytic?

Yes, they typically deviate less from the "ideal capacitor".

Quote:

I'm kind of intimidated by the size and price of film caps. would a 4.7 uF 50V blackgate N be enough?

If you look at BlackGate, then price is not much of an issue, is it? You can have Solen (metalized polypropylene) for about the same price. It is a bit larger, though.

 

[thislittlepiggy]

alright, i just purchased 4.7uF solen polypropylene caps as per your recommendation.

is it alright if i use generic ratshack cables to hook it all up, or will it degrade the signal? i think not, since the distance of the wire is so short, but maybe someone else has seen otherwise.

i hope it all turns out well...

 

[d-cee]

I wouldn't worry too much about it for now

Get the passive mod working, and then worry about those little tweaks

 

[danmagicman7]

Shouldn't soldering be done into C38 and C39? C12 and C13 aren't L/R...