[rajacat]

The leads of a new capacitor are too large for the holes in the PCB. Is there a safe way to enlarge the holes? Would splicing a smaller diameter lead to shortened old leads be acceptable practice?

Thanks,

-Roy

[randytsuch]

I have drilled out holes before, to do this kind of thing, but you need to be carefull here.

Sometimes, with a plated hole, they use the hole as a "trace", to make a connection between the bottom and top layers.  If they do this, and you drill it out, you have just broken the connection.  Of course, it can be fixed, you just have to make sure you reestablish the connection when you install the cap.

But, the much easier route is what you said, use a short piece of wire to connect the cap.  The problem with wire is that it introduces inductance, which usually defeats the purpose of the cap.  So, you need to keep the wire short, or you may be making things worse.

Randy

[rajacat]

Hi Randy,

A Mhdt Constantine dac is the subject of this mod. I have a bunch of Obbligato caps that I plan to use to replace most of the stock caps. The 2.2uf Obb. fit easily into the stock 1.0uf output cap holes but all the other mostly .1uf (5) caps have these oversized leads. I have some 25 gauge solid silver wire that I could use for the new leads. The leads would be about 1" long. I suppose that would be OK? It's a little frustrating after having these caps sent from Hong Kong. I do like the effect of the 2.2uf Obb. on the sound quality.

--Roy

[tanchiro58]

Hi Roy,

There is another way to mod your Constantin to sound more cleaner and warmer (I mean more musical) by replacing the stock cap along signal path 0.22mF/250V with a Jensen PIO 0.22mF/630V. I did modify to my MHDT DAC (I forgot the name but it is a second line after Paradisea) that way and coupling caps with NOS West-cap 1.5mF/400V and bypass with another NOS Gudeman 0.1 mF/600V. I think F100 did the same mod to his Paradisea.

I screw up my DAC by drilling the hole and lost the contact just like Randy mentioned.

Tan

[PSP]

IME, the best way to do this is to use a pin vise (for example, see: 
http://www.widgetsupply.com/page/WS/PROD/pin-vise-jeweler/BBH19 , but I bought mine at RatShack).  These usually come with a selection of very small drill bits.  You chuck up a small bit and drill out the hole (starting from the foil side works best, IME) by turning the drill bit slowly with your fingers. 

You can also use this to drill holes pretty much exactly where you want them... use the pin vise to drill a small pilot hole (part way through), and then a through-hole pilot using a slightly bigger bit with a power drill, and finally drill the desired diameter.

Peter

[randytsuch]

Hi Roy
Sorry, did not see the response to this thread until yesterday.

For some things, like an output coupling cap, then 1" leads aren't a big deal.
For other things, like bypassing power in a digital circuit in a dac, then a 1" lead is not good, and may make it worse then what you are replacing.  For digital circuits, you want very short leads, actually surface mount is best, for filtering high frequency noise.

My last comment is caps in not a one size fits all kind of thing.  Obbligato caps are supposed to be good for coupling caps (I am planning to use them in my squeezebox project), that does not necesarily mean they will be good for power filtering in a digital circuit.  I have no idea if they would be good or not, but the large size of these film caps makes it inpossible to install them with short leads, which makes it unlikely that they will do a good job filtering high frequency noise.  I have had good luck with oscons in digital circuits.  You could try the obs, and see, since you already have them.

Good luck with your project.

Randy

[rajacat]

Hi Peter,

Thanks for the pin vise tip.

Hi Randy,

Actually the leads are closer to 3/4". So far, after initial break-in, I'm very happy with the improvement in sound quality that the 2.2uf Obbligato cap enabled. I also bypassed the 2.2 with a .1uf Obbligato. I'm not so sure what the .1uf bypass added since I installed it while the 2.2uf was still burning in. One thing I know is that I prefer the digital output of my SB3 over the analog output of the SB3. The SB3 has the digital and analog mods. I also believe that the Obs. are better that the stock caps. It seems that Constantine/SB3 has greater extension and more air than the analog SB3 output. This might be system dependent since many have indicated that they prefer the output of the analog modded SB3.

Quiet Earth reported improved SQ using .47uf Audio Note PIO caps. The AN caps are physically about the same size as the Obbligato 2.2ufs.http://www.audiocircle.com/index.php?topic=33534.590

-Roy