Capacitor change in preamp (1 Viewer)

[Yogi]

I am going to replace the output capacitors in my ASL 2004DT preamp with auricaps. I have never done something like this. So are there any special skills I need to acquire before I embark on this endevour? Any special tools apart from a saudering iron some silver solder? I am thinking its a plain pull out the old cap and put the new one in and solder away. I did some soldering about 15 yrs back but it was simple soldering of wires. So please advice me if there is anything else that I should know about. Also what kind of improvement should I hope to see with this change? Any advice to this novice would be greatly appreciated.

 

[Yogi]

Last night I changed the two output caps from Multicaps to Auricaps. I also changed two DC blocking Benning caps with Auricaps of same rating and two other Benning caps in the signal path with Auricaps. Took me two hours to do it mainly because of the inaccesability of the PCB (had to dissassmble almost everything). In any case changed everything and soldered them with silver solder. Hooked it to my system and fired the preamp. Initial findings are that the mid-range now seems a little more juicier with a little more body. The top end also seems slightly smoother. The bass is the same with either caps. Cant really comment on the soundstage or the image specificity. I am already loving the new sound.

 

[Chu Gai]

hey buddy, you still humming?

 

[Yogi]

Yes Chu sadly I am still humming. Although the nature of hum seems slightly different the buzz component is slightly lower but the hiss component remains. I have no idea why. Could it be related to the leakage current of the new caps?

 

[Chu Gai]

God Yogi, so many possibilities, some of which were touched upon in an earlier thread, and honestly, without proper test equipment, we're all reduced to speculation and trial and error. And you know me Yogi, I hate to spend other people's money on whims. I think one thing I'd be doing is taking a look at the grounds and trying to determine if they might be at different potentials from each other. Have you considered posting over at AA or on Usenet?

 

[Yogi]

I did post at AA but that wasn't much help. All the grounds on the circuit boards etc in the preamp are screwed to the chassis. So I dont know what else could be causing the hum. I tried re-routing the various wires, sheilding them with copper tape (and grounding the tape) but still the hum remains.