Static in Adcom GFA-5503, right channel

kuntasensei

I hate reviving an old thread... but this deserves a follow-up, if only for comedy value. In the last two weeks, I bought a Parasound HCA-2003 from a user here at the forum to replace the Adcom GFA-5503. Because of the different spacing of the inputs, I also had to order slightly longer ICs. Since I still had the 3 2 ft. Blue Jeans Cables ICs I was using on the Adcom, I decided to use them for my subwoofer rig (one cable from AVR to Crown amp for Buttkicker LFE, one cable from AVR to ART-351 EQ then one out to Crown amp for SVS 20-39CS+).

Worked great the first night. The next morning, I power up my gear... and lo and behold, my subwoofer is making crackling noises and the level has dropped by about 3dB, which was pretty much the same thing that happened intermittently with the right channel of my Adcom. So I reach behind my EQ to check the connection... and though the IC was firmly in place, grabbing the plug made the level come back up and stopped the crackling. I twist the cable a little, crackling is back, level drops. So I grabbed a spare cheapo RCA cable from my closet, swap it out with the cable in question, and all is well... so it is obviously the interconnect, not the plug on the EQ. Pull it out from behind all my gear, and guess which cable it was? THAT'S RIGHT... THE ONE FOR THE RIGHT CHANNEL.

So now I'm thinking that all that time the Adcom spent in the shop with the tech scratching his head, unable to solve the problem may very well have been because the problem was the stupid interconnect having intermittent issues! Now, keep in mind that when I was originally troubleshooting the Adcom, I swapped ICs around to see if the problem followed a particular cable... but since it was so on-again/off-again, I could never track it down to a particular cable.

I e-mailed Blue Jeans Cable this morning and explained the situation, mostly to try to troubleshoot things. Wayne at BJC e-mailed me back:

As far as the crackling is concerned, we’ve had this come up once or twice before. What happens is sometimes the inner conductor will develop a tiny crack in it – not enough to break the connection, but enough to cause the issues you’re having. It’s extremely rare, and is the type of thing that is hard to test for because it’s not losing continuity – at least not during the manufacturing process. This is caused by the conductor annealing process while the cable itself is being made at Belden. A slight temperature variation during this process can make the copper slightly more brittle… and these brittle sections are impossible to test for after we receive it. As I said – it’s extremely rare, and will only occur over a few feet of any given 1,000 foot spool.

Since this is a manufacturing issue, I can authorize a replacement if you want one… just let me know, and I can get the wheels turning on it.

So, what do we take from all of this?
1) I feel like a dumbass. I should have thought to swap out all the ICs with some cheapo cables in the first place just to double-check, but with the problem being so sporadic in nature, it was just too hard to diagnose.
2) I have a strong feeling that the Adcom is totally fine. In the next week, I guess I'll hook it back up with the new ICs to make sure.
3) Even if the Adcom is 100% working... I'm pretty happy with the Parasound, and in fact have a Parasound HCA-1206 coming from another forum member so that my entire 9.1 setup is on external amplification. So... once I make sure the Adcom is actually in working order, I guess it'll end up for sale here. No regrets.
4) Let this be a lesson to those getting their start in separates the way I was with the Adcom: CHECK EVERYTHING TWICE. Otherwise, you'll spend months beating your head against a wall like I did!
5) Despite the headache this has caused, Blue Jeans Cables is pretty upstanding to offer to replace the cable 8 months after the fact, especially since I specifically said in my e-mail that I wasn't angling for that. I'm sure it was just a fluke, and I'm still going to order the ICs I need for the HCA-1206 from them once I know the lengths I need.

littlewoodboats

Murphy was putting in overtime on this one. Bummer for all of the hassle but cool you finally got it figured. I do not know if your Adcom is one of the leaky cap models or not but Big Sky does magic with Adcom amps. Parasound as well it seems.

Not that it matters but it would be interesting to hear what Belden has to say about a claimed manufacturing defect?

kuntasensei

None of the caps have leaked in the Adcom, and the 5503 isn't one of the ones typically associated with that problem. The guy who checked it out thought there may have been some leakage at one time, but it was just a discoloration of the board from long use. If you saw the inside of the amp, it looks damn near new. That's what kinda' blew my mind when they couldn't find the problem. If I end up selling it here, I'll crack the top and take a pic in the name of full disclosure.

I was actually going to send it to Big Sky for a restoration/repair... then the next day after I got a quote from them, I saw the Parasound here on the forums and ended up getting it for basically what I would have paid to have the Adcom restored. But if the IC was the problem (and I'm still gonna hook it back up and run it for a few days with the new cables to make sure), then the Adcom is probably in perfect working order. Like I said, I'm still not heartbroken that I ended up with the Parasound, because while the Adcom was a very nice improvement, the Parasound has a little better synergy with my older Polks. The Adcom is fantastically detailed and definitely improved music on my setup, but the Parasound has a slightly warmer sound to it that seems to work better with my RTi70s (which kinda' helps make up for their mid-bass deficiencies). Like I said, SYNERGY.

And honestly, a few feet out of a 1,000 foot spool doesn't sound unreasonable to me as far as defects go. BJC has been easy to work with and if I had known way back when that was the issue, they obviously would've made it right. Hell, I'm impressed that they're gonna send me a replacement just based on essentially the story I posted here, especially after 8 months and without even asking me to send the cable back to them. To me, that's solid business practices.

Clipdat

Nice, glad this story is going to have a happy ending and that you like your new Parasound. I ordered some speaker cables for my computer speakers from BJC and they made a noticeable difference. Glad to hear that their support is also solid. Stand up company!