Topic: AKG A61 swivels producing noise, loss of signal

[groovon]

Anyone else had irregularities with their A61 swivels? I've had one pair for years, bought new, never a problem and they never seemed to change the sound at all that I ever noticed.
I just bought a second pair off Ebay recently, and right away I hear noise out of one channel (sort of random, low-to-mid freq 'waffle', similar to wind noise), and a loss of signal on the other (or perhaps both). I've swapped the swivels channel to channel, and the noise follows. I tried rotating the suspect one, removing/reinserting, etc.
Remove them from the 460s and there's none of the noise at all, and signal level seems to go up as well. These two 460s are pristine and have tons of output.

It's puzzling, as these swivels look in excellent condition, and there's not much in them that could go wrong. The pins look straight, the threads and everything clean. I'll put them under the magnifier tomorrow and do a resistance/continuity check, maybe even take them apart and check the wire and solder joints, etc. I suppose it's possible a socket has loosened, or pin may have become worn...

Anyone have a contact for friendly AKG repair in or near CA? It's been 15 years since I dealt with anyone there, and I think they may even be out of state now.

Thanks!
Dave

[Dkrogh]

I can't say for certain but I don't know if the a61's are servicable by AKG.  If you want them to look at them Land Audio is the certified service for the US.

AKG Authorized Service Agencies:

AKG Acoustics, U.S.
+1 818-920-3237
akgusaservice@harman.com

Land Audio Services
471 Walton Ferry Rd
Hendersonville, TN 37075
+1 615-338-4443
landaudio@comcast.net

that info is taken from AKG's website: http://www.akg.com/site/distributoren/powerslave,id,12,nodeid,28,_language,EN.html

[groovon]

Thanks. Wow, they sure have delegated their service a long way from CA... AKG used to be 20 miles from here, and sometimes they'd even take a look at a mic while you waited!
The only thing I can imagine might need replacing is a pin, or one of those intricate little sockets. Doubt it could be 'resprung' successfully... I'm hoping a good clean might do the trick. /fingers crossed

[darby]

contact Richard Land

Land Audio Services
471 Walton Ferry Rd
Hendersonville, TN 37075
+1 615-338-4443
landaudio@comcast.net

I've had him do work for me in the past and he is quite good

[groovon]

Problem solved.
I put the swivels under a magnifier, and on one of them there was a small amount of yellow gunk (looked like dried and hardened rubber cement) around the lower third of the center pin. Some contact cleaner on a cotton bud and a bit of gentle scrubbing got rid of the gunk (there was one bit that was really stuck on there, quite a way up the pin). Did an overall cleanup with the contact cleaner including all of the threads on both mics and swivels (something I can well advise, if you've never thought to do it). Put 'em back together and voila, crystal clear output, no noise.
If you have A61s and C460/480s (or you swap CK6x capsules around a lot) I would seriously give them all a darn good regular clean, if you don't already do so - it can make a hell of a difference.

thanks guys

Dave

[DSatz]

groovon, congratulations on finding and fixing the problem. The swivel is in the ultra-high-impedance part of the microphone circuit, so any contamination can cause serious problems.

As to the change in service arrangements, AKG went on an acquisition kick in the 80s and 90s, borrowed a lot of bank money to do so, then got caught in an economic downturn in around 1993. Its bank panicked at a single-year loss and sold its majority interest in the company to the giant "Harman International Industries, Inc." conglomerate (which also owns what's left of several other formerly great companies such as Studer and JBL). AKG's branches outside of Austria were then completely reorganized under the new ownership.

By all accounts Richard Land does excellent work. I've only sent him two microphones for repair--both bought on eBay from buyers who'd said that the mikes were in perfect condition, but in fact both capsules needed replacing. I would say that about half the condenser microphones I've ever bought on eBay--which might be about 20 in all--have needed new capsules despite the sellers' claims. In most cases it doesn't seem to be overt dishonesty (though I've certainly come across that more than once), but more often it seems to be a lack of knowledge on the part of the seller, or in some cases, not wanting to know the actual condition of the mike. So I'm never surprised when I hear that something bought on eBay doesn't work.

--best regards

[groovon]

Hi DSatz, thanks - you're right, it doesn't take much to really upset things at that point in the circuit. There's actually a noticeable insertion loss using good swivels with clean contacts, something I'd previously been blissfully (wilfully) ignorant of.

(edit) I just found some old AKG spec sheets for the similar C451 swivels and the tubular capsule extensions, including the 3-foot-long one (which I assume are passive devices). AKG claim 'no insertion loss' with these, which I find almost impossible to believe. Not sure whether they made the same claim of the C460B accessories.

Possibly because of the ease of disassembly, I think people tend to give a quick visual check to the cap/body connections at best, and take it for granted things will just keep on working. Well, they're termed 'self-cleaning' contacts, after all!
BTW, the adhesive(?) residue (which looked like it may have migrated out of the pin/insulator joint) was the perfect color against the gold pin to escape a casual inspection.

Interesting bit of history there, thanks. Sad that it all comes down to money in the end. I bought my first pair of 460s just after they'd brought out the CK60-series caps (at which point they no longer needed the funny little adaptor to accept C451 caps). It must have been the early/mid '90s. The 460 preamp was the quiestest condenser mic around then, and was advertised as having been 'designed for digital recording'. I still love them for their transparency, low noise, and low phantom power requirements.

Also BTW, the Ebay seller in this case was completely honorable, and offered to accept a return if it came to it. If his name ever comes up here, I'd happily endorse him. I know he reads this forum and may even be a member.

cheers
Dave