Poor man's IC cooker?


I'm in the process of testing a number of new ICs for my preamp to amp link, and was debating what to do about burning them in. I want to get a quick turnaround on the burn in so I can spend more of the 30 day trial period offered by the manufacturers listening and comparing.

Since my peamp has dual outs I figured I could use one set as a burn point, letting me listen to the other output while cables are cooking on the first. So what I did was go to Ratshack and buy their 4 jack RCA phono board (274-322). I soldered 100KOhm 1/2W dummy loads to each of the outer jacks. I plug the cables from the preamp to the loads and have a nice stable load for burn in. I decided to use my FM tuner as a source. I have a Yamaha T-2, which allows me to tune so that I get a combination of FM white noise and some signal from a selected station. I set the preamp to half volume and let it go. My only concern is whether that's a good signal mix for burn in.

I figure 3-4 days of this and each pair of ICs will be burned in pretty well. And I can do it 24 hours a day without keeping myself awake. Does this sound like a decent plan?

I will, of course, run the cables with actual music for at least a couple of hours when they get inserted for listening.
tonyptony
That's a fine idea. I do a similar thing with speaker cables, hooked to the amp but not to the speakers. I place 8ohm power resistors on the speaker side of the cable. This way, I can burn them in without having the speakers play 24/7. For the sound source, I use an FM tuner also but fully tuned to the station. I should try your tuning method sometime.
Agreed with others, oughts to work fine, couple thoughts tho.
Twere it I, I'd probably drop the resistors from 100K to the minimum I could get by with without taxing the source and probably have the tuner sitting on a station that played music similar to what I listened to. However, your method may be better.
FWIW, last time I was in a goodwill store picking up $1.88 used albums I noticed a LOT of dirt cheap used recievers, cd players, etc.. This would keep your pre-amp from doing burn in duty and could prevent any negative audible effects from having additional cableing connected to the 2nd pre-out.
I'm glad to hear that this seems like a good way to go. Jeff, unfortunately the only sources I have are my turntable and CD player, neither of which I want to run for a couple of hundred hours straight.

I picked 100KOhms because that approximates the input impedance of my amp. I've been wondering if I would actually be able to do a better job if I cut that in half. That would still be high enough to provide a decent high impedance source for my preamp, and as it is pretty much a resistive load I shouldn't have any trouble with any sort of weird reactance. Or I could just turn the volume up on my preamp, I guess.
Hmm, that's a great thought, Jeff. We do have a Goodwill store a short drive away.
I just had a thought. I'm sure this has been discussed, but WRT dropping the load resistance... what is the more important component to burning in an IC - voltage or current? If I drop the load value I also drop the voltage across the two conductors in the cable. Granted I do increase the delivered current, but which one is more important?
Isn't a value that low a little risky, Bob? Is there a concern that a preamp may not be able to drive into a load that small without potential problems?
Not risky at all; I wouldn't have recommended that load if there were any issues in that regard. Even if you are driving at a full 1 volt line output level you are only running 1.6 milliwatts of power at 600 ohms. Even at 10 ohms load you are operating at only 100 milliwatts; any preamp should be able to output that without even flinching.
Okay, I see that. But that would suggest current is more important than voltage for IC burn in. Do we know this to be the case? I mean, it is a tradeoff to some degree. Isn't a higher voltage better for dielectric break in purposes?
Wally on his web site has a Cable cooker as part of his Deluxe Analog Shop.This owners manual instructions can be downloaded.
He recommends 5 Volts cooking no more for IC's,and 2 Volts no more for phono cables.
Hope this helps.
Tonyptony......the reigning theory is that voltage deals with the dielectric, and current deals with the conductors. This, of course, is simplistic, but it seems to pass muster with the engineers. I strongly suspect there is more going on with this, but to my knowledge no one has devised the tests nor gear to properly develop and/or perform the necessary tests to divine the answers. I personally think that much of what is going on is at least at a micro-level, and most likely at a nano-level....witness changes to turntable motors and sound with different belts of differing materials, and plugging turntable power supplies into power line conditioners....*something* is going on that has not been satisfactorily explained. The same for the phenomenon re: the conditioning of cables.

And as an aside, 76....the Cable Cooker(tm) is a trademarked name. Wally makes his own device, but it is not the Cable Cooker(tm). And the ~12 volts continuous that the Cooker provides (along with high current and a frequency sweep) does just fine with IC's, and phono cables. References are available. :--)
Combine all the concepts for the "best" cable cooker.
Buy a used receiver, and if you find one for $1.88 that's great... Tune to FM noise between stations and defeat the mute. You have those connectors from radio shack. Connect one side to the speaker-out!
The other side is the load. Get power resistors - 8.2 ohm 25W units. These should work well with most small receivers.
Connect the cables between the receiver and the load and slowly increase volume. You stop when the resistors get way too hot... Give them a few minutes at each step before you increase the volume level.
For a safety factor you may add a small fan to cool the resistors and the receiver. Most receivers are not rated to work at 100% duty cycle close to full power!
Cook cables for at least 6 hours. Some cables with heavy dielectric may need more than 24 hours even on this kind of a cooker.
Thanks for the link, Matty. The Hagerman looks pretty nice. A number of positive posts about it from Audio Asylum users, too.
The prob w/ FM is that there isn't anything below 50HZ or above 15kHz. And there sure isn't anything resembling dynamics...

I built the Hagerman and it works OK, though not as flexible as the Audio Dharma. I also am running the Isotek CD w/ great results, and it's only a 30 min track. On repeat play, with a series string of cables, it may be a nice alternative.