"Fixing" the Sony a9's overheating issue....hmmm.

Many years ago, while attending the University of Texas at Austin, I worked part time as a sales person for a middle-to-high end audio store that was located just off campus in the Dobie Residence Tower. We were on the bottom floor. We had cool stuff.

For an electrical engineering student it was more or less a dream job. I got to play with all the latest audio gear while listening to the favorite music of my generation. But we had clients who created interesting challenges...

One of the huge audio amplifiers we sold was from a company called, Phase Linear. Its claim to fame was it's ability to deliver lots and lots of power. Speaker-meltingly intense power. And there were some speaker systems that thrived on buckets of power.

I sold a system with the Phase Linear power amplifier driving a set of very good sounding, but inefficient speakers to an music lover who liked his music nice and loud. Wall shaking loud. Front row concert loud. He loved the way the amp and the speakers worked but he had one little problem: the fuses in his amplifier would fail frequently. Every week or so he'd come into the store, complain a bit about the amp shutting down, and buy another little box of fuses.

Then I didn't see him for a couple of months. He finally came back into the store to look at turntables (they were a thing back then) and just to visit a bit. Browsing like me, now, at camera shops...

I asked him how his Phase Linear amplifier issue was going and he told me that he'd permanently fixed the problem. No more blown fuses. All music all the time.

I was impressed and thought to pass his wisdom on to other customers in similar straits so I asked him how he fixed the issue.

"paper clips." That was the answer. He'd run out of fuses late one night and tried wads of aluminum foil. That worked but the contact wasn't as good as it could have been so he experimented with conductive materials at hand and found the paper clip to be the optimum "firmware upgrade."

In other news, Sony has fixed the a9 overheating issue with a "firmware upgrade."

(every ten degree celsius rise in operating temperature above the optimum target temperature of a semi-conductor device shortens the life of the device by half. Or so I am told... your engineers may disagree). 


  1. Kirk,

    Here is a more complete guide to fuse replacement:


  2. Hey. Turntables are still a thing in hipster-land. sat gathering dust on a shelf just next to the Canon AE-1 ;)

  3. Hi Kurt,

    Memories! I had a Phase Linear 400 and for awhile ran stacked Advents (remember that? you'd invert the top pair to align the tweeters next to one another). Don't recall serially blowing amp fuses but made sure the speakers were always fused, as with that much power it was easy to cook the voice coils. Advent had a "lifetime" warranty so the joke was on them.

    Remember SAE gear? The (enormous) amps could literally catch fire. Now that's entertainment.

    Audio nerds. Once a mid-priced hobby today there's no literally no limit to what one can spend. $30k for a record player, sorry, analogue deck? No problemo. Or you could buy a Honda.

  4. I'd forgotten about Phase Linear amps until I saw one in the Pink Floyd exhibition at the V&A Museum in London a couple of weeks ago. They were nice, but I found a better solution was a lower-wattage (and cheaper) Marantz amp into a pair of (un-cheap) Klipschorns. You still needed seat belts on the sofa to keep from getting bounced around by the sound.

  5. Ah yes, Audio Concepts. A great store Kirk, and I forgot you worked there. While attending UT I worked at the Co-Op Camera and Stereo departments and we sold Dyanco kits. So I assembled two mono Dynaco Ml\k150 tube amps, bought a pair of Dahlquist 10s with the sub from Audio Concepts, and listened blissfully to them via the Dynaco Mk5 preamp and a Pioneer high end preamp that I can't remember the model number. Having assembled even Heathkits earlier in my youth, I was always too scared to try the paperclip solution :-)

    Now that I have a bit more time, I am enjoying your teaching blogs and your work.
    OC Garza


Comments. If you disagree do so civilly. Be nice or see your comments fly into the void. Anonymous posters are not given special privileges or dispensation. If technology alone requires you to be anonymous your comments will likely pass through moderation if you "sign" them. A new note: Don't tell me how to write or how to blog!