Bob, Considering we burn-in, test, grade and carefully select each tube we sell I don't think $35 is ridiculous. Also, our tubes have a 90 day warranty. Regards, Jerry/AI's Service Mgr.
12 responses Add your response
I've been going with NOS tubes and they've lasted years. I have a pair of JAN's that are still alive after two years.
The big question is "Do you power off the M3A or use the stand-by mode?" I don't. I leave everything on all the time. All The Time.
My cdp has been on 5yrs and has never had a problem. Electronic gear doesn't like powering up and down.
I have had numerous AI products over the years and never had any trouble using AI's recommended tubes. They have always performed well and held up just fine.
You can also contact Kevin Deal at Upscale audio. The Russian type II and III tubes work well along with the "Rocket" tubes. You can read about these at www.upscaleaudio.com His website gives the price and description.
Audible Illusions advises caution when using NOS tubes in ours or several other mfgs open-loop no-feedback circuits. Also the 6DJ8 design was never really intended to be used in high performance audio circuits. They worked great in TV sets and oscilloscopes but they tend to be microphonic due to their small plates and thin mica structures. Most 6922 tubes have heaver mica structures and exhibit less microphony. We've found that the Russian, military grade, tubes perform the best in our circuits.
Regarding leaving your preamp on all the time, please understand the optimum life for good tubes is 2-3000 hrs. Our stand-by circuit prevents thermal shock and, over the past 20 years, we've proven it prolongs tube life. Regards, Jerry/AI's Service Mgr.
The AI supplied tubes work quite well and in the long run probably save you money and certainly will save you the frustration you're experiencing now. Just spend the money. Heck, I just layed out $140 for a pair of tubes for my newest preamp and it requires a total of nine tubes. There is no free ride, and IMO as a previous AI owner, the performance to cost ratio of these preamps is quite high.
Lugnut makes a good point. Even stock tubes from the Audio Manufacturer are usually tested and screened better.Don't forget they also want there stuff to sound there best.I have been buying stock tubes from Thor Audio for 8 years and never had a problem.Are they a little more expensive that way? Yah a bit ,but I know they have been screened and tested and with that I get great sound with long life...I would go with the Manufacturer.
I have a AI M3A (love it, great preamp), but I only get to listen on the weekends, sometimes every other weekend. I used to leave it on stand-by all the time, but more recently, like this summer with the heat, I have been turning the preamp all the way off (at the wall) off on Sunday night, and back on the following Saturday (or 2 weeks later). Is this going to be better or worse for tube life than just leaving it on stand-by at all times (which is certainly worse for the electric bill and the enviroment)?
Docknow, Judging from your message, I see nothing wrong with disconnecting AC from your M3a/audio system during long periods. I highly reccommend this practice during lightning storms. Your M3a uses apx 45 volts which won't make much of a dent in your electric bill. Don't know about the rest of your system. Regards, Jerry