I used to think that burning in cables must be the most soul-destroying of all audio chores … right up to the point where I acquired a new phono stage! Rumour had it that between 250 and 500 hours of play time would be necessary for its sound to blossom, which was going to involve a huge investment of time (you can’t just stick a turntable in ‘repeat’ mode) and money. Remember – stylus life for a top quality cartridge can be as little as 1000 hours, so to sacrifice a major proportion of that merely to burn-in the phono stage is not at all an attractive economic prospect. Fortunately, a product I’d chanced across during some random web surfing turned out to be the answer to my prayers.
Granite Audio’s CD101 Burn-in and RIAA test disc falls squarely into the “so simple it’s brilliant” category. Red Book CDs, as we know, are specified to realise a maximum output level of around 2 volts. On the standard CD101 disc, Granite Audio’s Don Hoglund has encoded a sequence of test tones, noise and music that, when played on a normal CD player, produces an output level of just 4 millivolts – equivalent to a typical Moving Magnet cartridge. So, all you have to do is connect a CD player to your phono stage’s input, set the CD101 to infinite repeat and go enjoy yourself while it burns in – job done! Those of us with low-output Moving Coil cartridges are more likely to want the CD101.1 variant (sold in the States exclusively by Music Direct); identical to the original but for an additional four-minute track, encoded at a lower 0.7 millivolt output level. While either disc can theoretically be run into an MC input, exclusively using this MC track avoids the risk of overloading an input that is particularly sensitive, or has limited headroom.
So, using Granite’s disc to burn in a brand spanking new phono stage is an absolute no-brainer. But if your current phono stage has plenty of hours on it, you don’t plan to invest in a new one and have no use for the selection of precisely-calibrated test tones … then the CD101 has nothing to offer you, right? Well, actually it does! While Granite’s website doesn’t broach the subject, it is often suggested that real-world phono signals are so low in level that they never properly burn a phono stage in anyway, even after years of use (similar logic appears to support the value of cable cooking your phono interconnects, but that’s a whole different can of worms). Hence, the theory goes that even a well-used phono stage can benefit from periodic exposure to the assortment of wide bandwidth signals provided on this disc … something I was willing and able to put to the test, given that my preamp’s MC phono input has seen regular activity for the last 20 years! A true A/B comparison was impossible, of course, so I did the next best thing; listened carefully to a sequence of favourite vinyl reference tracks, then left the CD101 disc playing continuously for 18 hours overnight, and revisited the same tracks at identical volume the following day. The difference really amazed me! There were obvious and significant gains across the board – more presence, liveliness, resolution, dynamics, transparency and bass control … in fact, I’ve never heard the old girl sound close to this good. It’s one of the great enigmas of this hobby that you can own a component for so long and never truly find out what it’s capable of … so don’t let it happen to you, OK!
Hopefully it goes without saying, but I’ll repeat the manufacturer’s warnings anyway – the disc is “not engineered for human consumption” and should not be listened to (its RIAA-compensated test tones are intended for monitoring through the preamp’s tape output). Most particularly, you should never attempt to play a conventional CD through the phono inputs (a potential Doomsday scenario, I suspect!). One final piece of personal advice; it’s not just phono cartridges that have a finite lifespan, CD drive mechanisms do too. I’ve seen a typical design life of 3000 hours quoted so, rather than use my prized digital front end for the task, it made sense to outlay $40 on a ‘disposable’ DVD player to perform all burn-in duty. Taking this approach also helps to safeguard against you (or anyone else in your household) accidentally inserting a normal CD while your player is connected to the phono sockets.
Granite Audio’s phono burn-in discs have been around for a good few years, yet a straw poll of my audio associates proved they are still nowhere near as well known as they should be. Priced very fairly at around the $35 mark, this brilliant accessory is an essential component of every vinyl-lover’s toolkit. Equally invaluable for treating a brand new phono stage or breathing fresh life into a well-used model, periodic re-application will also help to maintain peak performance. I can barely conceive of the time and effort that would have been necessary to get the new phono stage up to speed, had I not stumbled across the CD101.1 disc … and for that, Don Hoglund, you have my profound gratitude!