Many of us own vintage amps. Along with the classic tones they produce comes responsibility and maintenance. We make sure they’re loaded with quality tubes and get cap jobs done to keep them healthy and happy. Some of us even use Variacs to reduce the line voltage from our wall to meet the specifications the amps were originally built to work on—usually quite different from the typical 125v coming out of our AC outlets these days. But Variacs are big and heavy, and they’re also dangerous in the wrong hands. Bump the big voltage knob and you’re pushing more than 125v to the amp; back it down too far and you could run into a different kind of trouble. Unless you’re a brave soul, bringing a Variac to the club for your gig is flirting with disaster, since who knows what could happen in a dark and drunken environment! For those who care to go the extra mile (and you should if you own any vintage amp that requires less than 120v) the good folks at Vintage Sound Workbench have created the Tone Preserver.
The Tone Preserver is a dedicated line voltage reducer built to lower the voltage from your AC outlet to provide proper voltage for your beloved vintage amp that was build to run at 110 or 115v. It is heavy duty—built like a tank. I opened it up to see that it was neatly designed and beautifully built, definitely a labor of love. All of the labeling is done on black front plaques with engraved-looking white lettering and white sides. Very classy. Built in what looks like a military gray metal box with a large VU meter and a red chickenhead knob on the front, it’s decidedly simple to use. Plug it into the AC outlet, plug your amp’s power cable into the Line Out and you’re set. On the back are a Power switch, EIC Line In, AC Line Out and a 4-Amp fuse. The red knob is a 3-way switch that allows you to switch between the standard AC voltage coming from the wall or a -6 or -12v reduction. So if your AC power is coming out at 125v you have the ability to run it at 125, 119 or 113v. The VU meter always shows you an accurate readout of what the voltage is.
So, how does it affect the way your amp sounds? It’s subtle at best, but that’s not exactly the point. The point is safety, and anything else is a bonus. Using my digital meter to check the voltage assured me that it was in fact being reduced as stated by the VU meter (accuracy was within about 1v). Knowing my ’67 Plexi was safely running at 113v made me feel good and the amp sounded fantastic. You can never be too safe when running older amps. Let’s just say it was a lot simpler, lighter and safer than running a Variac for a club gig, which is exactly what I used to do. The Tone Preserver is small enough to fit inside your accessory bag. When you pull it out, you don’t have to worry about the setting of the voltage knob, just flip the red knob all the way to -12 and you’re safe.
There are a few things I would do to improve on the unit. First, I would add a light to the VU meter. As it stands there is no light at all and playing in a dark club without a flashlight (you do have a flashlight in your gig tool kit, right?) could make it tricky to see the settings. This could be a backlight on the VU or somewhere on the unit to help illuminate the front panel. The second thing I would do is to have more targeted markings on the VU meter. The meter on the Tone Preserver has indicators for 0, 50, 100 and 150 volts, with lines in between designating 5v increments. This makes it difficult to determine the voltage exactly without too much squinting and math. A big red mark at 120 on the meter would be nice, so you’d know where you are with regards to the target voltage.
The Final Mojo
Aside from those small issues the Tone Preserver is a winner and a must-have for anyone who wants to maintain the life of their vintage amp. It beats the heck out of a Variac for a safe way to power the amp, and it’s a lot lighter and simpler. You’ll also like the tone, because your amp will be operating much closer to its intended optimal voltage.
you own a vintage amp.
every amp you own runs on 120v.
Street $160 - Vintage Sound Workbench - vintagesoundworkbench.com