Backyard Guitars 509.308.0845

THD BiValve
January 9, 2008, 11:04 pm
Filed under: amps | Tags: , , ,

The BiValve is the versatile tube junky’s dream that you’ve already heard about. The power tubes are swap-outable in any combination, as long as they are octal based. It comes with the stock EL34s, but you can experiment with KT77s, 6V6s, E34Ls—whatever you want—and you don’t have to rebias when you swap tubes. It also has a built in Hot Plate attenuator so you can get a maxed out sound at a lower volume.

As you might expect, the sounds you can get from the BiValve range from garage nasty to AC/DC rockin’ to deep clean. It all depends on the settings you choose and, of course, the tubes you put in. $1395 retail.

THD BiValve


THD Heads
January 9, 2008, 10:39 pm
Filed under: amps | Tags: , , ,

The Flexi-50 is, as you may have guessed, a 50 watt head (switchable to lower wattage) that can take any octal based power tubes. Unlike the BiValve, you do need to bias each time you retube, but it’s pretty simple and instructions are included. It’s a single channel amp, but comes with a foot switch to initiate the Boost and Master Volume functions. So it’s a footswitchable single channel amp. How many of those have you seen?

In the words of Ed Degenaro of THD, the Flexi makes the BiValve sound broken. That isn’t to say the BiValve sounds bad, but that the Flexi sounds great. Obviously. Some people have said it sounds slightly Marshally, and I can see what some people mean by that, because it has that raw, throaty roar a Marshall has when it’s doing it’s thing, but it also has a pristine clean setting. In between the pristine and the roar are a wide variety of noises that will keep you happy for a long time.

You can hear sound clips at, or make your own sound clips by visiting the shop. $1795 retail.