Field Notes is where we share insights, information and opinions on subwoofers, hi-fi systems and the joy of sound. So, put on your favorite album, mix yourself a drink and kick back, you might be here awhile.
When we set out make T/i, we wanted to make the best possible
subwoofer for small to mid-size systems, adjusting only it's size,
not it's speed, clarity or chest thumbing low-end.
"By a country mile the No.25 produces the fastest,
tightest bass I have ever heard in my cinema room.
This might not be what you would expect from such
a sizable driver – we tend to think of smaller
woofers having the edge in terms of speed.
Yet each percussive event is so eye-wateringly
taut it has sharp edges."
- Richard Stevenson, Home Cinema Choice
There’s just something about tubes that are incredibly wonderful. Whether it’s the lovely orange glow from the power tubes, or the classic retro styling of many tube amplifiers or the lovely, harmonically rich sound of good tube amps. Whatever lights your fire, tube amps—even for those of us who mostly fire up electrons in a solid state–are fantastic. And when it comes to adding a REL or two to your tube rig, there’s are a trick you need to know.
First, understand that tube amplifiers don’t actually want to drive your speakers. They prefer the easier-to-drive impedance that their transformers provide. Think of it this way, the closer to 0 ohms a speaker load gets, the closer your amp is to driving a dead short. Tubes like to see around 30-50 ohms, speakers are down in the 4-8 ohm range. Which one is closer to a dead short? The speaker. So tube amps have this wonderful trick; they use an output transformer–the big heavy blocks at the rear of tube amps—which is nothing more than a lot of wire wound around an iron core. The whole purpose of this big coil, an output transformer, is to give the tubes a nice comfy impedance to drive, and thence on to your speakers. The transformer is like a warm wading pool placed between a hot tub and a cold swimming pool.