Fender Twin Reverb

One of the most venerable vacuum tube guitar amps ever made (the Fender Bassman being the other). Like all Twins, the amplifier uses four 6L6 output tubes (instead of 2) in a push-pull configuration, and use two smaller speakers instead of one 15". This resulted in much louder obtainable amplification, as well as a tighter, punchier sound.

Properly, it's a "Fender Twin Reverb", but nobody calls 'em that. Colloquially, it's just "Twin", or sometimes "Fender Twin". They've been made by the Fender company (under varying ownership) since the late 1950s, I believe. "Twin" what, you ask? Good question; two speakers, two input channels, something like that. I think these nominally put out 80 watts, though it might be a hundred. It's a loud bugger either way. God, I love it.

The sound is clear and thick, or a warm feral growl when you start to push it. Have you heard Exile on Main Street? That's a Fender amp sound. That whole record is a love story about Fender guitar amplifiers, their many voices, their many moods, and their beautiful, beautiful souls.

The two speakers are 12" in diameter. Like most Fender guitar amplifiers, it has two separate input channels: The first has volume, treble, midrange and bass pots, and a "bright switch". The other has all that, plus tremolo rate, tremolo depth, and reverb volume. The tremolo is mislabeled as "vibrato". Each channel has two input jacks: Low gain and even lower gain. On mine (late 1970s CBS), the master volume knob is also a push/pull switch which provides a slight gain boost: This is the most useless feature ever invented, because if you've got time to lean over and fiddle with the amp, you really don't need it. The first of the two channels, the "normal" channel, doesn't overdrive as soon as the other. Many poverty-stricken bands have run one or more mics into that spare channel as an ad-hoc PA.

The reverb and tremolo can be switched on and off with a foot switch; there are two RCA plugs on the back to plug the switch(es) into. The reverb defaults on, and the tremolo defaults off.

Naturally, the reverb is a spring reverb, with (IIRC; I don't feel like disassembling it right now) five springs. It's located in the bottom of the cabinet, and the signal to and from the unit runs through little cables with male RCA plugs on each end. The springs eat up a lot of gain (they're mechanical, after all), so there's an extra preamp stage on the returned signal. This is true of any spring reverb. Here's a neat trick: You can bridge straight across from reverb out to reverb in, and get a beautiful, fierce, massive, roaring distortion out of the thing, the like of which the amp just won't do under normal conditions. What does this do to that poor extra preamp stage, or to the massively overdriven tube(s) thereof? Nothing good, I'm sure. It's not something I do very often.

It is 26" wide, 20" high, and not quite 11" deep at the base of the cabinet where it is deepest. Like most guitar combo amplifiers, the back of the cabinet is open ("finite baffle"). There are pivoted "legs" on either side of the cabinet, which swing back to be stopped by pins: The idea is that you can tilt it back that way so it rests facing about thirty degrees up from the horizontal. The utility of this feature is obscure to me.

In addition to four 6L6GC tubes in the power amp, there are (IIRC) four 12AX7's and a 12AT7 in the preamp section. The output transformer is big. The chassis is like a tank (though not as tanklike as a Mesa-Boogie; I've got a Boogie 1x12" combo that weighs almost as much as the Twin does¹.)

Mine weighs damn near as much as I do³, if not more; well over 100 pounds (~45 Kg). It has four removable casters to roll it around on. It's not so stable on the casters, so you take them off when playing. (Look, if you never bump into things while you're playing, you're just not doing it right). With an open back cabinet, you can stick the casters onto the speaker magnets so they don't get lost.

Mine has aftermarket Pyle speakers, which sound wonderful. I once played a Twin of about the same vintage which had stock speakers, and it sounded really thin and lousy. Naturally, the speakers might not have been the problem there. I'm no amp tech.

Last time I retubed the thing, around 1994, the full set of tubes ran me about $120. I seem to recall having paid about $350 for it in Phillipsburg, NJ around 1989; I'm not sure if you can still find one in good shape for that price any more.

---

¹ Two amps? Yeah, sentimental reasons. There's also that 1965 (April²; "transitional CBS" I think it's called) 50 watt Fender Bassman head that I have absolutely no use for (nor ever did, come to think of it), but still can't seem to get rid of. It's in fair condition at best, anyway. It's not worth too much.

²That's April '65 if the arcane "date code" on the chassis is to be trusted; it's surely around that old, and it's got the pre-CBS gold grille-cloth and the "swoosh" logo, so I'm pretty sure I'm in the ballpark at least.

³Some time later: That figure was based on some deluded notions based on my weight back when... well, back when I still dragged amps around. That was a long time ago. Let's discuss something else now.

Personally, I have a few things to add to wharfinger's entry, though I know this is not a bbs.

Firstly, a lot of Fender twins are 100 watts, and most of the rest are 135 watts. This brings me to the division between the two. I'm guessing (with a reissue here) that most of the CBS and later models that are Blackfaces are 100 watts. Blackface twins were made throughout the entirety of the Twin Reverb run, and are what are being reproduced today. The difference, beside the output wattage, is that the Blackfaces do not have a master volume knob.

The other version, the Silverface, was produced various years during Fender history. These had a shiny metal face instead of a black plastic one, and both inputs ran through a master volume pot, which pulled out to add a gain boost. These amps also put out 135w, and were used by modern day guitar heroes like Kurt Cobain. the good thing about the minor gain boost is that it added enough growl to the signal that also heavily used effects such as Ibanez TS-9 Tube Screamers (which don't provide a large amount of overdrive) don't sound like pussy cats.