Why 2 channels in TWIN

Larry Robbins · Post by **Larry Robbins** » 18 Jun 2006 7:00 am

A few of the posts about Twin Reverbs of late has got me wondering, why did Fender make the amp with two channels? Most folks, myself included, use the 2nd channel for the lush reverb and the occasional call for tremlo. I dont think I have ever used the first channel. Of course being a young buck
"49" it could just be for some reason long before my time

. Any thought?[This message was edited by Larry Robbins on 18 June 2006 at 08:40 AM.]

Jon Light (deceased) · Post by **Jon Light (deceased)** » 18 Jun 2006 7:13 am

Like you, I always use the reverb channel--to the point that I made the simple (and sometimes controversial) mod to put reverb in Ch 1 too. With one less stage of gain, CH 1 is a purer and, to some, more toneful channel. I wonder if the designers were concerned with losing this channel in pursuit of an 'effects' channel and decided, rather than compromising, to make one of each. It would have been so utterly simple to have effects on both sides so I've got to believe that it was a deliberate choice.
It would be interesting to know the actual thought process behind this decision.

Larry Robbins · Post by **Larry Robbins** » 18 Jun 2006 7:33 am

How long have these amps been around? Mine is a 65Re.and I know they were around in 63.
Maybe the first channle was for the old"Mic in the first channel, guitar in the other" like some amps used to do?[This message was edited by Larry Robbins on 18 June 2006 at 08:39 AM.][This message was edited by Larry Robbins on 18 June 2006 at 08:40 AM.]

Mike Kowalik · Post by **Mike Kowalik** » 18 Jun 2006 7:43 am

Recently there was a Fender Twin for sale on eBay that was said to be a '57 model....

Bobby Lee · Post by **Bobby Lee** » 18 Jun 2006 7:51 am

Randy Smith of Mesa Boogie fame got his start modifying Fender amps to channel-switch with one input. I'm sure that some players used both channels before that with a simple A/B switch. It's pretty handy to have two different tones available.

Also, high-impedence microphones were common back then. It wasn't unusual for people to plug a mike and a guitar into the same amp for small venue gigs and rehearsals.

And then there's the accordian players who leeched from the guitarist's amplification when confronted with a big room.

This is why, to this day, guitarists hate accordians. It has nothing to do with the awful noise they make.

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<img align=right src="http://b0b.com/b0b2005.gif" width="78 height="78">Bobby Lee (a.k.a. b0b) - email: quasar@b0b.com - gigs - CDs, Open Hearts
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James Morehead · Post by **James Morehead** » 18 Jun 2006 7:54 am

Larry, reminds me of those teenage "garage band " days--mike in one channel served us for lack of a P.A. Sounded pretty good if you played loud enough! So we thought! HA!

Jon Light (deceased) · Post by **Jon Light (deceased)** » 18 Jun 2006 8:05 am

Mike K---before the Twin Reverb, a "blackface" amp, there was the Twin Amp--a tweed amp. Although a predecessor, it's a pretty different amp. The reverb amps came in....63?

My first amp, for my Farfisa mini compact organ, was an Ampeg flip-top. Ah yes--an accordian input. My organ would only play Lady Of Spain when plugged into that jack. Cool.[This message was edited by Jon Light on 18 June 2006 at 09:07 AM.]

Jim Sliff · Post by **Jim Sliff** » 18 Jun 2006 8:11 am

In the 50's Fender was also making multiple-channel amps - "2 hole", "3 hole" and "4 hole" - all with the intent of more than one player using it. Often one (or two) inputs were "mic" channels with different input impedance.

The first brownface (precursors to the more familiar blackface and silverface) amps had the same two-channel arrangement we're familiar with, although in some the reverb worked on both channels.

But the "normal" and "vibrato" (actually tremolo) channels were designed to be used as previously stated - either two players plug in, or a player and a singer. The lower-gain "normal" channel was seperated and simplified so the signal; wouldn't get loaded down and muddied with too much stuff hitting the reverb tank.

FWIW, try using an outboard reverb (or no reverb) and playing through the "normal" channel cranked up. the lower-gain structure means it'll stay cleaner with more headroom. Sounds REALLY good for chunky rhythm guitar - I like that channel with big Gretsches and Jaguars. It is a very rich sound and more articulate, since it's not running through a bunch of extra circuitry.[This message was edited by Jim Sliff on 18 June 2006 at 09:12 AM.]

Ken Fox · Post by **Ken Fox** » 18 Jun 2006 8:54 am

Channel one has two gain stages (each 12AX7 provided two gain stages). Channel two has three gain stages (uses 1/2 of V4, the other half is reverb recovery). Because of this, channel 1 and 2 are out of phase. With two players plugged into the amp you would get phase cancellation, especially apparent in the lower frequencies. Maybe that was a good thing?? Never tried it myself. However if you dasiy chain both channels with your guitar you will quickly discover it is not a good thing.

A great cure for that is to mod channel 1 to have reverb and tremolo, resulting in sharing of the 3rd gain stage with channel 2! Makes the amp a lot handier if you also voice channel 1 for steel as well (change 100K mid slope resistor to 56K). I like this mod for 6 string as well!!

Donny Hinson · Post by **Donny Hinson** » 18 Jun 2006 9:13 am

Because of this, channel 1 and 2 are out of phase.

Yes, that's how I was introduced to the "phasing" effect. A little-known mod I developed involved adding another jack in the volume pedal (wired slightly differently), and then feeding both channels of the amp. Then, by working the volume pedal, I got that "phased" effect. (I fooled many musicians with that trick!

) Later, a company in the late '60s (Maestro, I believe), developed a solid-state pedal to do the same thing.

David Doggett · Post by **David Doggett** » 18 Jun 2006 12:41 pm

If you look over on the Fender Amp Field Guide (http://www.ampwares.com/ffg/), you will see that the very first Fender amps all had mic jacks and two guitar jacks. Later they gave these jacks separate controls or "channels." The normal channel was for the mic, and didn't need the tremolo and reverb that later were added to the guitar channel. The multiple jacks per channel were for two players to use the same amp. Their tone and volume could be controlled sepatately by the controls on the guitars. In the '50s and early '60s I saw plenty of players use all these jacks for small venues without a PA or without enough mikes for everyone.

Years ago I use to run a stereo cord from the headphone jack of a home stereo receiver into the two normal jacks on my Fender amps. I unplugged the speaker and plugged in a set of headphones with an adapter to split the signal into both ears. It wasn't high fidelity, but I could practice along with the radio, tapes or LPs. At one point I had a 15" JBL in a separate cabinet. I had a Radio Shack tweeter and a crossover network I could use to make it a mono hifi speaker system. I would take the stereo signal from a home receiver headphone jack, run it into the two normal jacks of a Fender amp, and out the speaker jack into my makeshift mono speaker system. This arrangement cranked out way more volume, especially bass, than our typical cheap hifi receivers. I used it for home dance parties in the '60s. Turn out the lights, pass out the refreshments and crank up the volume on the Stones, the Byrds, Hendrix...ah, those were the days.

Incidently, I think the Twin got its name because of its two speakers, not the two channels. The Twin channels were always pretty much the same as the Super, Pro, etc.

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Student of the Steel: Zum uni, Fender tube amps, squareneck and roundneck resos, tenor sax, keyboards

[This message was edited by David Doggett on 18 June 2006 at 01:43 PM.][This message was edited by David Doggett on 18 June 2006 at 01:46 PM.]

Ricky Davis · Post by **Ricky Davis** » 18 Jun 2006 4:25 pm

While touring with Dale Watson all those years; we did many many live radio shows.
We would walk in with my Twin and my steel; his guitar; the bass player and the snare drummer....and me and Dale would plug into the reverb side and the bass into the dry side and had some of our best recordings ever; just like that.
Ricky

Clyde Mattocks · Post by **Clyde Mattocks** » 18 Jun 2006 5:59 pm

Years ago I saw Johhy & Jack and Kitty Wells
at the NCO club at Seymour Johnson (not a joke) A.F.B. Johnny Siebert was playing thru
the reverb side of a twin and they were using the dry side for P.A. I mentioned this earlier in another post, but Johnny
was playing a Fender 1000, D9th to minimize
string breakeage.

I sometimes take a twin out and put a Lexicon reverb in front of the dry side for
my steel and play my tele thru the reverb side. Saves space on small stages since my
normal set up is a Nashville 112 for the steel and a Vibrolux for the tele.

John Billings · Post by **John Billings** » 19 Jun 2006 10:30 am

Somewhere I have a cable that Dr. Z made me. It has a female RCA jack on one end, and a male 1/4" jack on the other. You plug the RCA into the reverb return cable from the reverb pan, and plug the 1/4"er into the input of channel 1 (the Normal channel). This gives you nice control of the reverb. The volume pot becomes a mix control, and the tone pots control the tone of the reverb. I don't recall having any out-of-phase problems, but I haven't done it in quite a while.
I believe the first Twin Amps came out in 1952.[This message was edited by John Billings on 19 June 2006 at 11:35 AM.]

Mike Fried · Post by **Mike Fried** » 19 Jun 2006 10:49 am

John, that is a popular and cool use of the normal channel. There is still a 180 phase issue, but you won't hear it very much because the normal channel is only getting the 100% "wet" signal (from the reverb tank). Very little of that 100% wet signal will phase-cancel when mixed in with the original signal from the vibrato channel. BTW, when using this mod, the original 'reverb' control knob becomes nonfunctional and should be turned to 0 to avoid adding open-input noise to the final sound. Also, the reverb tank outputs a pretty hot signal, so the '2' input jack of the normal channel will yield a cleaner reverb sound than '1'.

Frank Parish · Post by **Frank Parish** » 19 Jun 2006 11:50 am

When I first started out in 65 our two guitar players used one Fender Twin. We thought we were the real deal when everybody got their own amps! I'm using a Vibrasonic so I use the left channel for steel and the right side for lap steel. This is a newer model so it has reverb and tremelo in both channels.

John Billings · Post by **John Billings** » 19 Jun 2006 1:07 pm

Thanks for the info Mike. I used to do that with my 64 Vibroverb. But since the amp has become so valuable, it's safely tucked away!

Jim Peters · Post by **Jim Peters** » 19 Jun 2006 3:15 pm

I use the 2 channel mod all the time. I compress one channel, not the other. It is a great sound for bluesy rock guitar, the original attack thru one channel, a nice bloom with the compressed channel. Here is a cool hint: if you don't want to do the mod, use a dynacomp compressor in one channel. The output from a dynacomp is 180 out of phase from the input. Works great. JP

Gene H. Brown · Post by **Gene H. Brown** » 21 Jun 2006 5:58 pm

Well...my good buddy Ken Fox did some great things to my Vibrosonic when I sent it to him to work on. He left channel two the way it was from the factory with the mid range at around 500hz and then he took channel one and made the mid range at 800hz which gives me the best of two worlds, i can have the old fender sound or the new heavier mid range sound that most steel players prefer at around 750 to 800 hz. Also I have taken the guts out and put into a seperate cabinet and it makes both the speaker cabinet and amp cabinet easy to deal with, weight wise, I love that amp very much sound wise and convenience of moving around. Ken Fox does some amazing things with tube amps and is a great friend to boot.
Gene

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If You Keep Pickin That Thing, It'll Never Heal!

Andy Zynda · Post by **Andy Zynda** » 22 Jun 2006 4:35 am

Why 2 channels?
That's easy. Two is more.
Remember Leo Fender's philosophy.
-andy-