Which Input Jack to Use When Playing PSG Through Fender Twin

Jim Cooley · From: The 'Ville, Texas, USA

I recently took my silverface Twin in for its 35 year tuneup. The repair technician told me that when playing a PSG through a Twin, I should only plug into input jack #2. He said that the PSG's higher pickup output will overdrive the amp if input jack #1 is used. As far as I know, all of the amp's electronics are factory. Is he correct? Thanks.

-Jim-

Erv Niehaus · From: Litchfield, MN, USA

Yes, I believe that's the channel I use.

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

Why don't you plug into both of them and see which one you like better? There's no stock answer for this question.

Input 1 does have a higher gain, which can sometimes lead to distortion - but also a much higher input impedance, which can have a lot of effect on the tone. If you like the Input 1 tone better and don't get any distortion, you're good to go.

If you like the tone of #1 more and get distortion, you can cut the gain back by using a lower-gain preamp tube like a 5751 or 12AY7 in the first gain stage. If you're using the Vibrato channel (right hand, looking from the front of the amp), that would be the second preamp tube from the right, looking from the back of the amp. If you're using the Normal input (left hand, looking from the front of the amp), that's the first preamp tube from the right, looking from the back of the amp.

I had one hotly-wound PSG pickup which distorted both Inputs 1 and 2 - had no choice but to go to a 5751 to use that pickup. Ultimately, it was too muddy for my tastes, so I swapped it out for a less hotly-wound one - problems gone and it sounded better to me.

Erv Niehaus · From: Litchfield, MN, USA

I believe that reverb is on channel 2.

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

Yes, on a stock amp, the reverb and tremelo are only on the Vibrato channel. But there is a very simple, move-one-wire mod to put the reverb on both channels. I do this with all my 2-channel Fenders. Your tech should be able to do this easily if you want it - it's nice to have both channels available and it's easily reversible with no sign of modification.

Edited to add - I always distinguish between "Normal" and "Vibrato" channels, and then on each of these, there is "Input 1" and "Input 2". Just to be clear - if you're in the "Vibrato" channel (right-hand), then reverb and tremelo are available on either "Input 1" or "Input 2".

Keith Murrow · From: Wichita, KS

Jim, I assume you are talking about the difference between two input jacks on the same channel, rather than the difference between the two separate channels?

If so, I agree with Dave. There are just too many variables to make blanket statements like that.

FWIW, I run a stock MSA humbucker through a Hilton volume pedal into input 1 of the reverb channel of a silverface Twin. I get all the volume I need and very, very rarely ever get the signal hot enough to distort the input. Even then, it is only slight and not objectionable.

Jim Cooley · From: The 'Ville, Texas, USA

Thanks Dave,

I had not played my steel through the Twin in quite a while, but decided to experiment with the tone through that amp again. I do use the reverb/vibrato channel. I played through the Twin's #1 input jack regularly several years ago, with no distortion. When I played through #1 input this time, it distorted. The was also some distortion through input #2, although not as much. I also noticed more hum than usual. I replaced the output 6L6 tubes. That reduced the hum a little, but did not solve the issues. That's when I decided that it would be a good idea to have a repair tech go through it. The tech and I talked about using a lower gain preamp tube. However, he said that input #1 should not be used regardless. I am having him put the reverb on both channels.

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

Yeah, Jim - I also sometimes have issues with distortion on old SF Fenders. I just have to take each individual guitar/pickup/effects/amp combination separately.

Whatever works. I usually wind up putting 5751 tubes the second-from-right preamp position (Vibrato channel), but sometimes a 12AX7 works fine.

Another approach is to use a buffer to raise the input impedance when using Input 2 - e.g., Goodrich Matchbox, Sarno Freeloader, Sarno Steel Guitar Black Box (the one with the variable impedance control), or sometimes just a good buffering effect pedal. I recently got a Sarno Freeloader, and I really like it for running into a low-impedance input. I really am stuck on an input impedance near the 1 MegOhm on the old Fenders - I think it makes a huge difference. I've used other buffers, but this is my favorite so far.

You can also use a buffered volume pedal like the Hilton - my preference is an old Sho Bud pedal into the 1 MegOhm input impedance, but that's strictly up to personal taste.

Tony Prior · From: Charlotte NC

The tech is wrong, and you can tell him I said so....

Steel Guitar PUPS are like a good hi quality Gibson Humbucker. The Steel Guitar is a "Guitar"...

If you are having distortion on BOTH inputs with a Twin Reverb, there is a problem. With Steel Guitars the only time it would be remotely possible to have front end distortion using a Twin is if you are running the volume pedal flat out...if you are running your volume pedal ..average at 50% or so, a Twin should never distort at normal gig volume, either input , either channel. IF there is even slight distortion using input #2 with a Twin...well...that's a problem...

There are all sorts of reasons amps distort, power tubes is only one, preamp tubes is another...bad sockets, bad caps, power supply voltage not correct, bad ground, speakers......etc...

Input #2 on Guitar amps, not channel 2, has an approx 10DB pad to accommodate Instruments like Keyboards... Using input # 2 for Steel will result in the total loss of sustain as you add more V Pedal at the end of a phrase... this is why we use Twins and hi powered amps, for the sustain when we add V Pedal at the end of chords or glisses..whatever...

Use input #1 to get the most out of your amp, preamp,gain, headroom and best use of the tone stack circuits, use input #2 if you want to use your Twin in a smaller setting and not over power the situation.

To recap, input #2 is a padded input, it reduces the input signal from any source by approx 10DB.

Amps such as Twins, Showmans etc. have enough total power to compensate for the reduction of input gain on smaller gigs but if you do this with a 40 watt amp or less, you will not be happy. As Dave states above ( again and as always) try both inputs , see which best fits your situation but not because of what the tech says.

If I practice at home with my Twin, it's input #2, but on the gig , to get the headroom and sonic response needed, it's the primary input.

My personal experience has been using a 1970 Twin for over 20 years up and down the East Coast with a Sho-Bud Pro III, different pups now and then, always thru input #1. My current experience is using a 1971 Twin with my Carter, George L Humbuckers, and two different Goodrich pedals, always input #1 which is the proper input. Now, in all fairness, when I acquired the 71 Twin a few months back I rebuilt and serviced the chassis and replaced the 39 year old Utah speakers with new Emmi's.( Stock Fender Gold label Emmi's aka: HR Deville ) There is NO distortion from the Steel unless I am flat out on the V Pedal with amp volume up around 5 or 6 which would kill a dozen people anyway...me included...

Great amps, those Twins ! They get my vote for the best overall combo amp ever made.

t
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