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Fender "The Twin",aka The Evil Twin w/ Red Chicken headknobs Need Picture of PCB

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  • Fender "The Twin",aka The Evil Twin w/ Red Chicken headknobs Need Picture of PCB

    I have a question or a favor to ask of everyone. Or anyone who might be able to help me. I recently picked up a Fender "The Twin" with the Red Chicken Head Knobs. Its supposedly 150 watts and I believe it. But Its about 80lbs,with casters and 2 Custom Fender Blue Label 90 Watt 12" Speakers. Its got 5 12AX7's in the Preamp stage, (2) 12AT7's and (4) 6L6GC in the power section.Its got a dual spring reverb which is super strong. And it is absolutely the Loudest amp I have ever played!!!! It is so loud I cant gig with it unless I use a Powersoak. Right now I am using the Original Tom Scholz PowerSoak, Which will let me turn the volume up to 4 or 5, and then the tubes really start to sizzle and it will even sound like a top of the line Boutique amp. The gain is crazy, and it is a True 2 channel Amp!! Meaning you can run Channel one in Clean mode, and Channel 2 in Dirty mode at the same time. For a Dual Guitar Stereo Setup. Similar to my Line 6 Vetta 2 which has 2 independent amps which you can run at the same time for some crazy sounds. My current Rig is a Line 6 Vetta 2 with the Full Dual Pedal Foot Controller. Which for my style of music is perfect, I am into alot of Progressive Rock and even more Dream Theater. I only picked up the The Twin because the price was right and it was in good shape.

    Now here is the problem: On the front panel of "The Evil Twin", the first 2 of 4 guitar input jacks were broken. They worked, but u had to jiggle them to get them to connect. So I bought replacements for all of them. Now,, I have the Schematics for this amp and I am Certified Electronics Technician.So I was able to replace all the jacks with no problem,,,except for 1. That is the very first jack, which is ironically the worst broken one and also the last one I replaced. These jacks are stereo inputs are 4 in a row on the fron. The first 2 are for channel one with Switching Channel mode. The 2nd set of 2 are for Parrallel Channel Mode. My problem is with the very first 1/4" input jack.Since it is stereo it has 6 pins/conductors that have to be soldered into the front panel PCB (Printed Circuit Board). Well, while I was soldering it the tracing/etching/solder on the PCB board started to peel off, and I cannot find a schematic or a picture of what it looked liked before I started soldering it.

    So what I desperately need is for someone who has an Red Knob Evil Twin to open the amp and take a picture of the tracing and the connection area around the very first guitar input jack. This way, I can Solder it correctly, with jumpers if needed, and I wont have to worry about frying the amp.


    That being Said,,,, Is there anybody out there who has this same amp I just described who can open it up and take a picture of the PC board just inside the the front panel, and highlight the Solder joint's for the first stereo input jack????


    I would really appreciate it if someone could do that for me. I called Fender and they were unable to help me with this problem. It would be a big help if someone could do this for me. Or if you already have one apart or are selling one for parts. Then maybe we can work something out.

    Anybody who can help, please email me ytsejam777@yahoo.com

  • #2
    "Now,, I have the Schematics for this amp and I am Certified Electronics Technician."

    If you have the schematic, you should be able to trace the jack pins and figure out where they go,... not? Just find the jack on the schematic using its circuit board designation (i.e. "J1"- or whatever it is) and trace out what the pins are supposed to connect to.
    "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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    • #3
      NoTraceMarkings

      Originally posted by The Dude View Post
      "Now,, I have the Schematics for this amp and I am Certified Electronics Technician."

      If you have the schematic, you should be able to trace the jack pins and figure out where they go,... not? Just find the jack on the schematic using its circuit board designation (i.e. "J1"- or whatever it is) and trace out what the pins are supposed to connect to.
      Unfortunately the PC board has no desginations on it and the schematics are sparse at best. I would just be guessing. I would prefer to see it as itt was before the tracing starting falling off, then I will know what goes where.

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      • #4
        When you talked to Fender did you ask for a pcb layout drawing? I would think they should have it, perhaps they didn't understand what you were looking for.
        Tell them you have a red knob "the twin" and you need a pcb layout for the input jack board.

        As far as the "stereo" thing, it is not a stereo amp. Those 9pin input jacks are not being used for stereo function, but for switching various things.
        The 2 preamp channels can both be used at the same time (parallel mode) but there is only a mono power amp, which runs both speakers. So even if you are using both preamp channels at the same time, they get mixed together by the power amp.
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


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        • #5
          The schematic is common Fender style. The layout drawing for a The Twin is very crude. pretty much just a tube locator and a chart of tag numbers for the wiring.
          Education is what you're left with after you have forgotten what you have learned.

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          • #6
            I know this is not helpful now, but I have gotten into the habit of taking a picture of anything I work on before I start. Cost nothing in the digital age and has saved my ass many times.

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            • #7
              Without a pin-out (schematic) for that 9pin jack, this will be a tough task. The amp schematic shows where all 9 pins go, but that doesn't tell you which pin is which. You would have to check with your meter and draw up a schematic for the actual jack.
              Not sure if these pics will help, maybe you can blow them up or something:
              http://music-electronics-forum.com/a..._internals.jpg
              http://www.uraltone.com/blog/wp-cont..._redknob_1.jpg
              Originally posted by Enzo
              I have a sign in my shop that says, "Never think up reasons not to check something."


              Comment


              • #8
                G-One,,, Thank you very much for those Pics!! They are exactly what I was looking for!! And I can blow them up to see the exact tracings and solder points. I really appreciate your effort and help in this matter!! Not to mention the fact that you didn't write childish comments to my question, as is all I have found on the Official Fender Amp Forum. Apparently, some people think that if your an electronics technician you can read the minds of the engineers who built it. I really appreciate the photos and I will be able to finish putting in the last jack with the correct solder points.

                Sincerely,
                Jay

                Comment


                • #9
                  Glad to hear those pics will work for you, hope you can blow them up ok and still see something. I'll leave the childish comments till I reach second childhood, not far off .
                  Originally posted by Enzo
                  I have a sign in my shop that says, "Never think up reasons not to check something."


                  Comment


                  • #10
                    Attached is an additional photo that may be useful to you. It is from a 1990 "The Twin" amp.
                    At first glance the PCB pads/traces appear to be sorted together with solder but if you look close you will see that it's just residual solder flux.
                    Cheers,
                    Tom
                    Attached Files
                    Last edited by Tom Phillips; 05-31-2013, 02:24 AM.

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                    • #11
                      Thanks to everyone who helped out and sent me Pics!!! They were a big help. I have to hardwire the switch because the tracings were in such bad shape. But its working now. The only thin is I gave the footswitch I had away when I sold my other Amp. And I dont have another one. I was thinking of making just a quickie and checking to see that the channels still change. I also noticed that now, you have to pull out the guitar input cable out of the jack just a hair, like 1/8 inch,, very strange. I am gonna go back in an recheck everything to make sure I didnt miss a tracing or have a short somewhere.

                      Comment


                      • #12
                        Originally posted by g1 View Post
                        Without a pin-out (schematic) for that 9pin jack, this will be a tough task. The amp schematic shows where all 9 pins go, but that doesn't tell you which pin is which. You would have to check with your meter and draw up a schematic for the actual jack.
                        Not sure if these pics will help, maybe you can blow them up or something:
                        http://music-electronics-forum.com/a..._internals.jpg
                        http://www.uraltone.com/blog/wp-cont..._redknob_1.jpg

                        My Red Knob twin started making a random frying bacon sound recently until the red led on channel one started blinking and eventually went out. The thing is that i replaced one of the stereo input jacks in channel 1 and accidentally lifted some of the pads. Now the overdrive channel is bleeding to the clean channel, meaning no clean channel anymore. The channel 1 red light never returned.

                        I know its not a led problem in channel one as it does light up simultaneosly with the other led if you plug the guitar cable in channel 2. How to i tackle this problem?

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