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Where would be the best place to insert a reverb circuit into a tweed tremolux 5G9?

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  • #16
    There is an abundance of good information on how to do this here: http://el34world.com/Forum/index.php?topic=7957.0

    With respect, Tubenit

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    • #17
      I'm working on the layout now. Though I don't expect to finish in this round I will get it finished before the weekend is over... He said.

      To keep the amp as stable as it would be without any modification will require some changes to the layout you had planned to use. Wiring it with things layed out as they are is really asking for stability problems. No one want to get that far in and then find out they have a boat anchor without a major rework. So let's get it right the first time That said... I'm going to need you to relocate those reverb tank jacks.

      That's going to leave two unnecessary holes in the chassis. Is going to burn your toast?
      "Take two placebos, works twice as well." Enzo

      "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

      "If you're not interested in opinions and the experience of others, why even start a thread?
      You can't just expect consent." Helmholtz

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      • #18
        all right chuck, i am all in. were do you need them located? did you also need the preamp tubes rewired?

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        • #19
          Originally posted by Dandrix View Post
          all right chuck, i am all in. were do you need them located? did you also need the preamp tubes rewired?
          Even worse But it's not going to be nearly as bad as it could be There's going to be some board components that need to be shifted in order to accommodate a layout I have confidence in. But seeing how you're wired now I think it'll be easy enough once you see what I'm putting together. The up side is that I've done this a few times (understatement) and you shouldn't have much (if any) troubleshooting to do. And fewer compromises like HF bleed caps to mitigate instabilities, etc. You'll see what's up before the end of tomorrow as far as locations and what needs to be moved. It's all about having the signal chain go in one direction without being in close proximity to later in phase circuits or having to cross over itself too much with a lot of back and forth lead dress making signal leads redundantly long (and therefor sensitive to proximity). I've got most of it worked out now. Keeping in mind that there's work involved on your end. Your patience will be rewarded...

          He said

          I don't walk on water but I HAVE made several fully custom requests and have already worked out what I can get away with compared to what's most convenient. And I've seen what absolutely won't work without problems and had to solve for it. Trust me. I'll make it as easy as it can be to get to the good results you want. That said, nothing is guaranteed. But if there are any problems I'm setting up to be in the best position to fix them easily. Like I said, I've done this.

          And thanks for playing along. Before you get too thankful, this is actually fun for me.
          "Take two placebos, works twice as well." Enzo

          "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

          "If you're not interested in opinions and the experience of others, why even start a thread?
          You can't just expect consent." Helmholtz

          Comment


          • #20
            I know you are well along with this, but have you ever used a stand alone Fender tube reverb unit (6G15) into the amp input? With these older amp designs most players prefer that configuration and it also gives you a little boost.

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            • #21
              Originally posted by olddawg View Post
              I know you are well along with this, but have you ever used a stand alone Fender tube reverb unit (6G15) into the amp input? With these older amp designs most players prefer that configuration and it also gives you a little boost.
              Agree! But it's definitely more of a "host amp is run clean" kind of thing.?. Dandrix has indicated that he's a rocker and so I assume he's crunching it up. On board is a little better for that. And, of course, my recommendation of a dedicated post distortion reverb amp is best But that's bee's knees. I built one for a customer and "I" don't even have one. But I used it with my own rig (because that what I have, right?) before putting my stamp on it and sending it out. Always best to incorporate reverb as late in the circuit as possible if you intend to clip anything. JM2C
              "Take two placebos, works twice as well." Enzo

              "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

              "If you're not interested in opinions and the experience of others, why even start a thread?
              You can't just expect consent." Helmholtz

              Comment


              • #22
                Tell what you think? I could add the extra filter cap to the dog house? It looks like I could squeeze them all in there seeing the F&T’s are so small. Maybe, locate the One 5.1k/3watt resister at B3 Cap and the 5.1k top side on the board ( maybe next to biasing section)?
                Click image for larger version

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                • #23
                  Originally posted by Dandrix View Post
                  Tell what you think? I could add the extra filter cap to the dog house? It looks like I could squeeze them all in there seeing the F&T’s are so small. Maybe, locate the One 5.1k/3watt resister at B3 Cap and the 5.1k top side on the board ( maybe next to biasing section)?
                  [ATTACH=CONFIG]57994[/ATTACH]
                  Too many wires running back and forth to get to the resistor and back. Why not just put the resistor on the terminal strip? Raise it off the cap and it'll be fine. It's the last resistor in the chain so it won't get that damn hot. So if you're going to put that cap in the doghouse just make sure you run the ground to the preamp and NOT with the other caps.

                  I'm posting the layout in just a few minutes. The layout shows the added filter at the end of the board where you originally proposed, but it doesn't have to be there. It would make for a shorter lead though and that's always best. Adding length to that ground lead adds resistance and that invites parasitics. Since the preamp is the most sensitive to this I vote for your original location.
                  "Take two placebos, works twice as well." Enzo

                  "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                  "If you're not interested in opinions and the experience of others, why even start a thread?
                  You can't just expect consent." Helmholtz

                  Comment


                  • #24
                    Alrighty. I think I got this right though I've been a little foggy lately. I'm no doctor but I'll guess it's all the drinking

                    But seriously, this should be correct. Notice that the arrangement keeps the signals moving in one direction (for the most part) rather than going back and forth over later circuits. I used the original 5g9 layout board as a template for clarity. I know your amp isn't layed out exactly the same, but this should give you a consistent reference point for the circuits. Like I mentioned, you'll need to move some board components to locate the reverb build space where it is on this layout. I know the proportions are a little off too. Unavoidable, but it should be close. I layed out the additional circuits on a 7x3 eyelet space like you posted.

                    Attached Files
                    "Take two placebos, works twice as well." Enzo

                    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                    "If you're not interested in opinions and the experience of others, why even start a thread?
                    You can't just expect consent." Helmholtz

                    Comment


                    • #25
                      Originally posted by Chuck H View Post
                      Agree! But it's definitely more of a "host amp is run clean" kind of thing.?. Dandrix has indicated that he's a rocker and so I assume he's crunching it up. On board is a little better for that. And, of course, my recommendation of a dedicated post distortion reverb amp is best But that's bee's knees. I built one for a customer and "I" don't even have one. But I used it with my own rig (because that what I have, right?) before putting my stamp on it and sending it out. Always best to incorporate reverb as late in the circuit as possible if you intend to clip anything. JM2C
                      Yes that is the usual consensus... but it is very subjective. Neil Young and others might object. That’s why I asked if he had ever tried it. If you really wan to add it last on an old school amp one can use the old Maestro Reverb approach where the reverb unit parallels off of the speaker out and is essentially an extension amp with reverb and a speaker.

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                      • #26
                        Originally posted by olddawg View Post
                        Yes that is the usual consensus... but it is very subjective. Neil Young and others might object. That’s why I asked if he had ever tried it. If you really wan to add it last on an old school amp one can use the old Maestro Reverb approach where the reverb unit parallels off of the speaker out and is essentially an extension amp with reverb and a speaker.
                        True that about subjective. And yes, the Maestro type circuit is what I've been talking about here in other posts. I think Mojotone actually sells a SS reverb amp like this (it does have a tank and not a "brick" I think) that can be used with any amp. I built a tube reverb amp for a guy once years ago. I really like that arrangement.

                        EDIT: Ok, it was a few years ago I saw the Mojotone SS reverb amp. It seems they bumped their game and now only sell a tube version. So it's a lot more costly.
                        "Take two placebos, works twice as well." Enzo

                        "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                        "If you're not interested in opinions and the experience of others, why even start a thread?
                        You can't just expect consent." Helmholtz

                        Comment


                        • #27
                          Hi chuck,
                          With reference to the instruction of cutting mod reverb ground trace to isolate ground. I cut trace so, metal rivets no longer have continuity if small mounting board. As pictured
                          Click image for larger version

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                          I was not able to find instructions? accidentally deleted your instructions in our PM

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                          • #28
                            Pretty sure you only need to cut across the exposed copper portions. That way you can just dab some solder across then to restore the ground. Just the same, mission accomplished
                            "Take two placebos, works twice as well." Enzo

                            "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                            "If you're not interested in opinions and the experience of others, why even start a thread?
                            You can't just expect consent." Helmholtz

                            Comment


                            • #29
                              chuck,
                              fired up the amp today, had some debugging to to do. still got some issues to correct like tone pot controlling the volume (miss wired something)
                              trem. works! would like to better it if possible? slower speed etc.... and then the reverb..... its alive! it works pretty good up to about 5 on the dial then, it turns into white noise (static) by the time it gets to 12 it feeds back in typical fender reverb fashion. high pitch sequel, my reverb unit is out of the cabinet and on my floor at the present. got any ideas to remedy this new reverb? left voltages below, time to grab a beer!

                              All heater voltage 3.3 -3.1 vac
                              bias at 27 mv (JJ rated @ 29mv)
                              B1: 393 / B2: 391 / B3: 349 / B4: 332 added filter cap for preamp

                              5U4 344vac / 398vdc
                              6v6 pin1: -26 /pin3: 386 / pin 6: 392
                              6v6 pin1: -26 / pin3: 384 / pin 6: 391
                              V3 tremo. pin1: 288 / Pin2: 5mv / pin3: 1.7v / pin6: 391 / pin7: 293 / pin8: 295
                              V2 PI pin1: 227 / pin2: 20v / pin3: 32v / pin6: 217 / pin7: 21v / pin8: 32v
                              recovery 12ax7 pin1: 223v /pin2: 0 / pin3: 1.7v / pin6:230v / pin7: 0v /pin8: 1.7v
                              Driver 12at7 pin1: 389v /pin2: 7mv /pin3: 7v / pin6: 389v / pin7: 0v / pin8: 7v

                              V1 pin1: 173 /pin2: 2.2mv / pin3:2.7v / pin6: 172 /pin7: 0v / pin8: 2.7v

                              i have not had a chance to look over readings but, i was not sure what your were shooting for voltages on the reverb side of things?

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                              • #30
                                I didn't expect you to done with the project so soon. Usually there's a Q or two during the build process. But I'm very much like that too. Once I get a bug I'm all over it. So...

                                Leave the reverb down for now. I think the normal functions of the amp should be fixed before refining the reverb. And yes, I thought it might need refining. Not for squeal, but for level. I expected you to have a bit too much reverb. That's easily adjusted. What I'd really like to have the amp running properly and then "add the reverb" as it were.

                                You mentioned wanting to make an adjustment to the trem speed. I was under the impression that this was an already working amp (because of something you posted earlier I think). Is this the first time you're firing this up?

                                I'll look over the voltages as soon as I have time. I'm on duty right now. But I won't back burner you. You have my word. I know how it is when you flip the switch and it gets exciting.
                                "Take two placebos, works twice as well." Enzo

                                "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

                                "If you're not interested in opinions and the experience of others, why even start a thread?
                                You can't just expect consent." Helmholtz

                                Comment

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