Announcement

Collapse
No announcement yet.

A Shocking Old Tube Amp Question

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
  • #1

    A Shocking Old Tube Amp Question

    I picked up an old, Canadian made tube amp, a Riviera 725, made by Pepco.

    It has 2x 6V6 power tubes, 2x 12 AX7s and a rectifier tube. The guy I bought it from put in all new tubes, but gave me the old RCA's too, they still work.

    There isn't much info about these but apparently they are close to a Fender Princeton, very simple, 2 inputs, Volume, Treble and Bass controls.

    It sounds really cool, starts to break up nice at about 2 on vol and is loud.

    A couple problems, hum and the chassis is LIVE when plugged in even with the switches off, as me how I know:idea:!!

    I guess the fix would be to install an isolation transformer, although I am not too sure which would work. Hammond has a 169QS model http://www.hammondmfg.com/169.htm

    I was wondering if any amp tech's could give me some ideas as to what would be best.

    I don't have pics right now but can get some up if necessary.

    It only has the power tranny and what I would guess to be a choke as well. Most tube amps I have seen have 2 large trans and a choke?

    Anyway any help would be great and I will get up some pics so you can see this old thing.
    Last edited by FlyingSkull; 09-09-2009, 11:38 AM.
    "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
    Zakk Wylde
    Tags: None
  • #2
    It only has the power tranny and what I would guess to be a choke as well. Most tube amps I have seen have 2 large trans and a choke?
    I try to stay away from anything involving Trannies.
    I hooked up my accelerator pedal in my car to my brake lights. I hit the gas, people behind me stop, and I'm gone.

    Comment

    • #3
      Originally posted by Jacksonguy666 View Post
      I try to stay away from anything involving Trannies.
      Trust me I was shocked too.
      "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
      Zakk Wylde

      Comment

      • #4
        Originally posted by FlyingSkull View Post
        Trust me I was shocked too.
        Your response is that kind where I can't tell if you got my joke. I meant transsexuals.
        **Disclaimer** Obvisouly I don't have anything against them, just a joke.**Disclaimer**
        I hooked up my accelerator pedal in my car to my brake lights. I hit the gas, people behind me stop, and I'm gone.

        Comment

        • #5
          Sorry I can't help you with your question, but I just wanted to comment on old Canadian made tube amps.
          Just bought an old`70's Traynor Studio Mate combo amp last Sunday for $150.!
          What a great sounding amp!, has reverb and tremelo too!
          Well worth the $150. spent!

          Comment

          • #6
            Originally posted by MSGfan View Post
            Sorry I can't help you with your question, but I just wanted to comment on old Canadian made tube amps.
            Just bought an old`70's Traynor Studio Mate combo amp last Sunday for $150.!
            What a great sounding amp!, has reverb and tremelo too!
            Well worth the $150. spent!
            Ya it came with a Mesa Black Shadow in a nice birch cab too, so I'm not complaining, well worth it and I was thinking of doing a tube amp DIY project so I might use this one as the learning experience.

            Oh ya Jacksonguy, I got the joke, no worries!
            Attached Files
            "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
            Zakk Wylde

            Comment

            • #7
              Originally posted by FlyingSkull View Post
              I picked up an old, Canadian made tube amp, a Riviera 725, made by Pepco.

              It has 2x 6V6 power tubes, 2x 12 AX7s and a rectifier tube. The guy I bought it from put in all new tubes, but gave me the old RCA's too, they still work.

              There isn't much info about these but apparently they are close to a Fender Princeton, very simple, 2 inputs, Volume, Treble and Bass controls.

              It sounds really cool, starts to break up nice at about 2 on vol and is loud.

              A couple problems, hum and the chassis is LIVE when plugged in even with the switches off, as me how I know:idea:!!

              I guess the fix would be to install an isolation transformer, although I am not too sure which would work. Hammond has a 169QS model http://www.hammondmfg.com/169.htm

              I was wondering if any amp tech's could give me some ideas as to what would be best.

              I don't have pics right now but can get some up if necessary.

              It only has the power tranny and what I would guess to be a choke as well. Most tube amps I have seen have 2 large trans and a choke?

              Anyway any help would be great and I will get up some pics so you can see this old thing.
              First, drop the iso tranny idea. You'd still be shocked after installing, and you'd have to get a lot larger one than you specified.

              Chokes are not required. An output tranny is. You most likely have a power tranny and an output tranny. If the output tranny is much smaller than the power tranny, that's a bad sign. Either a cheap design or someone replaced the tranny with a sub-standard substitute.

              The issue is most likely your power switch. The power wires soldered to it are probably touching the chassis. Has the chassis been dropped or mutilated? After it's been powered down for a while, take the chassis out and see if it's been modified, it any wires are touching the chassic, etc.

              Maybe post some gut pictures. If you lived close to me or Cyg, we could probably help you out.

              Comment

              • #8
                Originally posted by DonP View Post
                First, drop the iso tranny idea. You'd still be shocked after installing, and you'd have to get a lot larger one than you specified.

                Chokes are not required. An output tranny is. You most likely have a power tranny and an output tranny. If the output tranny is much smaller than the power tranny, that's a bad sign. Either a cheap design or someone replaced the tranny with a sub-standard substitute.

                The issue is most likely your power switch. The power wires soldered to it are probably touching the chassis. Has the chassis been dropped or mutilated? After it's been powered down for a while, take the chassis out and see if it's been modified, it any wires are touching the chassic, etc.

                Maybe post some gut pictures. If you lived close to me or Cyg, we could probably help you out.
                Ok I'll get some pics of the chassis/wiring. I have had it out and from a brief look it does not appear tampered with or maimed in any way.

                I removed the power and standy by switch nuts, and pulled the switches from the chassis to see if maybe they were grounding against the chassis. The chassis still registered hot, I'll get some pics up soon and you can have a look, thanks!
                "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
                Zakk Wylde

                Comment

                • #9
                  You rang?


                  Absolutely, don't waste anything on an isolation transformer-it will not help as Don said.
                  Waiting for pix.

                  Comment

                  • #10
                    Pics




                    "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
                    Zakk Wylde

                    Comment

                    • #11
                      See that cap hooked up to the green wire coming from the fuseholder?
                      Clip it out, get rid of it, throw it away and don't replace it.
                      It's called a "death cap".

                      Then get a three prong plug and wire, connect the earth/ground wire directly to the chassis.
                      Connect the black wire side to the fuse/switch, then to the primary of the power transformer.
                      Then the white wire to the other primary of the power transformer.
                      Double check the chassis to a good known ground to make sure you didn't accidentally wire the chassis "hot". If it is hot then reverse the primary connections to the power transformer.

                      Oh, and that is not a choke, it's your output transformer.
                      Look at how it is wired to the speaker jack on the secondary and the power tubes on the primary.
                      Last edited by Cygnus X1; 09-09-2009, 05:06 PM.

                      Comment

                      • #12
                        Originally posted by Cygnus X1 View Post
                        See that cap hooked up to the green wire coming from the fuseholder?
                        Clip it out, get rid of it, throw it away and don't replace it.
                        It's called a "death cap".

                        Then get a three prong plug and wire, connect the earth/ground wire directly to the chassis.
                        Connect the hot side to the fuse/switch, then to the primary of the power transformer.
                        Then the other side to the other primary of the power transformer.
                        Double check the chassis to a good known ground to make sure you didn't accidentally wire the chassis "hot". If it is hot then reverse the primary connections to the power transformer.

                        Oh, and that is not a choke, it's your output transformer.
                        Look at how it is wired to the speaker jack on the secondary and the power tubes on the primary.
                        I thought only bad mushrooms had death caps.
                        Cool !!! Thanks for the help, I will try that out this weekend and advise you of the results.
                        "We were sitting on the bus one day and there were 5 of us hanging out. There was only one beer left in the cooler and we actually all took a little cup and split it. It was a pathetic day in a rock and roll when five grown men have to be sitting there sharing a beer. "
                        Zakk Wylde

                        Comment

                        • #13
                          Originally posted by FlyingSkull View Post
                          I thought only bad mushrooms had death caps.
                          Cool !!! Thanks for the help, I will try that out this weekend and advise you of the results.
                          Here's a whole article on how to do it.
                          It says "Fender" but the same still applies:

                          http://www.theguitarfiles.com/guitarfile644.html


                          Note the polarity switch is actually bypassed, you don't need it regardless.
                          Last edited by Cygnus X1; 09-09-2009, 05:07 PM.

                          Comment

                          • #14
                            Cool little amp. Very simplistic.

                            Comment

                            • #15
                              Originally posted by DonP View Post
                              Cool little amp. Very simplistic.
                              Agreed.
                              Some of the best sounding amps have virtually nothing in the chain to block the tone.
                              Get an OD pedal, and it's La Grange all day long!

                              Comment

                              Previous 1 2 template Next
                              Working...
                              X