Announcement

Collapse
No announcement yet.

Vintage 50's Console conversion, need advice!!!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Vintage 50's Console conversion, need advice!!!

    I just inherited an old Emerson tube Console Stereo. Nothing but AM radio, turntable and a tape input. It has an 18" speaker, a horn tweeter and two smaller 5" mid ranges. It has 2 EL84's/6BQ5's a 5U4G Rectifier and a single 12Au7. The console is in great shape. My dad had cut the speaker wires to attach his own amp to them......Lovely and now i cant figure out how to re attach as there are no schematics. I also need some advice as to if its even possible to turn this sucker into a guitar amp? how many watts would this sucker be putting out? How to determine if its a Push-pull or single ended amp? I bought an old harmony and only had to put in a new electrolytic cap and she sings beautifully. Im new to this tube business and i cant get enough :-) ......I figure its from the late 50's or even early 60's, it has the tweed front grill cloth. I will be posting some pictures of the amp and cabinet in the next few days.. Any help, suggestions, comments are greatly appreciated.
    Cheers

  • #2
    are you sure it is stereo? sounds to me like it is mono. if it is stereo it is probably about 5 watts on each channel with the el84s operating in single ended mode, if it is mono (which is what I expect is the case) it is about 12 to 15 watts with the el84s operating in push pull mode. the speakers will hook to the smaller transformer or transformers. are you sure that is the only tubes? check if it has 2 output transformers or just one. I have a feeling you are missing a preamplifier that would need to be used with it because you only have one pre-amp tube listed.

    Comment


    • #3
      Ok yes it is def a mono amp.There are other tubes in the tuner/pa system. It has 3x 6ba6's 1x 12ax7 and 1x 6BE6. The mono amp looks to have a plug with 4 wires, 14awg it looks like. they lead into the Tuner/Pa.They are wired to the larger transformer. In return from the pa/tuner is a mono rca patch to the mono amp. The speakers are disconnected. Two mid ranges and the tweeter are wired in series with the woofer having its leads dangling. There is a second plug on the mono amp.In the chassis it looks to be grounded (2 out of the 4 prongs) to the mono rca input and the smaller tranny. im assuming this is the speaker output plug? Im confused as to why the mono amp has a larger plug running to the pa. Is the signal not being switched via the pa/tuner (to radio, or tape, or phono) and fed through the mono rca? Thank you for your help. Im just so confused because its all seperated.Last question. How do i post pictures of the radio. Its much easier to just look at pictures. :-)
      Thanks a bunch

      Comment


      • #4
        im sorry make that 1x 12A7 2x 6AB6 and 1 x 6AV6.

        Comment


        • #5
          those four wires are most definately your positive DC voltage, ground, and heater lines. The 12au7 in the power amp is the phase inverter/driver stage. Yes the output of the smaller transformer will be going to the speaker plug. The real question is what output impedence the amplifier is supposed to be, maybe someone here will know what the norm was back then (if there was one). Once you get it up and running you might want to try injecting a guitar signal at various points in the pa circuit to find where it sounds best.

          to post a picture you just use the attach files underneith the reply to thread text box by clicking on manage attachments

          when injecting your guitar signal, make sure you dodn't do it at a DC point.. always at a grid of a tube or at least after a DC blocking capacitor (that you know is functioning)
          Last edited by drlowlow; 07-08-2008, 07:31 AM. Reason: safety

          Comment


          • #6
            Pics

            Here are some pics to help my poor descriptions.

            You can see in the picture of the monoblock the missing plug for the speaker.
            In the picture with the woofer and the horn tweeter, You can see the black and yellow wire come in from the side, they are actually coming from the two midranges wired in series then go down the back of the console and then are wired up to the horn tweeter. I have the 2 sets of speakers wires. The yellow and black and the green and black. i hooked the black wires to the two ground prongs on the speaker plug and then a green one for the woofer and a yellow one for the tweeters/midranges. It powered up, i got a slight sound when i directly hooked a source of audio to the input on the amp. but then my power tubes started to glow, really glow. So im assuming the impedance load is way off. If the speaker prong has 4 prongs, 2 are grounds....... the other two are for speakers? would perhaps the woofer be wired with the rest of the speakers in series?
            Attached Files

            Comment

            Working...
            X