Page 1 of 3 123 LastLast
Results 1 to 10 of 29

Thread: Sano Supersonic High Fidelity Amplifier......

  1. #1

    Sano Supersonic High Fidelity Amplifier......

    I managed to get a day off, and tried to mow between showers of rain and drizzle. At least while it was wet, I cleared a bench and set the Sano Supersonic project on it for pictures. Though the camera is constantly on the blink, today it worked well enough for some pictures.

    The amp originally had casters on the bottom. But at some point, those were moved to one end, and the Sano badge rotated. I removed the casters (one was broken in shipping) when I received it. Here is a picture of it laying on it's proper side:



    and another:



    the back:



    top:



    The next few are inside, before and after I removed both chassis':







    "We sleep safe in our beds
    because rough men stand ready in the night
    to visit violence on those who would do us harm."

    ---George Orwell

  2. #2




    The original mounting position of the power amp was just under the 15" speaker. No idea why it was moved, but I set the chassis over it's original mounting holes, and tried the tubes. They can be removed and inserted with no problem. I will mount it back in that position, once the cab has been cleaned and repairs made:



    Even though I can't dedicate any real repair time to it for another couple months, I can at least begin the cleanup and maybe make some cab repairs. A buddy at work suggested that I just clean it up and leave the old 'Road Warrior' as I found it. I'm considering that, as well.

    I have a rather large Ampeg dolly that would extend approximately an inch out, all the way around. But, the rubber feet fit just fine, and those casters are original Ampeg, and in good condition.

    Also, on top there is a plate with two 1/4" jacks, that were connected to the stereo input. I may reuse it or fab a nicer one. But, I'm thinking that this is a good spot for an effects loop, instead. For the moment, I don't plan to use the stereo input, though I will leave it completely functional if I should find a need for it.

    And, I have a set of replica Ampeg carry handles that I can put on each end. This beast is heavy, and those sure would help. I intend to leave the original handle on top.

    I'll report more as the process continues. Have a good one.

    Jack
    "We sleep safe in our beds
    because rough men stand ready in the night
    to visit violence on those who would do us harm."

    ---George Orwell

  3. #3
    Senior Member Jeff Haddad's Avatar
    Join Date
    Jul 2005
    Location
    southeastern PA
    Posts
    752
    Interesting project you've got there, good luck with it! That preamp chassis certainly looks colorful, nice right angle wire runs, too. The power amp chassis might have been moved to be at the bottom when it was on the casters so it wasn't too top-heavy. Are you planning on re-mounting the aux. 120v outlets?

    How does it sound?

  4. #4
    The power amp has all those nice right angles, as well.

    Got off work at a decent hour, today (Sun). So, I took a quick peek at a potentiometer code. According to this website:

    http://www.guitardaterproject.org/potcodereader.aspx

    This what I have for a code of 1346350:

    Potentiometer Info
    This potentiometer was made by
    Mepco/CentraLab, Inc.
    in the 50th week of 1963

    So, this is probably a new year model for 1964.

    I will install a grounded cord, as this will be a player. But, I won't re-mount the 120v outlet.

    I haven't powered it up, yet. Too much cleanup of the wiring, before that happens. Then, I'll bring it up on the lamp limiter and let it soak for a while. Reform the caps, and watch for any potential problems.

    Jack
    "We sleep safe in our beds
    because rough men stand ready in the night
    to visit violence on those who would do us harm."

    ---George Orwell

  5. #5
    Re-assembled the Supersonic and connected to the lamp limiter. It failed before I could go past my 60 watt bulb. I stepped through four bulbs, 25, 40, 60, and 100 watt. So, the first test is to remove the 5U4 rectifier tube and try again. It passed, as I observed the filaments begin to glow. PT is good. I dug out another 5U4 tube and started again. This time it passed, and began showing signs of working with the 60 watt bulb in place. I connected the guitar and the amps does indeed work. However, there was a slight hum, with all volume pots turned down. I stepped to the 100 watt bulb and the amp got louder. So did the hum. But, it works.

    Finally, removed the 100 watt and put a plug-fuse circuit breaker in lamp socket. Now the amp is really loud. And, the hum is some loud, but I'm enjoying the amp. The Reverb is really strong, so I've got a good spring tank, and I have the speakers connected correctly.

    While I was enjoying it, the amp developed a really loud hum that made playing impossible. Shut it down and put it back on the limiter. It still passed. Fired it up again off of the limiter, and it sounded really good for a few minutes. Then, the loud hum came back with a thud. I shut it down. I won't play it again until I've replaced the two canned capacitors in the power supply. Fortunately, that chassis is easy to remove, and the caps should be easy to get to. I will order the parts and begin work on filling the stripped out screw holes on the back. I have some new black washer-head #6 wood screws to re-install the back panel.

    Once the power supply caps are installed, I intend to connect a chassis ground from the bottom chassis to the top pre-amp chassis. A bit more towards de-humming the amp. Also, I will make an effects (FX) loop box to mount to the hole in the top, and fab up a cable to go between the Return and the RCA jack in the power amp. I will connect the pre-Amp output (RCA, as well) to the Send of the loop.

    Here's some pictures of my resulting progress:













    Note the replica Ampeg sided handles. And, the real Ampeg dolly underneath. The last two pictures are mainly to show the solder terminal (bottom left of the chassis picture) and the thermistor installed in series with the 'hot' line to the power switch.

    In my haste to get pictures, I forgot to snap one of the front, and my newly re-installed badge. Though it's missing the white back panel, it still looks good to have it back in its correct orientation. I will have more pictures when the next (and hopefully final) phase is done. Showing real promise. And, it's really clean for the first time in a very long time. Have a good one.

    Jack
    "We sleep safe in our beds
    because rough men stand ready in the night
    to visit violence on those who would do us harm."

    ---George Orwell

  6. #6
    Got out to the shop yesterday morning (19Jun), before the sweltering heat could run me out. Replaced one of the power supply canned caps (the just to the right of the power cord in the above picture), and brought it up on the lamp limiter. Just to ease the new caps into service.

    Made a big difference, but there's still some background hum. Disconnected the pre-amp and hum is still there. I'll change the other canned cap out the next time I have a cool moment from the heat. Really strong Reverb. The Tremolo will need cap replacement(s), as the oscillation starts and then decays to none. I've seen this quite a few times before, in a number of old amps. I don't have the correct schematic for this amp, but typically on the Tremolo the bypass cap on the cathode of the oscillator is the culprit. It can be a 20 or 25uf. Either seems to do the job. That'll be the first replacement.

    Also, need to troubleshoot the wiring on the power switch that's located on the pre-amp chassis. Power is always on, no matter the switch position. I never gave it a close look for mods or repairs. Will do so, now.

    The amp is really loud and clean. Sounding better and better, with each small fix. More to come. Have a good one.

    Jack
    "We sleep safe in our beds
    because rough men stand ready in the night
    to visit violence on those who would do us harm."

    ---George Orwell

  7. #7
    Super Moderator Default's Avatar
    Join Date
    Jul 2007
    Location
    Philly, or thereabouts
    Posts
    9,429
    That's a cool amp. Supposedly a much more hi fidelity amp Tham most other amps.
    "Steve, you are a man of many goats."~ capnjuan

    "Alternatively, you could just go the ultra-relic route with it. Basically go for a look that says the amp was on fire and they put it out using belt sanders."
    (amps - I need a "99" & "50")

  8. #8
    That's a super cool amp. Vintage version of a 3 way full range cabinet. Didn;t Sano do stereo amps as well?
    9 (nine) pieces of chicken (small), 1 portion of chips with garlic sauce, 3.50

  9. #9
    I have a Sano 250R and a 500R-12 which is similar to yours with the power amp in the bottom of the cabinet. The 250R has two 12" alnico speakers with a one piece chassis and is a wonderful clean sounding amp much different from a Mesa TA-15 or my 1964 Fender Tremolux. My 500R-12 is another story as I had it at an amp tech. here in town and it still is very noisy and seems to distort in a bad way after a few minuets of playing. I found a friend of a friend of mine is an amp tech. also and he has a couple Sano's so possibly he can fix it. The 250R runs 7591 as power tubes and the 500R-12 runs 8417 power tubes. They are very different sounding amps to my other amps and a different flavor is nice sometimes. Keep us up to date on your amps and I will let you know if I find some information on my 500R-12.
    Thanks John

  10. #10
    Senior Member
    Join Date
    Dec 2012
    Location
    Southern California
    Posts
    2,924
    Kinda makes me wish I had kept my hand in electronics, after Jr college, when I went for the Computer Science degree.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •