Sano Supersonic High Fidelity Amplifier......

59Panhead

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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':







 

59Panhead

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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
 

Jeff Haddad

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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?
 

59Panhead

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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
 

59Panhead

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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
 

59Panhead

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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
 

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That's a cool amp. Supposedly a much more hi fidelity amp Tham most other amps.
 

parker_knoll

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That's a super cool amp. Vintage version of a 3 way full range cabinet. Didn;t Sano do stereo amps as well?
 
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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
 

JohnW63

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Kinda makes me wish I had kept my hand in electronics, after Jr college, when I went for the Computer Science degree.
 

59Panhead

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Kinda makes me wish I had kept my hand in electronics, after Jr college, when I went for the Computer Science degree.
Never too late. Get a real basic kit and learn from that. Something in the Fender 5C1 or 5F1 Champ style. Great little single-ended scheme for a start. There are plenty of kit suppliers. Here's one:

http://www.tedweber.com/5f1-c-kt

I didn't pick this one for any particular reason. Never had one. I'd say leave off the cabinet, altogether. Build the amp and use or find a cheap cabinet on ebay. Your first doesn't have to leave home. Just leave it on the work bench.

Then, after you have a kit under your belt, try a scratch-built one. I'm not familiar with Guild S-E models, but I'm sure there's something comparable in their early lineup that can be easily built. With as many of the old NOS 6L6 metal-cased tubes that I have, I've threatened to built some S-E amps with these. Spec sheet says 19 watts max plate dissipation. I'm thinking something closer to the 6V6 range of 12 watts.

Heck, I can talk myself right into such a build. I like to make my own tag boards, though this would make for an easy point-to-point build.

Anyway, start a new hobby and build an amp. And, post your progress here.
 

JohnW63

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Let's see.. hobbies.

Photography, Online Sim racing, guitar playing and deal hunting, A classic Mustang I'm restoring.... Yep, I have hours I could be using instead of for sleep !

A guy at work has an older guitar amp he wants me to look at. Perhaps it will be a "gateway" amp project !
 

59Panhead

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Update - 11Aug15:

I didn't realize how long it's been since I put my hands on this amp. Life is just too complicated. I have a couple days off before working an 8-day stretch of long hours. It's a rotating schedule at the plant, so I know when it's coming.

I replaced the second canned capacitor in the power amp, and now that chassis is very quiet. It houses the Power Amp and Reverb. The Pre-amp is connected by means of a shielded cable, RCA plug on the end. I fabbed up a small metal project box with two closed-circuit phone jacks, and two RCA phono jacks. This is for an Effects Loop to mount in a rectangular hole on top of the cabinet. Before, there was a plate with two open-circuit phone jacks, paralleled with the 'Stereo' input. I believe that the onboard, four-pin stereo jack is for an accordion, as Sano catered to the accordion market. The amp is overall very quiet, even though the Pre-amp does not have a chassis around it. It's just mounted to the Faceplate.

Again the Reverb is plenty strong and the Tremolo is weak. I can see that a drawing is in order, at some point, to properly troubleshoot by. There is a Guitar input, Instrument input, and another unlabeled input. I'll inspect closer when I'm making a drawing. It's a lower gain, and is affected by the Master Volume, only. The Reverb, Guitar, and Instrument inputs have their on Volume/Gain pots. I'm thinking this one ties in somewhere downstream of the Guitar and Instrument.

What a really nice sounding amp this has turned out to be. With no history, a very trashy appearance (dirty inside and out), and many input modifications, it has come back to life in a fine way. I believe that I have it very stock, with the exception of my FX Loop. No wiring mods, on my part.

Next fix will be to straighten out the power switch, as it has no affect. Power is always on, if the power cord is connected. I use the switch on my limiter box, when I'm working on it. My limiter has a lamp socket, fuse holder with 3-amp fuse, and a typical wall switch (though I put one in rated for 20 amps). When I want full line voltage/current, I screw in a plug fuse replacement circuit breaker, in place of a lamp. The receptacle is protected by the small fuse, at all times. I also have a ground binding post (green), so that I can run an alligator jumper to a chassis that may not have a grounded cord.

Anyway, I'll snap a couple of pictures when the rest of the fixes are done. Particularly, the FX box and the front with the Sano badge rotated to it's correct position. More to come. Have a good one.

Jack
 

59Panhead

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Found the issue with the power switch. It is a 3-position switch, apparently is not original to the amp. I now have it wired to have one 'Off' position, and two 'On' positions. At least now, I can power it down with the switch. I will pick up a Carling short-bat power switch to replace it.

Also, I tested my FX Loop with the Pitchfork that I received from Doug. Sounds really good on this amp. But then, anything would sound really good on this amp, I believe.

I haven't made a drawing of the Pre-amp, yet. But, the unmarked input appears to be an original installation. It jumps way downstream to a point on the Standby switch. Which explains the weaker sound when connected here. Probably an input requiring some signal from an external Pre-amp.

This Standby is like that on the Guild amps that I have, as it grounds the signal.

Anyway, the weak Tremolo is the next issue to resolve. That will have to wait until next week. Too warm in the shop. Glad I had a cool morning out there.

Jack
 

59Panhead

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is it possible to get any dirt out of that Sano as it is, stock?
As in overdrive? If so, yes. Two ways.

I can use the FX loop to do so, with pedals for that purpose. And, adding an FX loop on any of these Supersonic models is very easy, with no wiring mods. Just build it like I did. That will be in upcoming pictures, and on a schematic.

And, I can tweak the gain up on the pre-amp stage(s). It's plenty loud, the way it's designed. I'm fairly sure that this amp is designed primarily for accordion and a more non-rock guitarist. It wouldn't take much to boost the gain on either the guitar or instrument channels. I plan to draw a schematic of the pre-amp, and can speak more intelligently on how it can be done, when I know how it's built. I have to make the drawing, mainly to troubleshoot the Tremolo. But, I'll have the whole drawing on hand, at that point.

Jack
 
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parker_knoll

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wow, this sounds like a great project. I've always liked these amps and the intelligent way they were put together, with full range speaker configurations etc. Looking forward to seeing your work. An effects loop is a must for me with what i do. I'm currently using a 1969 British Laney 100W PA amp with a great FX loop.

I got a bit of preamp gain by cascading two of the six (!) preamp channels together. Crude but I actually like the sound.
 

59Panhead

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Last Saturday (19Sep15), I dedicated the day to hand-tracing the Pre-amp circuit, and try to get it into a CAD drawing. I managed to make a pretty literal layout schematic, which also made for a very long day. All the components are tightly packed. Then on Sunday afternoon, I re-drew it to something closer to a conventional schematic. Conventional is difficult for me, as I tend to draw as I see it, which is why the first drawing happened.

Anyway, I can now troubleshoot the non-working Tremolo. Betting it's the cathode bypass cap on the oscillator. And now, I can assign component labels. Here's my latest revision, with unassigned labels. I'll post it again when I have them on the drawing:

http://www.mediafire.com/view/u7rlp7d7db7lcxw/Sano_50WR_-_rev_B.pdf

I have the canned capacitor for the Pre-amp power supply, and the 25uf-50v cap for the oscillator cathode bypass. I'll try to get those installed this weekend. That should hopefully be the final fix on the amp. At some point I want to make a chart and record all the pertinent voltages.

I also attached a picture to the same schematic file. The picture is of the Power Amp and Reverb circuits. It is from an Excelsior of the same model as mine, that Sano built and re-branded. Take a look and comment. Very busy circuit.

Jack
 

59Panhead

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Made a drawing that is more to convention.

http://www.mediafire.com/view/d6532rqf9vbffcc/Sano_50WR_-_rev_C.pdf

Plus, I replaced the pre-amp power supply de-coupling caps, as well as the Tremolo oscillator cathode bypass cap. If work hours permit this week, I'll re-install the chassis in the cabinet. Hopefully, the minor hum is gone, but mainly I'm hoping the Tremolo will work for the first time. I'll post the results. Have a good one.

Jack
 

59Panhead

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Replaced caps C1, C2, C3, C4, C5, C6, and C7. Refer to the last drawing, and find that these are all around V1b and V3a.

Tremolo does not work.

However, I made voltage readings on V3a (plate, grid, cathode) and found I had oscillation. The Depth pot at full, and Speed pot at minimum. To be honest, I don't know if there was voltage oscillation was there before, as I had not made those readings. I have been depending on sound for a sign of it. I checked voltage at V1b-pin 7 (grid), and had a very weak oscillation there. However, when I checked the voltage on pin 6 (plate) and pin 8 (cathode) of this tube, I found no oscillation.

So, more troubleshooting. More to come. Have a good one.

Jack
 
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