Understanding Soviet Guitar Wiring

[tvrobot]

Alright so due to "money reasons", I've had to postpone my "building of a guitar that can do all kinds of junk" project that some of you may or may not remember. Focusing on eventually building said guitar allowed me to stave off my GAS attacks but I could do so no more! I had to give in to my urge to buy ridiculous guitars and so I bought one. I bought a Kavkaz Rostov na Donu Stella (an 80's Soviet guitar; I have a soft spot for vintage Euro guitars). Anywho, I can't seem to find too much information on what exactly some of the switches are for (here's a website but it's somewhat vague cheesyguitars.com/stella.html; also the guy seems to be referring to a specific eBay listing as opposed to all "Stella guitars"; the Soviets seem to be like they were very inconsistent in what hardware/electronics they put on/in their guitars).

So once I received it (maybe a week or two ago), in what looked like a potato sack with a child stuffed in it with a string and piece of cardboard hanging off of it (it came from the Ukraine where I'm assuming boxes are illegal : P ), I didn't really know what all the switches did (I bought it completely on impulse). This is what I managed to learn:

BTW here's a video and some neat-o pictures of all this : D
s1096.photobucket.com/albums/g326/TVRobot/
(Scanner hasn't been working for some reason so that's the reason for the pictures of my awful hand-drawn diagram and the video)

PS Wiring diagram is with all the rest of the pictures.

-There are 4 On/Off switches, one for each pup.
-I can make some weird clicking noise when poking/touching the strings with my pick (nickel/silver Dunlop thumpick) when all pups are turned off.
-There is one RWRP pup on the guitar (the 2nd closest to the bridge). So any 2 pup combination of pup that includes said is (usually) hum-cancelling.
-There is a weird looking (kind of like a lightbulb switch), what I'm assuming is, the Mono/Stereo DPDT switch that I'd imagine splits the top two neck coils, and sends them to different outputs (explained in next hyphen/bullet/thingie).
-It uses a 5 DIN output (the same jack most MIDI instruments use; en.wikipedia.org/wiki/DIN_connector). One pin (and some weird middle thing) appear to be the ground connection, for lack of a better term. Then there appear to be 2 wires going to separate pins (said 2 outputs previously mentioned). Now I don't exactly know what goes to what output as I haven't bothered sending the two outputs to separate amps. I did make a makeshift 5 DIN to 1/4" mono cable (5 DIN ground connection(s) went to the mono ground, both outputs from the 5 DIN went through the single mono output). Because the guitar has no stereo function the assumed Mono/Stereo switch remains a mystery to me (and I'm not exactly sure how the Soviets went about wiring up to 2 different amps so *shrugs*). As to why they used 5 DIN they used it for the stereo function previously mentioned, phantom power for onboard effects (since their amps used 5 DIN jacks as well), and the ground. I'm gonna go ahead and guess it had something to do with the government not wanting the regular people to be using any capitalist-made amps they got their hands on.
-Potentiometers are weird. They have a 4th lug coming off of the back of each one of them (I'm assuming a ground connection or something?). The uppermost pot seems to be some kind of weird blend-ish knob (despite having 4 lugs as opposed to 6); when at 12 o'clock I have max volume and as I move left or right volume drops. The 2nd uppermost is what appears to be a master tone. Next is what appears to be a master volume. Then another master tone. Then another master volume. When turning them I can experience random jumps/drops in volume and scratchy noises). The volumes are all 100k while the tones are 68k.
-Capacitors wired to the tone knobs are oil-in-paper 0.05 picofarads.
-When tapping on the guitar's pickguard, said tapping noises will come through the amp (microphonics caused by no wax potting or something like that right?).
-The 2 lowermost of the previously unmentioned switches are completely mysterious. They can do anything from kill the signal from the pups entirely, allow for a jump in volume, or (this is my favorite) somehow "turn the pups back on" even when ALL of the On/Off switches are in the "Off" position. As for the last switch previously unmentioned, it appears to do nothing.

I basically just want to know what exactly the 3 unknown switches are/would be doing right now and then I'll worry about the pots later.

Irrelevant fun facts about the hardware:
-When the tuners are relaxed (no strings attached or just not very tight) the pickups will rattle when shaking the headstock. Gears are also visible.
-The guitar has a zero fret.
-The only way to adjust the truss rod is with a really skinny closed 7mm hex wrench (or something else that can turn a hexagon shaped washer looking thing).
-Fretboard wood inbetween the zero and first frets is discolored and doesn't follow the same grain pattern as the rest of the fretboard).
-Frets seem to be inconsistent in height. Also fretwire is really flat.
-With the bridge saddles moved forward all the way (with the screws and springs for adjustment taken out; roller saddles being held in place by string tension) and the bridge height as low as possible without taking out the weird gear/cog height adjustment thing the action is similar to the height of many of the acoustics I've played. Also the nut slots and where the saddles SHOULD be isn't lined up properly.
-There is a pop-up string mute inbetween the bridge and lowermost bridge pup.
-There was some kind of insect egg-looking thing in the trem cavity (if I had the arm it's intended to function similar to that of a Jaguar/Jazzmaster style trem).
-The peg for the strap at the bottom of the guitar appears to be missing while the upper strap peg is or has been replaced with a SPIKE! (Presumably for murdering capitalists : P )
-From time to time SOMETHING in the guitar rattles while playing (haven't managed to figure out what quite yet).
-Has what looks like a black poly finish and I have no idea what the body and neck are made of.
-The electronics cavity is so wide that the guitar sounds kind of like a chorus-ee acoustic (think of that Nirvana Small Clone kind of of chorus but acoustic).
-The body is ridiculously thin (1.25").

[thetragichero]

in soviet russia, guitar wires you
(sorry, some of the other guys will come by shortly and be more helpful... but i would burn/flush that insect egg. don't want a critter with no natural predators scurrying around!)

[newey]

The Cheesy Guitars site that you linked to earlier is the only place I know to get info on these Soviet-era guitars. So if there's no additional info there, I don't know where you would get anything else about the switching.

EDIT:

Although nothing specific about your guitar that I saw, I did find this article from Junk Guitars about soviet-era guitars with some general info. I thought it was interesting that the author claims that, in the late Sixties, it was impossible to find a working pay phone in Moscow as kids stole all the receiver parts to make homemade pickups!

[asmith]

Aug 16, 2011 10:04:31 GMT -5 newey said:

Although nothing specific about your guitar that I saw, I did find this article from Junk Guitars about soviet-era guitars with some general info. I thought it was interesting that the author claims that, in the late Sixties, it was impossible to find a working pay phone in Moscow as kids stole all the receiver parts to make homemade pickups!

Awesome. Todays kids just steal them from broken shop windows.

TelevizorRobot,

Can you open the cavity, and attempt to map out the circuitry please? Then post it and we'll all have a looksee.

Or alternatively, say what you'd like all the switches to do and we'll see what we can come up with. Of course we'll need to know exactly what all the switches are, DoublePole DoubleThrow, SinglePole DoubleThrow, etc.

[tvrobot]

There's a multiple pictures of the same (incomplete) wiring diagram in the Photobucket link. I'll try to make a nicer COMPLETE wiring diagram sometime soon (will probably make this one in Paint).

[asmith]

Whoops. My bad.

[newey]

tvr-

I think your suppositions, as far as they go, are likely correct.

The 4th tabs on the pots are no doubt to ground the cases. In fact, it looks like there are essentially grounds to the cases of every component . . .

And microphonics are a good guess for the random noises.

As far as the mystery switches, there's way too much complexity to tell very much from the photos. I'm still trying to digest the drawings, but I think we will need a clearer diagram of some sort.

You might also try emailing the guy at Cheesy Guitars for additional info, or posting your query to the VintAxe forums. Even if the guys at VintAxe don't know about the guitar, they may be able to point you towards someone who would.

[Yew]

Is it just me, or are those pickups humbuckers, but arranged like this


E B G D A E
|Coil 1| |Coil 2|
||||MAGNET||||

[newey]

Yeah, it seems the pickups are set up to give the top htree strings to one channel of the stereo signal, the bottom 3 to the other channel.

It would make a whole lot more sense if each coil had its own magnet, so that one could be reversed for hum-cancelling. Perhaps they do, and what seems to be a magnet on the bottom is just a baseplate. OTOH, TVR said the neck pickup is RWRP, which doesn't make sense if they are all split HBs.

So, apparently they're "dual single coils" (!).

Most stereo guitars send one pickup to one channel and a second to the other. But if memory serves, the old Gretsch White Falcon Stereo models used to have the "3 and 3" set-up- I think, it's been years since I saw one. Not sure if Gretsch had a similar dual-coil pickup or not, but it must have been something similar to get the "3 and 3" stereo set-up.

[Yew]

If the upper coil was out of phase with the lower coil, that should cancel the hum right? and possibly provide an intresting tone from the middle strings?

[newey]

In order to be hum-cancelling, one coil must be reverse wound, and also be reverse magnetic polarity, with respect to the other coil. A pickup which is both reverse wound and reverse polarity (RWRP) is not out-of-phase.

Switch the wires around, and we're out of phase; switch the magnetic polarity, but leave the wires "as is", and we're likewise out of phase.

Switch both the wiring and the magnetic polarity, and we're back in phase and hum-cancelling as well.

[tvrobot]

Aug 17, 2011 16:07:47 GMT -5 newey said:

OTOH, TVR said the neck pickup is RWRP, which doesn't make sense if they are all split HBs.

The uppermost bridge pup is RWRP (I think). I'll change the wording of it.

[popsaka]

...amazing find! The pups look almost like they're electro-magnetic -or maybe you still need to add a/c cord and plug into wall (comrade)

[ashcatlt]

Aug 17, 2011 22:16:51 GMT -5 newey said:

Switch the wires around, and we're out of phase; switch the magnetic polarity, but leave the wires "as is", and we're likewise out of phase.

Switch both the wiring and the magnetic polarity, and we're back in phase and hum-cancelling as well.

This is assuming that both coils are actually transducing the same same string at the same time. I think somebody mentioned that, but it's worth noting. In a "3-and-3" arrangement like this, the only likely phase cancellation would be on the D and G strings, and that's only if the sensing window of the coils is wide enough to overlap at that point.

[newey]

In a "3-and-3" arrangement like this, the only likely phase cancellation would be on the D and G strings, and that's only if the sensing window of the coils is wide enough to overlap at that point.

Good point, that explains it better. One would, presumably, also experience poorer channel separation on the D and G strings when used in stereo.

Earlier, tvrobot said:

I'm not exactly sure how the Soviets went about wiring up to 2 different amps so *shrugs*). As to why they used 5 DIN they used it for the stereo function previously mentioned, phantom power for onboard effects (since their amps used 5 DIN jacks as well), and the ground

I doubt their amps used DIN inputs; I suspect that you're missing a footswitch or two.

My guess is that the DIN ran from the guitar to a splitter box, from there to 2 amps, also might have been switchable from stereo to mono as well.

This would not have been a new idea at the time; Vox's "Guitar Organ" had a factory footswitch controller in the 1960's (to do lots more than is going on here, too!). Others did similar things.

One of the early "design impulses" (in quotes because it was never really a design "movement") in designing electric guitars was to sort of analogize the electric guitar to the electronic organ. An electric guitar was to a regular guitar as an organ was to a piano- so to make an electric guitar "better', make it more like its cousin, the electronic organ.

This meant lots of pickups, lots of knobs, and lots of switches. It meant a mute bar. And in some cases, it meant stereo output.

This design impulse sputtered and died in the West back in the mid-1960s, survived a few years longer in Japan, and then lived on into the 1980s in the Soviet Union. At some point, designers realized that most players wanted simplicity over a knobscape, but they perhaps never realized it in the USSR.

And, given the age of this thing, I doubt phantom power is involved. First of all, there doesn't seem to be anything active inside the guitar that would need power. Second, while the real pros in the West were using equipment with phantom power in that era, your average bar band rig back then didn't have it, and I doubt the Soviet amps were much advanced beyond the bar rig stage at the time.

Presumably all tube amps, too, since the Soviet supply of transistors, etc. was always iffy, what few there were went to military uses.

[tvrobot]

This one doesn't have any onboard effects but there were 2 that I know of that did (the Formanta (onboard fuzz) and the Solo II( onboard fuzz and phaser)). To my knowledge the Stella was the only stereo guitar produced in the USSR. The splitter box would make sense now that I think of it seeing that:

www.ebay.com/itm/SOVTEK-MIG-50-SOVIET-MARSHALL-VINTAGE-TUBE-GUITAR-AMP-/320745468808?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D2%26po%3DLVI%26ps%3D63%26clkid%3D2201461490385788982#ht_6374wt_1188

Also expect that nicer diagram later today or tomorrow.

[wuff]

Hello folks,
I am a german expat living now in Moscow and one of my russian friends gave me his Stella guitar as a birthday present! I was absoluty thrilled about it, since I am collecting some 80's guitars (mainly US made Washburn HM Series with the weird blood spots on it as well as Aria Explorer with blood design and Ibanez Destroyer). Yes you can guess I am pretty much a Metalhead, also owning a full JCM800 Marshall Stack. So the Soviet стелла ростов Дон makes a great match to its US counterparts. Especially since it is in pretty mint condition

Of course right after receiving the guitar, I checked the web for further informations about it and came across this forum and tvrobots thread. I saw all the pics he took from the circuit board, and since I am doing guitar electronics for a long time, it was just a matter of minutes when I started to pull out the board from my Stella as well
Before that, I briefly tried to hook up a custom made cable on the 5pin Din Jack, randomly operating all these crazy 8 switches and the 5 pots. The result in best case I would describe as quite "basic" The sound was either lacking crisp heights, solid bass or did not even come up at all. And a lot of hum if using the distortion channel on my Marshall. Since the Sovjet manufacturers spared any description on the switches and pots and lacking an operating manual, I decided to complete a schematic diagram to understand any dependencies

I posted the schematic already here in the Wiring Diagram Section guitarnuts2.proboards.com/index.cgi?action=gotopost&board=schem&thread=6107&post=59601 but let me post the diagram here again as well as my comments.


Actually the whole circuit seems to be designed by a technician or engineer rather than a guitar player. There are many options to set the switches, but only few of them really make sense while some of the settings (like switching on more than 2 pickups at the same time) will degrade the sound significantly due to phase shifts and interferences. Also the real use case for the split mode of PU3 and PU4 remains a mystery for me, same goes for the hi pass mode of PU1 and PU2, which only make the sound hollow and thin...

On my guitar I also made some small changes related to grounding by cutting the existing grounding cables and adding a star-like gounding instead. Also had the strings connected to ground through one of the star cables. This reduces hum significantly and makes the guitar more enjoyable - and these modifications can easily be reverted to put it back to original state.

Any comments are welcome
Cheers and "From Russia with Love"
Wuff

[wuff]

And here it is

[newey]

wuff-

Hello and Welcome to G-Nutz2!!

We really like folks who show up with solutions instead of questions (although questions are fine).

I liked your description of it being designed by an engineer, not a guitarist. That's exactly what it's like!

Or perhaps, several engineers. As my late father used to say, "One man can only do so much damage. To really screw something up takes a committee . . ."

It looks sort of retro and out of place among your '80s metal guitars, but a nice collection nonetheless.

[wuff]

thanks newey for your nice and encouraging words!
Yeah we can almost imagine how some sovjet engineers were sitting in the late 70s with a left over of pickups and switches from last 5 years plan and given the task by the minister of musical education to design a world class product outperforming the western competitors... Outcome was then the Stella guitar

cheers, Wuff

[asmith]

Wilkommen, wuff.

Your diagram says that S1 changes between normal & hi-pass, and S4 is an on/off switch, but I just wanted to clear something up. S1 and S4 actually work like this:

S1 connection	S4 connection	PU1 result
Up	Up	Hi-pass
Up	Down	Hi-pass
Down	Up	Off
Down	Down	Normal

The same is true for the S2 & S5 switches together.

Very odd guitar indeed. Now play Flight of the Bumblebee at 200bpm or it is off to the Gulag with you.

[wuff]

Hi asmith,
yes you are right, thanks for posting the correct settings, which are even more confusing than having S4 and S5 as simple on/off switches, cause now everything depends on S1 and S2 settings, including PU3 and 4! Very odd indeed. I updated the schematic accordingly.

And actually I am learning "Kalinka Malinka" and "Katyusa". Both are pretty famous songs and i hope my friends will not send me off to Gulag if I mess up my playing after some Vodkas :-p

[thetragichero]

this bit of thread necromancy brought to you by my bringing home one of these to clean up and sell for my dad and being lead here by the third google result. wiring diagram created by wuff has been rescued from the dead link and i shall also post here for posterity



mine has lacquer over the entire neck, including the fretboard and frets.... strange

[JohnH]

Hi thetragichero, very public spirited of you!

If you have one of these, can we see a pic? I love a good bit of soviet engineering, which is generally simple, solid and reliable, and heavy and a bit quirky and rough around the edges. Especially heavy and quirky and rough around the edges!