amp questions

[lordraptor1]

ok first off i will try to dumb this down in order to keep the train from derailing on this one considering all my posts on MLP seem to do.

ok with that said. i made a trade for a vintage amp today ( 1970's SG Systems SG-212 which was made by CMI ( chicago musical instruments), and here is what i was able to ascertain from almost a week of research and practically nothing online except a youtube video a guy made of one he picked up in which he mentions his needs serviced LOL.

1. was during the period gibson was owned by cmi
2. made in the 70's
3. used 8417 tubes


yeah that is it for internet research however, i did call music shop in OKC ok, where the guy said he owned a couple and he had all all kinds of paperwork and stuff (manuals, schems, tech manuals). however he didnt seem to keen on giving any more info, history, etc on the amp but he did happen to give a "value" of $1,200.00 on it.

so i guess here is what i would like to know:

1. was gibson owned in the 70's? specifically 72/73 ( which is best estimate i have found as to when amp was made)
2. does 70's sound about right?

and

3. does $1,200.00 sound about right for this vintage amp? the only things i can see wrong is a tar in the tolexby channel 1 ( most likely done during a service), 1 missing knob, and leather part of handle is dry rotted.

it was recently serviced ( by previous owner) and tubes replaced however it looks like the tech who did the service instead of using 6550 or EL34 to replace the stock 8417 tubes ( only assuming they were 8417 since that is what i read they had when new) he rebiased it for 6l6 tubes and also installed a JJ 12ax7. with that said think there would be a huge pain to change them el34/6550 tubes? would it be worth it? or should i just list it up for sale for the $1,200.00 the guy at the shop in OKC said it was "worth"? here is a pic of the amp.

persoanlly i think the clean is great and dont think i have heard anything better BUT i dont care for the distortion side of the amp, maybe it is because i only spent a few minutes with the amp because of the late hour and this amp is LOUD .

here is a pic of the amp:

 

[lordraptor1]

ok due to lack of replies i am going to go out on a limb and say the SG-212 amp is an extremely rare one as far as value who knows but at least i have an extremely rare piece. just wish chicago musical instruments had put "gibson" on it instead of SG System ( seeing as CMI owned gibson at the time), then i would have all the information i needed on it

 

[notjoeaverage]

Try these guys

Vintage Amps Bulletin Board • Index page

 

[frankv]

Looks like something from 2001 Space Odyssey... That's really old fashioned looking..

 

[chasenblues]

Some info on the amp in this old thread,If you may have missed it in your search.

SG System SG-212 - Amps and Effects - The FrugalGuitarist.com Forum - FrugalGuitarist.com


"The SG Systems guitar amplifiers, manufactured by C.M.I in California, a sister company of Gibson when they were both part of Norlin, were a hybrid design. They incorporate discrete FET preamplifiers with a tube output amplifier, somewhat like Leo Fenders Music Man amplifiers, which came later. SG amps tended to be big (and heavy). They sport oversized knobs and, usually, some sort of special voicing or effect.
Originally, these amplifiers used a single pair of 8417 output tubes which were squeezed hard to produce the rated 100 Watts. They also blew up a LOT. The overdrive feature of this model, which operated in a very nonsensical way, probably to circumvent Boogies then valid patents on switching overdrive stages in and out, used a mechanical relay for activation, tended to be "clicky" and was very difficult to adjust to achieve the desired amount of effect."



Links to images of the amp schematic
SG100G1of3.jpg Photo by myfoot | Photobucket
SG100g2of3.jpg Photo by myfoot | Photobucket
SG100G3of3.jpg Photo by myfoot | Photobucket

 

[lordraptor1]

thanks guys, i actually saw a youtube vid of david allen coe using one in 1975, and after alot of conflicting info from local places including tehm giving conflicting "worth quotes, i ended up calling norms rare guitars in cali ( which took a while getting someone to answer LOL) but the person i talked to at norms gave it a "worth" of $800 in good condition. as far as the tubes goes this one the one i have has been converted to 6l6GC tubes by previous owners tech due to him not being able to even find 8417 tubes anywhere LOL. i found a couple issues with it, first when i took the chassis out to clean the dust out of it i found 2 cracked tropical fish caps ( which i ordered off fleabay today) and i also found the ground plug on the power cord was broken off so i plan on replacing the cord as well. the only other issues is it missing a front panel knob on the phase shifter and the leather on the handle is dry rotted but for a 42/43 year old amp it is in really good shape.

i have a good idea why people dont like the distortion on the amp. to me it sounds like a 70's fuzz which would make sense seeing how popular fuzz was in the 70's LOL.

with that said it is a fine amp best suited for those who play "clean" but depending on what kind of dirt you are after unless it is a fuzz you will need to use pedals, also the phase shifter is nice but i still havent figured out exaclty how it works on the amp and tend to just run through a phaser pedal.

 

[ScottMarlowe]

I wonder how that FET preamp would respond to an OD pedal...

 

[lordraptor1]

I wonder how that FET preamp would respond to an OD pedal...

i havent tried a pedal yet at all myself but everyone i have talked to that know the amp says it takes pedal really well.

sdaly i dont have any dist/od/dirt pedals or i would try but it is going to be a few days to a week because while cleaning dust last night i found two cracked "trop fish" caps, and i noticed that the ground plug is missing on the power chord so i want to fix that to before firing it up again.

 

[lordraptor1]

anyone happen to know or have a pinout, schematic, or even any images of the inside of the phase shift footswitch or any idea as to how to make one? the reverb switch should be simple since it is a standard 1/4" jack style but the phase shifter is some hokey 6 pin plug

 

[chasenblues]

Couldn't you reverse engineer the foot switch off of the layout from the amp?

 

[lordraptor1]

Couldn't you reverse engineer the foot switch off of the layout from the amp?

i dont know, the guy i got it from had it serviced and at the time of service the tubes were changed to 6l6 and from what i understand it requires some rewiring of the circuit since it is a hybrid amp LOL. but it looks liek as long as the circuit is still intact it should be simple enough though thanks .

 

[Standard 64]

Weird lookin

 

[Davio]

Weird lookin

Aptly named, then...

 

[lordraptor1]

i took a screen grab from a youtube vid of david allen coe in 1975 and i edited the image and circled a particular point of interest, pay close attentiong to the red corcled area. enjoy

 

[lordraptor1]

new info couldnt find a date on the amp itself to determine age but the speakers are another matter which the speakers according to the numbers on them are eminence alnico made in 1974 so that puts the amp at the earliest of 1974 and due to no other dates present that i can find im going to say the amp itself was made in 1974 making it 41 years old ( coincedentally it is the same year as my nova and 1 year older than i am ). i also figured that most dont like the distortion on it because it is more like a 70's fuzz which was apparently very popular at the time. the guy in okc that i spoke with got upset because i quoted him on what he said value was asked me to remove it and then changed his "worth" price on it so i deemed him as an unreliable source and ended up calling norms rare guitars in cali. after a whole day of trying to get through and finally at the end of the day getting a person on the phone i aksed about the amp and what it was worth and was told $800 to $1200 to the right buyer which helps with an actual "worth". sadly most people use fleabay for worth and they just look for lowest price sold and dont bother to check condition, model, or type so "worth" is still debatable but i do think norms vintge guitars is reliable for "worth". to say i would actually get 'worth" is not likely but to just take the worth/value from someone that prices from fleabay would be silly IMHO.

so with that said worth is really not my concern anymore because if i sell or trade it and get a good amount or somethign i want or can use fine if not at least i have an extremely rare piece of guitar amp history

 

[chasenblues]

new info couldn't find a date on the amp itself to determine age but the speakers are another matter which the speakers according to the numbers on them are eminence alnico made in 1974 so that puts the amp at the earliest of 1974 and due to no other dates present that i can find i'm going to say the amp itself was made in 1974 making it 41 years old ( coincidentally it is the same year as my nova and 1 year older than i am.

According to this it wasn't produced for more than a year so 73/74 seems about right.(Scroll down to "Down Fall" in the link)


"in 1971, the cost to cover warranty repairs became too high for Standel to endure so CMI (Standel and Gibson distributor) covered the cost, and in doing so, acquired controlling interest in the company. By 1972, the Standel brand was replaced by SG Amplifiers (Standel Gibson) being manufactured in the Standel factory at 4918 Santa Anita Ave., El Monte, California. The SG line was a hybrid design (solid-state preamp, tube power amp), developed by Bob Crooks, which harkened back to the original Standel hybrid designs of 1963.

After just over a year of operation, the SG line of amplifiers was discontinued. and the old factory closed down."

https://en.wikipedia.org/wiki/Standel

Notice the address on the tag on back of the amp and the address referenced in the text/link..

 

[lordraptor1]

According to this it wasn't produced for more than a year so 73/74 seems about right.(Scroll down to "Down Fall" in the link)


"in 1971, the cost to cover warranty repairs became too high for Standel to endure so CMI (Standel and Gibson distributor) covered the cost, and in doing so, acquired controlling interest in the company. By 1972, the Standel brand was replaced by SG Amplifiers (Standel Gibson) being manufactured in the Standel factory at 4918 Santa Anita Ave., El Monte, California. The SG line was a hybrid design (solid-state preamp, tube power amp), developed by Bob Crooks, which harkened back to the original Standel hybrid designs of 1963.

After just over a year of operation, the SG line of amplifiers was discontinued. and the old factory closed down."

https://en.wikipedia.org/wiki/Standel

Notice the address on the tag on back of the amp and the address referenced in the text/link..

already read that and yep looks like the back on mine except the serial number on mine isnt a sticker, it is stamped, higher serial number than the one you posted to ( mine is a little more than 55k on the serial number LOL).

still trying to find a damn diagram for teh PSFS-1 ( footswitch) for it though. found a couple of "builders" but the links are actually dead, and references to people claiming to make them whch end up with a dead link, schematic sites that claim to have them for a fee but actually dont have them. i know it is 3 switches with 3 led's, and 6 wires to a plug but cant figure out how to make one and the diagram above is a little different than wha ti am actually looking at on teh board ( since the ps1a is built into the amp not standalone).

ANYway, thanks for the info that has been shared, nice to see im not the only old fart here

 

[ajay]

Can I ask what You traded for it? I hope that You didn't give him a nice Gibson or Fender for it. It just looks like You're in for a lot of work.
Also, have You considered getting ahold of David Allan Coe? He may still have his layin' around and he would probably let You borrow his pedal so that You could make a diagram. I have gotten responses from some pretty famous people. Just sound like a nice guy, and He'll probably get back to You. What do You have to lose? It doesn't cost much to send an email.


(update) I already asked him for You. I'll let You know if He gets back to me.

 

[lordraptor1]

Can I ask what You traded for it? I hope that You didn't give him a nice Gibson or Fender for it. It just looks like You're in for a lot of work.
Also, have You considered getting ahold of David Allan Coe? He may still have his layin' around and he would probably let You borrow his pedal so that You could make a diagram. I have gotten responses from some pretty famous people. Just sound like a nice guy, and He'll probably get back to You. What do You have to lose? It doesn't cost much to send an email.


(update) I already asked him for You. I'll let You know if He gets back to me.

actaully no work needed it actually works, just 2 cracked tropical fish caps easy fix and waiting on the parts .

i did trade a "gibson" for it, a gibson baldwin les paul . it was wired 50's with independant volume, straight neck, near perfect frets, low action and great sounding and easy playing. of course peeps here will bash that guitar saying it is crap and not worth anything but sadly i can say the same thing for a large number of gibsons i have seen over the past few years.

i could throw in some 2E104k caps and be done with it but i figured id just figured id replace them with what was in it since i got a good deal on 2 of them LOL.

amp actually sounds REALLY good clean, but the "distortion" side not so much probably because i have stated before it is a 70's fuzz distortion but i might not have the "sweet spot" set on the knobs to get the right sound for me and maybe i never will but hey clean channel + stomp boxes = goodness ( still wont beat my 87 peavey half stack though LOL).

 

[lordraptor1]

ok here to give you a basic idea of how this amp sounds i took a vid with my cell and uploaded it to youtube ( yes i know sound wont be good and that it will be compounded by trying to video with a cell phone while trying to play anyway here is the vid:

https://www.youtube.com/watch?v=Jsz-FepklhY