Understanding CMI guitars and amps

1bassleft · Posted: Tue Oct 03, 2006 12:11 am Post subject:

As a 115, it might have been aimed at the bass player. It'd be good for that; relatively distortion free for a tube amp and the 15" handling the low Hz. As you know, many a guitarist makes good use of valve bass amps (some bloke called Hendrix being one example).

I had a look at good ol' eBay for 8417s. Completed listings show that boxed-new pairs will cost around $100 but tested, matched pairs that have been used will come under that. That's one option. Another is to convert the amp to a more regularly available tube. I looked up the 8417 on TDSL (http://tdsl.duncanamps.com/show.php?des=8417 and, as far as pinouts go, the 6550 and the KT88 are your best bet. You might get away with just a bias-adjust but I would think the worst-case is a bit of resistor changing that a decent tech can manage asleep.

The only caveat is that the 8417 can handle whopping voltages and the SG-systems may well have applied them. The KT88 and certain 6550 variants can take it, but... IME, the old (gone) makers like General Electric (6550) and GEC/Genalex (KT88) made much sturdier tubes than the Chinese, Russians etc that are your source for new production. Unfortunately, GEs and GECs are as expensive or more than the 8417s are.

Looking at moderns that can live in an Ampeg SVT (so should survive in yours) there are the Svetlana 6550C (recently ceased production), the JJ Tesla KT88 and New Sensors 6550 offerings branded Sovtek, Electroharmonix (EH) and their "reissue" Tung-sol.

If you can manage a pic of your amp, it would be very welcome in this thread Smile

myfoot · Posted: Tue Oct 03, 2006 1:22 am Post subject:

Be happy to if I can get ahold of a camera.May take a bit before I can get one of my kids to let loose of it for a bit. Found this today: It's an ad on ebay, and I can't tell if it's the blue denim covring but looks just like this :
http://cgi.ebay.com/53974-Very-Nice-1974-SG-System-Amplifier-Ad_W0QQitemZ230021809484QQihZ013QQcategoryZ37837QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

SubZero · Joined: 03 Oct 2006 Posts: 1

Hi there everyone.

It's my first post here, found the forum while searching for information about my CMI.

For a few years now I have been looking for information about the company, as I have a CMI Gibson SG copy guitar. I don't play guitar that often as I'm a drummer, but a few proffesional guitarists that I know have used my guitar, and say that it plays the same, if no better, than original SG's.

I'm going to upload a few pictures of it later on when I clean it up a bit. Just thought I'd post now before I forget! If anyone needs any information on it, I'm happy to try an answer and questions that I can.

Thanks, Dean.

1bassleft · Posted: Wed Oct 04, 2006 12:39 am Post subject:

Welcome Dean and thanks for the pics. As you'd have read by now (glad that this thread is turning up in owner's searches Very Happy

) your CMI is made in Japan and imported by Marshall for UK sale somewhere between 1976 and 1980. Earlier in this thread, you'll see a list price of the time for your guitar. Am I right in assuming it's a bolt-on neck? All other CMI Gibbolikes have so far been.

The SG Systems amp in that catalogue:

looks to be covered in black rexine/tolex type material, but those big knobs are a Standel trademark look. Oh, and Angela's parts URL is simply www.angela.com

myfoot · Posted: Thu Oct 05, 2006 7:18 pm Post subject:

Shit , I was at daughters this morning and forgot to get her camera Crying or Very sad

@1bassleft I found this link today and thought of you (don't know why)
http://desmoines.craigslist.org/ele/209904537.html
I was looking around my area trying to find parts for my amp and this turned up. Anyway I sent an email to Standel amps and got a reply from the president :

Yes, Bob designed your amp. In fact, he was very proud of the SG amps.

The 8417 was an incredible tube, designed at the end of the tube era by the
old school designers and it had some really excellent specs. Because it
came out so late, there were not too many products designed using it and
there weren't too many made. As a consequence, not many people or
designer's are deeply familiar with them. However, Bob always looking to
take advantage of the best materials was very excited with it and really
liked the results.

Yes again, it is very likely you have the original speaker. I can say for
sure that the Altec was an optional upgrade.

And...Yes again, I would really appreciate a good copy of that schematic. I
have the schematic Bob gave me, however, it's not a very good copy.

Good luck and best wishes,

Danny McKinney-Pres.
The Standel Co.

1bassleft · Posted: Fri Oct 06, 2006 1:24 am Post subject:

That's a great piece of info for other Standel-CMI amp owners. I had read that support from Gibson et al for the products is still excellent. Unfortunately, Marshall don't seem to mention their offshoots anymore (including their CMI) and I haven't heard anybody praise the info available from them.

myfoot · Posted: Sat Oct 07, 2006 1:33 pm Post subject:

Won't be long now for the pics..brought son home from college and he brought his camera with as I requested; batteries are dead Shocked

anyway I'll get some batteries and up pics probably later today . Question for the gurus : Why won't his acoustic/electric play thru this amp? His strat ,sg and even his epi sheraton II play just fine ( very nicely I may add ) but his A/E does nothing. Is it because of active pickup? THe amp he uses at college (an old peavey tko ) plays just fine . Thanks for any info

1bassleft · Posted: Sun Oct 08, 2006 3:04 am Post subject:

Hmm, that's an odd one. Does the SG have "Hi" and "Lo" inputs? The preamp output from the AE will have a much lower impedance than a boggo guitar so the "Lo" input is a better bet. Even so, I have an active bass (again, preamp, not pup) and I plug it into vintage amps with no choice and it comes out just fine.

myfoot · Posted: Sun Oct 08, 2006 12:43 pm Post subject:

Yep, has Hi and Lo, I had him plug into both channnels and both HI and Lo and it made no difference. Anyway I went and bought a couple new cables (alll he has left around here are speaker cables ) so we'll try it out today with those . Those pictures are still coming , I was cooking a hog yesterday and my wife forgot to pick the batteries up for me. And yes that hog was good Razz

myfoot · Posted: Sun Oct 08, 2006 4:36 pm Post subject:

hope these are sized okay:

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