I Need Help With Motorola SH18N Speed Control!!

Hi again everyone! First off, thanks so much for the range of advice and expert opinions on servicing these changers. This really is an incredible, great sounding and operating unit that I am very fortunate to own. Once this issue is fixed I know I will have many more years of enjoyment with this machine before it ever needs more service.

I ran across a web page trying to search for an outboard AC variable frequency drive, and I think this would be a good solution if I decide not to try filing the motor posts: http://shop.grantfidelity.com/Consonance-PS-1-Turntable-Speed-Controllor.html. It's specifically designed for turntables and since it's only $75 I think I might give it a try. But before I commit to anything, does anybody reading this have experience with these types of frequency drives or know someone who does, and would this work on my Motorola? Even though this would probably solve the speed issue, I would hate to think that it might damage the changer or some other componentry that depends on a constant 60 Hz frequency for proper operation. (If this does work, it would also be money well spent since I can use it on my friend's 1965 Newcomb that spins about 3% slow.)

Thanks in advance and I hope this can be a possible solution!

Personally and professionally, I think you're some kind of obsessive nutcase to go to this amount of trouble over a cheap portable record player.

It's rather obvious that you cannot be satisfied with things the way they are...... IMperfect in an imperfect world.

MattTech wrote:Personally and professionally, I think you're some kind of obsessive nutcase to go to this amount of trouble over a cheap portable record player.

It's rather obvious that you cannot be satisfied with things the way they are...... IMperfect in an imperfect world.

It's also rather obvious that you are a judgmental audiophile who has done nothing in this post except bitch and moan about how "cheap" my record player is. You know what? Even if it is cheap (which is such a wrong assumption to make but I'll entertain the idea for now) it means a lot to me that I was able to give it a second life like it deserves, and I want to get the most enjoyment out of it I can. Please come back to this forum when you are ready to grow up and contribute with advice like the rest of the users on this thread have done.

Music Man,
As far as I can tell, nothing else in any phono, should be affected, if a freq. change is done to the motor only--The only possible thing I can think of is "induction" of noise into the audio circuit, but I doubt this will happen-- Ron Rich

Listen, I'm a professional servicer, and I know these things backwards & forwards.
You're a nitpicker in search of a holy grail from an inexpensive product.

Giving it a second life is fine - I restore these things for people all the time.
But I also understand their limitations and manufacturing tolerances, and expecting a common VM changer to perform with the accuracy a high-end studio changer is nonsense that I've no time for.
If someone came into MY shop insisting such rubbish, I'd tell them to leave.
You're obviously the judgemental audiophile, not me.
Keep following your crazy "desires" with speed controls and such, it's an audiofool thing anyway.

MattTech wrote:Listen, I'm a professional servicer, and I know these things backwards & forwards.
You're a nitpicker in search of a holy grail from an inexpensive product.

Giving it a second life is fine - I restore these things for people all the time.
But I also understand their limitations and manufacturing tolerances, and expecting a common VM changer to perform with the accuracy a high-end studio changer is nonsense that I've no time for.
If someone came into MY shop insisting such rubbish, I'd tell them to leave.
You're obviously the judgemental audiophile, not me.
Keep following your crazy "desires" with speed controls and such, it's an audiofool thing anyway.

Apparently you do have time for my "nonsense" because you've been posting here more often than anybody else! And to think you actually run a business with your attitude??

And unless you can tell me the name and brand of a different quality modern, four-speed, DC-driven portable record changer with a three channel system that exists other than these vintage ones, I really don't think my idea is that crazy. If there are record changers made nowadays that are like my Motorola in every feature and cost about the same, then we'll talk. But I don't think there are; I don't even think there were any portable three-channel record players made after the mid-1960s!

You have your opinion on these and I have mine, which is fine. But only one person on here started slamming me with crap about how "cheap" these things are when all I was originally asking for were ideas on how to get the speed back down a half-step...

All right guys--enough with the "flames" or I'll start "deleting posts--"----I see both of your points--but--
Keep it within the rules of the forum--civil--please--
Ron Rich (board moderator)

And Ron Rich, I appreciate the info. I think I will start saving my pennies and buy the outboard speed controller; even if I do start getting a noise using it, I can return it within a 3-month time period and get a full refund. Not to slam on Rob-NYC or anything - I still like his advice of trimming the motor shaft for some single-play TTs- but I think this is a better long-term solution, because I know that these old motors can drift farther and farther away-in positive or negative speed changes-from the proper RPMs. As others have also stated, the motor speed can vary even after putting a heavy stack of records on it! Using this electronic speed control will allow me to take care of that, whereas trimming the motor would not offer such precise control.

Make sure that the speed control is connected to only the motor, not the electronics. Insert it on both sides of the motor winding. If it puts out enough power, it should not cause the problems with the change cycle the way my device does.

I once improvised a turntable variable speed control with an audio signal generator, a guitar amp, and a transformer.

Record changer, you might be surprised at how many radio stations use that method to speed up the old QRK and other non-adjustable tables. typically it was: generator-PA amp with 70volt, or (better) an old RCA with 100 volt output and the table connected to that.

Often the 70 volt out was not strong enough to start the table so the engineer would give it a kick with his finger. This method was seldom used for on-air, mostly it was for dubbing to cart.

I had a Bogen industrial amp w/200w/rms and 115 v output. Needless to say an engineer friend bought that as soon as he heard me mention it.

Ron/NYC

Hi folks!

After tinkering around with the Motorola, I've fixed this problem! (And no, it had nothing to do with the supposed "cheapness" of the record player or VM turntable, as some people said.)

What happened was that for whatever reason, when the phonograph received a motor and changer cleaning, they had mistakenly left the old grease in the AC motor as well as some gunk on the inside of the turntable rim. This was causing the motor to overwork to compensate for the extra resistance in turning, and this lead to the problem of the faster-than-normal rotation. When I cleaned the motor and turntable by myself and put them back in the phonograph again, the table spins exactly right at all speeds! (I have a tuning record that plays four 30-second segments of the note A440 when you play it back at 16, 33, 45 and 78 rpm. I used a metronome to double-check, and all four speeds are where they should be!) And yes, I called the place that cleaned it and they gave a partial refund for their mistake of not cleaning those two components.

And as far as the radio stations go, I can indeed attest that many radio stations sped up the records they played by 2 or 3%. (This allowed the music to feel "peppier" and also shorten them so they could fit in more commercials during the breaks, and was such a small increase in length and pitch that most people couldn't even notice it unless they happened to use a pitch pipe or tuning fork while a song was playing.) I met a gentleman who worked as an AM radio DJ during the 1960s through the late 1980s, and he said this was extremely common and would even speed up tape reels.

Well, you are in the ballpark in your guess as to what happened here...but those motors can not run fast to "over compensate" -they have one speed and it can only go lower.

What happened is that "gunk' mostly in the form of dirt and rubber shed from the idler puck collected on both inside of the table rim and on the steps on the motor pulley. This has the effect of making the pulley slightly larger and the inside rim of the table slightly smaller.

Result: Faster speeds.

These tables and indeed most changers ran fast as built. The reason given is that a full stack of records would slow the table down and pitched-down music was more noticeable to the average person than slightly pitched-up, so that compromise was made.

About four years ago I found a late-70's Sony compact (AM-FM-Phono) the electronics worked perfectly after a little work, but the turntable was much too fast even after a thorough washing. There was a neat "tire" of rubber deposits on the motor pulley. I moistened it w/alcohol and scraped it off with a old MetroCard (plastic so it won't scratch).

It now ran "normally" fast.

Rob/NYC

Rob, thanks for the final input! As someone with perfect pitch, I was almost pulling my hair out when I couldn't listen to my favorite records because they played back half a step too fast! The only other experience I've had regarding this issue was with a Califone, and that model was equipped with variable speed control so it wasn't that big of a deal for me when the table still ran fast even when the variable speed selector was "properly" dialed in. It's interesting to me how nobody back then would have cared about things like this (except perhaps Vitaphone operators for the early talking films)...how did people with perfect pitch survive back then??