If you think you might want to ship, you could try ringing audiocraftsman. Mike is a really good no nonsense tech and unafraid of a challenge.
http://audiocraftsman.com
http://audiocraftsman.com
Motor repair for Goldmund Studio TT /w Pabst motor
Well, either I am seriously forum challenged (a possibility) or for the second time my thread on this subject has been removed and is not in the archives. I thought they archived everything, but I guess not. Moderator, could you please stop deleting this. Every time you do I lose all the posts from forum members.
I sent my motor to an electronics firm in California recommended by a friend in the industry. They took one look at it and wouldn't touch it because it had electronics in it and, I guess, they don't do that stuff.
The good news seems to be that the motor windings are very likely ok and the problem actually seems to be related to the internal electronics parts.
Since I saw smoke come out of the motor during my initial investigation of the problem, I had thought the windings were compromised. Removing the bottom cover of the motor reveals a circular circuit board but also visible through a gap where the wires enter the motor are some additional electronics parts. So, when the motor was returned to me I set about disassembling the damn thing myself. In addition to removing the bottom cover, this required removing a couple of C clips and other various bits.
I was expecting to see some heat damage but everything looks fine. There are a lot of Caps, Resistors, Transistors and other three terminal devices in this thing. I am leaning toward the theory that one or more of these transistors have failed and I will be testing them to see if I can locate the problem.
Word on the street has been that Pabst of Germany went out of business in the early '80s. However, in the latest issue of TAS I noted that the review of the Raven AC 3 TT mentioned that it uses a Pabst motor.
I sent my motor to an electronics firm in California recommended by a friend in the industry. They took one look at it and wouldn't touch it because it had electronics in it and, I guess, they don't do that stuff.
The good news seems to be that the motor windings are very likely ok and the problem actually seems to be related to the internal electronics parts.
Since I saw smoke come out of the motor during my initial investigation of the problem, I had thought the windings were compromised. Removing the bottom cover of the motor reveals a circular circuit board but also visible through a gap where the wires enter the motor are some additional electronics parts. So, when the motor was returned to me I set about disassembling the damn thing myself. In addition to removing the bottom cover, this required removing a couple of C clips and other various bits.
I was expecting to see some heat damage but everything looks fine. There are a lot of Caps, Resistors, Transistors and other three terminal devices in this thing. I am leaning toward the theory that one or more of these transistors have failed and I will be testing them to see if I can locate the problem.
Word on the street has been that Pabst of Germany went out of business in the early '80s. However, in the latest issue of TAS I noted that the review of the Raven AC 3 TT mentioned that it uses a Pabst motor.
21 responses Add your response
"Both turntables suffer (identically) from thin bass response, and resonance issues." Wow, not my experience at all. My Studio has amazing bass, solid foundation. Never thin. And zero resonance issues. Tried Sorbothane once and it killed dynamics and energy. Became clinical. Also the T3, once it is set up and tightened down can't really change so again, I'm not having the same experience you are. |
Hi John, the T3-F arms CAN be made to work, but they're a real PITA! And depending on your environment (changes in temperature and humidity) they don't hold their settings very well. Additionally (as with all linear trackers to some degree,) they are hard on cartridge cantilevers. And unless the arm comes with the latest PL8 control unit, it's 'no deal' (there are many reasons for this.) BTW, I have never seen a PL8 that is marked 'PL8' on the front panel. So you have to find a PL-7 and then check the rear panel ;~) Without trying to talk you out of a Studio, I have a second, never used, Studietto (with JVC quartz controlled motor.) It's in PERFECT cond. (including a pristine dust cover!) and I have the threaded Goldmund cone feet and Goldmund reflex record clamp to go with it (those two items alone are more than 300 bucks each if you can ever find them!) BTW (and this is important -- a lot of people don't know it): The Goldmund reflex clamp is essential for the correct operation of either the Studio or the Studietto turntables. Their platters have a concave surface, and the record has to be pushed down into the concave surface by the clamp (a simple record weight won't do it.) A SOTA reflex clamp is the only currently available clamp that will also work, but then the dust cover won't close! A lot of people say the Studio sounds better. I have no idea what they're talking about! Maybe it's some kind of 'vintage snobbery', or the fact that (due to the expensive wood base) the Studio cost more. However, due to that enclosed base, the Studio is almost impossible to dial in properly! Both turntables suffer (identically) from thin bass response, and resonance issues. The solution (which elevates their performance into the realm of $15,000+ turntables!) is to replace the springs with Sorbothane. . |
Willster, you're nothing if not thorough! Please come back and update this thread as you progress. One other idea I had (which at this point I'd not be surprised to learn you've tried) is to e-mail the fellow that has this site: http://de.geocities.com/bc1a69/index_eng.html He may have other sources we don't know about. Good luck. |
Thanks for the info. I ran across this discussion of using a Dual motor quite some time ago and am not quite ready to butcher my turntable in order to make the Dual motor fit, although it might come to that. I can send pictures to anyone who wants them, but I don't have a website where I can post information. At this point, I think my motor is fixable. I just put too much faith in the wrong guy. I may end up doing the work myself since no one else has proved reliable. There appears to be a dead short somewhere and I don't think the motor windings are damaged. My current top suspect is a voltage regulator. So, if I can sort out where the fault is, I should be able to affect repairs. I have a good understanding of electronics, but I don't have any experience troubleshooting. Each failed attempt at finding repair help has at least revealed additional info about the motor and it's condition. Hopefully, at some point the accumulated insights will reach critical mass and I'll get results, either by doing it myself or by finding appropriate help. Thanks to all who have taken an interest. I do appreciate it. |
Willster, it would be extremely helpful to those seeking to assist you if you would post a link to some photos of the motor, the electronics, the deck itself (showing motor location) and anything else even potentially germane to your issue. Without real visuals, we've only our imaginations to guide us. I'm sure you're getting frustrated, but this problem is one that can be resolved, so hang in, and take some photos. |
Willster, this is from Arthur Salvatore's site, maybe you can get some ideas from it: GOLDMUND STUDIO MOTOR REPLACEMENTS Below is potentially "Great News" for the owners of the Goldmund Studio turntables. It is from a veteran reader and contributor to this site; Here it is, slightly edited; "...I found out that an EDS-900 Dual 704 motor is nearly identical to the one used in early Goldmunds. Furthermore, the EDS-1000, used in the Dual 701/721, is an IMPROVED vesrsion. I recently aquired three junky Duals and will check these motors out. If this, indeed, is true, than older Goldmunds can be kept going indefinitely. Dual Europe has both new EDS-900 ($300) and the EDS-1000 ($650) in stock, but they can be salvaged form old tables for next to nothing (I paid $140 for three). Will keep you posted as to feasabilty of retrofitting. You can let all stranded Goldmund owners get in touch with me for any questions they have. Goldmund Europe still has miniature motors for the arm in stock ($300 a pop)." This update from the same reader arrived a few days later; "Dual motor update: Dual 701/721 motors are larger in diameter, so some machining is required. Other than that, they could be used. Of course a HANDY guy can do it. Dual power supply must be used. Not a DIRECT replacement, no. Dual 704 looks to be much closer from a picture, but I won't know till I get it (next week)." Futher Correspondence- These updates are from the same helpful reader above. After a little editing; "Final breakdown on the replacement motors from Dual tables: Dual 701/721, EDS 1000/EDS 1000-II- These motors are 5.5" in diameter, while the original Goldmund Papst is 4 3/8", so machining is required. Dual 704 (may be also 504, never got that, EDS 500 motor), EDS 900 motor- IDENTICAL top, diameter, color etc. Major difference: circuit board extension beyond housing about 0.5" x 1.5", so some machining is required. This motor is not as thick as the original, has less of a magnet and as a result, less torque. Dual's own platter is much lighter. EDS 1000 has more torque and it is smoother than original Goldmund. There is a posting on Audio Asylum by a Goldmund Studietto owner who actually wanted to replace a WORKING Papst with an EDS 1000 to acheive smoother ride. Further, both motors are fed via their own electronics, and MUST be used with it. It is not bulky, will fit inside. All in all, I would only recommend these if all other options are exausted (that is, the original motor replacement at about $500, if you can find one). I paid $50 for a Dual 704, so it is a cheap fix, but Goldmund platter probably will have to be given a spin to start turning! The last word- The Dual 704 (EDS 900) motor definitely wouldn't work - not enough torque. So forget about quick cheap fixes." Personal Note- This reader deserves thanks for sharing his time, investment and efforts. After everything is said and one, the EDS 1000 motors, found in the Dual 701/721, can still work, though "some machining is required". They may even provide an improvement! |
Bad news. The guy that I put so much faith in doesn't want to spend any more time with my motor, even though he never completely isolated the problem. He has a back log of work and thinks he could repair three of his typical jobs for the time it would take him with my motor. It's a complete cop out. I still think he could probably help me get it going again but he isn't willing. We never even discussed a fee for the work. I would have been willing to pay him for his time. I have few alternatives. The last time I talked to him he told me all the things he thinks I should do to find and repair the problem. I went to him because he is better equipped and prepared for such work. Overall, very disappointing. I've set the motor aside for the moment. Maybe when I'm not so annoyed I'll start in on it again. |
I decided to call a local repair person recommended to me by a friend. I was then astounded when, with only the knowledge that it was a DC direct drive motor this fellow literally described the internals to me over the phone. He then listed all the most common problems associated with this motor type. He'd never heard of Goldmund or Pabst. I was impressed enough with his obvious experience that I decided to take a chance and take the motor to him. After seeing it, he suggested a couple of other possible problems to investigate as well. This guy is one of a kind and a dying breed. His shop was full of mostly midfi gear; Pioneer, Technics, etc. His only real experience with better brands was McIntosh, Marantz and the like. He continued to amaze me with his knowledge of electronics, not to impress anyone, but just in his normal conversation about repair possibilities. He told me to call him in a week if I hadn't heard from him. So, I'm very encouraged that he can get my motor rolling again. I'll post again with the results. |
As Willster suggests, the platters of the Studio and Studietto turntables are part of the (direct drive) motor system. And the Pabst setup is quite different from the JVC version (which is also quartz crystal speed controlled.) The MSRP of the Studio (without arm) was from $3000 - $4500 during the three years it was made. I think the more expensive table you are referring to was the Reference -- a belt driven TT that was made from 1987 -1992 and cost $19,000 - $32,500 over its production lifetime. The new Reference (without arm) is $250,000. Go for it! . |
Dweller...It would probably seem the way to go to someone not familiar with this table but is obvious to anyone who has examined it closely. The way the platter and motor are configured precludes the use of an off the shelf generic replacement. I still haven't run across any info regarding switching to the JVC motor used in later versions but had the impression that there was some incompatibility difficult to deal with. Not sure if that's what you meant but your museum curator comment leads me to believe that there is an opinion you are not expressing here. Don't know what your disposable income is like but I simply don't have the cash to replace this turntable with anything comparable. I have been told that when this table was first put on the market, it was the most expensive turntable in the world. Twenty five years ago it cost $13000. Don't know what that would be in today's dollars but I couldn't afford it in even in 1980 dollars. Thanks for the link references, everyone. I think I've already seen some of this info but I'll definitely check it to make sure |
Pabst is alive and well. The problem is that the motor used in that TT is no longer made and no parts exist for repair as far as anyone (including Goldmund) knows. The JVC motor which was later used in both the Studio and Studietto is available and/or can be repaired. One person that may have further information (like for instance, where there might be a working Pabst motor you could scavenge) is Brian Hartsell (brian4tar@aol.com) at the Analog Room in an Jose, CA. (408) 971-6158 You should also check out the information here: http://www.goldmund.com/oldsite/old/wwpage9.html click on 'Vintage Page' under Vintage Equipment Support. . |