Author Topic: Hello from WV  (Read 973 times)

typecrazy789

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Re: Hello from WV
« Reply #15 on: May 06, 2019, 08:50:03 AM »
Well, the unit is now recapped (and re-bulbed; none of them were working prior, and I changed them all out when I had the amp/preamp out). I checked all the tubes as well when I had it all out and one was faulty that affected the FM radio side of the preamp so that was replaced.

I was able to mount the Stanton 500 by drilling out the rivets in the old Magnavox cartridge holder and reusing that, and then soldering new clips in place of the original ones.

I hid a small preamp in the back of the unit bottom right where there's plenty of room, and ran that output to the phono input on the preamp since I'd presumed the ceramic input could handle the line level of the external preamp...I'm a little surprised at how rolled off it sounds, but I want to try it in the tape input channel as well in case there's any internal EQing happening in the phono input, which I can't tell as I don't have the schematic.

I haven't adjusted the VTF yet but so far all appears to work as it should save the stylus is sitting down on the disc too far close to the edge of the record - not sure how to adjust that but it I'm guessing there's an adjustment somewhere. I was pleasantly surprised that the changer is able to discern a 10" LP from a 12" LP, I wasn't expecting that.

I need to remove the turntable and service it better but for now I just wanted to make sure this setup would work. New idler coming from VM - I was able to get this one slightly working with acetone but it's mostly rock hard. ]

Anyway, back in business.

19and41

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Re: Hello from WV
« Reply #16 on: May 06, 2019, 10:43:58 AM »
It was tough on the turntables with them mounted so the heat generated within the cabinet could vent beneath them.  I guess they just weren't planning on them being put to use after 60 years.   ;D

That is a good looking set and a good job done on it!
"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

TC Chris

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Re: Hello from WV
« Reply #17 on: May 06, 2019, 09:02:53 PM »

I hid a small preamp in the back of the unit bottom right where there's plenty of room, and ran that output to the phono input on the preamp since I'd presumed the ceramic input could handle the line level of the external preamp...I'm a little surprised at how rolled off it sounds, but I want to try it in the tape input channel as well in case there's any internal EQing happening in the phono input, which I can't tell as I don't have the schematic.


Congratulations on the restoration and the update on the cartridge.  As to the rolled-off highs, I understood that ceramic cartridges didn't require much EQ because their output roughly matched the RIAA curve inversely anyway. But then, my older Maggie has selectable EQ for the principal competing curves of the day (1956), so they must have designed some in.  The only other easy explanation s some sort of impedance mismatch.  But that seems unlikely.

I look forward to more reports.

Chris Campbell

typecrazy789

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Re: Hello from WV
« Reply #18 on: May 08, 2019, 08:10:25 AM »
Thanks so much - waiting on the idler and will report back. I also ordered motor mounts as the speed selector is one speed off (78 won't work, and the other three are one setting off) so I'm thinking that's because the motor has slipped from where it should be positioned. Looks like I'll have to actually service the unit soon instead of just putting the idler on and waiting for a good time, but I'll need to get all that worked out before I can address the SQ issue.

typecrazy789

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Re: Hello from WV
« Reply #19 on: May 13, 2019, 11:20:51 AM »
I pulled the turntable out yesterday and cleaned out and re-lubricated the bearings and oiled the motor, plus replaced the motor mounts all of which solved any speed issues—prior it wouldn't spin at 78 at all as the idler wasn't aligning with the motor spindle correctly.

Still having frequency response issues, though, if I use the phono input as it's just slightly rolled off compared to the tape input and multiplex inputs, to my ears. I realize this is a subjective thing but I'd guess anybody reading this wouldn't have trouble hearing the difference. Does anybody know for sure if the phono inputs were EQ'd in any way? It'd be wonderful if there's a way to "flatten" the phono input to essentially make it line level and EQ matched to the other inputs.

I've been running it through the FM Multiplex input but with that I'm getting slight bleed through of the radio with the phono signal if the FM is tuned to any station, so not sure if that's possible to work around. By not using the phono input to run the turntable I'm also losing the benefit of the shut-off feature.

Regardless, 78s in particular sound incredible on this unit...loud Fats Waller around here this morning. (With a 2.7 mil stylus.)

Bill

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Re: Hello from WV
« Reply #20 on: May 14, 2019, 05:18:11 PM »
Fats Waller, he was quite the character.  And I bet he was misbehavin!  ;)

Bill

electra225

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Re: Hello from WV
« Reply #21 on: May 14, 2019, 10:22:03 PM »
When you changed the cartridge and added a pre-amp, you changed the basic character of the instrument.  I'm not surprised it does not work right.  Running audio thru the MPX input is not going to work.  Running it thru the phono input is not going to work.  Using the tape input works best, depending on what your audio source is.  Tape decks tend to work best.  CD changers can work well, depending on what they are and if they have a line-level output or not.  If you put everything back like Magnavox built it, and all those components are in good shape, capacitors changed, resistors checked, bias voltage correct, it will sound as good as it was designed to.  Doing otherwise may result in less-than-satisfactory results, as you have already learned. 
I don't need Google.  My wife says she knows everything.

typecrazy789

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Re: Hello from WV
« Reply #22 on: May 15, 2019, 11:52:32 AM »
It's all easily put back as Magnavox had it, if need be, even the failed ceramic cartridge - nothing here is permanent.

But along these lines, I cannot get the turntable to play at the correct speed at any of the three speeds I've tried (I don't own a 16 RPM) - it's noticeably slow, and seems to be getting worse day by day. I oiled the motor, cleaned and oiled the platter bearing and spindle parts (and if you spin it by hand, it seems like it turns for days) and cleaned and oiled the idler mount. I've also tried adjusting the idler height, to no avail. Cleaned the inside of the platter, and the idler itself. Wondering if I over-oiled the bearings? I'd think as freely as it turns that's not the case but wondering if I should back up and review my work along those lines.

It's just a hair slow, but it's consistent and noticeable if you are familiar with whatever's playing.

electra225

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Re: Hello from WV
« Reply #23 on: May 15, 2019, 01:12:52 PM »
Did you pull the motor apart, clean the bearings WELL, then re-oil the bearings?  If you did not pull the motor apart, that is something you should consider doing.  The upper bearing is known for seizing.  You should document the wiring scheme, remove the wiring and the motor.  Then pull the end caps off the motor, soak the bearings at least overnight in lacquer thinner.  I like to use a half-gallon glass jar to soak the bearings in.  This procedure may damage/remove the paint on the motor end caps, so be prepared to repaint as necessary.  If your soaking procedure is successful, you will see plenty of dirt and gunge floating in the thinner.  After you get the bearings clean, blow them out with compressed air to dry the felt wicks thoroughly.  Re-oil using turbine oil, not 3-in-1 or anything like that.  You need an oil that will not turn to gum, and turbine oil is the preferred type to use.  I believe there is a schematic in Downloads at the top of this page for an S-600 Collaro changer.  Print it out and follow directions how to set the drive up.  Your mounts are new, so the motor is the next step.  Be careful when you put the drive sheave back on the motor shaft.  That thing can move enough so the drive tire will not align with the steps on the motor shaft.  If you need further assistance, don't hesitate to ask.  Good luck.

Another thought.....Don't be too aggressive with the spring that holds the drive onto the motor shaft.  That spring is a critical part of the drive system.  If you stretch it, the drive system may be disturbed where it won't align properly.
I don't need Google.  My wife says she knows everything.

typecrazy789

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Re: Hello from WV
« Reply #24 on: May 22, 2019, 08:30:06 PM »
I cleaned and relubricated the motor as you outlined, reassembled, and STILL have a pitch issue, except oddly I've discovered that it seems like it's only at 33 - 45 and 78 both are slightly slow but it's just a fraction of a tone and I can live with that, whereas 33 is noticeably slower than it should be. I'll check with a strobe when I get a chance but there's not any question it's not close to the pitch it should be. I'll get there!

typecrazy789

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Re: Hello from WV
« Reply #25 on: May 22, 2019, 10:01:35 PM »
An addendum - I discovered this evening the Turntabulator app, which measures platter speed simply by placing your iphone on the turntable. According to it, my 33 is actually 31.9, and my 45 is 43.7.

TC Chris

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Re: Hello from WV
« Reply #26 on: May 23, 2019, 12:17:52 AM »
Long ago I was given a Garrard RC-80 changer that was, as I recall, considerably fast.  All I could figure twas that it had a motor and drive diameters designed for 50 Hz, not 60.  If you have done all the cleaning/lubing possible, have you also rotated every component by hand to see of any are binding?  The speed at which the turntable rotates is determined by the motor speed and the motor spindle diameters, assuming minimal friction in the drive train.

Chris Campbell

electra225

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Re: Hello from WV
« Reply #27 on: May 23, 2019, 11:15:06 AM »
IF the motor has been disassembled, the bearings THOROUGHLY cleaned, then PROPERLY re-lubed, the drive tire replaced and the motor mounts replaced with the CORRECT mounts, then my only suggestion is this.  I believe I remember your saying that you adjusted the tracking of the drive tire to the motor shaft.  If that is the case, you need to "Un-adjust" that so it is right again.  You may still have the drive tire running between two speeds.  Perhaps it is running between 33 &16 when it is on "33" and it is running between 33 & 45 when it is on "45".  That adjustment is critical and is covered in the service documents.  The platter should actually run a tad fast with no records on it, say something around 34 rpm (in 33) or a touch over.  That is so when you have a stack of records on the platter, the platter does not run slow.  Those Collaro four-pole motors are quite robust and are not known for running slow when properly serviced.  My thinking is that you still have something not quite right.  Good luck.
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Motorola Minion

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Re: Hello from WV
« Reply #28 on: May 23, 2019, 02:29:33 PM »
I have had that adjustment off as well, it is important. If you run the motor and pulley, platter off, it will be obvious if the tire is not riding correctly.

I have heard from some other forum members that this cartridge (link below) is a great ceramic replacement. I have not tried one yet but enough of the RCA (feather-ride) and Motorola (Astatic 133 or Sonotone 9t) cartridges have hardened compliances that make even new styli sound bad.  :(

The output voltage and tracking force of 2-4 grams is not very different from the originals, so I just may need to try it  8) on a Motorola first. https://thevoiceofmusic.com/catalog/part_detail.asp?PNumberBase=P188
Tubes - Magical - Tubes

Dave

typecrazy789

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Re: Hello from WV
« Reply #29 on: May 24, 2019, 08:31:22 AM »
That adjustment is critical and is covered in the service documents.

You are a genius - that's exactly what it was, I'm running now at 33.2 RPM. The service manual indicated adjustments by sight (3/4" above the base at 16 RPM, etc.) so I had just set it visually not realizing what a critical and "touchy" adjustment it is. A slight turn or two and I was at the correct speed, more or less.

I now have some very slight wow, even after having cleaned and lubricated everything and rechecking my work several times, so I'm not sure what that could be except I seem to be missing a washer under the idler wheel - the manual says that "most units" have these and mine has none, so I'm not sure if they were lost when I initially changed out the idler wheel weeks ago and I didn't see them, or if mine just never had them in the first place. Of course the idler itself and platter rim are clean and dry.

The motor has quite a lot of torque and the platter will turn effortlessly and endlessly when spun by hand so whatever is causing the wow must be at the idler, I'm thinking.