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-   -   Webcor 121 record changer question (http://www.videokarma.org/showthread.php?t=268091)

maxhifi 11-23-2016 11:43 AM

Webcor 121 record changer question
 
Have an early 50s Webcor, OEM for Electrohome. Thought it would be a promising little project, VM has replacement rubber parts, and it came with a factory magnetic cartridge and a 4 pole motor. Thinking to convert to a DJ cartridge and track at 4-6 grams.. ok so sounds like a plan.

Got the sams, and also Beitmans service manuals, and encountered a potential show stopper.

I haven't actually taken apart the player yet, but it looks as though the change cycle drive gear is ALWAYS ENGAGED, i.e. the gear is constantly turning during playback, and is driven by a smaller gear attached to the centre of the platter. This is in sharp contrast to a Garrard, where the change drive gear is only driven actually during a change cycle.

I think this is a serious defect in the Webcor design, if there's always gear teeth meshed it will make noise.. ever hear a quiet gearbox? (I haven't)

Can someone who has worked on one of these confirm my fears?

nasadowsk 12-02-2016 05:28 AM

It does, see: https://www.youtube.com/watch?v=7HcxbxDqesg

Remember that these early changers were put into systems with pretty much no frequency response, and heavy tracking cartridges that weren't really sensitive to much.

Olorin67 12-04-2016 01:44 PM

That's how the earlier webcors were designed, later ones went to a more normal set up, the later ones look similar except they use a semaphore type size sensor. The later ones might be a drop in replacement, if you want to upgrade. They did use a fiber gear to reduce noise, but these older ones were probably not as quiet.

Hagstar 12-04-2016 04:25 PM

Quote:

Originally Posted by nasadowsk (Post 3174151)
It does, see: https://www.youtube.com/watch?v=7HcxbxDqesg

Remember that these early changers were put into systems with pretty much no frequency response, and heavy tracking cartridges that weren't really sensitive to much.

And since this is an antique phono forum anything else isn't appropriate to post here. Plenty of hifi forums. Is anything good for records we should be talking about here? Of course not. This is by its very nature a vinyl chewing forum. Or is antique 1970?

Electronic M 12-04-2016 05:31 PM

Quote:

Originally Posted by Hagstar (Post 3174282)
And since this is an antique phono forum anything else isn't appropriate to post here. Plenty of hifi forums. Is anything good for records we should be talking about here? Of course not. This is by its very nature a vinyl chewing forum. Or is antique 1970?

If you take the antique shop definition of antique anything pre-1980 and modern craft crap is antique....If you take the dictionary definition of antique then the only fair game is windup 78RPM stuff...I personally think all is fair game, and if I see a good rock LP being played on a machine that will not necessarily be reasonably gentle with it I think it is also fair to point that out to it's owner before they possibly accidentally damage a prized album.

maxhifi 12-05-2016 11:39 AM

Early 1950s equipment could very well have good frequency response and low distortion, the fact that this 1953 vintage changer was equipped with a magnetic cartridge and 4 pole motor speaks to that fact. Just because a lot of old things sound bad doesn't mean they all do. If you take a look a thing the posting history here you will see most of the discussion is about tube era record players, with a small minority about acoustic phonographs. I posted here because I know this form is frequented by people who refurbish changers, also, the people at videokarma are more likely to have repaired these items than at audio forums, which consist mainly of users.

I figured out what I need to do is just grease it up really well, am gonna give it a try.

Hagstar 12-05-2016 04:17 PM

Points well taken but I suppose a sticky in the forum with DANGER RECORD DAMAGE info would be warranted. Antique I assumed meant simply tube era, mostly changers, and acoustic in this context. Also I spaced out myself about only mono records on mono players. Honestly I haven't played an LP since 1999 and plum forgot....:nono:

Olorin67 12-05-2016 06:43 PM

a 1953 webcor won't damage your records if working properly, although if it has a Mono cartridge from that era it should not be used for stereo records. Might not be the best changer for stereo though, since there may be some rumble or noise. Ive played mono records on these and didn't notice any issues with noise. As long as the tracking isn't over 6-8 grams, you wont be wearing out records prematurely, sure, the wear rate may be more than if played on a 1.5 gram unit, but if the records are clean it wont wreck them. Back in the 1950s RCA did studies of how many plays you could get out an Lp at varius tracking forces (mono records and 1 mil stylus) and they showed that the wear was negligible at 8grams (good for a thousand plays or more without audible noise, thats equal to maybe 5-6 grams with a .7 mil stereo needle.
A webcor changer of that vintage should do fine with a modern Shure DJ cartridge tracking at 5 grams or so, although it wont be as quiet as better modern gear, I'm sure it would still beat one of those plastic Crosleys hands down. I see posts on audiophile boards all the time about how people who use old changers are "ruining" records and its just not so, if its set up properly. Obviously if you have a unit where the counterbalance spring for the tonearm is missing and the needle worn down to a chisel point that's another story. I had one VM changer that was in that condition when I got it, and the record grooves changed color as the record played...

maxhifi 12-06-2016 02:37 PM

Shure DJ cartridge is the plan - & a re-wire for stereo. I was really surprised by how this changer works but will roll with it now.


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