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 Post subject: Cartridge Confusion
PostPosted: Mar Thu 01, 2018 12:02 am 
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Joined: Aug Fri 25, 2017 9:06 pm
Posts: 30
Bear with me hear. With many thanks to you guys and especially Senior Steve, I now have two functional tube console phono players. I recapped my phono only Motorola SK41 and it's working great. My Zenith with the in house changer is still a work in progress. I recapped the amp but it still hums more than I think it should, so some work yet to do. The changer works but the platter is still a bit slow so I will have to change the idler, which is available at Voice of Music. But still cartridge issues. I have an old Astatic 710, and also an EV 26 (I think). The EV is physically a bit larger but they both fit and work. The glue has dried out and allowed the ceramic parts to come out. Since I was unsure about the condition of the any of the stylii (?) I ordered a "new" one that was cheap on ebay, but it turned out to be old and the soft material basically disintegrated when I tried to install it.

Since both of these cartridges work, I would like to use them. But what I have run into is that using the cartridge as designed the 45/33 needle allows the cartridge to drag on the record when the inner ceramic part is installed correctly. I was able to make it work by flipping around the red ceramic part, by having the little black rubber V groove support the 45/33 needle. But that part is supposed to support the 78 needle, as far as I can tell. The 45/33 needle is only modestly supported by a rubber "button" that doesn't really do anything. When installed that way the cartridge face just drags on the record, even with the pressure set at 3 grams. I don't know if this is just typical age-related stuff or what. Maybe I just need to start over with new parts. There is just very little clearance between the needle and the cartridge face. Please check out the pics and see if any of this makes any sense, which I kind of doubt.


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 Post subject: Re: Cartridge Confusion
PostPosted: Mar Thu 01, 2018 2:12 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2599
Location: Haledon NJ USA
The cartridge shown in your first 4 photos is a Euphonics design. The Astatic 710 is Astatic's knock-off of the Euphonics cartridge.

An EV-26 is a smaller cartridge:

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 Post subject: Re: Cartridge Confusion
PostPosted: Mar Thu 01, 2018 3:08 am 
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Joined: Feb Tue 02, 2016 2:38 am
Posts: 184
Location: Saint Paul, Minn
Hi Homer, thanks for the compliment! On the cartridge, my thought is, there is part of the rubber yoke missing. The picture you have with the rubber yoke towards the camera (#2883), I see a place for one of the needles, but not the other one. When the ceramic elements and yoke are in place, the shaft of the needle should fit in the yoke, and it should also also be stiff enough that it should not push the needle into the recess of the cartridge with only 3 grams force on the needle. On the picture that has the cartridge assembled, I couldn't see the rubber yoke on either side, however the needles look like they are in the proper position. The rubber yoke should project out of the cartridge enough that it will "saddle" the shaft of the needle.

I had a ev26 cartridge when I first picked up a Zenith console that while it produced output, it was bad because the tone arm must have been resting on the needle for years and years. The yoke didn't protrude far enough and when the tone arm went on the record it recessed into the cartridge and wouldn't play, pretty much slid across the record. In that case I did end up replacing it with a newer cartridge (not the same as original though). I'm wondering if this may be your issue with the cartridge. Hope this helps.

Treat it as a mechanical issue, the vibrations have to get from the record to the ceramic elements.

As far as the hum issue, does it hum all the time or can you change the level of it with the volume control. That might make a difference on how to attack the issue.

Steve


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 Post subject: Re: Cartridge Confusion
PostPosted: Mar Thu 01, 2018 4:53 am 
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Joined: Aug Fri 25, 2017 9:06 pm
Posts: 30
Hey Steve! The hum seems to be an all the time thing, volume doesn't seem to change it. But I still I haven't gotten around to doing the tune side capacitors yet....

I was wondering the same thing about the cartridges having something missing, but it seems weird that they both would be missing the same thing. But they are also both old and obviously not in the best condition. I can make them "functional" , but I want it to be correct. I guess the logical thing would be to email Voice of Music and get a whole new cartridge and needle setup.


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 Post subject: Re: Cartridge Confusion
PostPosted: Mar Thu 01, 2018 4:56 pm 
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Joined: Feb Tue 02, 2016 2:38 am
Posts: 184
Location: Saint Paul, Minn
Hi Homer, there are a couple of electrolytic capacitors on the tuner chassis, and if you haven't done the recapping on there, it might be one reason. What you can try is to pull the 12au7 (v12 on the photofact), and see if the hum is lower. If it is, that places the issue on the tuner chassis, and at the same time will tell you how much hum the output stage is producing. Hum with the 12au7 tube pulled should be very low. I know you recapped the power supply chassis. Keep us informed.
Cartridges can certainly be problems, luckily even if you can't get exact replacements, there are aftermarket cartridges that will work, and usually aren't as expensive.

Steve


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