Sound Issue relating to stylus pressure/inconsistency

Wurlitzer 2150, rebuilt amp, ceramic stylus upgrade, 3500hz crossover installed to push the highs to a horn tweeter.
I have been wrestling with the sound for quite some time now and I think I have finally narrowed down the issue. (Which is not to say the issue is originating somewhere else.)
I was playing a record and it sounded very muddy. I reduced the stylus pressure (on the Wurlitzer, the record is held vertically, so the pressure comes from a spring that can be compressed or decompressed by virtue of a screw). Played the same record and it sounded great. I mean it really sounded great. Played another record and it sounded pretty bad, so I increased the stylus pressure. Played the record again and it was perfect. Went back to the previous record and it did not sound as good. Tried a third, same story. It is as if each record has an optimum stylus pressure. All the records were in good shape, mid-late 70's, stereo. Is this a matter of slowly dialing it in to find the optimal pressure? I also wonder if the balance of the tonearm comes into play (again, on this jukebox, gravity pushes the stylus down toward the center of the record so a counterweight is used to provide the proper amount of 'weight') It seems to me as though the tonearm has a slight difference in this downward pressure at the start of the record versus towards the end. It also seems like the sound will sometimes deteriorate about halfway through the record. Only other piece of info was when the amp was rebuilt it was modified for the ceramic cartridge and, at the same time the auto volume level capability (not sure that's what it is actually called) was disabled. It appears there is a difference of opinion on whether that should have been done or not. I toss that out there in case this would be symptomatic of that circuitry having been bypassed.

Thoughts?
Thanks
Brooks

Hi Brook,
Just my opinion--some of this is related to which cartridge was installed, and if it is installed properly. Of course balance and pressure are also involved. I prefer to leave the Automatic Gain Control (AGC), aka Automatic volume control (AVC) intact, in all cases, but once again, that's just my opinion. Ron Rich

Well, it is interesting in that Bill also said it sounded like the cartridge was the culprit. I purchased a conversion kit. Since I installed it, it is certainly possible that I messed it up; although I'm not really sure how I could have done so. The wiring was pretty straight forward (splicing together the R and L channels and splicing the ground so that 4 wires turn into two) It would seem to me if I had messed it up, the sound would be much more problematic.

Assuming the cartridge needs replacing, are there any brands/models you recommend as well as places that carry them?
Thanks
Brooks

As I was searching for ceramic cartridges, I remembered someone saying they put on a magnetic cartridge. Replacing the cartridge is a bit of a pain and it is my understanding that magnetic cartridges last a lot longer and provide much better sound than ceramic, so I'm wondering if it makes sense to make the change to magnetic.

I see where turntableneedles.com has the following preamp: http://www.turntableneedles.com/LKG-RIAA-Turntable-Phono-PreAmp_p_3888.html, which appears to be what is needed. Is this what I would use and, if so, how would it be wired? I'm specifically interested in knowing where I take it from stereo to mono. With the ceramic cartridge, it is taken down to mono at the cartridge. If I went with a preamp/magnetic cartridge do I keep the stereo signal into the preamp and then combine the channels coming out of the preamp?

Of course, this assumes it makes sense to go to magnetic rather than stick with ceramic.
Thanks for thoughts/recommendations
Brooks

Brooks, I read that you've made quite a bit of progress on that machine.

I can't explain why there would be a great difference in sound quality based on VTF. I have always used 3- 3½ gram on the Wurlitzers along with a Pickering DAT series magnetic cart. I hope that the muddiness was not caused by the highs being erased by excessive tracking pressure. 70's records were nearly all styrene.
The Stanton version of the magnetic I used was: http://www.stantondj.com/stanton-cartridges/400v3.html Though it may not be available now that the company has been sold.

The proper way to wire these for mono is at the cart R-L and RG-LG. There is noting wrong with running it stereo down to the pre, but there is no point here unless you are planning to convert the machine to stereo with a later amp. Depending on the cart & preamp used and what has been done to the amp, it -may- be necessary to add a pot between the preamp and the amp input to attenuate the signal to prevent overload. I've used anything from 50K to 100K, whatever I had at-hand.

Rob/NYC

Thanks Rob. So, does the pre-amp I provided the link for seem like a reasonable option? (I found the Stanton 400 v3 is available.)

Most importantly, what is your recommendation as far as sticking with ceramic or going to magnetic? Should I get another ceramic cartridge or go ahead and make the switch to the Stanton with preamp?

Thanks

I don't think the model/type/stats of this ceramic cartridge were mentioned at all.
That would help in determining things from others.

Goat -I don't know what ceramic you have installed, but the difference between that and a magnetic has always been worth it -especially since you have upgraded the speaker system.

The W1800 I have here has the older Pickering version: http://s1192.photobucket.com/user/Rob-N ... ort=2&o=18

The preamp you've selected looks to be average and Ok. I often built a pre into the existing amp. Otherwise I just use a Radio Shack # 42-2109 probably NLA but these cost about $25 and are very good and easy to mod (if desired). There are a number on E-bay.

Rob

Rob-NYC wrote:Goat -I don't know what ceramic you have installed, but the difference between that and a magnetic has always been worth it -especially since you have upgraded the speaker system.

The W1800 I have here has the older Pickering version: http://s1192.photobucket.com/user/Rob-N ... ort=2&o=18

The preamp you've selected looks to be average and Ok. I often built a pre into the existing amp. Otherwise I just use a Radio Shack # 42-2109 probably NLA but these cost about $25 and are very good and easy to mod (if desired). There are a number on E-bay.

Rob

Rob, Gary Stork at VM also sells a suitable magnetic preamp as well for $18.
http://www.thevoiceofmusic.com/catalog/ ... ies=Preamp

MattTech wrote:I don't think the model/type/stats of this ceramic cartridge were mentioned at all.
That would help in determining things from others.

I purchased a kit on ebay to convert to a ceramic cartridge from the stock Cobra. The kit included a tonearm (the ones from a Wurlitzer 2300 + have the holes to accept a 1/2" std mount cartridge), wires, a new spring and the cartridge. The cartridge came in an unmarked plastic case and I could not see anything on the cartridge itself (although I did not look that closely). My guess is that it was the least expensive cartridge the guy could find, which seems to add credence to the belief that the cartridge has failed.

You might either ask the seller, or see if you can ID the cart. from what is shown at needles4jukeboxes---Ron Rich

Modifying such things as a tonearm and its related stuff is having to deal with critical components.
The Cobra cartridge is designed for RF modulation to the preamp, while a ceramic should feed a whole different animal input.
The amp itself would need modifications to adapt it to a new input source.
I've converted the 1100 with great results with the P51-3 cartridge, but of course my background in electronics service gives me the ability to make the proper modifications.
Then there's balancing issues, and friction to eliminate/minimize as well. - and a vertical play type of arm is much harder to work with than horizontal/traditional players.
And since the "no-name" cartridge is of questionable quality, who knows what the problems are now.
It's really impossible at this point to specualate or even diagnose over the internet after all this has been done.

Well, I bit the bullet based on Rob's recommendation and am going the magnetic route. Purchased a NOS Realistic 4101A. It appears to be the same as the 4109 except it is made in Japan instead of N Korea. What the heck, might as well go for the best! Also purchased based on Rob's recommendation. (I've finally discovered that in this new age it is not important to be right or wrong but to be able to blame someone else if you are wrong...of course, taking full credit when you are right! )

I could not find the Stanton 400.V3 anywhere, even used but did end up finding a new Stanton 500 ALII with a conical needle ( I understand elliptical is not the way to go with 45's). Anyhow, it seems to be a reasonable swap for the 400 as it tracks from 3-5g. As a bonus, I figure it close enough to Rob's recommendation that I can blame him again.

Anyhow, it will keep me busy for a bit, which keeps the boss happy. I have a couple of other things going on with it on the aesthetic side while I wait on these things. I do; however, have one other question. Stylus tracking force. The manual shows a device used by the service guy to set tracking weight. These appear to be unobtanium. However, there are lots of inexpensive digital gauges out there. It is difficult to tell from the pics, but it appears that they would work in the vertical position I need. Anyone have any experience with or recommendations for a tool to help with setting the tracking weight?

Thanks
Brooks

Brooks,
A suitable Gage is made by Neuses. Google it to find a used one, or look above in the "Where to find it "post, for any/all of the legitimate jukebox parts suppliers--most of them sell it-- Ron Rich

Ron Rich wrote:Brooks,
A suitable Gage is made by Neuses. Google it to find a used one, or look above in the "Where to find it "post, for any/all of the legitimate jukebox parts suppliers--most of them sell it-- Ron Rich

OK
Thanks