Califone Mystery Hum

Hi all,

I recently acquired a Califone 1155 record player that I want to use to digitize some 16" transcription records I own. Here's the problem, though: the cartridge on it is one that I have NEVER seen on a Califone before, and uses an LP/78 stylus that is held in place by a lockring as opposed to the more common Astatic 89T "powerpoint" all-in-one cartridges. I can't make out the rest of the printing on the cartridge, but I can see the letters "BSR" pressed into the top of the cartridge assembly beneath the headshell. According to the instruction sheet in the right speaker, the cartridge replacement number is part No. 7-35-55.

The issue that I am having is that I was listening to the unit last night, and it does something very odd: Whenever I play a shellac 78, it plays them wonderfully and as clear as daylight. However, when I am playing a vinyl record, an audible hum comes through both speakers, but ONLY when the stylus enters the groove! It can't be turntable rumble, because there is no hum at all coming through the speakers when I place the stylus in a vinyl record's dead wax - only when the stylus enters the groove will it begin to hum. And it does it on all the 33s, 45s and vinyl 78s I own, so it's not like it is a problem unique to only one vinyl record. The unit works fine other than this.

Is this cartridge on the fritz, or is just a little tweak all that is needed to fix this? And if I have to replace the cartridge with something more modern, will this one do?

http://all-unique.com/califone-0291-rep ... p-251.html

Thanks!

Replace the cartridge and call it a day.

OK thanks! I was thinking this issue was being caused by the cartridge; I just wanted to get a second opinion to make sure it wasn't an internal wiring problem or something that is more complex.

I'm also looking at this cartridge (http://www.thevoiceofmusic.com/catalog/ ... ategories=) to replace the one currently in the unit; should I get this one or stick with the other one I found in my first post (http://all-unique.com/califone-0291-rep ... p-251.html)?

"MusicMan" there are a few points to be made here.

You are hearing rumble from the T-T. The reason it appears less pronounced when the stylus in on a blank surface is that there it is mostly subjected to vertical vibration. When nestled in a grove it is intimately coupled to the disk and much more affected by horizontal vibration, and that it what the motor produces.

On 78's this is less noticeable due to the masking effect of the surface noise and much higher output.

I suggest removing the platter and check that the motor grommets are reasonably supple and that the drive puck is also not excessively hardened. The pucks on these institutional players are generally harder to begin with because the sort of people operating the machine will not likely bother to disengage the drive to it's neutral position and a depression will form. Look also for any rubber deposits that adhere to the motor shaft, these cause vibration.

If you are comfortable in working inside the unit I suggest add a "mono" switch to parallel the input from the cart. This will substantially reduce rumble and phase-cancel a lot of surface noise. You can use a miniature toggle switch from Radio Shack. If the unit is not going to play stereo disks you can just solder a jumper across the terminals where it enters the circuit board.

As for the cart, if both channels sound balanced when playing a mono record, I can't see the point in replacing one cheap ceramic cart with another.

I have two of the older versions of Califone P.A/ phonos. On one I replaced the Power point with a magnetic and preamp. I used a Pickering NPAC (similar to V400 series). This is a fairly rugged and stiff stylus cantilever which is necessary due to the fact that the arm is not balanced and the bearings are not that great. The two machines came from my old primary school. One is the last tube model using two 6L6s and the other a 1968 transistor w/approx 22w output. The older one has the Starlight center drive motor which is somewhat quieter than the later which uses a 10" platter but rim drive and two pole motor. I haven't used either one in years but keep them for sentimental reasons.

Rob/NYC

Put the turntable in the neutral position and put the stylus in the grooves. Then turn the turntable by hand. Also try it with the motor on or off.

- If the hum is there with the motor on, but the turntable not turning, the motor vibration is getting to the pickup through the turntable mounting. The motor mounts are probably at fault.

- If the hum is there only when the turntable is turning, the stylus may not be seated in the saddle when there is no drag from the groove. The same thing happens when the record is turning -but there is no groove. Since this happens on microgroove, but not 78, the stylus assembly might be bent, or it might have a force bias toward the saddle when in the the 78 position.

- If the hum is there only when the motor is driving the turntable, something is wrong with the drive assembly or the motor.

- The larger diameter of the 78 portion of the drive spindle might smooth out motor vibration.

- If the unit has automatic recording curve compensation (or you select a 78 compensation curve) it reduces the bass output with a 78.

- I once drove myself crazy trying to find a sudden appearance of rumble in my turntable. I did all kinds of tests. I finally tried a different record. The rumble was in the record itself. It was a demonstration record I was trying to use a classical piece from for a wedding. I since found out that every copy ever made of it has that rumble.

Hi guys, I fixed the problem - it turns out that the turntable bearings AND the motor mounts were dried up and/or loose. I have since replaced those, and the player is ready to go - no more rumbling that puts a diesel engine to shame! Thanks for your help in resolving this oddball problem!