"grinding" audio interference. Magnavox micromatic 1sc230r

Greetings Phonoland,

I have owned a Magnavox portable suitcase player for many years but it hasn't seen any use in a couple years, mainly due to bad sound quality. I can only best describe it as a grinding or static coming through the speakers which seems to start at a moderate volume, then crescendo and the sound drops off. If I remember correct the grinding eventually comes back and drops off and so fourth. This static happens if the unit is powered on, even if the platter is not even spinning and the needle not on a record. If memory serves, this was also more prevalent on one channel as I remember disconnecting that channel.

I have done a bit of research hoping to at least diagnose the problem myself but am not finding much help online. I am happy to have found this forum as I never really thought about the damage that could be caused by continuing to use the player. I hope that the community here can help me either troubleshoot and fix it myself, or find a experienced person in the Seattle area to help me fix it. I have reached out to a couple places already and they say they do not want to work on them as they are mechanically challenging. Though I feel this is more electrical problem than mechanical as it operates great, just terrible sound.

I would love to get this dialed in and sounding great again. Any help would be very appreciated!

Check with Harold Hagen 206-768-1043 I THINK he can/will help you out--.
Ron Rich

Thanks for the help Ron. I wanted to “poke” around a little inside the turntable a little before I reached out to him and see if I could get a little more information to give. Here’s what I found:
The large tube is what was causing the “grinding”. It was a little loose and with it properly secured the noise has gone away. Sound quality however is still not great. A bit muffled. I’m going to replace the needle but I was wondering if replacing the tubes might also help with sound quality. Also is the capacitor easily removable like the tubes are? If so could that help at all with the sound?

If replacing the tubes is worth it, any leads on a good place to pick some up? The skinny tubes read Magnavox 491, and Sylvania ef DCN. The large tube is Magnavox 206.

Large Brown capacitor reads:
TYPE FP
MFD VDC
120 150
80 150
20 150
270023-32
35-6206h 85° C

To answer you honestly--if you do not know how to change that cap, you really should not be "working" on this unit--
You also do not have any tube numbers that I recognize--Ron Rich

Ron Rich wrote:To answer you honestly--if you do not know how to change that cap, you really should not be "working" on this unit--
You also do not have any tube numbers that I recognize--Ron Rich

That's right Ron, best left to someone experienced.
Lord knows all the "horror stories" I've seen from "putzing around" without a clue.

Yes horror stories indeed which is why I am here to get guidance on what I can do myself. Am i risking the thing lighting on fire by simply removing/replacing cap and tubes? If they simply plug in and out whats the harm in replacing them with the appropriate replacement? Could anybody provide any guidance on how I might find appropriate replacements based on what I have now?

yazoo wrote:Yes horror stories indeed which is why I am here to get guidance on what I can do myself. Am i risking the thing lighting on fire by simply removing/replacing cap and tubes? If they simply plug in and out whats the harm in replacing them with the appropriate replacement? Could anybody provide any guidance on how I might find appropriate replacements based on what I have now?

Capacitors do not "plug in".
Tubes do, but changing them in vintage equipment is not the answer.
Much more underneath the chassis is now going on.
Parts have deteriorated from aging.
Being an experienced tech and knowing these things well, it's a job for the knowledgeable and experieneced only.
As for "online advice" - I cannot train you across a screen to know how to troubleshoot and rectify all the problems - that would take years.
Some things simply cannot be done over the internet, however advanced it is .

The "tubes" are OK to replace--they do "plug"-in-out. The Caps, however not only do not plug/unplug, they are probably not available in that "package", anymore---and if not properly installed can surely catch fire, "explode", and cause great harm to both you, and your equipment.
I don't want to be the one responsible for any mis-happs, small or large !
If you wish to learn, many books are available, and many schools also teach "electronics". Ron Rich