Seeburg USC-2 w/ TSA 10 code B amp.

Hi Everyone,
Here's an update on the original post about the TSA 10 heat sink question, all the parts arrived and were installed in the Amp, Dim-bulb tested w/speakers attached and it passed the test!
Installed the rebuilt DCC back into the USC-2( it had already passed the Dim-bulb test), it worked fine. Scanned properly, didn't select any records at that point because of no way to reject them until the amp was installed.
Installed the rebuilt Amp today and the USC-2 worked fine!
The only problem now, when playing a record, all I get is the scratchy sound like at the end of a record, no music whatsoever. I did a quick check of the needles and there appears to be a tip on the end of each one. The noise comes on both sides with both needles. Could both needles be bad or is there another explanation that someone might have? I've checked the connectors on the bottom of the pickup assembly as well as the connectors on the left side of the mech. and I've sprayed the volume control with Deoxit 5 and worked the volume knob and it moves OK. I'm confused
Any thoughts would be appreciated before I order new needles.....
Thanks,
Steve K.

Hi Steve,
What happens if you remove the phono input red/blue plugs, and play a record ?
What happens if you remove the "mech" (mute) plug withOUT the motor running ?
Ron Rich

Hi Ron,
When I removed the phono input plugs on top of the amp and played a record, I heard the scratch a little, no music. Then I removed the mech. plug and I heard the scratch and then it stopped. I plugged the mech. back in, selected a record, it played with no scratch but very faint volume, I could hardly hear it even with the volume knob up all the way. The scratchy noise is gone, thank-you, but now no volume, do I need to adjust the gain?

Thank-you,
Steve K.

Is it possible for you to post an audio or AV recording? That would speed things up a bit.

Rob

Hi Rob,
I've got some volume now, when I started to touch the RCA plugs coming from the top of the amp and the RCA plugs on the left bottom side of the mech. things started to improve and I got some volume. I also checked the connectors on the bottom of the pickup arm and got some intermittent noise. I'll clean all of the connectors tomorrow and see if things get better. It seems to be a cable issue??
Another problem, there is no bass, regardless of the setting on the amp, tomorrow is another adventure....it should be cooler out in garage.

Thank-you for your help so far....
Steve K.

Steve, measure each pickup lead from the cart at the RCA plug. You should see around 460 ohms/ch a few dozen higher or lower is no problem. Wiggle the wires a bit to help find any breaks or points of resistance.

The input impedance is fairly important due to the fact that Seeburg goofily designed the input with the cart being being also the voltage divider that sets the forward bias on the first transistor

That is why, when you remove the pickup plug and touch the input you don't get a hum as with a "normal" amp. The first stage is biased to cutoff with no pickup to divide the voltage at the base.. ....Well, they did save one resistor and one electrolytic cap per channel .

BTW: If bass comes back with only one pickup plugged in, it indicates someone wired the cart out of phase. This is part of what you can run into on these old, tinkered machines.

Rob

Hi Rob,
Will check those readings tomorrow...thanks Rob.
Steve K.

Steve,
If you heard "scratchy noise" with the RCA plugs out--you have internal amp problems !
Measure the input plugs as per Rob's suggestion--I have NEVER seen that audio cable fail in those models--I have seen the cartridge socket destroyed, many times, by incorrect handling when removing/replacing the cartridge. Is the nylon still intact--the "keeper" still in place -- wires looking straight going down the side of the arm ?
Do not attempt to "adjust" anything on the amp! Ron Rich

Hi Rob, Rich
I checked the resistance at the "fast-on" connectors at the base of the pickup assembly, the right side (blue) is OK it measured 488 ohms, the left side (red) didn't get any reading except at one point when I was switching the scales on the meter, 117k ohms showed up. I checked the wires coming from the cartridge down the arm and everything is in place nice and neat, all the retainers are in place. It appears to be the way it is supposed to be. I removed the cartridge from the top of the arm and the socket came free from the arm, so I checked continuity on all the wires from the cartridge socket to the fast-on connector at the base and there is continuity on each wire from the cart. socket to the connector. The wiring seems to be OK. I'm figuring the cartridge is bad, can it be repaired? If not, are replacements available?

Thanks for your help!
Steve K.

Steve,
I seriously doubt the cartridge is bad, unless some "clown" has bent a post, or two----only saw one bad one of those in my life, and it was "brand new", way back in 1972 ! Measure at the cart. pins, themselves--My guess would be the cartridge (white Nylon), SOCKET connectors, have been "expanded" due to improper cartridge removal ( see instructions on mech cover ! ) ( My two "guides" cover this in detail). Ron Rich

The posts on the cart. are straight and even, no evidence of bending, so I'll check readings at the cart. pins and then I'll check the sockets and bring the guides with me.....thank-you Ron
Steve K.

Hi Ron,
After a couple hours investigating, the tone arm wire at the top of the arm, where it goes into the white nylon connector and the female connectors inside the white connector seem to be the problem. I selected a few records to play and while they were playing I sat in the back and wiggled and jiggled the four wire bundle that goes to the cart connector on the arm. I got sound sometimes, I got a lot of static noise sometimes, I got nothing sometimes, it would depend on the wiggle. There is a problem with the wires and the 4 female connectors inside the white nylon connector for the cartridge. It needs to be re-wired with new female connectors. I'll have to find phono cartridge wire and female cartridge connectors somewhere in order to make a good connection, that seems to be the problem area right now.

Thanks,
Steve K.

Hi Steve,
It does NOT need "new" female connectors, they can be removed and "reformed",("bent-squozen"?) to work just fine--done did it 1000, or more, times--see both my Seeburg Mechanism Guide {for how I remove the tone arm assembly}, and / or my Seeburg MicroLog Trouble Shooting Guide {for how I cope with the wires/socket} --it MAY need new wire--depending upon how carefull you are when you repair that problem.
For a "quick fix"--that may or, may not last too long--spray Deoxit 5 on the cartridge posts, and CAREFULLY place the cartridge back on the arm, remove it, and replace it several times--this SOMETIMES works--do NOT spray anything into the socket itself !!! Ron Rich

Hi Steve,
You mentioned a couple of post above about "touching RCA plugs--"
The only RCA plugs involved with the audio, on that model phono, are the ones on the amp. itself. The wire going to them should be routed through the center of the heat sink. The other ones, on the side of the service switch assembly, are for the Tormat read-out loop. Ron Rich

Hi Ron,
I was thinking about that also, I've done that with the molex connectors in the Rockolas that I've worked on, if need be there seems to be some slack in the 4 wire going up the arm to the cart. I did wiggle the RCA plugs on the AMP and got some static before I cleaned them up a little. I meant to say the connecter that says "pickup" on the mounting on the left of the record rack, I checked and cleaned that also.

I'll get back to the cart./connector issue in a couple days, I need a break from that machine to clear my head....

Thank-you for all of your help so far,
Steve K.