I have a 1979 vintage Toshiba tuner / amp, a 1990's vintage Sony CD player and some really nice Polk Audio speakers. I have a Dual turntable that sat unused for a couple decades until I finally got it up and running again. All good when playing CD's but when I play a vinyl album the left channel / speaker goes mostly dead. Occasionally it breaks through but it's mostly dead. I know next to nothing about electronics and stereo stuff, I just like to listen to music. It seems like the problem is with the old amp, not the speakers or turntable but I'm not sure. Is there a repair for the tuner? Any experts out there that can weigh in?
Who knows something about (old) stereo equipment?
- Thread starter Fullmetaljacket
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My first suspect would be the RCA output cables from the turntable. Chances are that the cable ends and/or jacks are dirty or corroded. Try spray contact cleaner or bronze wool.
venomballistics
Member
next stop, the cartridge head connections followed by the stylus
pantannojack
US Veteran
I have had a Technics receiver since 90. It went dead on one half and a stereo engineer quoted about 150$ to fix it. I went with a new Denon unit for 250$. Big mistake, it is a piece of **** and if I touch the wrong button, it dies long term until I isolate all power sources and must re program.
digi-shots
Member
Can you unplug the speaker? If you can, unplug both, moving the left to the right and vice versa.. See if the problem "follows"the bad speaker. It could be the jacks have some oxidation.
venomballistics
Member
In such cases, it'd do you well to learn some analog electronics.
a decent solder sucker, soldering skills and an internet connection to look up part numbers can go a long way toward salvaging these things
I spent a goodly chunk of time breathing the smoke from a Weller Variable.
venomballistics
Member
As anyone who travels the road of 22 frets should
outta_ammo
Member
Another thought is that the left channel of the phono preamp stage in the Toshiba is toast.
Several years of electronic experience.
CDs playing OK -
Cables from CD to Amp in the Tuner are OK
Both channels of amp are OK
Wires to speakers are OK
Speakers are OK
Turntable left channel not working.
1) Possible bad switch in amp - one that selects turntable.
Check - plug RCA cables in the turntable inputs.
Touch center connectors - with a finger - you should hear HUM
Your body will pull enough 60 cycle out of the air.
Verify this with both channels.
If both amp channels work HUM problem is up stream at turntable or cables. (But you checked the cables for HUM test.
Since turntable is NOT working on one channel most likely suspects are Cartridge or the signal wires in the turntable.
needsmostuff
Member
With old analog controls and mechanical switches, it's more than likely a hunk of spunk in the switch. They are complex but in reality, they rely on mechanical contacts. They get gummy and lose spring tension. Any of the switches were capable of dropping a channel intermittently and in this case, it sounds like the mode selector switch (where you switch it to phono). It's probably a rotary switch and a good test is to rotate it all the way, back and forth a multitude of times. Then check if it's coming thru.
Next step is to pull the cover (unpluged of course) and get to the back of all the rotatory switches. The object is to spray tuner cleaner in any opening abundantly while turning the knob from the front back and forth.
Back in the day, I fixed a lot of intermittencies that way and got the rock a rolling.
Next step is to pull the cover (unpluged of course) and get to the back of all the rotatory switches. The object is to spray tuner cleaner in any opening abundantly while turning the knob from the front back and forth.
Back in the day, I fixed a lot of intermittencies that way and got the rock a rolling.
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Dominator X-1, and when you die, they can bury you in it.
Advice above is awesome as an old analog engineer not a lot to add without putting eyes and hands on the device.
This forum is awesome where else can you get this advice as well as expert revolver advice. Just saying….
This forum is awesome where else can you get this advice as well as expert revolver advice. Just saying….
venomballistics
Member
Given the vast expanse of the internet knowledge base. Angry pixie taming is probably one of the most tangible forms of voodoo one could become a practitioner of.
Between the endless sea of schematics and the scads of data sheets put out by manufacturers, there's no reason the common man cannot extend his knowledge beyond licking 9v' s to test them.
Just do it
But licking 9Volts is fun and impresses the girls. Shows you are multi talented. 
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I still do that and, heaven help me, I kinda like it.
I'd try all above but have a new stylus on the way. Could be that simple. I'm curious, up above somebody got a Denon for +/- $250. I got a fairly decent Denon receiver about 20 years back and I know I paid less than $1000 for a mid-priced range. It can play two different outputs, like radio on my deck and surround sound in the house. I have one speaker that's taking a dump soon, I think an RBH, the front-right one. Need to get serious with the connections cleaning. Nobody notices but me. With the original problem, connections and probably the needle/stylus. Good luck, and ROCK ON!
Oh, you can get a decent turntable at decent price now days.
Oh, you can get a decent turntable at decent price now days.
Oh, what kind of albums are you playing, as in music style? Disco is dead so don't even try that! Throw on some Ten Years After and make it do what it's made for. After that some ELP and maybe a little Doors.
If you're going to install a new cartridge, be sure to use the Dual cartridge alignment gauge. If you've lost it, you can get one on eBay.
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If the amp/speakers work in CD mode then switch the turntable's RCA output plugs at the amp.
If the problem is now on the right side speakers then the problem is in the turntable or it's output cables/plugs.
Clean/tight plugs and jacks are necessary.
A voltmeter can verify the AC output of the turntable in the millivolt range.... 2-7 or so?
Clip leads are useful as you want to wiggle the wires, while holding the RCA plugs steady to eliminate a cable issue and if okay, then gently wiggle the plugs at the receiver. With my old AR tables they are hard wired at the turntable and have RCAs at the amp input.
I worked on Base as an electronics tech and off Base in a TV/Stereo shop, in the late '60s, to pay for my flying lessons with the Aero Club at Castle, plus decades on mainly boats, certified factory service, and guitars/amps or just about anything that needs electron excitation for the family/friends.
"Honey the the hair blower ain't working!!!
Teaching yacht owners to be safe when troubleshooting or installing their gear and use a meter correctly was always a fun day at the office.
Meters and Scopes are helpful if you know how to use them correctly to troubleshoot the turntable.
Impeccable soldering skills are a plus with those tiny wires if that's the problem.
If the problem is now on the right side speakers then the problem is in the turntable or it's output cables/plugs.
Clean/tight plugs and jacks are necessary.
A voltmeter can verify the AC output of the turntable in the millivolt range.... 2-7 or so?
Clip leads are useful as you want to wiggle the wires, while holding the RCA plugs steady to eliminate a cable issue and if okay, then gently wiggle the plugs at the receiver. With my old AR tables they are hard wired at the turntable and have RCAs at the amp input.
I worked on Base as an electronics tech and off Base in a TV/Stereo shop, in the late '60s, to pay for my flying lessons with the Aero Club at Castle, plus decades on mainly boats, certified factory service, and guitars/amps or just about anything that needs electron excitation for the family/friends.
"Honey the the hair blower ain't working!!!
Teaching yacht owners to be safe when troubleshooting or installing their gear and use a meter correctly was always a fun day at the office.
Meters and Scopes are helpful if you know how to use them correctly to troubleshoot the turntable.
Impeccable soldering skills are a plus with those tiny wires if that's the problem.
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