Technics SA-202 volume issue

Drucifer83

New Member
I'm hoping that someone can help me out because Googling has turned up nothing. I have a Technics SA-202 that is putting out too much volume on the right channel. Even when the volume is at 0 there is still sound coming out. The left channel doesn't really come in until volume is at about 3. I've cleaned all the pots with Deoxit hoping that might be the issue but it hasn't solved the problem. It does the same thing no matter the source. It does the same thing on both the main and remote speaker outputs. Any help would be greatly appreciated.

Thanks!
 
Time to change the volume pot?

Especially if at higher volume (say, at 6 o'clock) the channels are balanced, it's probably the volume pot itself. You can test with a weak signal source, like an mp3 player with its output volume turned down.

They do go bad. I had to replace pots in at least 10 amps and receivers, mostly volume pots that had imbalance similar to what you describe, but in 2 cases also tone control pots and 1 balance pot (that I remember). If the pot's tracks are damaged, cleaning won't help.

If you have a spare pot, switch and test if the problem still occurs.
 
First check if the sounds balances between channels at higher volume pot setting to make sure that the volume pot is the culprit.

Someone based in the US will be better suited to advice you on where to look for replacements. I'm in Europe and buy parts locally.

I saw that there's one on the auction site, search for "Technics SA-202 Original Volume Control. Tested. Parting Out SA-202 Receiver" (no affiliation). It's not cheap though, I'm sure there are much cheaper options.
 
I've tested it and it does balance out at higher levels. The right channel comes in at around 3 and it seems to balance out at around 6.

Looks like the part number is EWFMKA031BF5, but a search online shows that its not available anywhere.
 
Greetings;

This is the 200 model with poor schematics for basic voltages.. Sounds to me that "3" on the dial to engage the amp would be about right for a lower watt amp. No service manual on the 202 but look alike.. you'll have to compare the circuitry.

http://www.hifiengine.com/manual_library/technics/sa-200.shtml

that's a lot of comparison but the Thd looks worthy of examination. I don't like the power IC chips but that maybe simply a power supply on a power leadl not getting the boost it needs or failing caps etc. but I didn't look for bias pots either. Hope it helps.
 
That's assuming that input signal is always the same or similar. It normally isn't.

Volume pot only attenuates (and may affect the loudness circuit, if it has a loudness tap), so whatever ALWAYS happens around 3 or 6 on the dial regardless of the input signal level, the reason is probably the pot itself. To test it properly, best to try first with a loud source (like built in FM tuner, or a CD player), and then connect a weaker source, like an mp3 player with volume at 30% or lower and try again. If in both scenarios the right channel comes in at the same volume pot position, and then balances out at the same position - not a voltage issue.

I would still bet on the volume pot, with this kind of behavior it's very often the cause. And I've found reports of volume and balance pots going bad in SA-202.

Drucifer83, if my search is correct, for your Technics you need a 250 kOhm logarithmic pot with 'D shaft'. If you can't find one exactly like that, maybe just get something with a different shaft and change the volume knob. Make sure that if physically fits in the space it will be in.

Don't bother looking for it with the Panasonic part number, this exact pot is not available anymore.

If you can't find a volume pot that physically fits, there is a workaround. You can buy or make an inline variable attenuator and put it in the tape loop. If you want to buy, they are quite cheap, 7-12 bucks will get you one. Search for "CALRAD 10-105" or "Rca Level Controller" to see some examples.

If you want to build one, buy any stereo volume pot (logarithmic/audio taper is better), and solder RCA wires to it.

Then plug the thing in the tape loop, put TAPE MONITOR switch to TAPE position (and best block it in that position with something). Then set the added pot to the position, at which your normal listening level is at 7 on the Technics' volume pot. It's far from ideal, but at least it will give you balanced sound at your normal listening level.
 
Thank you guys for your help. It looks like I can find a pot for around $10. When I have time this weekend I'll make sure it'll fit. I'll report back once I replace as to whether that fixed the problem or not.
 
Cool that you got a pot fast. Donor orig? one with a "D" shaft?

rlisin I missed post #4.. could have saved myself some writing. Nice idea on the work around in a pinch.
 
Maybe I should make a thread about this workaround solution, channel imbalance at low volume pot setting is a very common problem with vintage amps and receivers. I have a few myself for which I could not find replacements for volume pots.

Drucifer83, I hope the new pot solves your problem. Do let us know!
 
I haven't gotten the pot yet, I just priced it out. I haven't had a chance to get it yet. I'll definitely let you know what happens.

rlisin, A thread on the workaround solution would be great though. I was a little confused about set-up for that but interested nonetheless.
 
Alright, I finally got my receiver fixed and I couldn't be happier. It definitely was the volume pot that was the issue, but it was a little weirder than I thought it would be. I pulled the "original" pot out and took it to my local electronics store. I explained the issue and the guy there tested the resistance and inspected it. He said that it looked like it had been pieced together. The person who owned it before me must have tried to replace the pot. I'm guessing that he broke the knob on it (some of the knobs are a little bent, but I was aware of that when I bought it and they don't cause any issue.) He probably ran into the same issue that I had with not being able to find one that was the right size. He guessed that he must have used the original back section of the pot and took the front part off of another one that matched in size. Unfortunately the part he used to replace the front (along with the knob) was linear and not variable. Whether it was just a pot gone bad or someone Frankensteined a new one together using incorrect parts I'm not totally positive about.

Anyway, the only 250K variable pot I could find was too small. I bought it anyway. I broke the connector nubs (I'm not sure what they are actually called) off the original one and soldered them onto the new one's nubs. Soldered the new one into place, hit it with some De-Oxit and now I'm jamming out to some Alice Cooper.

Thanks for your help in steering me in the right direction.
 
I am a new member, first post, and need a replacement-balance pot for a Technics 202. Does it need to be an exact one, or is there a range based on specs that I can use? It's for a system i put together for my daughters birthday in 2 weeks and the one I got on ebay needs this part. Any help is appreciated. (Not sure if this should be a new thread, its tbe only one I found here)
Thanks,
James
 
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