Vintage Turntables: Time to Throw in the Towel?

[Aerobat]

The issue with the JVC is the speed wavers--not a huge amount, but the strobe light moves to one side and then sort of lurches back; it's impossible to get it to sit still.

The switch in question is the 33/45 selector switch, and there have been suggestions here and elsewhere online that these switches can go bad over time and cause speed problems. I don't think it is the main power switch for the unit, unless I'm mistaken?

It's a 125V switch, looks like power to me.

 

[VintageDutch]

The lettering on the switches is the rating it can function... This has much to do with sparks, isolation etc...

The lettering says nothing about the function it is used for...so it can read 230 volt 5 amps but still switch 5 volt and 10 mili amps...Or audio sorces ... or what ever...

 

[cmnparlance]

It's a 125V switch, looks like power to me.

If you look at my photos in post #223 above, the black switch in the close-up pics is controlled by a knob on top next to the platter for selecting 33 or 45 (I didn't take any pics of the knob but it can be seen if you look up photos of the TT: JVC JL-A40).

Read the comments from Mizuno Takahashi here:

http://thevintagehifishack.com/1977-jvc-jl-a40-professional-turntable-for-both-stereo-quadraphonic/

That's where I got the idea that the switch may be the problem.

 

[cmnparlance]

Yes those switches can go bad but it is only after replacing that you know for sure..
As far as I can see your switch also has 3 connections..

So okee..lets switch (no pun intended) to a earlier post of you..





First of al... yes some Vintage gear lovers can paint rosy pictures... But...(this is the hard part) They are willing to put in time and effort to learn skills. (or they are "grown naturely")

What I mean You are thinking about ditching a very nice TT because maybe a 2 dollar switch is kaput ... That does not make sens to me...
Really it is not hard to buy a 10 dollar fine soldering iron...a 4 dollar 4 mm thick, small roll of 60/40 Soldering (with core) wire and a 20 dollar simple measuring device.

Ask arround in you neighbourhood for that youngster or better yet that grumpy oldtimer who is happy and willing to learn you the basics. It really is not that hard.
I gues ones you learned to use a computer.... it is not much harder... really!
Ones the smoke or Sodering Fumes clear you might find yours self writing a succes storie in rosy language here on AK!

Stupid question.... What is your location? Europe? USA? Canada?

OK, so to confirm: A switch like the one you pictured should work, given that there are three wires that need to be connected, correct? I'm asking because as I said, the old switch doesn't have the prong on the bottom (but it may have a third prong on the side, I'll have to check).

As to your responses to my other points: I would love to have the knowledge and skills to be able to fix vintage gear. But it's a matter of priorities--at this point in my life I only have a few hours a week I can devote to tinkering around. And I'd rather use my free time actually listening to records, as opposed to troubleshooting the equipment. I don't mind spending SOME of my time doing that, though, which is why I'm on this forum in the first place. And I really like this JVC table, which is why I haven't just given up on it.

In terms of just finding a neighborhood person to show me the basics, I don't know if it's quite that easy--especially in COVID times--but there are a few local people who have done some work for me before (who I mentioned in other comments here) who may be able to help me.

My plan was to buy an inexpensive soldering iron and whatever else is needed to install the switch and attempt to do it myself. Is that something you think I could do with guidance from here, YouTube tutorials, etc.? BTW to answer your question, I'm in the US.

 

[Aerobat]

If you look at my photos in post #223 above, the black switch in the close-up pics is controlled by a knob on top next to the platter for selecting 33 or 45 (I didn't take any pics of the knob but it can be seen if you look up photos of the TT: JVC JL-A40).

Read the comments from Mizuno Takahashi here:

http://thevintagehifishack.com/1977-jvc-jl-a40-professional-turntable-for-both-stereo-quadraphonic/

That's where I got the idea that the switch may be the problem.

OK the black switch. Put a continuity tester on the leads and see which leads are connected when the switch is in 33RPM. Then short those two leads with a jumper and see if the problem goes away. All you need is a cheap multimeter and a piece of wire with clips on it. If you don't want to do this you should take it to someone who services electronics. I don't see your location in your profile but perhaps there's an AK member near you.

 

[VintageDutch]

Got a bit of bad news...
There is probably more going on then just a bad switch...

I just fixed a DD TT with pulsing speed problems...
It was a head scratcher...but It turned out that the Pre adjustment circuit of the 33 and 45 RPM adjustment was faulty.. replaced the adjustment pots, Recapd it including Polypropuleen caps and replaced the resistors connected to that pre-adjustment...
Rock solid now...

SO If you do not have the skills (yet) to fix it yourself, I Can help you out if you live in Europe for no more then the cost of the Parts and shipment.
Now it is up to you... Send me a personal message if needed...

For everybody reading this.... This is a one time offer for @cmnparlance only.

 

[cmnparlance]

Got a bit of bad news...
There is probably more going on then just a bad switch...

I just fixed a DD TT with pulsing speed problems...
It was a head scratcher...but It turned out that the Pre adjustment circuit of the 33 and 45 RPM adjustment was faulty.. replaced the adjustment pots, Recapd it including Polypropuleen caps and replaced the resistors connected to that pre-adjustment...
Rock solid now...

SO If you do not have the skills (yet) to fix it yourself, I Can help you out if you live in Europe for no more then the cost of the Parts and shipment.
Now it is up to you... Send me a personal message if needed...

For everybody reading this.... This is a one time offer for @cmnparlance only.

Thank you for all the ideas you've had here, and thank you for offering to look at the TT yourself--alas, I am not in Europe so I don't think that would be an option.

So, the more I learn, the more I feel like the problem isn't the switch. As I have mentioned elsewhere on this thread, the speed (according to the strobe) lurches or jumps with every rotation, whereas my understanding is that if the 33/45 switch were the problem, the speed would probably fluctuate more wildly or play much too fast or too slow. In my case, the *average* speed the platter spins at is fine, it's just that there is excessive wow caused by cyclical speed fluctuations.

But just to be sure, I did try cleaning the switch out one more time--I sprayed DeOxit around the button and into a few very small openings near it, hoping some of the stuff would seap inside, then I worked the button 100 times or so. Strangely enough, when I tested it out after that, the strobe seemed to lock in okay at 45 RPMs, but when I switched it to 33 and fine tuned the speed, it started to jump again--and then when I tested 45 again it wavered as well.

I'm not sure how much of this thread you've read, but I did have someone look at this TT a few months ago and he changed out the capacitors and transistors on the control board, but it didn't seem to make a difference in the speed.

I've heard that these problems can be caused by things like faulty chips, or even the motor itself wearing out or things falling out of alignment over the years--all of which seem like they'd be much more difficult, or at least impractical, to fix. At this point I'm feeling like there's not much more that can be done without spending money and I'm hesitant to do that right now. I may think about selling it or hold onto it for a while and think more about what I want to do.

Thanks again, and let me know if you have any other ideas.

 

[BillWojo]

Does it jump at the same spot with each rotation or is it random? If random, replace the switch.
Those switches are very difficult to clean properly. They are cheap. Find a replacement and try it.
I don't know if you can read a schematic but that switch is inline with either the 33 or 45 RPM trim pot depending on what speed is selected. You cleaned the pots and it helped a lot but the circuit is still going through one or the other switch contact in that switch.
If your unsure of yourself to solder it, find someone that can.

BillWojo

 

[VintageDutch]

@cmnparlance
Thanks for the pointers.... I have that ichy feeling the repair guy you used over look something....

Could you please take a picture of the PCB so that we can see the set-up and come up with new idea's

 

[VintageDutch]

Just glansed through your posts.... am I correct to think I read somewhere it is about Technice SL-D3 TT?

Then this should be the guts of it

What will go wrong over time are those pesky little Pots.. I think they are reverd to as P1 and P2.

They should cost about 50 cents each... lets make them expensive... they would cost 5 dollar each... 30 minutes max soldering out and in and re-adjust... would cost about 30 buck...So totals to 40 dollars max...but probably way less

 

[cmnparlance]

Does it jump at the same spot with each rotation or is it random? If random, replace the switch.
Those switches are very difficult to clean properly. They are cheap. Find a replacement and try it.
I don't know if you can read a schematic but that switch is inline with either the 33 or 45 RPM trim pot depending on what speed is selected. You cleaned the pots and it helped a lot but the circuit is still going through one or the other switch contact in that switch.
If your unsure of yourself to solder it, find someone that can.

BillWojo

It's not random; the strobe jumps pretty much at the same spot every rotation. Sometimes I think it wavers twice per rotation--one big jump, and then a smaller nudge in the same direction, every time the platter goes around. This is what made me think the switch was not actually the culprit, based on comments from a few others on this board and elsewhere.

That, plus the genuine part (which you recommended instead of any old switch) now being discontinued and the fact that to do the replacement, I would need to either buy soldering equipment and do it myself, or have someone else do it--it just started to not feel worth it, since it sounds like the symptoms are unlikely to be a switch issue anyway.

I am curious though, is the speed jumping as opposed to randomly wavering a sign of something else that can be pinned down? A problem with the platter perhaps?

Thanks again for all your help.

 

[cmnparlance]

Just glansed through your posts.... am I correct to think I read somewhere it is about Technice SL-D3 TT?

Then this should be the guts of it View attachment 2109655

What will go wrong over time are those pesky little Pots.. I think they are reverd to as P1 and P2.

They should cost about 50 cents each... lets make them expensive... they would cost 5 dollar each... 30 minutes max soldering out and in and re-adjust... would cost about 30 buck...So totals to 40 dollars max...but probably way less

So, the TT I’ve been talking about is a JVC JL-A40.

I also have a Technics SL-D12, which also has slightly unstable speed, but it’s not as bad.

 

[VintageDutch]

Okay...@cmnparlance It looks like a nice TT so why bin it? I really don't get it..

I just downloaded the service manual of your JVC and cut out the Circuit diagram for you


In the down left corner You see the 33 /45 switch... It is the simplest thing ever..
In that same corner you also see VR1 and VR 2... They are also simple run of the mil adjustable pots. value 5k each..

The same guy that did you recap, should be able the replace these pots and the switch in less then no time... It really is that simple...
If you want I can send you the service manual via email or you can download it yourself at https://elektrotanya.com/jvc_jl-a40_sm_1.pdf/download.html#dl

Just make sure you wait untill the countdown changes to "download". I am not related to that site at all but I found several service manuals there... Had no problems with it ever..
Keep us posted

 

[wushuliu]

All of that appeals to me too, as well as the aesthetics of the old gear.
I've read many, many forum comments where people assert that old, quality direct drive turntables rarely have serious issues that can't be solved by cleaning pots and lubing. However, that simply hasn't been my experience. Once you get into things like caps, chips, switches, etc., and the prospect of spending hours and days doing research, tracking down parts online, troubleshooting, and all the rest, the idea of just spending a few hundred bucks to get something mediocre but brand new starts to be a lot more appealing.

Maybe I've just been unlucky? But I feel like sometimes online posters paint too rosy a picture of the vintage gear landscape as it currently exists.

I read the first few pages, then hopped down to the end here and sad to see you're still struggling. Yes, I do think you drew the short stick on wonky tables. To have acquired so many tables and have them all be problematic is not the norm. On the other hand, it's 2021 and these tables are now 40+ years old.

One tip from past experience is to make sure the power plugs are nice and clean. Go over them with some DeOxit or what have you. The plugs are the first point of contact so if they've got 40+ yrs of oxidation that will absolutely impact speed/strobe performance.

 

[cmnparlance]

Okay...@cmnparlance It looks like a nice TT so why bin it? I really don't get it..

I just downloaded the service manual of your JVC and cut out the Circuit diagram for you
View attachment 2110637

In the down left corner You see the 33 /45 switch... It is the simplest thing ever..
In that same corner you also see VR1 and VR 2... They are also simple run of the mil adjustable pots. value 5k each..

The same guy that did you recap, should be able the replace these pots and the switch in less then no time... It really is that simple...
If you want I can send you the service manual via email or you can download it yourself at https://elektrotanya.com/jvc_jl-a40_sm_1.pdf/download.html#dl

Just make sure you wait untill the countdown changes to "download". I am not related to that site at all but I found several service manuals there... Had no problems with it ever..
Keep us posted

Hi, and thanks again for your ideas. I'll take a look at the schematic when I have a chance later.

To answer your question, "why bin it?"--yes, it is a nice turntable, and that's why I've spent so long trying to figure out how to get it working, and why this process has been so frustrating--so close and yet so far, as they say.

However, I began to feel like the specific problem I'm experiencing is likely unrelated to the 33/45 switch or the speed pots, and so I sort of gave up on replacing them. Replacing those parts would require me to either learn how to do it myself, or have someone do it for me. To be honest, I'm sort of hesitant to ask the guy I took it to before to help me with this, since he was so generous with his time and work before, and where he's located isn't just around the corner or down the street, so I don't really want to ask him to help unless there's a very good chance that doing that work would help solve my issues.

In your opinion and given your experience/expertise, do you think the speed "jumping" every rotation is perhaps due to those parts malfunctioning, or would that cause different symptoms? I know you can't guarantee anything, but my sense at this point is that those parts would cause a different set of symptoms. I get that we'll never know until we try, but I want to get a sense of what my chances are first--maybe an unrealistic thing to hope for, I know.

 

[cmnparlance]

I read the first few pages, then hopped down to the end here and sad to see you're still struggling. Yes, I do think you drew the short stick on wonky tables. To have acquired so many tables and have them all be problematic is not the norm. On the other hand, it's 2021 and these tables are now 40+ years old.

One tip from past experience is to make sure the power plugs are nice and clean. Go over them with some DeOxit or what have you. The plugs are the first point of contact so if they've got 40+ yrs of oxidation that will absolutely impact speed/strobe performance.

Hi, thanks for the sympathy! I'm honestly not trying to get people to feel sorry for me; I started this thread because I was genuinely curious whether my situation was normal or if I've just had a string of bad luck--and the consensus seems to be (as you say) that it's probably the latter. That actually encourages me a bit, since it means that if I decide to replace the decks that I have, I stand a good chance of finding replacements in better shape, or at least ones that will be easier for me or the people I know to fix up.

But as you said, these TTs are now quite old and as time goes on, all this vintage equipment will have more problems (including some that are impossible or at least impractical to solve--unobtainable parts failing, mystery issues like the ones I've had, etc.).

Your suggestion about cleaning the power plugs is a good one, and seems so obvious and yet I don't think I've seen anyone suggest that before, strangely. I will definitely try that when I get home later--just to clarify, you're just talking about the prongs that plug into the wall, correct? Or where the power cord connects inside the turntable?

Thanks again.

 

[VintageDutch]

@cmnparlance
I hear you buddy... Really.. IMHO yes.. the turntables we use are getting old, but there build like they don't build them anymore...
The TT I worked on for myself was dead as a Doddo... I froze over Hell to get it working again...I just wanted to know what caused the problem..
No mine was odd... Someone F***ed up and made a mess for me to sort out... As I understand from you there no word about that ...

So here we go.... IFFFFFF the guy who replaced the caps in your TT did a good job (and that is an IFFF) then you should have no problem replacing the the identified parts and get it properly working again..

So replace the 33 /45 switch... and also see VR1 and VR 2... They are also simple run of the mil adjustable pots. value 5k each..
These three parts are cheap to get, and fairly easy to install if you are capable of soldering. (and I mean electronic's soldering, not copper pipes..)

SO you need a soldering iron good for electronics and some Soldering Tin 60/40 with flux core..the real stuff.

I promise You feel a King when you are done and all functions like it should. Now that would be a good story to share round a campfire





And now the "What if" there always is a very small chance that one of the HALL effect switches in your motor is defect...
In that case you would need to replace the motor... That chance however is less then 20%.|

And even that one is cost effective https://www.ebay.com/itm/Technics-S...217013?hash=item4b712b66f5:g:2LcAAOSwd9heAIXT

 

[VintageDutch]

If you need tips for soldering correctly... let me know...

 

[cmnparlance]

I have to say I appreciate your tenacity with this, and your encouragement.

I believe the person who fixed the caps and resistors did a good job. He has done other repair work for me and it's been great, and he has also done lots of work for other people successfully. Also, the speed issue didn't get any worse after he did the work, so I don't have any reason to think he did anything incorrectly.

You seem pretty convinced that replacing the switch and the pots will correct the issue; can I ask why you are so confident in that assessment? Other people I've talked to say there are all sorts of other things that could be wrong--chips, motors, perhaps there's even a problem with the platter geometry?

I'm a bit busy with other things at the moment, so realistically I don't think I'd be doing the soldering and everything in the next week or so. And I'd still need to purchase the parts. Why don't I check back in with you when I'm ready to move forward?

Thanks again.

@cmnparlance
I hear you buddy... Really.. IMHO yes.. the turntables we use are getting old, but there build like they don't build them anymore...
The TT I worked on for myself was dead as a Doddo... I froze over Hell to get it working again...I just wanted to know what caused the problem..
No mine was odd... Someone F***ed up and made a mess for me to sort out... As I understand from you there no word about that ...

So here we go.... IFFFFFF the guy who replaced the caps in your TT did a good job (and that is an IFFF) then you should have no problem replacing the the identified parts and get it properly working again..

So replace the 33 /45 switch... and also see VR1 and VR 2... They are also simple run of the mil adjustable pots. value 5k each..
These three parts are cheap to get, and fairly easy to install if you are capable of soldering. (and I mean electronic's soldering, not copper pipes..)

SO you need a soldering iron good for electronics and some Soldering Tin 60/40 with flux core..the real stuff.

I promise You feel a King when you are done and all functions like it should. Now that would be a good story to share round a campfire





And now the "What if" there always is a very small chance that one of the HALL effect switches in your motor is defect...
In that case you would need to replace the motor... That chance however is less then 20%.|

And even that one is cost effective https://www.ebay.com/itm/Technics-S...217013?hash=item4b712b66f5:g:2LcAAOSwd9heAIXT

 

[BillWojo]

@cmnparlance, several folks on here have given you good advice, mine came after a look at the schematic as I'm sure others did as well. For the few dollars it would take to replace the parts why not just do it! If the problem remains than we can look at other more unlikely causes.
From your post it's pretty clear that you have no technical or service experience while people who DO have experience you seem to question and ignore. I would hate to be your auto mechanic.

BillWojo