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Hitachi HT-353 Won't Hold Speed, Pulsates

desertrat748

desertrat748

Super Member
Hitachi HT-353 won't hold stable speed.Pulsates very evenly about every second and drops to about 32 rpm. Using RPM app on Iphone to check it and it's showing 33.08rpm, -1.55%, 3.14% w/f

After several attempts it is showing 1.54% wow/flutter at 34.04 rpm and same at 33.85rpm.

Don't know if there is a fix for this. Any help would be greatly appreciated. I don't have a lot into this but I'd like to keep it as it's quartz locked and decent overall.

dr
 
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Does anyone know where to start with this? I would be willing to attempt to replace some capacitors or diodes if I could get a little help or direction? Or maybe if anyone knows of a decent shop that I could send it to that wouldn't charge an arm & leg for it. I'm out in Arizona and the local shop here in town doesn't seem to be able to fix turntables very well but they are able to charge some high prices for their attempts.

I will take a pic of the circuit board and post it up. Maybe someone here would be kind enough to share any knowledge they may have. I thought quartz locked would be more reliable but I guess they have their own share of problems.
 
desertrat748 said:
Does anyone know where to start with this? I would be willing to attempt to replace some capacitors or diodes if I could get a little help or direction? Or maybe if anyone knows of a decent shop that I could send it to that wouldn't charge an arm & leg for it. I'm out in Arizona and the local shop here in town doesn't seem to be able to fix turntables very well but they are able to charge some high prices for their attempts.

I will take a pic of the circuit board and post it up. Maybe someone here would be kind enough to share any knowledge they may have. I thought quartz locked would be more reliable but I guess they have their own share of problems.
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Do the basic DeOxit treatment first.
http://www.audiokarma.org/forums/in...diots-guide-to-using-deoxit-revisited.207005/

See page six of the service manual before you start.
https://www.vinylengine.com/library/hitachi/ht-353.shtml

Best of luck with DeOxit/cleaning all the switches. :thumbsup:
 
Thank Balifly,

All is now well and fixed speed issue! Success!

Need to check wow and flutter, set voltage tomorrow in the morning. Too late and tired now.

I had downloaded the manual last night from vinylengine and missed the part on speed adjustment. Re-read it again after your reply and saw where it was adjustable for each 45rpm (must set it first according to manual) and then the 33 rpm via two adjustable resistors.

Locks up but still showing some flutter on the strobe. Will use multi-meter tomorrow to adjust voltage (just a quick guess tonight) and hopefully wow/flutter won't be too much.

Thank you thank you thank you!!! Very happy camper now. I'm glad I'm learning to read.

Also, cut cue wasn't working. Used Hodgen One Shot to clean and free up sticky mechanism. Works great now. I feel like a HT-353 expert now! Willing to help others with similar problems...

Regards
dr
 
Last edited:
Updates! LOL! Couldn't be happier! Checked wow/flutter, according to RPM app., it's 0.18% and speed is rock steady at 33.34 rpm. Locked in really well. This Hitachi HT 353 measured 2nd best for wow/flutter out of 5 tables. Thanks again for the help!
 
desertrat748 said:
Updates! LOL! Couldn't be happier! Checked wow/flutter, according to RPM app., it's 0.18% and speed is rock steady at 33.34 rpm. Locked in really well. This Hitachi HT 353 measured 2nd best for wow/flutter out of 5 tables. Thanks again for the help!
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Enjoy! :music: :thumbsup: :thumbsup:
 
Well I’m a happy camper. Bought a pair of hinges and spinning some Black Keys with Empire 2000e/3. Absolutely love it.

Apparently the Hitachi is easy to work on and decent overall.
 
Hello, I have the same problem with the HT-353 turntable. Please provide a more detailed description of the removal of this problem.
Thank you.
 
Please download the service manual from vinyl engine. There’s a link provided above. The procedure is detailed and outlined specifically as step eight on the manual page 5. It is a little complicated but you have to adjust the resistors as pictured in the diagram with a volt meter. I cannot give a better detailed description than the manual.

Good luck with your adjustment.
 
ppeettrr said:
Hello, I have the same problem with the HT-353 turntable. Please provide a more detailed description of the removal of this problem.
Thank you.
Click to expand...

It's a little hard to know what your issue is without a little more info. Can you describe what is happening? It may be something else so I don't want to say this will cure it. Have you taken the 353 apart yet? Are you familiar with circuits and electricity? It's really easy but if you are not comfortable with electronics, it may be easier to have a local tech. do it for you. Did you download the manual? It outlines the steps really well.

Seriously took me longer to take it apart and put back together than adjust. Was only about a 10 min. job for someone who hasn't ever worked on one before. Small screwdriver, flat blade for adjustments, a small Phillips to remove the bottom cover. A multimeter or voltmeter. 3 pairs of hands to help you hold, adjust, and maintain the table, meter, screwdriver.

You will have to identify the VR 101 and 102 from the main pcb. Next identify the #10 pin on the IC103 chip and adjust the 45 rpm 1st, then 33 rpm via the VR 101/102 and get the #10 pin down to 0.6 volts or lower. That's the number ten pin and they want you to use the 21 pin off the main pcb I believe as the ground. The 21 pin is on the lower left as you view the pcb and the 101/102 resistors are lower left but just a few inches in towards the center.

Hardest part is to get it all open and still have access to adjust everything from underneath and actually seeing how to adjust the 102/103 resistors. They don't look like they can be but they really can.

Let us know where you are in the process and I will try my best to walk you through it, assuming you have the same issue as I did.

Best of luck,

dr
 
Thunderbox said:
I love it when I see excellent advice posted in the forum.
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I haven't found the DeOxit to be really useful with this model Hitachi. Quartz locks don't usually have a pitch control that causes trouble like the Pioneer PL-4 or PL-5. With the 353, the speed selector is a rotary model switch. I haven't had any trouble with my Hitachi models with their selectors, unlike the PL-5 that has lots of trouble and DeOxit is a great option..

Now the service manual is excellent advice for the 353. It is really well written for the most part and how manuals go.
 
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