Toshiba SC-330 Power Amplifier Repair

[@АндрейЗ-й3л]

Если кому ещё интересно - проблема решается установкой в схему разрядного резистора между "-"и 0 шинами питания усилителя. Конденсатору отрицательного плеча питания в 10000мкФ просто некуда разряжаться. Положительное плечо быстро разряжается через лампы подсветки. Более грамотно решить задачу можно установив реле, запитав его обмотку от "+", а его NC-контакт через резистор будет смыкать "-" на общий провод. Параметрический стабилизатор трогать вообще не нужно было, в печатной схеме явная ошибка. При резисторе в 15К он просто не будет стабилизировать. Всем удачи!

[@JayanthKDass]

Thanks for the video. I have similar problem in my Cosmic Lab-3000 amplifier. Having struggled for a long time, I have just kept it in a corner in my workshop to attend it later some time. Seeing this video I have got fresh inspiration to take up the job again. Please keep posting your videos. Regards!

[@TheManFrayBentos]

Excellent. I have one of those with the same vicious crackle and pop, awaiting investigation. It's been on the rountuit pile for a few years now. Your video spurs me on to do something with it.

[@jc5454]

www.diyaudio.com/forums/solid-state/224831-vintage-toshiba-330-power-amp-repair.html I fikxed mine in this thread with same symptoms

[@polcat79]

I have the same toshiba amp and pre amp and I'm experiencing the same probelm. Left channel is intermittent and cracking.

[@guanip]

I have a SC-335 and it does not work, it was working and heated a little low volume and stopped ringing. I would like to make an update of electronic components and wanted to know if there is a possibility to use the same cabinet and put everything inside new? And if you could get the wattmeter? Thank you

[@DaveElectronics]

Hi, yes you could just reuse the cabinet and get a stereo amplifier kit and a vu meter driver kit from ebay, but that’s a shame in my opinion. The toshiba sc-335 is a decent amplifier, built with good components. My suggestion is to give a try to repair it. If it’s beyond economical repair, you can of course keep just the cabinet and put an amplifier kit inside..

[@alan2112drums]

What is likely the problem if the right channel needle meter is not working properly (the light is not working and the needle barely moves)? Did you simply solder in an LED instead of the OEM bulb?

[@DaveElectronics]

The problem of the not working meter was a bad resistor on the main board from what i remember. The bulbs were actually working, but they produced very faint light (not enough for me at least), so I replaced them with bright white LEDs instead. The LEDs required a resistor, but basically i soldered them in place of the bulbs

[@DaveElectronics]

The lightbulb and the meter circuit are completely separate anyway so, in your case it could be a bad contact on the meter and a burnt bulb..

[@alan2112drums]

Thanks for your help. Would have loved to see an overhead view of your board work on this project.

[@sherjeelshoaib89]

i have got technics su 7600 the prob was left channel gives op smoothly but frequently left start giving 5 v dc and reverse _5v as well i chekecked power transistors drivers aswell i did every thing.....i cant get anything wrong then i replace differential ltp which takes ip signal and feed back ....that was notorious i took 2 transistors general-purpose and make it work yahoooo

[@antoniolongoni8788]

my amp sc-330 work , but the two voltometers not work and channel right have big noise , what the problem

[@MrTopsoil911]

If u are looking at the amp from front . what order do the d688 and 718 go in?

[@MrTopsoil911]

Is it d688 then 718 718 and d688?

[@DaveElectronics]

Hi, can’t remember right now, but i think you got it right..

[@domi7007]

Hello, do you have a link to the shematic? thanks

[@DaveElectronics]

Hi, there you can find the manual: www.hifiengine.com/manual_library/toshiba/sc-330.shtml