I have to say , that was one excellent narrated tutorial. Also a Fantastic repair lesson. You should be narrating for the Discovery channel or animal planet ! Very passive voice and clearly spoken..thank you
Very nice narration, and very thorough testing of all circuits. I have the HA-4700, I actually prefer it to STK amplifiers, although this one does seem a little better constructed. You now have a new subscriber, love your work mate.
Nice job on the LED retrofit. My first reaction was that 20ma was more than necessary, but it does seem that you get a brightness on the panel indicators close to matching the original brightness which I think is a worthy goal.
Hi, great video, could you tell me where you found the "Service Manual". I have a Hitachi HA-300 amplifier that I need a service manual for. One channel not working. Thanks BK
Hi there I've got a ha2700 it makes static sounds when I turn balance treble and bass. Could I squirt contact cleaner on them from the inside? Thank you
Pretty puny relay and power caps for a power output of 77W per channel. Otherwise, an impressive attention to detail for the circuits and features of this amplifier.
I assume you mean for the LED current. The LED datasheet specifies them for normal operation at 20 mA and states their maximum permitted forward current is 30 mA. The selection indicators do appear very bright, though, so there would be scope to reduce the current a bit.
![Electronic Circuitry Diagnosis And Fault Finding! [Repair]](/img/1.gif)
I have to say , that was one excellent narrated tutorial. Also a Fantastic repair lesson. You should be narrating for the Discovery channel or animal planet ! Very passive voice and clearly spoken..thank you
Thank you JoulesperCoulomb - Another superbly well explained and thorough repair. Cheers!!
Your the best, please put more videos like this out.
Very nice narration, and very thorough testing of all circuits. I have the HA-4700, I actually prefer it to STK amplifiers, although this one does seem a little better constructed. You now have a new subscriber, love your work mate.
Clear and wonderfully explained. Thanks!
Great repair video - many thanks.
Cheers, John
Always a brave moment to short the speaker outputs hoping the short circuit protection works OK, can be expensive if it does not!!
Thanks for these videos,I appreciate
Nice job on the LED retrofit. My first reaction was that 20ma was more than necessary, but it does seem that you get a brightness on the panel indicators close to matching the original brightness which I think is a worthy goal.
thanks, I have same ampli but i dont have sound out, no relay click , led of power is off but other leds of tape aux phono are on
Hi, great video, could you tell me where you found the "Service Manual". I have a Hitachi HA-300 amplifier that I need a service manual for. One channel not working. Thanks BK
Bought a vintage hitachi amp but it doesnt sound like it used to.Used to hear more bass and detail in the music. Would a service improve it?
Hi there I've got a ha2700 it makes static sounds when I turn balance treble and bass. Could I squirt contact cleaner on them from the inside? Thank you
Impressive videos by the way
Pretty puny relay and power caps for a power output of 77W per channel. Otherwise, an impressive attention to detail for the circuits and features of this amplifier.
Hello my friend , i have that amplifier and only phono input works do you have schematics to send me
Xin chào ban, mình ở Việt nam hiện mình có 1 cái HA- 4800 còn hoạt động nghe nhạc bình thường hệ thống đèn yếu
I like blue indicator lights myself, and use a resistor
Where can I contact this gentleman to see if he will carry out some servicing . Thanks
+Music Fan Send me a message via the form at zx.zigg.net .
No videos for 3 years....I hope you are well and OK.
I've sent another message via the link you sent and I've made sure the email address is correct
Brilliant =)
Hi still no email it's listed below unless I'm missing something
25:01 Without any problems?... It sounds like you fell into a goldfish bowl... Now that's a problem!
Lord Xelous The acoustics of that corner of the room aren't very good. It didn't sound nearly so bad as the recording suggests, though.
I think that 20mA is too much.
I assume you mean for the LED current. The LED datasheet specifies them for normal operation at 20 mA and states their maximum permitted forward current is 30 mA. The selection indicators do appear very bright, though, so there would be scope to reduce the current a bit.
+JoulesperCoulomb The brightness was rather bold :-)
Hi I've sent you a message
+Music Fan I've received what I believe is your message, but you didn't enter a valid e-mail address and so I cannot reply.