I love these small size period amplifiers. I'm in a small room and all I use is a Pioneer SA-5300 that I refurbished, and it sounds lovely. Very basic, easy to repair, great sound, plenty of volume for normal listening. You can't help but love those big silver control knobs either.
Hey Dave I have the HA-250 one below this (doesn’t have meters) and despite being fairly low power it is a very sweet sounding amp. The fusible resistors hitachi used often drift big time and cause problems. Mine is due a service.
Great fix as always Dave, I've always been a huge fan of Amplifiers and Receivers that have VU meters, It's such a shame that modern day amps etc don't use them anymore.
I've got a Daiwa SS330W power supply I use for my home base HF radio. The meters in that unit had no lighting at all, so I installed a LED globe between the meters. I used solid core wire to support the globe. The result is great. I can read the meters no problem now.
Nice job, and another amp saved from a possible fire. Small power but quality sufficient for small rooms with a pair of high efficiency speakers. These meters are a real deal with these LED strips. It's a relatively easy thing to do when you have plenty of space. When the old coloring plastics are burnt, you can use colored LEDs, or glue small parts of color filters. Another solution is to use some nail varnish, but blue or green are not specially easy colors to find.
I replaced a few with series chains of 3mm green LED's soldered together in strips of 5, to get close to 12V, and then a series resistor to trim current to desired brightness. Lasts longer than the incandescent lamp and green silicone sock, and the green is very close to the original as well, and no more hot spot.
Hitachi did make some good stuff nice work with the led,s they look good i put normal bulbs in my kenwood as it was easy to do but the bulbs themselves are not always easy to find replacements for i got mine from germany with the green filter led,s look perfectly fine .
Picked up a HMA9500 from the scrapyard, and of course it was there for a reason, one channel cooked more than the other. SRBP boards all well toasted, and I really did not need a 2kW room heater, so stripped it apart, and took it back to the scrapyard as a collection of scrap metal instead, and made some small profit. Have been using parts of it elsewhere though, especially the big 15000uF capacitors, they came in handy for replacing other dead ones. One channel slowly rising DC offset till it went into protection, with the lamp lighting. Still got the mosfets though, the linear ones are not easy to get, might even use them as well. All the fuses were intact on it, and all original, just the brown boards were all cooked almost black.
Are the screws holding the meters' back side through the clear lens, or they are screwed into the clear lens? If they are screwed into the lens, it might be possible to pop the meter apart, leaving the lens in the front panel. But it doesn't matter too much, because the external LED strip worked a treat! It's a very dumb design if the bulbs are not replaceable in the meters, not even together with the meters. I'm a bit tempted to take a look at the service manual, but I'm too tired and lazy to do so now.
OK, I couldn't resist, and downloaded the service manual. Interesting. Accoding to the schematic, the original bulbs are 12V 55mA with two paralelled 330ohm resistors in series with them. But the parts list does not list the bulb as replacement part, while it does list the meter as a replacement part! So the bulb is supposedly not replaceable in the meter, but the meter itself should be replacable according to the manual. Of course no one would throw away a perfectly working meter because of a blown bulb. If it can be removed, the bulb can be replaced, it's just not the 'official' way according to Hitachi. But how on Earth they want the meter to be removed without ruining the front panel? Some designer drank a bit too much sake the other day...
Have seen stuff like that once in awhile. There will be part numbers for each part of an assembly, but with note that you have to order the whole assembly and can't get individual parts.
Can I ask why you didn't use something like hot glue to affix the LEDs instead of the tape? Would the glue melt from internal heat? Just wondered. I would have done it and wanted to know if you think it would have held up.
The led strip won't go anywhere. No heat to worry about. Tape is more than good enough. If you have ever tried to unwrap a wire that had been taped up years ago you will know what I am talking about. Hot glue would work too but tape is easier to remove if adjustment is needed.
The build quality dates this amp, this was made when the japanese showed the rest of the world how to make gear that looked good as well as sounding good. Here in the UK we knew how make good sounding amps, but the build quality was terrible compared to the ones from Japan. These old amps are a pleasure to work on compared to the latest gear with takes days to get access to faulty parts, then you can't test it until it is all back togeather, only to find that you have more faults. As they saying goes "They don't make them like this anymore"
@@theanimatronicscollectoran4193 The Japanese gear from the 70's was built to last, and are far easier to repair than the latest models. I was a young Hi-Fi tech in that era, and still have a number of Pioneer receivers that were left for repair, but the customers refused our quotes and failed to collect them. I paid for the parts, and they are all in full working order, all they need is a little tlc on the switches and pots and the odd new bulb that are easy to replace unlike this Hitachi with embeded bulbs.
I like the fact that a lot of people (including myself) are holding on to thier vintage audio equipment because now new audio equipment is becoming more than expensive .
Yes I have a fair bit of vintage gear myself. It's only as expensive as people are willing to pay for it. A year ago a sansui 9090 was selling for 1900 at the vintage stereo shop and I see they have one now for 900. That's a 1000 drop in a year. Should have sold mine when the price was high 😒. I played in crypto a few years ago. I made a little and got out before it went up. Should have held out but got nervous and bailed. Lots got greedy and they are paying they price now. I learned my lesson as did many others with Nortel.
@@TD75 I did a little better than that I got in around 11:00 and got out around 30. Yes I know people that held on a little too long and they're now feeling the pain.
I was thinking warm white LED's as soon as you mentiond the screws, LOL. They will outlast the amp. I've always found Hitachi to be very reliable, but with odd design choises at times.
In the ‘Hifi Engine’ Hitachi HA-270 service manual, there is a picture of the front were the faceplate is removed, so there is a normal way to remove it.
Just fixed one of the low power receivers, 25 watts per channel, fuse protected speaker outputs. Left channel blown fuse, no left channel, Pioneer SX-636. Flakey bias trimmer pots, got them cleaned and bias set, and been running it for a couple of days now. Checked the Capacitor ESR and tested very low, so I am not changing them, however here is the sad part: Unit is unplugged, rail caps discharged, the capacitor I was trying to test by clipping on these stupid alligator clips with rubber booties over them to the leads on the component side. I did short out the capacitor under test prior to hooking up the ESR tester. The clip popped off the lead of the capacitor and briefly shorted out the metal bodied pre driver transistor collector to the base lead and sent a sparky pop! There is a -40v power supply that was still charged (I was not concerned about it) and sent that right to the base of the driver transistor 2SA777 and damaged it. (note: edit, clarified what was shorted) I was smart enough to hook a 60 watt dim bulb up prior to turning it on, because the light bulb lit up and the right channel was humming. Got the KSA1013YTA on order from Mouser, I hope that is the correct replacement. Will order the complement set as well, they are cheap enough @ 43 cents each. KSC2383YTA is the replacement for the 2SC1509 NPN. The originals are 1 watt and the new ones are 900mW, which I don't think will be a problem. Enjoyed the video Dave, just do what you do the way you do it. Use your own best judgement, and some common sense and never mind the armchair quarterbacks that don't work on this stuff themselves.
@@12voltvids I've also seen machine screws and pieces of small copper tubing stuck where the fuses should have been. That is about as dangerous as putting pennies in those old glass plug fuse panels lol.
Sadly, solid state storage such as sdcard and/or usb stick don't last as long, and usually corrupted video's and/or audio can be recovered with FFmpeg. Many would stick their files on usb stick that were given out for free at shows, and wonder their files become corrupted. That fuse placement is literally so dumb, and can't decide what's worse a wire soldered across the fuse or the wrong fuse type. When I was 1st getting into electronic's at young age had learned the hardway to always use the correct fuse.
Not a bad basic amplifier, hitachi made some decent products. Not super duper hi-fi but quite usable. Yes the meter screws are a stupid design, i've seen that with c.b radios where the screws that hold the front panel switches in are behind a thin brushed aluminium facia plate. Very short sighted manufactures :-(
Fact, you don't need as much power as you think. The big problem is big amplifiers, at least many of them are not real clean at low power. So the solution make your speakers very inefficient so you need more power to drive the speakers as at higher power levels the crossover distortion is greatly reduced. So in the late 70s and early '80s manufacturers got into a power war to see who could outdo the other for sheer power. Reality check nobody needs more than about 40 watts per channel with a pair of half decent efficient speakers. That's all I run on my main music system for my vacuum tube amp into some relatively efficient B&W speakers. Sometimes I'll put my sb7000s on it. The sound is fantastic and I can rattle all the China in the china cabinet with only 45 per channel. My friend thinks he needs 1,500 watts per channel and he has it with some huge but very inefficient speakers and he's probably driving 2 to 300 w just to listen at a comfortable level but not really any louder than I'm getting out of my efficient speakers at 30 Watts.
@@12voltvids Yes i know about the sensitive and insensitive speakers. A 5 watt per channel amplifier can sound loud enough with sensitive speakers. The insensitive speakers i call disco speakers.
Wow! They just threw in any size fuse and thought they could just call it a day lol. Most of the time just changing the fuse isn't going to fix it. If a fuse is blown there's usually a reason. Fuses just don't blow out like light bulbs do from excessive use. Anytime I find a blown fuse, I'll check continuity of the circuit and then I'll put an ammeter in place of the fuse to see how many amps it's pulling and if it's pulling more than what the rating calls for, that'll tell me that something else is wrong.
Fuses do fail due to repeated stress or shorted speaker wires. The idea is to have a fuse with a lower rating than the max current of the transistors. Under an overload the fuse pops. Put in a larger fuse and guess what goes pop first.
Good work around, taking a chance removing that aluminum face would of caused some bending, ouch! PS I like when you call shoe maker repairers "Boneheads"! I got others names but I guess we all need to keep it PG here!
We used to call my grade 8 electronics teacher Mr Bonehead. I guess I can get away with saying that now because that was 45 years agoand I think he was probably pushing about 60 at the time so I'm sure he's no longer around.
@@12voltvids I am sure you see it all if I were to ask what the craziest repair you have seen you would not be able to pick one I am grateful that you are here it helps a guy like me to understand and not be scared to try a new way to fix an issue that can be fixed in other ways If you ever have a stereo reel deck that has auto reverse playback and in reverse both right channels are playing in reverse play and show how to fixit I have that issue with my teac a-4010-sl I would just like to make a request when you have a deck with this issue thank you for such a great channel and showing and sharing your talent jon
So what caused the problem? The dummy putting in a wrong fuse! Wow he probably had a bad speaker and it kept blowing the fuse so he tried a bigger one and the wrong one on top of that! Boy that could have blown more things up in that amp as well but lucky it didn't Nice fix!
All these old amps have shitty speaker connections. Basically metal screws. Very easy to cause a short The transistors usually never blow because the outputs have a higher rating then the protection fuse.
I love these small size period amplifiers.
I'm in a small room and all I use is a Pioneer SA-5300 that I refurbished, and it sounds lovely.
Very basic, easy to repair, great sound, plenty of volume for normal listening.
You can't help but love those big silver control knobs either.
Hey Dave I have the HA-250 one below this (doesn’t have meters) and despite being fairly low power it is a very sweet sounding amp. The fusible resistors hitachi used often drift big time and cause problems. Mine is due a service.
Great fix as always Dave, I've always been a huge fan of Amplifiers and Receivers that have VU meters, It's such a shame that modern day amps etc don't use them anymore.
Hitachi made some beautiful hifi components, I liked their minidisc recorders
I've got a Daiwa SS330W power supply I use for my home base HF radio. The meters in that unit had no lighting at all, so I installed a LED globe between the meters. I used solid core wire to support the globe. The result is great. I can read the meters no problem now.
Dave, Great job, the led stripes’ color is beautiful, life is much longer than original bulbs.
I'm pretty happy how they look. Very close to original.
Nice job, and another amp saved from a possible fire.
Small power but quality sufficient for small rooms with a pair of high efficiency speakers.
These meters are a real deal with these LED strips. It's a relatively easy thing to do when you have plenty of space. When the old coloring plastics are burnt, you can use colored LEDs, or glue small parts of color filters. Another solution is to use some nail varnish, but blue or green are not specially easy colors to find.
I replaced a few with series chains of 3mm green LED's soldered together in strips of 5, to get close to 12V, and then a series resistor to trim current to desired brightness. Lasts longer than the incandescent lamp and green silicone sock, and the green is very close to the original as well, and no more hot spot.
Hitachi did make some good stuff nice work with the led,s they look good i put normal bulbs in my kenwood as it was easy to do but the bulbs themselves are not always easy to find replacements for i got mine from germany with the green filter led,s look perfectly fine .
Picked up a HMA9500 from the scrapyard, and of course it was there for a reason, one channel cooked more than the other. SRBP boards all well toasted, and I really did not need a 2kW room heater, so stripped it apart, and took it back to the scrapyard as a collection of scrap metal instead, and made some small profit. Have been using parts of it elsewhere though, especially the big 15000uF capacitors, they came in handy for replacing other dead ones. One channel slowly rising DC offset till it went into protection, with the lamp lighting. Still got the mosfets though, the linear ones are not easy to get, might even use them as well. All the fuses were intact on it, and all original, just the brown boards were all cooked almost black.
Are the screws holding the meters' back side through the clear lens, or they are screwed into the clear lens? If they are screwed into the lens, it might be possible to pop the meter apart, leaving the lens in the front panel. But it doesn't matter too much, because the external LED strip worked a treat! It's a very dumb design if the bulbs are not replaceable in the meters, not even together with the meters. I'm a bit tempted to take a look at the service manual, but I'm too tired and lazy to do so now.
OK, I couldn't resist, and downloaded the service manual. Interesting. Accoding to the schematic, the original bulbs are 12V 55mA with two paralelled 330ohm resistors in series with them. But the parts list does not list the bulb as replacement part, while it does list the meter as a replacement part! So the bulb is supposedly not replaceable in the meter, but the meter itself should be replacable according to the manual. Of course no one would throw away a perfectly working meter because of a blown bulb. If it can be removed, the bulb can be replaced, it's just not the 'official' way according to Hitachi. But how on Earth they want the meter to be removed without ruining the front panel? Some designer drank a bit too much sake the other day...
Have seen stuff like that once in awhile. There will be part numbers for each part of an assembly, but with note that you have to order the whole assembly and can't get individual parts.
1:42 - Why blow a perfectly good fuse? :)
Can I ask why you didn't use something like hot glue to affix the LEDs instead of the tape? Would the glue melt from internal heat? Just wondered. I would have done it and wanted to know if you think it would have held up.
The led strip won't go anywhere. No heat to worry about. Tape is more than good enough. If you have ever tried to unwrap a wire that had been taped up years ago you will know what I am talking about. Hot glue would work too but tape is easier to remove if adjustment is needed.
@@12voltvids THanks for your wisdom
@@12voltvids hot glue is also easy to remove, all you need is IPA. It literally slides right off after soaking it a bit with a q-tip.
The build quality dates this amp, this was made when the japanese showed the rest of the world how to
make gear that looked good as well as sounding good.
Here in the UK we knew how make good sounding amps, but the build quality was terrible compared
to the ones from Japan.
These old amps are a pleasure to work on compared to the latest gear with takes days to get access to
faulty parts, then you can't test it until it is all back togeather, only to find that you have more faults.
As they saying goes "They don't make them like this anymore"
I have a Pioneer amp and that thing is 50 years old. And still working.
@@theanimatronicscollectoran4193 The Japanese gear from the 70's was built to last, and are far easier
to repair than the latest models.
I was a young Hi-Fi tech in that era, and still have a number of Pioneer receivers that were left for repair, but the customers
refused our quotes and failed to collect them.
I paid for the parts, and they are all in full working order, all they need is a little tlc on the switches and pots and the odd new
bulb that are easy to replace unlike this Hitachi with embeded bulbs.
I like the fact that a lot of people (including myself) are holding on to thier vintage audio equipment because now new audio equipment is becoming more than expensive .
Yes I have a fair bit of vintage gear myself.
It's only as expensive as people are willing to pay for it. A year ago a sansui 9090 was selling for 1900 at the vintage stereo shop and I see they have one now for 900. That's a 1000 drop in a year. Should have sold mine when the price was high 😒.
I played in crypto a few years ago. I made a little and got out before it went up. Should have held out but got nervous and bailed. Lots got greedy and they are paying they price now.
I learned my lesson as did many others with Nortel.
@@TD75 I did a little better than that I got in around 11:00 and got out around 30. Yes I know people that held on a little too long and they're now feeling the pain.
I was thinking warm white LED's as soon as you mentiond the screws, LOL. They will outlast the amp.
I've always found Hitachi to be very reliable, but with odd design choises at times.
I got given a top-loading Hitachi VCR many years ago that had that stuck-down aluminium. It was covered in dents!
You're a genius. Love your videos. Pity I can only just about clean tape heads and rollers lol
Another fantastic work-around !
Dave, I'm surprised that the fuse didn't have alum. foil wrapped around the old one.
In the ‘Hifi Engine’ Hitachi HA-270 service manual, there is a picture of the front were the faceplate is removed, so there is a normal way to remove it.
It's glued on. Good luck removing it without scratching it.
Very Creative as always
Just fixed one of the low power receivers, 25 watts per channel, fuse protected speaker outputs. Left channel blown fuse, no left channel, Pioneer SX-636.
Flakey bias trimmer pots, got them cleaned and bias set, and been running it for a couple of days now. Checked the Capacitor ESR and tested very low, so I am not changing them, however here is the sad part:
Unit is unplugged, rail caps discharged, the capacitor I was trying to test by clipping on these stupid alligator clips with rubber booties over them to the leads on the component side. I did short out the capacitor under test prior to hooking up the ESR tester. The clip popped off the lead of the capacitor and briefly shorted out the metal bodied pre driver transistor collector to the base lead and sent a sparky pop! There is a -40v power supply that was still charged (I was not concerned about it) and sent that right to the base of the driver transistor 2SA777 and damaged it. (note: edit, clarified what was shorted)
I was smart enough to hook a 60 watt dim bulb up prior to turning it on, because the light bulb lit up and the right channel was humming. Got the KSA1013YTA on order from Mouser, I hope that is the correct replacement. Will order the complement set as well, they are cheap enough @ 43 cents each. KSC2383YTA is the replacement for the 2SC1509 NPN. The originals are 1 watt and the new ones are 900mW, which I don't think will be a problem.
Enjoyed the video Dave, just do what you do the way you do it. Use your own best judgement, and some common sense and never mind the armchair quarterbacks that don't work on this stuff themselves.
I remember seeing a 80's sanyo stereo on ebay with aluminum foil in the back for the speaker fuses.
Quality engineering right there 🤣
I used to see fuses wrapped with cigarette paper foil come into the shop.
@@12voltvids I've also seen machine screws and pieces of small copper tubing stuck where the fuses should have been. That is about as dangerous as putting pennies in those old glass plug fuse panels lol.
Proud of you!
Sadly, solid state storage such as sdcard and/or usb stick don't last as long, and usually corrupted video's and/or audio can be recovered with FFmpeg. Many would stick their files on usb stick that were given out for free at shows, and wonder their files become corrupted.
That fuse placement is literally so dumb, and can't decide what's worse a wire soldered across the fuse or the wrong fuse type. When I was 1st getting into electronic's at young age had learned the hardway to always use the correct fuse.
USB sticks and memory cards can be corrupt by unplugging them without first clicking on remove safely. That is what i suspect she did.
Excellent as usual 🤙
Certain Onkyo amplifiers from the 80s are so had speaker fuses I have one of the Onkyo model 80 I don't remember the rest of the model
Interesting videos as always!
Not a bad basic amplifier, hitachi made some decent products.
Not super duper hi-fi but quite usable.
Yes the meter screws are a stupid design, i've seen that with c.b radios where the screws that hold the front panel switches in are behind a thin brushed aluminium facia plate.
Very short sighted manufactures :-(
Fact, you don't need as much power as you think. The big problem is big amplifiers, at least many of them are not real clean at low power. So the solution make your speakers very inefficient so you need more power to drive the speakers as at higher power levels the crossover distortion is greatly reduced. So in the late 70s and early '80s manufacturers got into a power war to see who could outdo the other for sheer power. Reality check nobody needs more than about 40 watts per channel with a pair of half decent efficient speakers. That's all I run on my main music system for my vacuum tube amp into some relatively efficient B&W speakers. Sometimes I'll put my sb7000s on it. The sound is fantastic and I can rattle all the China in the china cabinet with only 45 per channel. My friend thinks he needs 1,500 watts per channel and he has it with some huge but very inefficient speakers and he's probably driving 2 to 300 w just to listen at a comfortable level but not really any louder than I'm getting out of my efficient speakers at 30 Watts.
@@12voltvids Yes i know about the sensitive and insensitive speakers.
A 5 watt per channel amplifier can sound loud enough with sensitive speakers.
The insensitive speakers i call disco speakers.
Wow! They just threw in any size fuse and thought they could just call it a day lol. Most of the time just changing the fuse isn't going to fix it. If a fuse is blown there's usually a reason. Fuses just don't blow out like light bulbs do from excessive use. Anytime I find a blown fuse, I'll check continuity of the circuit and then I'll put an ammeter in place of the fuse to see how many amps it's pulling and if it's pulling more than what the rating calls for, that'll tell me that something else is wrong.
Fuses do fail due to repeated stress or shorted speaker wires. The idea is to have a fuse with a lower rating than the max current of the transistors. Under an overload the fuse pops. Put in a larger fuse and guess what goes pop first.
Good work around, taking a chance removing that aluminum face would of caused some bending, ouch!
PS I like when you call shoe maker repairers "Boneheads"! I got others names but I guess we all need to keep it PG here!
We used to call my grade 8 electronics teacher Mr Bonehead. I guess I can get away with saying that now because that was 45 years agoand I think he was probably pushing about 60 at the time so I'm sure he's no longer around.
👍👍👍👌
you will get better sound reproduction if you use a all brass screw as a fuse >:)
Wow what morons putting in that fuse leave. It to you to fix it you can do it all great job jon
See this all the time.
@@12voltvids I am sure you see it all if I were to ask what the craziest repair you have seen you would not be able to pick one I am grateful that you are here it helps a guy like me to understand and not be scared to try a new way to fix an issue that can be fixed in other ways If you ever have a stereo reel deck that has auto reverse playback and in reverse both right channels are playing in reverse play and show how to fixit I have that issue with my teac a-4010-sl I would just like to make a request when you have a deck with this issue thank you for such a great channel and showing and sharing your talent jon
So what caused the problem? The dummy putting in a wrong fuse! Wow he probably had a bad speaker and it kept blowing the fuse so he tried a bigger one and the wrong one on top of that! Boy that could have blown more things up in that amp as well but lucky it didn't Nice fix!
All these old amps have shitty speaker connections. Basically metal screws. Very easy to cause a short
The transistors usually never blow because the outputs have a higher rating then the protection fuse.
hit-o-chi
Nothing on the left - sounds about right. Everything on the left is broken.