hi, I destroyed the volume potentiometer of my 7800 ... could you tell me if it is possible to find a spare one? or if you know some alternative product that can be good ???
I have the same problem which those blue equalizer lights doesn’t move anymore when I play the MP3,I don’t know if the relay or the display board is the problem with my 7800 amplifier,I would appreciate if u can tell me if I need to replace the relay to make it work again.Anyone suggestions would be appreciated thank u!
@@SevenFortyOne it could be the relay or the power capacitors,I’m guessing.I order the relay already,So I’ll start from there then if still don’t work I’ll go for the 2 capacitors to be replace.
@@YT32-16branch yeah, he not, i got a SA7800 unit like years ago, the old man who i got the amplifier from, told me that it was at his friend for service, and he opened up the amplifier before use and he thought that is too dodgy, so he sent it to me to do whatever i can, like amplifier were gone, the service have done its own diy amplifier out of the driver transistor, and there were heating caps everywhere, the main filter caps were all bulgy, and the amplifier was only made a meter spark. Vu meter was all gone cause of the good service guy accidentally gave direct dc at the wrong location. So i fixed mine, recapped, i rewired the transformers, cause at this point all the transistors were gone and i only able to get Bc639 & bc640 which is lower voltage rated thus i got 2SC4793 & 2SA1837 for the drivers that were closest available, and for power, i got 2SC3519 & 2SA1386, i have put 2 on each side of the amplifier, so i have 4 output transistors/ch. so i rewired the transformer to give out +-32dc i recapped whatever i had locally, (Elite caps, and some of Nichicons that was available.) I completly rebuilt the VU from led, works like original, looks like original, cause i was aware that i want those leds to be at the same positions as the original were, just the marking missing like, (tape, phono, tuner, aux, L, W8Ohm, R, 0.001, 0.01, 0.1, 1, 10, 80) those lights are absent from my board sadly. i was unable to do that, amplifier is assembled. I have a little hum, those days im on hum hunt! Thats pretty sad that the service guy have messed up the unit so bad, but i got the unit for completly free, so i cannot complain i guess.
@@SevenFortyOne Thanks I will try it. One guy sells this one with changed transistors and I'm thinking about the deal. He told me that it sounds like the original which he has in his colection. Can an amp with changed transistors sound like one with original ones?
@Chaim Uriah DAMN IT ACTUALLY WORKED! I just got access to my IG account within about 45 mins of using the site. Just had to pay 15$ but definitely worth the price =) Thanks so much, you saved my account!
hi, I destroyed the volume potentiometer of my 7800 ... could you tell me if it is possible to find a spare one? or if you know some alternative product that can be good ???
I have the same problem which those blue equalizer lights doesn’t move anymore when I play the MP3,I don’t know if the relay or the display board is the problem with my 7800 amplifier,I would appreciate if u can tell me if I need to replace the relay to make it work again.Anyone suggestions would be appreciated thank u!
I can't really tell you what's wrong. You'll have to get the schematic and try to figure it out on your own
@@SevenFortyOne it could be the relay or the power capacitors,I’m guessing.I order the relay already,So I’ll start from there then if still don’t work I’ll go for the 2 capacitors to be replace.
@@vintagestereocollector4159 Sounds like you have no clue of what you are talking about...
@@YT32-16branch yeah, he not, i got a SA7800 unit like years ago, the old man who i got the amplifier from, told me that it was at his friend for service, and he opened up the amplifier before use and he thought that is too dodgy, so he sent it to me to do whatever i can, like amplifier were gone, the service have done its own diy amplifier out of the driver transistor, and there were heating caps everywhere, the main filter caps were all bulgy, and the amplifier was only made a meter spark.
Vu meter was all gone cause of the good service guy accidentally gave direct dc at the wrong location.
So i fixed mine, recapped, i rewired the transformers, cause at this point all the transistors were gone and i only able to get Bc639 & bc640 which is lower voltage rated thus i got 2SC4793 & 2SA1837 for the drivers that were closest available, and for power, i got 2SC3519 & 2SA1386, i have put 2 on each side of the amplifier, so i have 4 output transistors/ch. so i rewired the transformer to give out +-32dc i recapped whatever i had locally, (Elite caps, and some of Nichicons that was available.) I completly rebuilt the VU from led, works like original, looks like original, cause i was aware that i want those leds to be at the same positions as the original were, just the marking missing like, (tape, phono, tuner, aux, L, W8Ohm, R, 0.001, 0.01, 0.1, 1, 10, 80) those lights are absent from my board sadly. i was unable to do that, amplifier is assembled.
I have a little hum, those days im on hum hunt!
Thats pretty sad that the service guy have messed up the unit so bad, but i got the unit for completly free, so i cannot complain i guess.
What do you use to clean it
+Tyler Cook I cleaned the outside with Windex and used Deoxit (electronic contact cleaner) on the inside of the switches and controls.
Thank you!, another question, where can you get these relays? I have a pioneer amp SA-750.
+Tyler Cook Mouser or DigiKey are probably your best bet...
So if I plug my pioneer amp into 220 volts will it go twice as loud ?
พัง...
What make are these transistors?
I don't remember. But if you search for the service manual it should be listed in there
@@SevenFortyOne Thanks I will try it. One guy sells this one with changed transistors and I'm thinking about the deal. He told me that it sounds like the original which he has in his colection.
Can an amp with changed transistors sound like one with original ones?
I don't know if you would notice a difference if he used quality parts. It depends on if the new transistors have the same specs as the old
@@SevenFortyOne Thanks for the fast answer. I will listen to both an if I don't like it the guy sells Sa 708 too :D
@@tropikfare Power-Transiwstors have no effect on the sound.
PIONEER OMEGA. EL PROFESIONAL.
@Chaim Uriah DAMN IT ACTUALLY WORKED! I just got access to my IG account within about 45 mins of using the site.
Just had to pay 15$ but definitely worth the price =)
Thanks so much, you saved my account!
@Sam Dayton you are welcome :)