Hi, Your videos have a lot going for them, the production is quite polished, so I encourage you to keep going. Only thing, really the only thing that detracts from them, as others have already mentioned in some of your other videos....is that the sound level is way too low...which is quite ironic from someone who appears to be an audio nut ! ;-) I mean I am watching your videos on my phone, because no other choice at the moment, and I can barely hear what you say even with the volume cranked 100%, in a very quiet room. I guess that would be easy to fix ! :-) Keep up the good work
wow...great video...keep it up...i believe your videos are the best because of your use of the schematics...could you tackle a peavey GPS3500 next? they are a beast....find one with blown power transistors on one or both channels...it is very hard to troubleshoot....
I've analyzed the schematic for the power supply and, other than a really primitive temperature and peak-current limiter for the supply chopper transistors, there is not much protection circuitry. That means that, as long as the power supply can shove a lot of current into the power amplifiers without overheating and without exceeding the rating of the transistors, it will do it indefinitely until something gives. In this case, it kept sending power through the transformer to the secondary but, due to the shorted load on the secondary, the rails didn't raise to a voltage high enough for the soft-start relay to make, consequently burning up the soft-start resistors.
The plastic is pretty conductive for heat. Think of it as a thermal pad but smaller and more electrically isolating. At least that is my understanding, someone can correct me if I am wrong.
I have a Yamaha P7000 which I am facing a big problem when I turned it on it sent a big spike to the speakers and I need your help for this issue many thanks
hi sir am a DIY repair man, i have a yamaha XP2500 the protection light was on, can you help me to locate the problem because i have no idea. thank you . new sub.
Eugene, Sorry I've never worked on the Crown Xti 4002, nor have I worked on any units that communicate with a PC. If you'd like to discuss more, please send me an email. nick@duality-er.com
I have the same amp, just had it repaired a few days ago, 2 transistors had blown costing almost £20, i bought the amp 17 years and i have used it almost every day, i would call that very reliable )
It's has the same idea but more advanced. It has variable power rails instead of multiple rails It looks like a hybrid between class D and class AB. The power supply changes its voltage output along with the audio signal. But in switch mode pwm style.
It's the small square shaped component with a yellow top just in front of the bulk capacitors. Yamaha used a switching power supply vs. a linear power supply in this unit so they could get away with a smaller transformer.
A class D amplifier powered by a switching power supply. Can one think of a worse setup? A class A/B amplifier powered by a linear power supply basically lasts forever. These switching turds fail by just looking at them.
@@KneppaH class g is the correct term i think for this setup as the output gets closer to clip the voltage rails rise to stay just above + and below - mimicking the audio output, class h just switches the rails at higer set points as they get close to the set clip points 👍🏻 class g is almost infinitely variable up to the power supplies maximum available power where class h is switched in 2 3 sometimes 4 stages
I'm a electronics tech myself and totally agree 👍with how each stage is checked.
Very good fault finding skills..
one of the best troubleshooting videos ive ever come across.... step by step.... lovely
Great work sir. Logical step by step fault fiding and repair. I learned a lot. Thank you
I know im a few years late here, great vid. I own 2 of these amps and they are excellent.
Excellent repair! My humble thanks.
Excellent work 👍
Thanks for this video im planing to buy this kind of model. This help a lot. Thank you... 73...
graciass amigo!!
Hi,
Your videos have a lot going for them, the production is quite polished, so I encourage you to keep going. Only thing, really the only thing that detracts from them, as others have already mentioned in some of your other videos....is that the sound level is way too low...which is quite ironic from someone who appears to be an audio nut ! ;-)
I mean I am watching your videos on my phone, because no other choice at the moment, and I can barely hear what you say even with the volume cranked 100%, in a very quiet room.
I guess that would be easy to fix ! :-)
Keep up the good work
wow...great video...keep it up...i believe your videos are the best because of your use of the schematics...could you tackle a peavey GPS3500 next? they are a beast....find one with blown power transistors on one or both channels...it is very hard to troubleshoot....
Thanks for the feedback. I'm looking into buying a broken GPS 3500. If I can get it for the right price I'll buy/repair & put up the video.
@@dualityrepair4770 my i know your good name please
I've analyzed the schematic for the power supply and, other than a really primitive temperature and peak-current limiter for the supply chopper transistors, there is not much protection circuitry. That means that, as long as the power supply can shove a lot of current into the power amplifiers without overheating and without exceeding the rating of the transistors, it will do it indefinitely until something gives. In this case, it kept sending power through the transformer to the secondary but, due to the shorted load on the secondary, the rails didn't raise to a voltage high enough for the soft-start relay to make, consequently burning up the soft-start resistors.
goooooooooood job
Can you tell me how to adjust the bias on this amP? 1 channel seems to be lower than the other unless i parallel the input and then its equal .
me puedes ayudar de como funciona su interruptor :´c
Great job, I have a power cerwin vega cv5000 won’t turn on at all can you help me please?
I always get the OnSemi equivalent output transistors
Can you make a video of the dummy load and how to build one
where did u get the resistors
How to make power suply 110v to 220v.information please
Thanks for the video , I have the same video. BUT one channel is not working
Any chance you can share the schematic of this amp please?
Can you show me why the fan is not working and no sounds but the power is on
How does insulating the transistor from the heat sink allow heat to be effectively dissipated?
The plastic is pretty conductive for heat. Think of it as a thermal pad but smaller and more electrically isolating. At least that is my understanding, someone can correct me if I am wrong.
Please make a video yamaha Rx-v795a amplifier standby power on problem.🙏🙏🙏
Suresh, if I could find one of those units with that problem, I’d gladly make a video.
Мастер.
My YAMAHA P3500S is no signal,the power can on,no ptoteck but they are no sound,what wrong with it? thanks you.
ខ្ញុំកំពុងធ្វើតែធ្វើមិនដំនើរការទេ
I have a Yamaha P7000 which I am facing a big problem when I turned it on it sent a big spike to the speakers and I need your help for this issue many thanks
Hi Vincent, it’s best to email me so we can discuss in detail the issue you’re seeing. nick@duality-er.com
Already send you one email and waiting for your answer many thanks
@@vincenttony833 hi vincent. did you evet get the yamaha.fixed?
Can you fix my p5000s?
Tell me what operational amplifiers are in it? Company name ?
It wouldn't be great of you would show us how are you looking for shorts with multimeter
hi sir am a DIY repair man, i have a yamaha XP2500 the protection light was on, can you help me to locate the problem because i have no idea. thank you . new sub.
Hi my Crown Xti 4002 usb don't work the computer recognize it only as a unknown device this is on Win 7 and Win 10 tried everything and it wont work.
Eugene,
Sorry I've never worked on the Crown Xti 4002, nor have I worked on any units that communicate with a PC. If you'd like to discuss more, please send me an email. nick@duality-er.com
Is this a reliable amp in general?
Gives me nausea just looking at it’s layout!
Not sure. After the repair, I only tested it for a few hours before sending it back to the owner.
I have the same amp, just had it repaired a few days ago, 2 transistors had blown costing almost £20, i bought the amp 17 years and i have used it almost every day, i would call that very reliable )
Bonjour
What class is this?? Is this class h?
It's has the same idea but more advanced. It has variable power rails instead of multiple rails It looks like a hybrid between class D and class AB. The power supply changes its voltage output along with the audio signal. But in switch mode pwm style.
ito yung original na yamaha
Where is the Transformer?
It's the small square shaped component with a yellow top just in front of the bulk capacitors. Yamaha used a switching power supply vs. a linear power supply in this unit so they could get away with a smaller transformer.
@@dualityrepair4770 And a normal transformer wouldn't work with this amplifier design.
Please take off your ring - safety first!
A class D amplifier powered by a switching power supply. Can one think of a worse setup? A class A/B amplifier powered by a linear power supply basically lasts forever. These switching turds fail by just looking at them.
its a class a/b with a switching power supply 👍🏻 the sanken output transistors used give it away
@@antonyarchibold6127 And it's a bit like a class H but with variable voltage rails instead of a few fixed voltage rails.
@@KneppaH class g is the correct term i think for this setup as the output gets closer to clip the voltage rails rise to stay just above + and below - mimicking the audio output, class h just switches the rails at higer set points as they get close to the set clip points 👍🏻 class g is almost infinitely variable up to the power supplies maximum available power where class h is switched in 2 3 sometimes 4 stages
@@antonyarchibold6127 you're right. I often mix those to up.