Sapphire XS4600 Amplifier no power

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mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

lilviper wrote:
mbc230 wrote:
Silverhorse wrote:FDP55NO6 is a good replacement I think.
The color code of the resistors is difficult to see (I'm not so good with colors) I think it's orange / black / brown / gold than it is a 300 Ω 5% resistor.
Cut one leg of one resistor and than you can measure the resistor value with your multi meter. It should read 300 Ω.
It is actually a Brown Black Violet Gold Violet and it is a 5 band resistor. The multimeter I have purchased has blown fuses so I will check it when I get the new fuses. Thank you.
Fuses are typically for the current measurement, shouldn't affect the resistance measurement.

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The fuses inside my Fluke 83V were blown out so I installed some new ones and now it is reading correctly. Thank you.
lilviper
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Re: Sapphire XS4600 Amplifier no power

Post by lilviper »

mbc230 wrote:
lilviper wrote:
mbc230 wrote: It is actually a Brown Black Violet Gold Violet and it is a 5 band resistor. The multimeter I have purchased has blown fuses so I will check it when I get the new fuses. Thank you.
Fuses are typically for the current measurement, shouldn't affect the resistance measurement.

Sent from my SM-G988U using Tapatalk
The fuses inside my Fluke 83V were blown out so I installed some new ones and now it is reading correctly. Thank you.
You're welcome. Glad you learned something here. Fuses are required for current measurements only, and don't affect the resistance measurement.

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Silverhorse
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Re: Sapphire XS4600 Amplifier no power

Post by Silverhorse »

did you measure the gate resistors?
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Silverhorse wrote:did you measure the gate resistors?
Did you happen to see the color code I last posted and no I have not yet as I have been busy with other projects and work, but I will get to it. Thank you.
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

mbc230 wrote:
Silverhorse wrote:did you measure the gate resistors?
Did you happen to see the color code I last posted and no I have not yet as I have been busy with other projects and work, but I will get to it. Thank you.
So I de-soldered one side of the amp and measured the gate resistor and got 30.4 ohms according to the reading on my DMM. Did you also see the color code I put out on it? Thank you.
Silverhorse
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Re: Sapphire XS4600 Amplifier no power

Post by Silverhorse »

in previous post I was wrong :roll: with the 3 band. The 3th band is the multiplier number

the color code is orange / black / brown
orange = 3
black = 0
multiplier brown = 1
gold = 5% tolerance

so this is a resistor of 30 Ohm 5% resistor

the 5th band is brown, I don't know what this means, maybe others on the forum know this.

If you replace the 30 Ohm resistors and the fet's than see what happens when you power up the amp.
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Silverhorse wrote:in previous post I was wrong :roll: with the 3 band. The 3th band is the multiplier number

the color code is orange / black / brown
orange = 3
black = 0
multiplier brown = 1
gold = 5% tolerance

so this is a resistor of 30 Ohm 5% resistor

the 5th band is brown, I don't know what this means, maybe others on the forum know this.

If you replace the 30 Ohm resistors and the fet's than see what happens when you power up the amp.
I will buy the parts, but I want to make sure I am buying the right resistors as it is a 5 band. There is no orange on the resistor itself though. Does that even make a difference? Pardon my ignorance I am just trying to understand.
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

They are actually 30R1 (30.1Ω) 1% tolerance. The color bands are orange - black - brown - gold - brown. Few color bands shift a lot from heat soak and age. You sometimes have to pull them and look at the bottom, or look for one doing the same job in another part of the circuit. 9 times out of 10, if it's just discolored, you can just measure it with the meter. Resistors have to get stupid incredibly hot to change their value much. I've done a little demo on my fb group where I had some power resistors glowing red, their color bands were ash, I let them cool down and they still measured in spec!

I'm sorry I'm late to this party, but the one half of the supply is for sure toast as the others have said dollars to donuts the other side is stuffed too. It may still be functioning, but it's going to be a game of roulette. Fix it all and do it right and you won't have to do it 2 or 3 times.

That said, something caused the supply to die. There are basically two reasons they fail. A) the supply is starved for current, either due to inadequate power wiring, bad ground, or just terrible electrical. B) there is a fault in the poweramp that caused the power supply to try to supply to much current and self destructed.

In the second scenerio you are going to have to track down the failures in the poweramp. These amps were entry to mid tier amps when they were built, and they ended up seeing a lot of abuse just due to the budget ranking they fell into. A lot of younger inexperienced people bought them, and then tried to treat them like their high end brothers. You are more than likely going to have your work cut out for you.

Good luck!
Jason
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
Silverhorse
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Re: Sapphire XS4600 Amplifier no power

Post by Silverhorse »

thank you for passing by Jason!
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote:They are actually 30R1 (30.1Ω) 1% tolerance. The color bands are orange - black - brown - gold - brown. Few color bands shift a lot from heat soak and age. You sometimes have to pull them and look at the bottom, or look for one doing the same job in another part of the circuit. 9 times out of 10, if it's just discolored, you can just measure it with the meter. Resistors have to get stupid incredibly hot to change their value much. I've done a little demo on my fb group where I had some power resistors glowing red, their color bands were ash, I let them cool down and they still measured in spec!

I'm sorry I'm late to this party, but the one half of the supply is for sure toast as the others have said dollars to donuts the other side is stuffed too. It may still be functioning, but it's going to be a game of roulette. Fix it all and do it right and you won't have to do it 2 or 3 times.

That said, something caused the supply to die. There are basically two reasons they fail. A) the supply is starved for current, either due to inadequate power wiring, bad ground, or just terrible electrical. B) there is a fault in the poweramp that caused the power supply to try to supply to much current and self destructed.

In the second scenerio you are going to have to track down the failures in the poweramp. These amps were entry to mid tier amps when they were built, and they ended up seeing a lot of abuse just due to the budget ranking they fell into. A lot of younger inexperienced people bought them, and then tried to treat them like their high end brothers. You are more than likely going to have your work cut out for you.

Good luck!
Jason
WOW! Thank you for the great explanation Jason. I am ready to tackle it myself as this is for sure a learning experience for me. I got this amp in a lot of amps that I bought. I had to take those in order to get the one I wanted. I have no history on this amp at all. I bought it this way. So I thought I would use this one as a learning experience to try and fix it myself. I am by no means an expert, but I am willing to learn. I will purchase those parts and start there. What is the common thing that you described to look at after I replace these parts? I guess it could be a lot of things, but what could be the obvious things to check? Thank you very much and I appreciate your feedback really much along with Silverhorse.
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

That's a question I do not have time to fully answer, but in short, once you make repairs power the amp with a current limited supply. For this amp it should power up with as little as 2a available. Monitor current while it powers up. I personally monitor current any time an amp is powered on my bench and it's a very good habit to form. If the amp will not power up on a current limited supply, or if it powers up and draws the maximum current the supply can source, then it still has an issue. The current limiter will help keep your new parts from going up in smoke.

If it draws high current, chances are there are shorted outputs or faulty drive circuit. You can remove the rectifiers to isolate the poweramp from the power supply. If the high current goes away and the amp idles at less than ~1.5a for this model, then the power supply is now likely OK and the fault is after the rectifiers. Test the output transistors. In the xs amps they are mosfets so you will test like you tested the power supply fets. If you find a faulty output, you must replace it as well as all its parallel parts and their compliments. The xs uses either irf540/9540 pairs or irf640/9640 pairs. DO NOT REPLACE THEM WITH ANY PART WITH A SUFFIX OTHER THAN pbf. Irf640n/9640n or irf640z/9640z are not compatible and will work for a short time and then have spurious and random failures. The number one best advice for the xs and tantrum series amps is this, if you find a faulty output, it is best to rebuild the entire channel. The drivers and predrivers are extremely cheap parts. It's less than a few dollars to rebuild the channel. It's well worth it to save future headaches.

The #1 piece of advice I can give you overall is to buy Perry Babbin's guide. It has answers to nearly any question you will have and it starts from the absolute very beginning. From reading the stuff you were writing at the beginning of your thread, you have no understanding of what you are dealing with. I don't say this to be rude or discourage you, but rather to explain why the guide will be worthwhile. I've been doing repairs for more than 20 years and doing it full time for the last 3 or so now. I still sometimes consult his guide. It has info in it for every level of tech and it starts from the beginning, which is what you need. It will be the best $60 you could spend.

Good luck,
Jason
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote:That's a question I do not have time to fully answer, but in short, once you make repairs power the amp with a current limited supply. For this amp it should power up with as little as 2a available. Monitor current while it powers up. I personally monitor current any time an amp is powered on my bench and it's a very good habit to form. If the amp will not power up on a current limited supply, or if it powers up and draws the maximum current the supply can source, then it still has an issue. The current limiter will help keep your new parts from going up in smoke.

If it draws high current, chances are there are shorted outputs or faulty drive circuit. You can remove the rectifiers to isolate the poweramp from the power supply. If the high current goes away and the amp idles at less than ~1.5a for this model, then the power supply is now likely OK and the fault is after the rectifiers. Test the output transistors. In the xs amps they are mosfets so you will test like you tested the power supply fets. If you find a faulty output, you must replace it as well as all its parallel parts and their compliments. The xs uses either irf540/9540 pairs or irf640/9640 pairs. DO NOT REPLACE THEM WITH ANY PART WITH A SUFFIX OTHER THAN pbf. Irf640n/9640n or irf640z/9640z are not compatible and will work for a short time and then have spurious and random failures. The number one best advice for the xs and tantrum series amps is this, if you find a faulty output, it is best to rebuild the entire channel. The drivers and predrivers are extremely cheap parts. It's less than a few dollars to rebuild the channel. It's well worth it to save future headaches.

The #1 piece of advice I can give you overall is to buy Perry Babbin's guide. It has answers to nearly any question you will have and it starts from the absolute very beginning. From reading the stuff you were writing at the beginning of your thread, you have no understanding of what you are dealing with. I don't say this to be rude or discourage you, but rather to explain why the guide will be worthwhile. I've been doing repairs for more than 20 years and doing it full time for the last 3 or so now. I still sometimes consult his guide. It has info in it for every level of tech and it starts from the beginning, which is what you need. It will be the best $60 you could spend.

Good luck,
Jason
Thanks Jason for the honest advise and no offense taken at all. I know I do not know much of anything and since I do not do this for a living it is hard to to retain it as I do it every once in a blue moon and I am familiar with Perry's website and he actually referred me here as he is not familiar with Phoenix Gold amplifiers. I am just trying to solve the power issue first. Then once I tackle that part then I will dive more into the channel stuff. I am not claiming to be expert by any means, but I need to learn and well $60 dollars is a little much for me to spend right now as I just bought a voltmeter and now these parts. So I will do one thing at a time. It sounds like you know your stuff and it is a pleasure to converse back and fourth with you, but this is the only amp I plan on working on at this point. I do not have any others to work on. Thank you for your advise and I will keep you updated. Much Appreciated.
lilviper
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Re: Sapphire XS4600 Amplifier no power

Post by lilviper »

Silverhorse wrote:in previous post I was wrong :roll: with the 3 band. The 3th band is the multiplier number

the color code is orange / black / brown
orange = 3
black = 0
multiplier brown = 1
gold = 5% tolerance

so this is a resistor of 30 Ohm 5% resistor

the 5th band is brown, I don't know what this means, maybe others on the forum know this.

If you replace the 30 Ohm resistors and the fet's than see what happens when you power up the amp.
According to my handy dandy 5 color resistor color code ring. 30.1 ohm 1%?Image

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Silverhorse
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Re: Sapphire XS4600 Amplifier no power

Post by Silverhorse »

Yes, you are right
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote: Wed Feb 03, 2021 7:49 pm That's a question I do not have time to fully answer, but in short, once you make repairs power the amp with a current limited supply. For this amp it should power up with as little as 2a available. Monitor current while it powers up. I personally monitor current any time an amp is powered on my bench and it's a very good habit to form. If the amp will not power up on a current limited supply, or if it powers up and draws the maximum current the supply can source, then it still has an issue. The current limiter will help keep your new parts from going up in smoke.

If it draws high current, chances are there are shorted outputs or faulty drive circuit. You can remove the rectifiers to isolate the poweramp from the power supply. If the high current goes away and the amp idles at less than ~1.5a for this model, then the power supply is now likely OK and the fault is after the rectifiers. Test the output transistors. In the xs amps they are mosfets so you will test like you tested the power supply fets. If you find a faulty output, you must replace it as well as all its parallel parts and their compliments. The xs uses either irf540/9540 pairs or irf640/9640 pairs. DO NOT REPLACE THEM WITH ANY PART WITH A SUFFIX OTHER THAN pbf. Irf640n/9640n or irf640z/9640z are not compatible and will work for a short time and then have spurious and random failures. The number one best advice for the xs and tantrum series amps is this, if you find a faulty output, it is best to rebuild the entire channel. The drivers and predrivers are extremely cheap parts. It's less than a few dollars to rebuild the channel. It's well worth it to save future headaches.

The #1 piece of advice I can give you overall is to buy Perry Babbin's guide. It has answers to nearly any question you will have and it starts from the absolute very beginning. From reading the stuff you were writing at the beginning of your thread, you have no understanding of what you are dealing with. I don't say this to be rude or discourage you, but rather to explain why the guide will be worthwhile. I've been doing repairs for more than 20 years and doing it full time for the last 3 or so now. I still sometimes consult his guide. It has info in it for every level of tech and it starts from the beginning, which is what you need. It will be the best $60 you could spend.

Good luck,
Jason
Well All. I soldered all the new fets and gate resistors and still have the no power issue. I cleaned the solder joints up and installed all the new parts and now I am loss as to what to do next. Any other suggestions?
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

I just went back and looked at your pictures more closely and I noticed that 3 of the channels have diodes fitted in place of outputs. Are these the mosfets you replaced, or did you replace the power supply mosfets that we told you were going to need replaced? If you didn't replace the power supply fets, it's never going to work. If you did, and did so correctly, there are still many factors that could be keeping it from powering up. Many times the pwm ic or the buffers which drove the power supply mosfets get damaged when the supply fails badly. There are literally dozens of things that could be going on, that's why I recommended perry's guide so strongly.

Frankly, you would be better off selling the silly fluke meter you bought, buy the guide and a 10-15 meter from Amazon. There is no need to have a fluke, especially when you are as strapped for cash as you said you were.
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
mbc230
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote: Mon Feb 15, 2021 4:41 pm I just went back and looked at your pictures more closely and I noticed that 3 of the channels have diodes fitted in place of outputs. Are these the mosfets you replaced, or did you replace the power supply mosfets that we told you were going to need replaced? If you didn't replace the power supply fets, it's never going to work. If you did, and did so correctly, there are still many factors that could be keeping it from powering up. Many times the pwm ic or the buffers which drove the power supply mosfets get damaged when the supply fails badly. There are literally dozens of things that could be going on, that's why I recommended perry's guide so strongly.

Frankly, you would be better off selling the silly fluke meter you bought, buy the guide and a 10-15 meter from Amazon. There is no need to have a fluke, especially when you are as strapped for cash as you said you were.
I replaced the power supply mosfets (six of them) that are in the pictures along with the Gate Resistors (six of them) as Silverhorse mentioned that were circled. I actually like my new meter and it has helped a lot, but like I said Perry told me to get help on this forum as he is not familiar with these amps and also I do not see a point to buy a guide for just one amp. I do not have anymore to repair, but this one, but I am also trying to get basic understanding. I am a newbie and know that, but a little guidance is always appreciated. I am straped for cash as in I do not want to throw money down an empty hole. I am fine with learning, but I am only doing as instructed. Are the power supply fets in the pictures on the left side of the amp near the big caps? Do you have a wiring schematic of this amp so I know what is what? These are the things that make it hard to understand. Where in the pics do you see those diodes? Not knowing where all these parts on the amp make it hard to actually follow you. I have read Perry's online guide, but his guide only provides basic things and he repeated to me that he does not have knowledge to repair these types of amps. I again appreciate all your guidance.
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

You are missing the point. Switching power supplies in automotive amplifiers are basically the same across virtually every make model and power, only the scale changes. The basics that you are missing, are things like how to recognize what parts of the amplifier do which jobs, how to properly identify and test components, and best practices for a repair - meaning things like what all needs replaced for a given failure.

It would literally take dozens of hours for us to put this all in a digestible format that would explain to and guide you, and the cincher is that Perry has already done that. You can fix any phoenix gold amplifier with the information in the guide. I've been doing this since before I ever became aware of his guide, possibly before he actually started publishing the guide, I learned from books at the library and later from school and books I purchased. You can learn without that resource, but it's going to be a much harder path. I know it sounds rude, but I personally don't have time to spoon feed everything all the way back to ohms law, and you are basically saying that you want to take a college course, but don't want to buy the textbook because you can find some stuff online.

If you want to learn, the easiest path forward is to spend that very little bit of money. By far the smartest and least expensive thing to do if you aren't interested in doing this as a hobby or business is to just send it to a good tech.

I do not have, nor have I ever seen a schematic for an xs amplifier. I've seen nearly any other line, but never xs. They are not anything special though and share much in common with nearly any "n-channel only" mosfet output linear amp. They are extremely similar to most Rockfords of the same era, only imo a bit more robust in the same power class.

I'll attach your pictures below with some notes. If you were not the one who replaced the transistors with diodes, then this is going to be an even more in depth repair than expected. Anytime another "tech" has done that much "troubleshooting" and left it like that means that there are likely to be a ton of issues. The other picture shows the "two banks" of power supply mosfets. We can only see one of the two banks in your pictures, but they are smoked. That is why I said in my initial reply that the second bank is likely bad as well. If you only replaced the one side, that's almost certainly why it's still not powering up, but even if it were, you have several channels missing lots of critical parts.

Good luck,
Jason
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M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
mbc230
Posts: 25
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Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote: Mon Feb 15, 2021 8:14 pm You are missing the point. Switching power supplies in automotive amplifiers are basically the same across virtually every make model and power, only the scale changes. The basics that you are missing, are things like how to recognize what parts of the amplifier do which jobs, how to properly identify and test components, and best practices for a repair - meaning things like what all needs replaced for a given failure.

It would literally take dozens of hours for us to put this all in a digestible format that would explain to and guide you, and the cincher is that Perry has already done that. You can fix any phoenix gold amplifier with the information in the guide. I've been doing this since before I ever became aware of his guide, possibly before he actually started publishing the guide, I learned from books at the library and later from school and books I purchased. You can learn without that resource, but it's going to be a much harder path. I know it sounds rude, but I personally don't have time to spoon feed everything all the way back to ohms law, and you are basically saying that you want to take a college course, but don't want to buy the textbook because you can find some stuff online.

If you want to learn, the easiest path forward is to spend that very little bit of money. By far the smartest and least expensive thing to do if you aren't interested in doing this as a hobby or business is to just send it to a good tech.

I do not have, nor have I ever seen a schematic for an xs amplifier. I've seen nearly any other line, but never xs. They are not anything special though and share much in common with nearly any "n-channel only" mosfet output linear amp. They are extremely similar to most Rockfords of the same era, only imo a bit more robust in the same power class.

I'll attach your pictures below with some notes. If you were not the one who replaced the transistors with diodes, then this is going to be an even more in depth repair than expected. Anytime another "tech" has done that much "troubleshooting" and left it like that means that there are likely to be a ton of issues. The other picture shows the "two banks" of power supply mosfets. We can only see one of the two banks in your pictures, but they are smoked. That is why I said in my initial reply that the second bank is likely bad as well. If you only replaced the one side, that's almost certainly why it's still not powering up, but even if it were, you have several channels missing lots of critical parts.

Good luck,
Jason
Hi Jason. I completely understand what you are saying and I use Perry Guide online and have read it, but as you stated you do not have dozens of hours and I do not know the history of the amp and i did not replace anything in the amp at all. Those diodes were there when I opened up the amp. I bought six brand new mosfet's and six gate resistors and replaced the old ones. I know Perry's guide is online so isn't that the same thing? I will spend more time reading it and understanding it, but I know all amps work the same way, but the designs are much different. I like your outline of those pictures and that does help a lot. Can you tell me what books worked for you? I really want to do a deep dive into electronics and learn the circuits etc., but I thought this would be an entrance into that world, but it seems more complicated then what I thought. I totally appreciate you putting up with a newbie like me and I know your time is limited so I will not ask anymore of you. Thank you for all you have provided.
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

The guide perry sells is not the same as the free website. The guide he sells goes step by step through every piece of information you need to fix nearly any amplifier. The bcae website is more of a primer on car audio in general. The guide is the equivalent of going to trade school to learn how to do repairs.

In mobile audio there is really only one common power supply design. Things that vary are components used and amount of parts in parallel working together to scale the power level it's capable of supplying. There are a few other esoteric power supply designs, but they mostly date back to the early to mid 80's before higher current mosfets were starting to come into their own. There is an entire section in perry's guide about how the power supply works, how to identify what parts are which, and even has some detailed information on those early designs that you may never even come across.

Poweramps are where things very the most in mobile amplifiers, but even so, most class ab amps with bjt outputs are very similar. Every single original pg design with bjt outputs is based on the exact same poweramp, just scaled for different loads and power levels. Unfortunately the xs and tantrum amps deviated from the more established design. These amps use n-channel mosfet outputs, which are cheaper and potentially more robust, but at the cost of requiring some gymnastics in the drive circuitry to drive all n-channel fets. I personally do not care for the sound of these designs, but they are pretty tough and they were meant to be entry level amps.

Even so, as I mentioned before, the xs amps are very similar to other "mosfet" output amps of the same era. You can almost always work backwards from an intact channel (each channel should have all the same part numbers with the first digit advancing from 1-4 for a 4 channel amp) this isn't always the case for 100% of the parts in a channel, but in pg amps I don't think I've ever caught them fudging more than one or two part numbers in an entire multi channel amp. You can almost certainly always sort it out by comparing all the other channels, all for pictures, or simply ask if a component is correct.

Perry does not get a lot of pg stuff in his area, but just because he sent you here does not mean you should take that as meaning his guide will not be helpful. He is simply trying to tell you that he does not have notes or detailed pictures of the model. If he doesn't have anything to study on the model, it is pretty tough to troubleshoot it long distance. If it were in front of him he'd be able to sort it out on no time. Once you see the guide, you'll understand at how methodical and detailed his thought process is and a lot of what you are dealing with will make a heck of a lot more sense.
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
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Jacampb2
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Location: Beaverton 48612

Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

BTW, I don't believe I've ever worked on a xs4300, so it's possible I'm incorrect about those diodes not being stock. They're should be at least 4 more mosfets somewhere for the other channels, and they may actually be there under the crossover board. Normally in the tantrum amps, and I've fixed plenty of those, those locations populated by diodes in your amp have smaller bjts involved in bias and driving the outputs.
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
mbc230
Posts: 25
Joined: Mon Nov 02, 2020 11:50 am

Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote: Wed Feb 17, 2021 7:52 pm The guide perry sells is not the same as the free website. The guide he sells goes step by step through every piece of information you need to fix nearly any amplifier. The bcae website is more of a primer on car audio in general. The guide is the equivalent of going to trade school to learn how to do repairs.

In mobile audio there is really only one common power supply design. Things that vary are components used and amount of parts in parallel working together to scale the power level it's capable of supplying. There are a few other esoteric power supply designs, but they mostly date back to the early to mid 80's before higher current mosfets were starting to come into their own. There is an entire section in perry's guide about how the power supply works, how to identify what parts are which, and even has some detailed information on those early designs that you may never even come across.

Poweramps are where things very the most in mobile amplifiers, but even so, most class ab amps with bjt outputs are very similar. Every single original pg design with bjt outputs is based on the exact same poweramp, just scaled for different loads and power levels. Unfortunately the xs and tantrum amps deviated from the more established design. These amps use n-channel mosfet outputs, which are cheaper and potentially more robust, but at the cost of requiring some gymnastics in the drive circuitry to drive all n-channel fets. I personally do not care for the sound of these designs, but they are pretty tough and they were meant to be entry level amps.

Even so, as I mentioned before, the xs amps are very similar to other "mosfet" output amps of the same era. You can almost always work backwards from an intact channel (each channel should have all the same part numbers with the first digit advancing from 1-4 for a 4 channel amp) this isn't always the case for 100% of the parts in a channel, but in pg amps I don't think I've ever caught them fudging more than one or two part numbers in an entire multi channel amp. You can almost certainly always sort it out by comparing all the other channels, all for pictures, or simply ask if a component is correct.

Perry does not get a lot of pg stuff in his area, but just because he sent you here does not mean you should take that as meaning his guide will not be helpful. He is simply trying to tell you that he does not have notes or detailed pictures of the model. If he doesn't have anything to study on the model, it is pretty tough to troubleshoot it long distance. If it were in front of him he'd be able to sort it out on no time. Once you see the guide, you'll understand at how methodical and detailed his thought process is and a lot of what you are dealing with will make a heck of a lot more sense.
Jacampb2 wrote: Wed Feb 17, 2021 8:01 pm BTW, I don't believe I've ever worked on a xs4300, so it's possible I'm incorrect about those diodes not being stock. They're should be at least 4 more mosfets somewhere for the other channels, and they may actually be there under the crossover board. Normally in the tantrum amps, and I've fixed plenty of those, those locations populated by diodes in your amp have smaller bjts involved in bias and driving the outputs.
Well pardon my ignorance I thought the website is Perry's book. That is totally my bad and I am sorry I misunderstood you. I get it and I just have to decide on how I want to proceed. I really want to get into electronics more then just repairing an amp. I guess that is why I am trying to watch my spending. As I know I can throw parts at this amp or for that matter any electronic that I want to fix. So that is where I am torn. I have to really decide on what direction to go. I might just put this amp on the shelf until I get more advanced in my knowledge of electronics. Thank you for all your help with this and you by far have been the most helpful with this. By the way you are not rude in anyway I do not take it like that. You sound like you are a realist as I am too. I just need to learn is all and that will come with time and experience. Thanks again.
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Jacampb2
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Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

I forgot to reply with books I've found useful.

Pretty much anything by the author Randy Sloan or Douglas Self. I have multiple books by both authors. Both authors write on the theory, principles and design of poweramps and preamps. Neither one will go into much detail about power supply design, and the stuff they do touch on will be about mains powered supplies, not 12v SMPS. They are still very good resources, but I don't think I've ever come across an author that writes about mobile amplifiers specifically, except Perry, but his material is more textbook then design theory.

It can get very easy to bury yourself and get discouraged. Even EE's specialize. It's OK to have broad interests, but it's best to narrow your scope to whatever field you find most interesting, master it as best you can and then broaden and branch out from there. Unless you are some kind of a savant, you'll be doing yourself a disservice by shelving stuff and moving to a different facet. That's a recipe to end up with a lot of things of which you have just a superficial understanding, and cluttered shelves. A lot of stuff you'll learn about audio amplifiers will be useful across multiple areas of electronics expertise--basically anything "analog electronics" will be well served by learning about audio amplifiers. Not nearly as much so if you want to learn about digital electronics repair and design. The fundamental building blocks remain the same, but a lot of digital design characteristics are things that won't even be on our radar. Then there is rf power electronics, that shit is straight witchcraft, 9 out of 10 EE's will agree there :mrgreen:

Just don't lose sight of the fact that you are supposed to be enjoying yourself and I'm sure you will be fine. 20+ years ago I struggled with justifying every extraneous purchase as well. Now I do this full time and I stock around $20K in parts. It will come, it just takes patience and perseverance.

Later,
Jason
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
mbc230
Posts: 25
Joined: Mon Nov 02, 2020 11:50 am

Re: Sapphire XS4600 Amplifier no power

Post by mbc230 »

Jacampb2 wrote: Thu Feb 18, 2021 7:50 pm I forgot to reply with books I've found useful.

Pretty much anything by the author Randy Sloan or Douglas Self. I have multiple books by both authors. Both authors write on the theory, principles and design of poweramps and preamps. Neither one will go into much detail about power supply design, and the stuff they do touch on will be about mains powered supplies, not 12v SMPS. They are still very good resources, but I don't think I've ever come across an author that writes about mobile amplifiers specifically, except Perry, but his material is more textbook then design theory.

It can get very easy to bury yourself and get discouraged. Even EE's specialize. It's OK to have broad interests, but it's best to narrow your scope to whatever field you find most interesting, master it as best you can and then broaden and branch out from there. Unless you are some kind of a savant, you'll be doing yourself a disservice by shelving stuff and moving to a different facet. That's a recipe to end up with a lot of things of which you have just a superficial understanding, and cluttered shelves. A lot of stuff you'll learn about audio amplifiers will be useful across multiple areas of electronics expertise--basically anything "analog electronics" will be well served by learning about audio amplifiers. Not nearly as much so if you want to learn about digital electronics repair and design. The fundamental building blocks remain the same, but a lot of digital design characteristics are things that won't even be on our radar. Then there is rf power electronics, that shit is straight witchcraft, 9 out of 10 EE's will agree there :mrgreen:

Just don't lose sight of the fact that you are supposed to be enjoying yourself and I'm sure you will be fine. 20+ years ago I struggled with justifying every extraneous purchase as well. Now I do this full time and I stock around $20K in parts. It will come, it just takes patience and perseverance.

Later,
Jason
Really good information and again thanks for the assistance you have provided. Just a shot in the dark. Would you fix this amp for a fee? What would you charge to fix this amp if I sent it to you? I have a full time job now along with another side thing that I do so I am just trying to broaden my skill set if that makes any sense.
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Jacampb2
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Joined: Sat Apr 19, 2008 11:57 pm
Location: Beaverton 48612

Re: Sapphire XS4600 Amplifier no power

Post by Jacampb2 »

Yes, I do take repairs from all over the US and I have a few clients outside North America as well. I have a tremendous amount of backlog right now though and have been actively turning down new work and clients for a while. If you would like to pm, I'll give you details on how to get on my wait list, I also have a few other folks I can recommend if you are in a huge hurry.

As for repair costs, that is not something I am willing to estimate over the internet, there are just too many unknowns. I do however offer a flat rate service for the Phoenix gold amps effected by the faulty Panasonic HF and HFZ caps in the power supply.

Thanks,
Jason
M: M100, M44 for a custom amp project
Zx: Zx500, Zx450, Black Zx350
ZxTi: 4 Zx600Ti's, 1 Zx400Ti
Ti: 5 800.1's & 900.7 for a custom amp project. 1 1200.1, 1 1000.2
Tantrum: 2 1200.1's, 1 600.4, 1 500.2
XS: XS6600
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