Hello everyone,
'Back in the day' I remember a few people upgrading their PPI Art series amps to handle more power... I believe the people were replacing the output transistors/fets and adding windings to the toroidal transformer. Does anyone have any details about this upgrade, specifically on the A600.2? This is more for curiousity's sake than anything else -- I always wondered precisely what they did to upgrade them.
Thanks,
Brad
'Back in the day' I remember a few people upgrading their PPI Art series amps to handle more power... I believe the people were replacing the output transistors/fets and adding windings to the toroidal transformer. Does anyone have any details about this upgrade, specifically on the A600.2? This is more for curiousity's sake than anything else -- I always wondered precisely what they did to upgrade them.
Thanks,
Brad
Why do you want to ruin a fairly well manufactured device by Boosting it ?
You know, the engineers that designed and built it intended for it run safely for a long time. So they built it with safe-guards internally so your car would not get burned up.
In fact the Art series .2 was a beefed up version of their prior car amps. With a whole slew of engineered build ups inside like:
1: Extra heavy windings on the power toroid
2: Extra heavy duty fets in the power supply
3: High current noise inductor on the power rails
4: Modular ceramic channel driver cards
5: Heavy duty internal fuse
6: high current driver stage to the outputs to accomadate low impedence loads with failure.
7: Art series heatsink that allows for water cooling modification ( rarely used but possible back then). Shame most installers didn't have a clue about fluid dymanics and Hydraulics, so it never really got off the ground, or worked properly when installed.
8: heavy duty ground buss connection for speakers to the power supply.
9: Heavy duty high current isolated rectifiers in the power supply.
10: Low impedence detection circuitry to auto adjust the amps performance, and protection under short ciurcuit condition.
11: A regulated power supply to compensate for a cars poor electrical system. ( fairly standard back then)
Plus a few other things that I have forgotten over the years. So you see the .2 series art amp were already beefed up by professional engineers to handle the 2 ohm revolution back then.
Plus you need to consider the hard engineering facts that the heatsink while a work of art was a limiting factor in the entire design.
They offered a water cooling option as I mentioned above, but who knew how to use it properly.
But hot-rodding a amp has to take into consideration the mass of the heatsink.
So lets say you boost the amp to deliver 2 ohm performance at a 4 ohm load. well you have just Maxxed out the heatsink design. What are you going to do with all that increased heat load on the electronics and the sink ?
And what if you now try to run a 2 ohm load on the heated up beast? Well now you start to see the problem when you go tampering with someones elses design.
Plus to get a 3Db difference in output to your ear, you must almost double the amplfiers output power in watts.
And that means double the heat load on the sink. Now what are you going to do when it gets hot and cuts off, or fails outright.
Heat kills electronics by aging it and causing connection failures, and silicon degredation due the heat stress induced fractures in the crystal structure.
Running silicon at junction temps above there ratings causes failures.
I hope I have given you some food for thought. I also want to leave you with a honest suggestion.
If you really feel you need 2.5 million watts RMS of audio power, then I suggest that you go out and buy 2.5 million watts of amplifiers at 4 ohms and 12 volts.
1: It will keep you out of the repair shops, and 2: it will also keep you from being disappointed in the system performance your looking for.
Does this make sense? Maybe, I have had a amplified car stereo since 1975, and I have been repairing amplifiers since 1985, so maybe, just maybe I might have a bit of insight on this end of your best interests
You know, the engineers that designed and built it intended for it run safely for a long time. So they built it with safe-guards internally so your car would not get burned up.
In fact the Art series .2 was a beefed up version of their prior car amps. With a whole slew of engineered build ups inside like:
1: Extra heavy windings on the power toroid
2: Extra heavy duty fets in the power supply
3: High current noise inductor on the power rails
4: Modular ceramic channel driver cards
5: Heavy duty internal fuse
6: high current driver stage to the outputs to accomadate low impedence loads with failure.
7: Art series heatsink that allows for water cooling modification ( rarely used but possible back then). Shame most installers didn't have a clue about fluid dymanics and Hydraulics, so it never really got off the ground, or worked properly when installed.
8: heavy duty ground buss connection for speakers to the power supply.
9: Heavy duty high current isolated rectifiers in the power supply.
10: Low impedence detection circuitry to auto adjust the amps performance, and protection under short ciurcuit condition.
11: A regulated power supply to compensate for a cars poor electrical system. ( fairly standard back then)
Plus a few other things that I have forgotten over the years. So you see the .2 series art amp were already beefed up by professional engineers to handle the 2 ohm revolution back then.
Plus you need to consider the hard engineering facts that the heatsink while a work of art was a limiting factor in the entire design.
They offered a water cooling option as I mentioned above, but who knew how to use it properly.
But hot-rodding a amp has to take into consideration the mass of the heatsink.
So lets say you boost the amp to deliver 2 ohm performance at a 4 ohm load. well you have just Maxxed out the heatsink design. What are you going to do with all that increased heat load on the electronics and the sink ?
And what if you now try to run a 2 ohm load on the heated up beast? Well now you start to see the problem when you go tampering with someones elses design.
Plus to get a 3Db difference in output to your ear, you must almost double the amplfiers output power in watts.
And that means double the heat load on the sink. Now what are you going to do when it gets hot and cuts off, or fails outright.
Heat kills electronics by aging it and causing connection failures, and silicon degredation due the heat stress induced fractures in the crystal structure.
Running silicon at junction temps above there ratings causes failures.
I hope I have given you some food for thought. I also want to leave you with a honest suggestion.
If you really feel you need 2.5 million watts RMS of audio power, then I suggest that you go out and buy 2.5 million watts of amplifiers at 4 ohms and 12 volts.
1: It will keep you out of the repair shops, and 2: it will also keep you from being disappointed in the system performance your looking for.
Does this make sense? Maybe, I have had a amplified car stereo since 1975, and I have been repairing amplifiers since 1985, so maybe, just maybe I might have a bit of insight on this end of your best interests
Like I said, I was more interested from a curiousity standpoint than anything else. I knew a few people doing this stuff when the Art series was at it's peak. It always fascinated me and they would never tell me the 'secret' behind what they were doing.
Thus, I was on a search for their trade secret.
As I alluded to before, I wasnt interested in doing it to my amps. To be quite honest, my subs cant handle the power that a bridged A600 puts out anyway, thus why would I waste my time upgrading it?
I guess my curiousity isn't worth the time to get an explanation.
Regards,
Brad
Thus, I was on a search for their trade secret.
As I alluded to before, I wasnt interested in doing it to my amps. To be quite honest, my subs cant handle the power that a bridged A600 puts out anyway, thus why would I waste my time upgrading it?
I guess my curiousity isn't worth the time to get an explanation.
Regards,
Brad
Sorry Brad,
I was just trying to guide you away from this way of doing things. As I personally have seen the results of peoples efforts to bolster other peoples hard engineering.
Plus you have the gist of what those folks did to the amp. The details are another matter.
If it sounds like I'm being vague, well I am for a reason.
This is a public forum and I don't want to be responsible for someone else's actions
I'm sure my moderator would not appeciate it either
So please forgive me if I was hard on your question, and please don't take it as being hard on you as a person
The details your asking for could be misused by a lessor experianced person, and the damage could get fairly extensive.
It takes alot of reverse engineering to actually see where mods could safely be added, and have actual real world gains.
Especially concerning PPI amps as they were some of the best back in the day. I myself had 3 PPI 2150am's, and they Rocked !
And I'm sure by my first response you know I know the insides of your amp, and just about any other brand you can name. I have seen them all, and repaired most of them more than once in my time.
Take care, and try to understand my reason's for not divulging the engineering you asked for. I could do anything I want to my own amps, but I leave them alone, unless they need repair. And then I spend exactly want it costs to replace each and every component exactly as some engineer somewhere wanted them to be.
I was just trying to guide you away from this way of doing things. As I personally have seen the results of peoples efforts to bolster other peoples hard engineering.
Plus you have the gist of what those folks did to the amp. The details are another matter.
If it sounds like I'm being vague, well I am for a reason.
This is a public forum and I don't want to be responsible for someone else's actions
I'm sure my moderator would not appeciate it either
So please forgive me if I was hard on your question, and please don't take it as being hard on you as a person
The details your asking for could be misused by a lessor experianced person, and the damage could get fairly extensive.
It takes alot of reverse engineering to actually see where mods could safely be added, and have actual real world gains.
Especially concerning PPI amps as they were some of the best back in the day. I myself had 3 PPI 2150am's, and they Rocked !
And I'm sure by my first response you know I know the insides of your amp, and just about any other brand you can name. I have seen them all, and repaired most of them more than once in my time.
Take care, and try to understand my reason's for not divulging the engineering you asked for. I could do anything I want to my own amps, but I leave them alone, unless they need repair. And then I spend exactly want it costs to replace each and every component exactly as some engineer somewhere wanted them to be.
In a way you'd almost be making a new amp, it takes a great deal of time, and after everything, you'd be better off just purchasing an amp with more power. You could beef up the transformer, diodes, capacitors, and probably gate drive (extra capacitance on those think ones..), then run more current.
I didn't respond earlier because I didn't have anything for the amp you specified. This post covers modifications in general.
You should know that modifying an amplifier to produce more power turns the amp into something that is only good for short term operation unless you can significantly increase cooling.
To get more power from an amplifier you need to do one of two things. You can increase the rail voltage or you can increase the current capacity of the amplifier.
Increasing the rail voltage is definitely the most difficult way to get more power from an amp but it will allow the amp to produce more power into a given load. For example, if the amp can produce 200 watts into a 2 ohm load, increasing the rail voltage will allow it to produce more power into that same load. To get more rail voltage, you MAY be able to simply disable the regulation for amps with regulated power supplies. This can often work well for lighter loads but when driving an amp into its toughest rated load, the gains in power output will often be minimal. In most amps, you will need to rewind the secondary of the transformer or at least add a few windings. If the secondary is wound on top of the primary windings, rewinding the secondary is not too difficult. If the primary is wound on top of the secondary, you would have to rewind the entire transformer to rewind the secondary. When increasing the rail voltage, there are several problems that you will have to deal with. The rail caps were likely selected to handle the rail voltage of the amp as it was originally and not much more. If you replace the caps, it's unlikely that you'll be able to find caps of the same value that will fit in the alloted space so you'll have to use caps with less capacitance. If the amp uses IC regulators, they may not be able to withstand the increase in input voltage. If the amp uses discrete regulators, the increase in voltage may not destroy the regulators but you may have to change a few resistor values to keep the zeners from overheating. With either type of regulator, the power dissipation will be greater which means that they will run hotter. If the regulators were not mounted on the heatsink, you'd need to add a heatsink or relocate them to the main heatsink (under the board is often a good location if there is enough clearance). The rectifiers are likely going to be OK unless you significantly increase the rail voltage. The output transistors may need to be upgraded. Even if they can handle the voltage, they will be passing more current and dissipating more power. Depending on the range of the biasing control, it may be necessary to make a few modifications to the resistors in the biasing circuit. Other problems would have to be handled on a case by case basis.
An easier way to get more power is to increase the current capacity of the amplifier. With this type of modification, the voltages remain the same so there is no need to be concerned with the rail caps, the regulators or many of the problems associated with the previous modification. People who do this typically want to be able to run the amp into a lower ohm load. For example, instead of being able to drive two 4 ohm speakers per channel, this type of modification would allow you to drive three 4 ohm speakers per channel. Depending on how conservatively the power transformer was designed, it may not be necessary to make any changes to it. At most, you would add a single turn to each of the secondary windings. This would help prevent the rail voltage from sagging under the heavier load but it would add even more load to the power supply transistors. Generally, you would allow the supply voltage to sag a little more than normal and not add the extra turn to the secondary windings.
No matter the type of mod, you will most definitely need to use the heaviest possible transistors in the power supply. This may require that you modify the drive circuit. It could be as simple as changing the drive resistors but it could be more complex depending on the design.
For the outputs, you would use the largest (physically) components you could fit into the alloted space. The larger transistors would have more surface area and would be able to pass more heat to the heatsink which means that they would operate at lower temperatures. You would also select the transistors with the highest current rating available for the rail-rail voltage in use.
If the amplifier uses sil-pad insulators, you could do better with mica, metallic or ceramic insulators. Even Kapton is likely to be better than the sil-pads.
As I said earlier, you can not expect to be able to use a modified amp at full power for extended periods of time without increased cooling. For the heatsink, this could mean using water cooling or moving air at a very high rate over the fins of the heatsink. The problem doesn't end with the heatsink mounted components. Components like the transformer, inductors and filter caps would also run hotter. To keep these cool, you would need to use forced air cooling (air flowing through the inside of the amplifier).
Even with the best mods, don't expect a significant increase in output power. Even if you get 50% more power (200 watts to 300 watts), the difference will generally barely be audible.
You should know that modifying an amplifier to produce more power turns the amp into something that is only good for short term operation unless you can significantly increase cooling.
To get more power from an amplifier you need to do one of two things. You can increase the rail voltage or you can increase the current capacity of the amplifier.
Increasing the rail voltage is definitely the most difficult way to get more power from an amp but it will allow the amp to produce more power into a given load. For example, if the amp can produce 200 watts into a 2 ohm load, increasing the rail voltage will allow it to produce more power into that same load. To get more rail voltage, you MAY be able to simply disable the regulation for amps with regulated power supplies. This can often work well for lighter loads but when driving an amp into its toughest rated load, the gains in power output will often be minimal. In most amps, you will need to rewind the secondary of the transformer or at least add a few windings. If the secondary is wound on top of the primary windings, rewinding the secondary is not too difficult. If the primary is wound on top of the secondary, you would have to rewind the entire transformer to rewind the secondary. When increasing the rail voltage, there are several problems that you will have to deal with. The rail caps were likely selected to handle the rail voltage of the amp as it was originally and not much more. If you replace the caps, it's unlikely that you'll be able to find caps of the same value that will fit in the alloted space so you'll have to use caps with less capacitance. If the amp uses IC regulators, they may not be able to withstand the increase in input voltage. If the amp uses discrete regulators, the increase in voltage may not destroy the regulators but you may have to change a few resistor values to keep the zeners from overheating. With either type of regulator, the power dissipation will be greater which means that they will run hotter. If the regulators were not mounted on the heatsink, you'd need to add a heatsink or relocate them to the main heatsink (under the board is often a good location if there is enough clearance). The rectifiers are likely going to be OK unless you significantly increase the rail voltage. The output transistors may need to be upgraded. Even if they can handle the voltage, they will be passing more current and dissipating more power. Depending on the range of the biasing control, it may be necessary to make a few modifications to the resistors in the biasing circuit. Other problems would have to be handled on a case by case basis.
An easier way to get more power is to increase the current capacity of the amplifier. With this type of modification, the voltages remain the same so there is no need to be concerned with the rail caps, the regulators or many of the problems associated with the previous modification. People who do this typically want to be able to run the amp into a lower ohm load. For example, instead of being able to drive two 4 ohm speakers per channel, this type of modification would allow you to drive three 4 ohm speakers per channel. Depending on how conservatively the power transformer was designed, it may not be necessary to make any changes to it. At most, you would add a single turn to each of the secondary windings. This would help prevent the rail voltage from sagging under the heavier load but it would add even more load to the power supply transistors. Generally, you would allow the supply voltage to sag a little more than normal and not add the extra turn to the secondary windings.
No matter the type of mod, you will most definitely need to use the heaviest possible transistors in the power supply. This may require that you modify the drive circuit. It could be as simple as changing the drive resistors but it could be more complex depending on the design.
For the outputs, you would use the largest (physically) components you could fit into the alloted space. The larger transistors would have more surface area and would be able to pass more heat to the heatsink which means that they would operate at lower temperatures. You would also select the transistors with the highest current rating available for the rail-rail voltage in use.
If the amplifier uses sil-pad insulators, you could do better with mica, metallic or ceramic insulators. Even Kapton is likely to be better than the sil-pads.
As I said earlier, you can not expect to be able to use a modified amp at full power for extended periods of time without increased cooling. For the heatsink, this could mean using water cooling or moving air at a very high rate over the fins of the heatsink. The problem doesn't end with the heatsink mounted components. Components like the transformer, inductors and filter caps would also run hotter. To keep these cool, you would need to use forced air cooling (air flowing through the inside of the amplifier).
Even with the best mods, don't expect a significant increase in output power. Even if you get 50% more power (200 watts to 300 watts), the difference will generally barely be audible.
Help with PPI A404.2 & A600.2
Heya all!... I used to be really into car audio but due to work load I had totally lost touch with it since I graduated from college.
Anyways its been over 10 years and I just pulled my old system out from storage and was thinking of how to rebuild it.
I can't recall the full wiring setup and I can't find any email contact for tech support on the PPI homepage... I hope someone can help me out here.
The A600.2 is supposed to be able to be bridge and run at 600watts at 4ohms... does anyone know if its possible to run it stable at 2ohms to crank out 1200watts?
Does anyone know where I can find wiring diagram of how to bridge the amp?.... for these 2 amps?
Here's what I was thinking of doing...basically bridging the A404.2 to run the front splits.... running the A600.2 for the rear splits and finally bridge another A600.2 mono to run the subby...
Does anyone have any suggestions?... Its sounds a bit simple and not overly technically but its been along time since I messed with systems. I hope that I can get some suggestions from all of you.
Would either run my old 20bit clarion DRX9255 or change to the newer 24bit clarion decks as source.
Any help or suggestions would be much appreciated! thanks ALL!
PS. has anyone used the butler audio tube amps before?... any idea how the butler tube amps would perform hooked up the the clarion 24bit bur brown DA converters?..
Heya all!... I used to be really into car audio but due to work load I had totally lost touch with it since I graduated from college.
Anyways its been over 10 years and I just pulled my old system out from storage and was thinking of how to rebuild it.
I can't recall the full wiring setup and I can't find any email contact for tech support on the PPI homepage... I hope someone can help me out here.
The A600.2 is supposed to be able to be bridge and run at 600watts at 4ohms... does anyone know if its possible to run it stable at 2ohms to crank out 1200watts?
Does anyone know where I can find wiring diagram of how to bridge the amp?.... for these 2 amps?
Here's what I was thinking of doing...basically bridging the A404.2 to run the front splits.... running the A600.2 for the rear splits and finally bridge another A600.2 mono to run the subby...
Does anyone have any suggestions?... Its sounds a bit simple and not overly technically but its been along time since I messed with systems. I hope that I can get some suggestions from all of you.
Would either run my old 20bit clarion DRX9255 or change to the newer 24bit clarion decks as source.
Any help or suggestions would be much appreciated! thanks ALL!
PS. has anyone used the butler audio tube amps before?... any idea how the butler tube amps would perform hooked up the the clarion 24bit bur brown DA converters?..
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