Now, now. Don't be so hard on the boy.
Kilowatt is a very earnest young individual (I believe he is well under 18 years old). I doubt if he has never smelled his own flesh sizzling and I'm sure he still thinks he can never die. Hope he is not persuaded otherwise anytime soon.
Actually Kilowatt is not being quite as suicidal as he sounds. Residental power in the US is provided from a center grounded secondary winding on the utility transformer. If you connect across either hot leg of this to ground you get 110 VAC. If you connect across the two hot legs you get 220 VAC. This means that technically you could directly rectify the 220 VAC and connect signal ground to the earth ground without creating an electrocution hazard. (Directly recifying the single ended 110 VAC would be a different matter).
Note: Technically feasible and wise are not the same thing. All your comments about noise and interference are valid. I can't imagine that this system would sound very good.
I believe that what Kilowatt is trying to do is create a concert level sound system at very low cost. I do not believe this system will ever be used inside a residence, but rather will be set up in some kind of an outdoor setting (I recall mention being made in an earlier thread of connecting directly to a utility pole transfomer).
For some reason Kilowatt is fixated on the price of amplifiers as being the big issue. In reality to actually achieve the kind of SPL he wants is going to require 5-10 times the cost of the amplifiers. Personnally I would look at high efficiency (horn) speakers if I was looking for high SPL on a budget, but I am not the one doing this so there it is.
Hope this has set your mind a little bit at ease. At least he hasn't joined up with one of the fascist paramilitary organizations that seem to infest Montana. A little high power audio and the oportunity for self imolation seems downright normal compared to that.
P.S. I already coined the name KillerWatt for him a few months back. Didn't seem to stick then.
Peace,
Phil
Kilowatt is a very earnest young individual (I believe he is well under 18 years old). I doubt if he has never smelled his own flesh sizzling and I'm sure he still thinks he can never die. Hope he is not persuaded otherwise anytime soon.
Actually Kilowatt is not being quite as suicidal as he sounds. Residental power in the US is provided from a center grounded secondary winding on the utility transformer. If you connect across either hot leg of this to ground you get 110 VAC. If you connect across the two hot legs you get 220 VAC. This means that technically you could directly rectify the 220 VAC and connect signal ground to the earth ground without creating an electrocution hazard. (Directly recifying the single ended 110 VAC would be a different matter).
Note: Technically feasible and wise are not the same thing. All your comments about noise and interference are valid. I can't imagine that this system would sound very good.
I believe that what Kilowatt is trying to do is create a concert level sound system at very low cost. I do not believe this system will ever be used inside a residence, but rather will be set up in some kind of an outdoor setting (I recall mention being made in an earlier thread of connecting directly to a utility pole transfomer).
For some reason Kilowatt is fixated on the price of amplifiers as being the big issue. In reality to actually achieve the kind of SPL he wants is going to require 5-10 times the cost of the amplifiers. Personnally I would look at high efficiency (horn) speakers if I was looking for high SPL on a budget, but I am not the one doing this so there it is.
Hope this has set your mind a little bit at ease. At least he hasn't joined up with one of the fascist paramilitary organizations that seem to infest Montana. A little high power audio and the oportunity for self imolation seems downright normal compared to that.
P.S. I already coined the name KillerWatt for him a few months back. Didn't seem to stick then.
Peace,
Phil
The prices for high power amplifiers are very high for what you get inside.
Example : The famous brand ''X'' cost 1500 $ and have 2x1500W /2ohm.
For this money you will have this :
Toroidal transformer 4000VA = 150$
Capacitors 12 x 2200uF = 30$
Power Devices 64 x TO3 MJ... = 140$
Heatsink and 2 big fan = 30$
Other ( cheap ) components = 50$
Case ( 4 rack space ) = 50$
Total cost for this is no more 400$. You will pay the diference (1100$) just for '' I don't know how '' .
Best regards
Example : The famous brand ''X'' cost 1500 $ and have 2x1500W /2ohm.
For this money you will have this :
Toroidal transformer 4000VA = 150$
Capacitors 12 x 2200uF = 30$
Power Devices 64 x TO3 MJ... = 140$
Heatsink and 2 big fan = 30$
Other ( cheap ) components = 50$
Case ( 4 rack space ) = 50$
Total cost for this is no more 400$. You will pay the diference (1100$) just for '' I don't know how '' .
Best regards
djdan said:
Actually that is overstating things. I own two QSC amps, the PLX1602 and the PLX3402. I paid $800 for the 1602 (2 x 800W/2 ohm) and $1100 for the 3402 (2 x 1700W/2 ohm). That works out to $0.50 and $0.35 per watt respectively.
For that I got reliable, lightweight amps with built-in subsonic filters, limiters and bridging circuitry. The amps have XLR inputs and both banana plugs and Speakon NL4 output connectors. In addition when and if I ever need to upgrade I expect they will retain their resale value well.
Compare that to a pair of 250W/4 ohm MosFet amps I built from Randy Sloans book. Here is what I spent (working from memory)
2) Etched and drilled PCBs 50$
2) Surplus Heatshinks 40$
4) Output Devices 20$
1) 750 VA torroidal transformer 80$
1) 3U Rack case 55$
2) 75V, 25000 uF Filter Caps 65$
1) Circuit Break/Power Switch 15$
2) Speakon NL4 Jacks 20$
2) Stepped attenuators 10$
Numerous other small parts 65$
---------------------------------------------------------
Total 420$ US
That assumes my labor has zero value, estimate I spent a total of 30 hours building this amp. Realistically I could make them in about 10 hours with practice. I could also shave the cost of the PBC's to about $10 if I bought them in quantity.
Ignoring my labor, just the parts only cost me $1.19 per Watt. It also ignores that fact that in order to get the output devices at all I was forced to buy 25 of each (minimum buy quantities).
Explain again how this is supposed to be cheaper? I am amazed at how inexpensive decent pro audio gear has become. Take a good look inside one of the QSC amps. There is an incredible amount of engineering involved. Take a look at the schematic for this amp and tell me you could make it for less than $1100.
http://www.qscaudio.com/support/library/schems/plx3402.pdf
Phil
haldor said:
You are right that is an incredible schematic. I suppose the reason we like to make amps is mostly for the personal satisfaction of making something work on your own. I agree that for huge power levels pro-audio is the way to go. They have a track record that is impossible to reproduce DIY. At kilowatt levels (no pun intended) reliability is more important than anything.
For lower power levels (i.e. less than 300W) I think DIY is definately cheaper and much more rewarding. I've got this amp I've been designing for months now still on the breadboard getting better and better each week. Just added an offset servo and next is the bias servo =). Got the offset less than 1 microvolt with a DC coupled input. I don't know of many commercial amps that can do that.
Montanna Madness ?
Hello Phil,
Re the US 220V - Errr, yep I agree that it should work fine except for the problem af accessing the two phases, and what happens when one phase circuit breaker trips. ..... Rhetorical question !.
Oh, and the smell of one's own cauterised skin is distinctly unpleasant, also the 3 months of chiropractic treatment to sort my back out.
Me thinks that young Kilowatt needs to spend some time at the local pro-audio hire shop, or get some weekend work as local crew for a hire company and see how it is done.
Kilowatt ARE YOU LISTENING ?.
We don't want you to die !.
Amen, Eric.
BTW - the QSC's that Phil mentions are good, darn good.
Crowns are excellent too, but expensive to repair.
Don't touch a Mackie with a bargepole.
Hello Phil,
Sorry, I did not mean to be too hard on the boy - I just felt he needed some stern words to help him understand his folly.
Re the US 220V - Errr, yep I agree that it should work fine except for the problem af accessing the two phases, and what happens when one phase circuit breaker trips. ..... Rhetorical question !.
Oh, and the smell of one's own cauterised skin is distinctly unpleasant, also the 3 months of chiropractic treatment to sort my back out.
Me thinks that young Kilowatt needs to spend some time at the local pro-audio hire shop, or get some weekend work as local crew for a hire company and see how it is done.
Kilowatt ARE YOU LISTENING ?.
We don't want you to die !.
Amen, Eric.
BTW - the QSC's that Phil mentions are good, darn good.
Crowns are excellent too, but expensive to repair.
Don't touch a Mackie with a bargepole.
Re: Montanna Madness ?
220 V breakers in the US are ganged together with a metal bar, if one trips they both trip. Would be very unsafe if they didn't.
I agree that a short stint working in pro audio is just what young Kilowatt needs, in fact I recommended same earlier in this thread. Nothing like finding out just how far a much it really takes to do serious sound reinforcement. I use my 3402 to drive one pair of 18" subs. And that is for a dinky little club rig (typical crowd size 150-300 people). Fellows that do this on the scale that Kilowatt is thinking about often have 20 to 30KW of amp power.
Phil
mrfeedback said:
220 V breakers in the US are ganged together with a metal bar, if one trips they both trip. Would be very unsafe if they didn't.
I agree that a short stint working in pro audio is just what young Kilowatt needs, in fact I recommended same earlier in this thread. Nothing like finding out just how far a much it really takes to do serious sound reinforcement. I use my 3402 to drive one pair of 18" subs. And that is for a dinky little club rig (typical crowd size 150-300 people). Fellows that do this on the scale that Kilowatt is thinking about often have 20 to 30KW of amp power.
Phil
I've almost given up telling my daughters to quit smoking. Ah, to be young and invincible again... No, thanks.
Wow, so many posts and I haven't had time to defend myself!😱
Lets see, where do I begin? First of all, thanks for the advice, to those of you that have been helpful. I will of course have low level isolation transformers, DC protection, cutouts, insulated hookups, double insulation in the amp, etc. Since it will be illegal to run it in most places where 220 is present, I will likely run it form a great and powerful generator most of the time. If I'm running it (carefully) at low levels in my house or whatever, I'll just have to live with any interference that makes it through the power supply's inductive filtering. Balance might also be a (slight) problem. Just so you know, I would like to build the system myself for the satisfaction and experience, not necisarily to save money, though that would be nice. I don't plan on renting it out or anything unless it's been really proven and inspected, etc.
Someone said that they thought I was trying to hide behind my "Kilowatt" alias, but I'm not, and my name, e-mail address, etc. are available on the site. To make it clearer yet, my name is Chris Fredin, my main e-mail is fredin@mcn.net, e-mail me if you like, and I'm 16 and near the end of my sophomore year in high school. Think whatever you want about me. By the way, I don't claim to be invincible or have non-conductive skin or audio expertice. Another thing, you all know that I kind of want to go with my plans as they are (basically, but there will no doubt be some more big changes to come), and you all get pissed off and say you've had it with me because I don't change my plans to just how you say, and you think I'm ignoring you out of stubborness and there are many many posts on the site that put me down for this. It's not true. What am I supposed to do? Just shut up about my project because I have certain specs and features in mind? Obviously, it's better to stay and listen to the advice that may save me grief and maybe even my life despite some of your discouraging posts.
Post like this: "For some reason Kilowatt is fixated on the price of amplifiers as being the big issue." and this: "From his posts on this thread, it seems to me that this KILLERWATT guy does not really have any proper idea of what he is talking about." are NOT true.
And post liek this: "On further reflection, IMO this guy is a BIG TOSSER !. You are correct Helix, I'm not going to bother with this clown any further." All I can say is- fine! if that's what you think of me, leave and don't listen to me.
Perhaps you think I should regret coming up with this 7200W idea, as it is a burden to me, and I will have to do a lot of thinking and a lot of work to complete it, and I get put down about it in every thread, but I'm in it now, and it will (hopefully) be soooooo cool when it's done.
Lets see, where do I begin? First of all, thanks for the advice, to those of you that have been helpful. I will of course have low level isolation transformers, DC protection, cutouts, insulated hookups, double insulation in the amp, etc. Since it will be illegal to run it in most places where 220 is present, I will likely run it form a great and powerful generator most of the time. If I'm running it (carefully) at low levels in my house or whatever, I'll just have to live with any interference that makes it through the power supply's inductive filtering. Balance might also be a (slight) problem. Just so you know, I would like to build the system myself for the satisfaction and experience, not necisarily to save money, though that would be nice. I don't plan on renting it out or anything unless it's been really proven and inspected, etc.
Someone said that they thought I was trying to hide behind my "Kilowatt" alias, but I'm not, and my name, e-mail address, etc. are available on the site. To make it clearer yet, my name is Chris Fredin, my main e-mail is fredin@mcn.net, e-mail me if you like, and I'm 16 and near the end of my sophomore year in high school. Think whatever you want about me. By the way, I don't claim to be invincible or have non-conductive skin or audio expertice. Another thing, you all know that I kind of want to go with my plans as they are (basically, but there will no doubt be some more big changes to come), and you all get pissed off and say you've had it with me because I don't change my plans to just how you say, and you think I'm ignoring you out of stubborness and there are many many posts on the site that put me down for this. It's not true. What am I supposed to do? Just shut up about my project because I have certain specs and features in mind? Obviously, it's better to stay and listen to the advice that may save me grief and maybe even my life despite some of your discouraging posts.
Post like this: "For some reason Kilowatt is fixated on the price of amplifiers as being the big issue." and this: "From his posts on this thread, it seems to me that this KILLERWATT guy does not really have any proper idea of what he is talking about." are NOT true.
And post liek this: "On further reflection, IMO this guy is a BIG TOSSER !. You are correct Helix, I'm not going to bother with this clown any further." All I can say is- fine! if that's what you think of me, leave and don't listen to me.
Perhaps you think I should regret coming up with this 7200W idea, as it is a burden to me, and I will have to do a lot of thinking and a lot of work to complete it, and I get put down about it in every thread, but I'm in it now, and it will (hopefully) be soooooo cool when it's done.
Hey please be nice to KiloWatt!!!
He wan't to learn something. So help him instead!
When i was in this age (16) the worst thing was to get hit by "elder" people ... Maybe this forum should have a "birthday" in the profile??
Sonny
He wan't to learn something. So help him instead!
When i was in this age (16) the worst thing was to get hit by "elder" people ... Maybe this forum should have a "birthday" in the profile??
Sonny
Hi Kilowatt,
For what it's worth I have never put you down. And in fact I have explained why what you are planning is not totally crazy to several people that are scared to death of what you described. By the way just so you understand in other countries you couldn't do what you are planning safely. That is the reason why people like mrfeedback are so concerned about your plans, in their countries what you are describing would be an electrocution waiting to happen.
I am glad you are not easily chased off. I personnally would not attempt this project without having worked my way up through a series of several smaller models first to prove out my design. After all it is going to be very expensive if you make a mistake or miscalculation somewhere and smoke all of your output devices the first time you power the thing up. I should know since I have done exactly that. About the only good thing about having been forced to buy 25 of each of the output devices was that at least I had plenty of spare parts "ouch".
About the "fixated on the price" comment. You have repeatedly stated in earlier threads that the main reason you are pursuing this design is to save the cost of the power supply transformer so there is some justification to this observation is there not? This is not a slam, I just don't think you realize how much high power speakers and crossovers cost. The amp you are building is probably only going to end up being more than 10 to 20% of your total system cost so saving a few dollars on the amps isn't going to have a big impact on the total cost of creating your system.
I will say again if I were you (which I'm not) I would find a local PA company and go hang around there after school. The pro audio business still follows the master and apprentice model so if you make yourself useful you have a good chance of being taken under someone's wing and learning more about this business than I will ever know.
Only after you start actually putting together and using real high power systems will you understand what it really takes to do this. Serious kick butt sound systems are built around the speakers, not the amps. You can pick up older used amps for peanuts. I have some old Crest amps I would love to unload, my QSC amps put out twice the power and weigh half as much and my back isn't getting any younger.
Phil
For what it's worth I have never put you down. And in fact I have explained why what you are planning is not totally crazy to several people that are scared to death of what you described. By the way just so you understand in other countries you couldn't do what you are planning safely. That is the reason why people like mrfeedback are so concerned about your plans, in their countries what you are describing would be an electrocution waiting to happen.
I am glad you are not easily chased off. I personnally would not attempt this project without having worked my way up through a series of several smaller models first to prove out my design. After all it is going to be very expensive if you make a mistake or miscalculation somewhere and smoke all of your output devices the first time you power the thing up. I should know since I have done exactly that. About the only good thing about having been forced to buy 25 of each of the output devices was that at least I had plenty of spare parts "ouch".
About the "fixated on the price" comment. You have repeatedly stated in earlier threads that the main reason you are pursuing this design is to save the cost of the power supply transformer so there is some justification to this observation is there not? This is not a slam, I just don't think you realize how much high power speakers and crossovers cost. The amp you are building is probably only going to end up being more than 10 to 20% of your total system cost so saving a few dollars on the amps isn't going to have a big impact on the total cost of creating your system.
I will say again if I were you (which I'm not) I would find a local PA company and go hang around there after school. The pro audio business still follows the master and apprentice model so if you make yourself useful you have a good chance of being taken under someone's wing and learning more about this business than I will ever know.
Only after you start actually putting together and using real high power systems will you understand what it really takes to do this. Serious kick butt sound systems are built around the speakers, not the amps. You can pick up older used amps for peanuts. I have some old Crest amps I would love to unload, my QSC amps put out twice the power and weigh half as much and my back isn't getting any younger.
Phil
I see it both ways - in a sense, if you see someone doing something dangerous, you should say something.
On the otherhand, hell, I get in race cars, smoke, and all other sorts of stuff. IF someone knows the risk, and is willing to take it, so be it.
And finally, the worst things adults do to kids is kill their imaginations - amazingly enough what we think impossible as adults is often proven wrong by kids who don't listen to us.
(Although, I do agree with the idea of humping some pro gear around would be useful. I did it. Which made me appreciate some folks gear. Hump one of those 1K pound Showco speaker cabs around and you like the lightwieght stuff.)
On the otherhand, hell, I get in race cars, smoke, and all other sorts of stuff. IF someone knows the risk, and is willing to take it, so be it.
And finally, the worst things adults do to kids is kill their imaginations - amazingly enough what we think impossible as adults is often proven wrong by kids who don't listen to us.
(Although, I do agree with the idea of humping some pro gear around would be useful. I did it. Which made me appreciate some folks gear. Hump one of those 1K pound Showco speaker cabs around and you like the lightwieght stuff.)
I didn't think Hoary knew anything about PRO-SOUND. 😀
Hello Chris, it is good to hear that you are still in one piece.
And thanks to other posters for the timely advices and experiences.
Chris, even better to get a job as local crew on international touring shows - this is guaranteed to cook your mind !.
Although I have not done any for 2 years or so (too busy running my repair shop), I have worked as local crew at the local (Perth) major venue, for shows such as AC/DC, Kiss, U2, M. Jackson, etc, etc, etc........(long list).
This sort of experience really opens up the senses to what BIG audio is all about, and the equipment, and the whole organizational thing.
If you are polite, you can get to to see/hear the afternoon soundchecks, and ask some intelligent questions of the sound operators.
AND, hey, you get to see the shows for free, AND get paid !. 😀
I'd be going down the Local/Touring experience route before getting my self in too much deeper.
Phil is absoloutely correct - the amplification is actually a minor cost in the whole scheme - there is the costs of speakers, desk, effects rack, multicores, etc, etc, to pay for first.
ALSO - One BIG amp is not a good idea because of redundancy - Pro rigs run plenty of amps, so if one goes down mid show, it does not really matter.
Regards, Eric.
Hello Chris, it is good to hear that you are still in one piece.
And thanks to other posters for the timely advices and experiences.
Chris, even better to get a job as local crew on international touring shows - this is guaranteed to cook your mind !.
Although I have not done any for 2 years or so (too busy running my repair shop), I have worked as local crew at the local (Perth) major venue, for shows such as AC/DC, Kiss, U2, M. Jackson, etc, etc, etc........(long list).
This sort of experience really opens up the senses to what BIG audio is all about, and the equipment, and the whole organizational thing.
If you are polite, you can get to to see/hear the afternoon soundchecks, and ask some intelligent questions of the sound operators.
AND, hey, you get to see the shows for free, AND get paid !. 😀
I'd be going down the Local/Touring experience route before getting my self in too much deeper.
Phil is absoloutely correct - the amplification is actually a minor cost in the whole scheme - there is the costs of speakers, desk, effects rack, multicores, etc, etc, to pay for first.
ALSO - One BIG amp is not a good idea because of redundancy - Pro rigs run plenty of amps, so if one goes down mid show, it does not really matter.
Regards, Eric.
What someone learns in this job and is very important is the correct grounding of the equipment. I have heard from profis in this work that a lot of problems come up from bad grounding of the system. Problems like humms buzzings and so on. Its a very interesting job but needs all your time. Very long hours. Its not for me I guess.
Unfortunately, there's not much opportunity like that around here. If there was an AC/DC concert within 500 miles of my hometown, I'd go😀 .
I'm not sure how I would go about getting "big sound" experience. All I can really do is read some books on amplifier design, which I have, build some amps (like I'm doing, I'm working on a Leach amp now) and then maybe try to get something to run on +/-160V and build up to what I want- the 900W into 12ohm channel. I've looked at Holton's and Slone's designs for some insight. Most of my challenge is in getting the amp to run well and stable with the high supply right?
As far as speakers go, I was going to tri-amp it with my big amp as just bass, but I may go back to my original plan of just tri-amping it using the 8 channels of the beast alone, as they will each have an adjustable crossover. No other amps. This will take away a lot of my power, but maybe I can make up for it in speakers. I'll still be left with a bad-*** system. Because of funding, it'll be a deal where I just have the amp and just enough speakers to handle the power, but I can always stack on more speakers. I won't need anything else but the amp, speakers, cables, EQ, and source for what I'll be doing.
P.S. Hope no one thinks too differently about me if you didn't know my age before.
I'm not sure how I would go about getting "big sound" experience. All I can really do is read some books on amplifier design, which I have, build some amps (like I'm doing, I'm working on a Leach amp now) and then maybe try to get something to run on +/-160V and build up to what I want- the 900W into 12ohm channel. I've looked at Holton's and Slone's designs for some insight. Most of my challenge is in getting the amp to run well and stable with the high supply right?
As far as speakers go, I was going to tri-amp it with my big amp as just bass, but I may go back to my original plan of just tri-amping it using the 8 channels of the beast alone, as they will each have an adjustable crossover. No other amps. This will take away a lot of my power, but maybe I can make up for it in speakers. I'll still be left with a bad-*** system. Because of funding, it'll be a deal where I just have the amp and just enough speakers to handle the power, but I can always stack on more speakers. I won't need anything else but the amp, speakers, cables, EQ, and source for what I'll be doing.
P.S. Hope no one thinks too differently about me if you didn't know my age before.
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