Thanks, guys.
I talked with a friend yesterday who is into Marshall pro gear. He said that they are making some 500w models on 80v rails. I haven't looked into it yet. Just wondering why 100v is your figure, not discounting you.
EDL, you images did not appear on your posts. I'd love to see them. You can email them to me if you'd like.
5 pair of o/p is not too bad. I expected 6-10 pair for stability at that power level. I've not used the peices you mentioned before but will try them for sure. I still think about common TO-3's when I think about bipolars. It's just what I've used most.
Thanks for your help, again! This site rocks!
Roger
I talked with a friend yesterday who is into Marshall pro gear. He said that they are making some 500w models on 80v rails. I haven't looked into it yet. Just wondering why 100v is your figure, not discounting you.
EDL, you images did not appear on your posts. I'd love to see them. You can email them to me if you'd like.
5 pair of o/p is not too bad. I expected 6-10 pair for stability at that power level. I've not used the peices you mentioned before but will try them for sure. I still think about common TO-3's when I think about bipolars. It's just what I've used most.
Thanks for your help, again! This site rocks!
Roger
hello Roger!
500W on 8ohm means 89,5V peak voltage. The losses are: 11,18V ripple voltage if the caps are 10000uF per rail, 3V: output transisitor "Uce-loss", 1V for emmiter resistor, 1V for rectifier.
So 90V+11V+3V+1V+2V=106V
This is the need for idle rail voltage. So you need a 2*75V-AC transformer.
80V rails (if they aren't stabilized) is enough for 280-300W-RMS (8ohm) power.
I think these amp's are working for 4ohm loudspeakers, so they give 450-500W RMS power on 4ohm.
I'll post the pics in another way.
500W on 8ohm means 89,5V peak voltage. The losses are: 11,18V ripple voltage if the caps are 10000uF per rail, 3V: output transisitor "Uce-loss", 1V for emmiter resistor, 1V for rectifier.
So 90V+11V+3V+1V+2V=106V
This is the need for idle rail voltage. So you need a 2*75V-AC transformer.
80V rails (if they aren't stabilized) is enough for 280-300W-RMS (8ohm) power.
I think these amp's are working for 4ohm loudspeakers, so they give 450-500W RMS power on 4ohm.
I'll post the pics in another way.
for 33000uF caps per rail you'll need only 98V. that means a 2*69V-AC trafo.
anyway I would suggest you to build two 400W-8ohm-RMS amp.
this way you will need 89V rails (2*89V-AC trafo, rated at 600VA) if you use two 22000uF/100V caps per rail.
400W would be easier, because:
-you can use 200V output devices (for example mj15022/23)
-you can easly buy 100V rated filter caps
Rembember that Andrew wrote: 200-220V DC is between the rails! thats really dangerous! (60V can be sometimes lethal!)
anyway I would suggest you to build two 400W-8ohm-RMS amp.
this way you will need 89V rails (2*89V-AC trafo, rated at 600VA) if you use two 22000uF/100V caps per rail.
400W would be easier, because:
-you can use 200V output devices (for example mj15022/23)
-you can easly buy 100V rated filter caps
Rembember that Andrew wrote: 200-220V DC is between the rails! thats really dangerous! (60V can be sometimes lethal!)
That is true. What I am concerned about is the drivers being rated 500wrms. I've killed many a voice coil with half it's power rate, but never with more. I all ways try to over power a speaker and keep the volume control down. (overpower=10-20% more power than rated rms)edl said:
Even the high quality amps I've used don't seem to drive large, high power woofers very well at loud levels. So I was hoping to get close to their rating.
As for the high voltage, I don't mind working with it. I do it all day long. But I don't want to be locked in to buying specailty caps and toro's. Plus, I do like to use the TO-3's for outputs. These posts have given me much to think about. I'll contact pyle to see what they think about 400w instead of 500w. But I think it's a better idea, anyway. Thanks again guys,
Roger
RogerG said:
Do you have big rocks taped to the cones? Otherwise permanent hearing loss would occur with sustained listening at 10W. I ran 4x15 inch drivers in big horns with a 60W amp and I never came remotely close to clipping them - not even when my brother and I would crank up Tool or Fear Factory until we couldn't stand it any louder. I could easily drown out my brother's metal band practicing in the basement with this rig.
With highly compressed, heavy metal music, 100W would probably induce pain. Next stop: DIYHearingAids.com
You might want this sort of power, but you don't need it at home - and with drivers loaded in a proper horn it's insanity.
He came for amp advice not health related advice. Let him have his 500 watts. 
RogerG: In PA rigs, the rating is usually at 4 ohms so a 500 watt amp is actually 300 watts into 8 ohms. This can be achieved with a 500va toroid and 62-0-62 vac secondaries. If our friend decides to go non-bridged, then the MJ21193/4's are hard to beat at 100vdc rails, they have the best 100v SOAR's out there. Even better than MJ21195/96 at 100v (200vce).
RogerG: In PA rigs, the rating is usually at 4 ohms so a 500 watt amp is actually 300 watts into 8 ohms. This can be achieved with a 500va toroid and 62-0-62 vac secondaries. If our friend decides to go non-bridged, then the MJ21193/4's are hard to beat at 100vdc rails, they have the best 100v SOAR's out there. Even better than MJ21195/96 at 100v (200vce).
Thanks for standing up for the new guy, K! I feel at home,now. HAHA! Bad pun,I know.K-amps said:He came for amp advice not health related advice. Let him have his 500 watts.
RogerG: In PA rigs, the rating is usually at 4 ohms so a 500 watt amp is actually 300 watts into 8 ohms. This can be achieved with a 500va toroid and 62-0-62 vac secondaries. If our friend decides to go non-bridged, then the MJ21193/4's are hard to beat at 100vdc rails, they have the best 100v SOAR's out there. Even better than MJ21195/96 at 100v (200vce).
Anyhow, Edl suggested going 400/8. The more I think about it, the better that sounds. 400/8 is what, 650/4? I think that'll do us. I have a habit of over-building things. So, if a 500Va toroid will work, I'll go with 600-700Va and, so on for other parts. I don't mind spending money on power supplies, outputs and drivers and, heatsinks. As experience tells me these are the most critical devices for stability.
I dought these amps would ever see a driver of less than 8ohms. But some 8ohm prosound woofers can produce loads of 3.5ohms durring playback. So, I would want to make it as tollerant of load as I could. Crown seems to be very good at this, but you really pay for it.
Anyhow, I know that this is a tall bill. But it can be done. All though I'll conceed that it may not be much cheaper than buying a corporate brand. But it will be much more fun to build it myself. With the help of all you, of course! Thanks
Roger
RogerG said:
Roger,
I never said the MJ's are 200 v devices
only that at 200v rails there is no better BJT pair out there in terms of robustness.In the 250v range, you have the MJ150024/25 then the 21193/94/95/96 devices. In real life they differ in terms of what rails are good for them. I have known the 21193/94 to be the better ones on 200v rails. At 180v rails it s a toss.
600Va with 89V rails is what Edl posted earlier. Sorry, type-o!
Why not 500/8? Well, it was my starting point. But as you know, you start, then refine, fine tune, then build. It's shown to me that 500/8 will take >100V rails. I wouldn't be concerned with that, except that I would like to use common parts, ie rated for 100V.
As I've said, I'm no designer, more a repair tech. Slightly more, though. So I don't have the rules and equations sunk in memory for knowing what it takes to make power. I will, though. I came here to get educated on what I don't know.
So when I ask a question like; "what will it take to blow a 1000w driver out of it's basket and make me deaf as stone simultainiously?", it's because I want to know.
Yes, I am very aware that 30-50w can produce db levels that will blow your ears out. Klipsh-cornwall(spelling) proved that one beyond discussion. And as far as needing vs wanting 400-500 watts; I don't need a 500bhp 455 GTO either. But a friend and I are building one anyway! After which, the second 450bhp, 383cid fiero project will get under way.
At this point, your posts have been more condescending than helpful. If you have a differing opinion, state it and, leave it be. I will consider it, as you most likely have more experiance than I. But if you would like me to take what you say to heart, please back it up with facts about the question. Instead of "With highly compressed, heavy metal music, 100W would probably induce pain. Next stop: DIYHearingAids.com"
Sorry to the rest of you that you've had to sit through that.
Jeff, if you would like to share your knowledge of what a low power amp can do with me further, please email me about it. I will take emails from this site.
Roger
Why not 500/8? Well, it was my starting point. But as you know, you start, then refine, fine tune, then build. It's shown to me that 500/8 will take >100V rails. I wouldn't be concerned with that, except that I would like to use common parts, ie rated for 100V.
As I've said, I'm no designer, more a repair tech. Slightly more, though. So I don't have the rules and equations sunk in memory for knowing what it takes to make power. I will, though. I came here to get educated on what I don't know.
So when I ask a question like; "what will it take to blow a 1000w driver out of it's basket and make me deaf as stone simultainiously?", it's because I want to know.
Yes, I am very aware that 30-50w can produce db levels that will blow your ears out. Klipsh-cornwall(spelling) proved that one beyond discussion. And as far as needing vs wanting 400-500 watts; I don't need a 500bhp 455 GTO either. But a friend and I are building one anyway! After which, the second 450bhp, 383cid fiero project will get under way.
At this point, your posts have been more condescending than helpful. If you have a differing opinion, state it and, leave it be. I will consider it, as you most likely have more experiance than I. But if you would like me to take what you say to heart, please back it up with facts about the question. Instead of "With highly compressed, heavy metal music, 100W would probably induce pain. Next stop: DIYHearingAids.com"
Sorry to the rest of you that you've had to sit through that.
Jeff, if you would like to share your knowledge of what a low power amp can do with me further, please email me about it. I will take emails from this site.
Roger
RogerG said:
Edl is A-ok on his advice. You can get 400 watts 8 ohms and 650 watts 4 ohms using a 800va Transformer with 62-0-62 vac volt rating with 86 vdc rails. If you want some Toroids for this, i can direct you to some cost effective vendors in the US.
A 500va toroid will drop rails and you will end up with 300-350 watts depending. A 1kva toroid with 95% regulation will get you up to 430 watts into 8 ohms. (All 86vdc). Using 93vdc will get you 470 watts 8 ohms and 96vdc with 95% regulation will get you 500 watts 8 ohms, however you will not find many circuits out there for 96vdc rails.
K-amps said:
Roger,
I never said the MJ's are 200 v devices
In the 250v range, you have the MJ150024/25 then the 21193/94/95/96 devices. In real life they differ in terms of what rails are good for them. I have known the 21193/94 to be the better ones on 200v rails. At 180v rails it s a toss.
Sorry, I missunderstood. I have never used the 211**'s before so I will take you at your word. How do they sound compaired with 15022/3's? If you can compare the two.
Roger
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