My first post about a high power mono block went well. Thanks to all. It did help. But I have to ask a few more questions.
I know that 500wrms@8ohms is a load of power. But it's done everyday by many. My moto is, If it's man made, this man can learn to do it!
Some local hifi techs that I know suggest taking a working amp design, maybe 300w/8ohms and altering it for the power I'm looking for. The names Marshall and Peavey have come up.
This seems like a good idea to me. If I know anything here it's that I don't know enough to start from scratch. But reengineering a working design has got to be tricky.
Also, I'm trying to figure in to all this that I listen to heavy metal. The music is distorted, low frequency and, should be played loud!
Do any of you think it's better to mod a working design?
Does the circuitry class matter?
If so, why?
Does my choice in music affect the design?
Any info helps, so please share it with me.
Roger
I know that 500wrms@8ohms is a load of power. But it's done everyday by many. My moto is, If it's man made, this man can learn to do it!
Some local hifi techs that I know suggest taking a working amp design, maybe 300w/8ohms and altering it for the power I'm looking for. The names Marshall and Peavey have come up.
This seems like a good idea to me. If I know anything here it's that I don't know enough to start from scratch. But reengineering a working design has got to be tricky.
Also, I'm trying to figure in to all this that I listen to heavy metal. The music is distorted, low frequency and, should be played loud!
Do any of you think it's better to mod a working design?
Does the circuitry class matter?
If so, why?
Does my choice in music affect the design?
Any info helps, so please share it with me.
Roger
Hi,
go classAB, some others might recommend the new classes for a bass driver.
Do not consider ClassA- too hot and at your voltages you must keep the output cool so you cannot go Hi Bias either.
The SOA of the output is seriously affected by transistor case temperature forcing ultra heatsinks into your design. Probably fan cooled, the fan noise might not be a problem after a couple of nights. You will have gone deaf by then.
good luck
go classAB, some others might recommend the new classes for a bass driver.
Do not consider ClassA- too hot and at your voltages you must keep the output cool so you cannot go Hi Bias either.
The SOA of the output is seriously affected by transistor case temperature forcing ultra heatsinks into your design. Probably fan cooled, the fan noise might not be a problem after a couple of nights. You will have gone deaf by then.
good luck
Hi Roger!
I guess that in most comercial designs you would need to change the
power supply..... transistors with required voltage rating (input and VAS) and higher voltage rating + power in the output stage....
power... adjust all bias settings accordingly....
...adjust frequency compensation....
One convinient point:
You can use the mechanical set up and may be some protections as
delayed speakers relay ....
But by the way: For your ears the difference between 300W and
500W is just a small step. Just 2.2 dB. Not worth much efforts!!
But you could pick a working amp which delivers 2 x 300W into 4 Ohms and bridge it to a mono 600W/8Ohm mono block...
My
....be careful, you might loose some fun after hammering your ears to deafness....
By Markus
I guess that in most comercial designs you would need to change the
power supply..... transistors with required voltage rating (input and VAS) and higher voltage rating + power in the output stage....
power... adjust all bias settings accordingly....
...adjust frequency compensation....
One convinient point:
You can use the mechanical set up and may be some protections as
delayed speakers relay ....
But by the way: For your ears the difference between 300W and
500W is just a small step. Just 2.2 dB. Not worth much efforts!!
But you could pick a working amp which delivers 2 x 300W into 4 Ohms and bridge it to a mono 600W/8Ohm mono block...
My
....be careful, you might loose some fun after hammering your ears to deafness....
By Markus
Thanks for the health advise, guys. Do you handle bad backs, too? Obviously kidding!ChocoHolic said:@Andrew:
... I see you had the same concerns about Roger's health...
...overlapping answers...
Really, the input is great. A/B class did seem to have advantages. Less heat being one of them.
I posted about this when I first joined the site. For ideas on what it take to do it. I know that 300w will be nearly as loud as 500w. And I'm kicking around another suggestion that I go with 400w/8ohms. I'm just trying to match my driver ratings as close as I can.
I am worried about my choice in music. I need an amp I can lean on pretty hard without hurting it. But it must be able to reproduce what I put into it. Which will be very heavy and distorted anyway. Will my love for metal make an amp design impossible?
Roger
I would think that you might need some headroom with that type of music. I would suspect also a faster slew rate would help keep up with the harmonics (or distortion)generated in Metal music. This distortion is specific and can be easily "distorted". Faster slew would certainly keep up with the high freq.'s better. Too much freq. compensation and it may sound muddy.
I would buy an amp that will not blow the speaker drivers, i e rated less. Speaker diaphrams don't move linear after about 60% anyway. Might even under-rate the speakers a little for these tunes.
Avid Tool listener...
Chris
I would buy an amp that will not blow the speaker drivers, i e rated less. Speaker diaphrams don't move linear after about 60% anyway. Might even under-rate the speakers a little for these tunes.
Avid Tool listener...
Chris
hmm, your imense power requiremets got me thinking, Mr.Elliot has some nice projects out on his page, this being a 500W sub amp, but there is nothing that keeps you from using this as a fullrange amp..
http://www.sound.westhost.com/project68.htm
the output devices used are fairly fast devices from on semi, i see no reason for this amp not to have a decent slew rate..
it may be a possibility?
-marius
(immortal - Wrath from Above)
Metal Roxx
http://www.sound.westhost.com/project68.htm
the output devices used are fairly fast devices from on semi, i see no reason for this amp not to have a decent slew rate..
it may be a possibility?
-marius
(immortal - Wrath from Above)
Metal Roxx
As a Heavy Metal music lover myself, one thing with the genre is that it doesn't have too much of a dynamic range (everything is loud, there are no quiet bits really). This meens that you require less headroom than say classical. 250W will go quite deafening with this style of music unless you have already had your hearing damaged by standing too close to the speaker stacks at Iron Maiden concerts
Lets face it 500W is only 3db more than 250W and after 2 minutes just before clipping you won't be able to tell the difference
Chris
Lets face it 500W is only 3db more than 250W and after 2 minutes just before clipping you won't be able to tell the difference
Chris
I would love a good high power tube. But the cost isn't bearable right now.Peter M. said:
Hearing isn't bad yet. But again, my concern is the drivers I have call for 500w. I'd like to get close to that. No other reason, really.Chris Jennings said:As a Heavy Metal music lover myself, one thing with the genre is that it doesn't have too much of a dynamic range (everything is loud, there are no quiet bits really). This meens that you require less headroom than say classical. 250W will go quite deafening with this style of music unless you have already had your hearing damaged by standing too close to the speaker stacks at Iron Maiden concerts
Lets face it 500W is only 3db more than 250W and after 2 minutes just before clipping you won't be able to tell the difference
Chris
Roger
Even though is says it will handle 500W RMS, actually putting 500W RMS into it will reduce the life expectancy, stretch the spider, and is rough on the bass reflex. You might look into using more speakers with a seperate dynamic range, more amp channels with less power each. Then you can filter the inputs instead of the outputs to get full range overall cutting the bandwidth of each amp and boosting efficiency. Also correct for phase differences in the responce of the different speakers. You can then use a large amp for bass and it won't have to be that fast. Since the bass is where most power is used, the higher freq., faster amps can be much smaller.
I wouldn't put more than 350-400W continuous to this speaker. Sound quality would be better. Of course there is no substitute for LOUD!!
I wouldn't put more than 350-400W continuous to this speaker. Sound quality would be better. Of course there is no substitute for LOUD!!
Are the speakers you are using/planning on using bi-ampable? Mids and tweeters don't need anywhere near that power. One option is a lower power but very clean amp for mids/highs then a high power but 'dirty' amp for the lows. Distortion is not as much of an issue with bass frequencies. When a speaker is rated at 500W and it is say, a three way so there are 3 drivers in the box the total power may be 500W but each speaker handles only a portion of that power. A long time ago I burned some tweeters this way even though the box was rated plenty high I ran a sine at 20kHz in the tweeter with about 100W. Sucker was burned in no time (not to mention I can't hear 20kHz so was a REALLY stupid thing to do).
When I did DJ and live sound we were always at least bi-amping and most times tri-amping. Gives you the most control, best sound and then all that power can be dedicated to where you want it.
When I did DJ and live sound we were always at least bi-amping and most times tri-amping. Gives you the most control, best sound and then all that power can be dedicated to where you want it.
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