custom amp

K-5BLAZER

K-5BLAZER

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I have an idea in my head on making a custom amp and would like to know if one control/driver board can run more then one pair of backplane boards
 
Gepetto

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K-5BLAZER said:
I have an idea in my head on making a custom amp and would like to know if one control/driver board can run more then one pair of backplane boards
Click to expand...
You are not the first to have that idea...will let others chime in.
 
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MarkWComer

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Ambitious project!

I wonder- pads 11 & 12 on the driver board is your power input, so that will have to attach to one power supply or another, not both at the same time. A wild assumption says that the other pads should be able to drive two sets of backplanes, but current and voltage differences in the backplane circuits may overfeed the 400 or put excess load on the 700. I think you’re asking for some sort of imbalance between the backplane sets.

Actually, this is above my electronic pedigree, but I have some suspicions...
 
K-5BLAZER

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MarkWComer said:
Ambitious project!

I wonder- pads 11 & 12 on the driver board is your power input, so that will have to attach to one power supply or another, not both at the same time. A wild assumption says that the other pads should be able to drive two sets of backplanes, but current and voltage differences in the backplane circuits may overfeed the 400 or put excess load on the 700. I think you’re asking for some sort of imbalance between the backplane sets.

Actually, this is above my electronic pedigree, but I have some su spicions...
Click to expand...
you make good points. I may have to use 2 boards or use 2 sets of 400 backplane boards. I would not mind doing 2 sets of 700 boards but I think that would be too much for a 15a braker.
 
wattsabundant

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I don't understand what this accomplishes. The first thing I thought of is the V/I limiters will interact. A one time custom transformer is going to be incredibly expensive if you can find somebody to build it.
 
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wattsabundant said:
I don't understand what this accomplishes. The first thing I thought of is the V/I limiters will interact. A one time custom transformer is going to be incredibly expensive if you can find somebody to build it.
Click to expand...
yes the transformers are the worst problem even if my idea could work I may have to give up.
 
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this is the power specs from the crown k2 if I am not mistaken it is the most powerful and only made in USA pro amp they made that did not use a fan.

Power output: 500 watts into 8 ohms, 800 watts into 4 ohms, 1,250 watts into 2 ohms (per channel, stereo mode
I do not have to hit these numbers however I do want to be able to run 2 ohm stereo
 
K-5BLAZER

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the only reasons for trying this is to do something noit one has and after a year I can not live with the fan in my 800csl and I would like a little bit more power then the 400wpc @ 4 ohms rms that it gives
 
wattsabundant

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K-5BLAZER said:
this is the power specs from the crown k2 if I am not mistaken it is the most powerful and only made in USA pro amp they made that did not use a fan.

Power output: 500 watts into 8 ohms, 800 watts into 4 ohms, 1,250 watts into 2 ohms (per channel, stereo mode
I do not have to hit these numbers however I do want to be able to run 2 ohm stereo
Click to expand...
Crown built industrial amps for MRI systems in the early 80's Maybe they still do. The Macrotech 10,000 would do10kw into half an ohm or so. It ran on 208 three phase. The output section was an H bridge, similar to what a stereo amp is configured for mono. It only put out about 50 volts but had tons of current capability. There was a claim that one amp could run the entire PA at Indy. there were 4 replaceable heatsinks with 8 ouputs on each heatsink.

A friend of mine bought a truckload, literally, of these amps for cheap. I tested them. I also used one as a variable frequency source driving a step up transformer at my day job. They had a phase loss detection circuit that I disabled for a few people who ran them single phase input at clubs.
 
K-5BLAZER

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MarkWComer said:
Technical exercise and exploration. Do it because you can!

Making a long storiy short, going to the moon only proved that rocks is rocks, but we did it!
Click to expand...
I do agree with this but wattsabundant is right so it is time to stop dreaming and ask another question how much amp can I put in a 5U chassis and not go over my 15 amps drown
 
J!m

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What about this:

My Counterpoint amps are rated at 250 into 8 ohms. The designer (Mike Elliott) told me a "trick" where the amp runs balanced (left channel HI; right channel LO) ad this gives 500 into 8 ohms with no increase in THD + Noise. Bridge operation is (if I remember) 700 watts into 8 ohms but THD + Noise is doubled. I believe these will drive 2 ohms (if not bridged) but that is not something I'm concerned with as my speakers are 6 ohm nominal.

I don't know if this will wotk with ANY amp, but the procedure is to run the balanced out from your preamp to the amp; run HI to the center pin of the left RCA and the LO to the center pin of the right RCA. FLOAT THE SHIELD AT THE EMP END (I.E. don't connect the shield at the amp end) Then your speakers run off the RED (positive) terminals ONLY- LEFT channel is the positive and RIGHT channel is the negative. Mind the polarity to avoid inverted phase.

@Gepetto do you think this would work the same with a PL or WOPL?

No fans; tons of sweet, clean power and no custom transformers (although Counterpoint had a division that made all their transformers custom for themselves and outside companies)
 
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J!m said:
What about this:

My Counterpoint amps are rated at 250 into 8 ohms. The designer (Mike Elliott) told me a "trick" where the amp runs balanced (left channel HI; right channel LO) ad this gives 500 into 8 ohms with no increase in THD + Noise. Bridge operation is (if I remember) 700 watts into 8 ohms but THD + Noise is doubled. I believe these will drive 2 ohms (if not bridged) but that is not something I'm concerned with as my speakers are 6 ohm nominal.

I don't know if this will wotk with ANY amp, but the procedure is to run the balanced out from your preamp to the amp; run HI to the center pin of the left RCA and the LO to the center pin of the right RCA. FLOAT THE SHIELD AT THE EMP END (I.E. don't connect the shield at the amp end) Then your speakers run off the RED (positive) terminals ONLY- LEFT channel is the positive and RIGHT channel is the negative. Mind the polarity to avoid inverted phase.

@Gepetto do you think this would work the same with a PL or WOPL?

No fans; tons of sweet, clean power and no custom transformers (although Counterpoint had a division that made all their transformers custom for themselves and outside companies)
Click to expand...
Yes run noninverted into one channel and inverted into other channel
 
grapplesaw

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I got a dual 500 that’s 600 watts per channel 8 ohms with a white oak control board. Far less hasssel that what you are proposing.
pm me if you want to know more
 
J!m

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Running dual mono blocks you keep the speaker cables as short as possible, which helps the amp control the speakers (improved damping factor).

Long balanced runs from pre amp to amp won’t pick up noise like a long single-ended cable can.

It was a win-win-win for me. (Other than the outlay for a second amp)
 
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