Hey everyone. This is totally insane. But I intend to render my
design of a line of high power amplifiers.
There will be 6 models in the line.
ZN50 = 50W @ 8ohms
ZN65 = 65W @ 4ohms
ZN300 = 300W @ 4ohms
ZN450 = 450W @ 4ohms
ZN500 = 500W @ 4ohms
ZN2000 = 1000 X 2 @ 4ohms / 2000W X 1 @4ohms
I would like some ideas as to good output transistors to use in these amplifiers.
The ZN2000 already has a complete power supply that I built which will suffice for up to two ZN2000's before reaching its limit.
The PSU output voltage is regulated at +/- 50V so that I may facilitate about an 80V swing in bridge mode.
This means that the transistors don't have to be high voltage, but they must be high in current.
Any suggestions for transistors that will be good as outputs in all these units? They will all be built with the same bandwidth capability and thus need a good high frequency transistor that will have a good slew rate. The transistors will operate in push-pull class AB.
Any ideas??
2000W too insane???
design of a line of high power amplifiers.
There will be 6 models in the line.
ZN50 = 50W @ 8ohms
ZN65 = 65W @ 4ohms
ZN300 = 300W @ 4ohms
ZN450 = 450W @ 4ohms
ZN500 = 500W @ 4ohms
ZN2000 = 1000 X 2 @ 4ohms / 2000W X 1 @4ohms
I would like some ideas as to good output transistors to use in these amplifiers.
The ZN2000 already has a complete power supply that I built which will suffice for up to two ZN2000's before reaching its limit.
The PSU output voltage is regulated at +/- 50V so that I may facilitate about an 80V swing in bridge mode.
This means that the transistors don't have to be high voltage, but they must be high in current.
Any suggestions for transistors that will be good as outputs in all these units? They will all be built with the same bandwidth capability and thus need a good high frequency transistor that will have a good slew rate. The transistors will operate in push-pull class AB.
Any ideas??
2000W too insane???
I think you might be asking a bit much to expect 1 or 2 Kw from +/-50v rails.
This pretty much precludes the use of Mosfets due to the extra driving voltage swing you'd need , which is a shame 'cos they are quite cheap for high current outputs.
to get 1Kw from these rails you would need to swing about 20A almost rail-rail discount any losses, which in reality would probably mean closer to 30A allowing for output driver losses.
I was told not to be optimistic when I said I wanted 500w from +/- 70v rails..... maybe the smarter folk in the group can give a better answer.
Ray
This pretty much precludes the use of Mosfets due to the extra driving voltage swing you'd need , which is a shame 'cos they are quite cheap for high current outputs.
to get 1Kw from these rails you would need to swing about 20A almost rail-rail discount any losses, which in reality would probably mean closer to 30A allowing for output driver losses.
I was told not to be optimistic when I said I wanted 500w from +/- 70v rails..... maybe the smarter folk in the group can give a better answer.
Ray
I pulled up a spreadsheet I made a while back that relates desired output to transformer requirements. It seems to work at low to moderate powers so I can't say for sure the extrapolation is 100% valid. Nonetheless, here is what it tells me:
For 500W/ch @ 8ohms you need a transformer rated 72-0-72, 1,400VA (2-channels). 2,800VA if the load will be 4 ohms.
It doesn't say directly what you need to get 1,000W/ch @ 4 ohms - Watts don't really double just by attaching a 4ohm speaker. I would guess to get 1kW @4 ohm you need the equivalent of 700w/ch @ 8 ohms, which yields an 85-0-85 4kVA transformer (2-channels). And of course many parallel output devices.
As an aside, the same spreadsheet says you will want 140,000uF smoothing capacitance per RAIL.
An additional nice benefit is you can use those cool huge gold plated fuses that I see in the catalogs for automotive sound.
For 500W/ch @ 8ohms you need a transformer rated 72-0-72, 1,400VA (2-channels). 2,800VA if the load will be 4 ohms.
It doesn't say directly what you need to get 1,000W/ch @ 4 ohms - Watts don't really double just by attaching a 4ohm speaker. I would guess to get 1kW @4 ohm you need the equivalent of 700w/ch @ 8 ohms, which yields an 85-0-85 4kVA transformer (2-channels). And of course many parallel output devices.
As an aside, the same spreadsheet says you will want 140,000uF smoothing capacitance per RAIL.
An additional nice benefit is you can use those cool huge gold plated fuses that I see in the catalogs for automotive sound.
Duo said:Hey everyone. This is totally insane. But I intend to render my
design of a line of high power amplifiers.
There will be 6 models in the line.
ZN50 = 50W @ 8ohms
ZN65 = 65W @ 4ohms
ZN300 = 300W @ 4ohms
ZN450 = 450W @ 4ohms
ZN500 = 500W @ 4ohms
ZN2000 = 1000 X 2 @ 4ohms / 2000W X 1 @4ohms
I would like some ideas as to good output transistors to use in these amplifiers.
The ZN2000 already has a complete power supply that I built which will suffice for up to two ZN2000's before reaching its limit.
The PSU output voltage is regulated at +/- 50V so that I may facilitate about an 80V swing in bridge mode.
This means that the transistors don't have to be high voltage, but they must be high in current.
Any suggestions for transistors that will be good as outputs in all these units? They will all be built with the same bandwidth capability and thus need a good high frequency transistor that will have a good slew rate. The transistors will operate in push-pull class AB.
Any ideas??
2000W too insane???
Think big! I hear they have a used nuclear power plant for sale shortly in North Korea. That'll take care of most of your worries....
Jan Didden
PS You may want to skip the 50, 300 and 450W versions. They are barely differing in perceived sound level to the 65 and 500w versions respectively.
Thanks for all the replies.
Firstly, I know 45volt rails sounds quite small. The point is, to get 2000W into 4ohms, I will be bridging two amplifiers that each have rails of 45volts. This means around 90V swing into the speaker.
Secondly, the reason for so many different models of amplifiers is that there will be very different requirements and uses for each model.
I know, 450 and 500 is an extremely small difference, but the amps will have different designs and features.
Really, I might just make a model for 500W instead of one for 300, one for 450, and one for 500.
I still have to conceptualize a bit.
Anyway, any ideas for high current and medium voltage audio output transistors? I'm definitely looking for high quality here!
Thanks.
Firstly, I know 45volt rails sounds quite small. The point is, to get 2000W into 4ohms, I will be bridging two amplifiers that each have rails of 45volts. This means around 90V swing into the speaker.
Secondly, the reason for so many different models of amplifiers is that there will be very different requirements and uses for each model.
I know, 450 and 500 is an extremely small difference, but the amps will have different designs and features.
Really, I might just make a model for 500W instead of one for 300, one for 450, and one for 500.
I still have to conceptualize a bit.
Anyway, any ideas for high current and medium voltage audio output transistors? I'm definitely looking for high quality here!
Thanks.
With 50 volt rails especially unregulated ones you will not
be able to reach your design specs.
My uberamp uses regulated +/- 65 volt rails and in bridge
form with 48 output transistors can only put out 800@8
or 1600@4.
Think Mj21195/mj21196. Lots of them. With +/-75 volts
and 60 output transistors you will still barely get to 2000@4.
The SOA will be extremely close.
be able to reach your design specs.
My uberamp uses regulated +/- 65 volt rails and in bridge
form with 48 output transistors can only put out 800@8
or 1600@4.
Think Mj21195/mj21196. Lots of them. With +/-75 volts
and 60 output transistors you will still barely get to 2000@4.
The SOA will be extremely close.
I picked the aussieamplifiers.com av800 as my choice
for DIY monster amp. It was tested at 550w@ 8 ohm,
1100w @ 4 ohm, 1600w @ 2 ohm, 2 ohm being short term
test, +110V rails, 20 output stage transistors. (1kw version)
The PCB layout I'm doing has different versions,
24, 28, 40, 60 output transistor per channel.
Realistically, the 60 will not be made by me, maybe
if I lose my mind some more, I will try the 40 version.
These are non-bridged power ratings.
Bridged mode = scary power , the power supply is your
bottleneck.
I'm almost done with my reference pcb layout for the
24 and 28 version. Almost done integrating various
protection circuits into the basic av800 design,
been testing the circuits on the bench for a few weeks.
For 1 ohm or 0.5 ohm continious operation driving
monster woofers of modern era, you might want to venture
into the land of class T or D.....
/// monster amps are fun ///
/// smoke test ///
/// kabooom ////
for DIY monster amp. It was tested at 550w@ 8 ohm,
1100w @ 4 ohm, 1600w @ 2 ohm, 2 ohm being short term
test, +110V rails, 20 output stage transistors. (1kw version)
The PCB layout I'm doing has different versions,
24, 28, 40, 60 output transistor per channel.
Realistically, the 60 will not be made by me, maybe
if I lose my mind some more, I will try the 40 version.
These are non-bridged power ratings.
Bridged mode = scary power , the power supply is your
bottleneck.
I'm almost done with my reference pcb layout for the
24 and 28 version. Almost done integrating various
protection circuits into the basic av800 design,
been testing the circuits on the bench for a few weeks.
For 1 ohm or 0.5 ohm continious operation driving
monster woofers of modern era, you might want to venture
into the land of class T or D.....
/// monster amps are fun ///
/// smoke test ///
/// kabooom ////
Duo said:
If you're bridging those two channels, you should get 4,000 watts, not 2,000 watts.
We're using the Motorola MJL3281A (NPN) and MJL1302A (PNP) in the InnerSound Kilowatt Monobloc (1,000 into 8, 2,000 into 4). DigiKey's selling the Toshiba equivalents (2SC3281 and 2SA1302). The Motorolas are more linear.
se
Interesting ideas. Yeah, the TIP transistors are good transistors, but I don't think they're at all suitable for my design. I need much faster and more linear transistors. And a slightly higher voltage.
2SA1302/2SC3281 are perfect, but I didn't know that digikey sold them. I might take that up, if not, even get the Motorolas, those are very nice transistors.
The design is a two channel bridged mono amp. This is to facilitate having lower voltage supply rails and making the amps cheaper to build.
2SA1302/2SC3281 are perfect, but I didn't know that digikey sold them. I might take that up, if not, even get the Motorolas, those are very nice transistors.
The design is a two channel bridged mono amp. This is to facilitate having lower voltage supply rails and making the amps cheaper to build.
Sorry about the bridge to 4000W controversy. It's 500W unbridged and 2000 bridged. I figure I'll need 20 transistors per channel. That means 40 transistors per amp. If I use the A1302/C3281 pairs. That also means $324.80 for output transistors for both amps. Add tax and we come to $370.27 grand total. Hmmm, shipping should push it close to $390.00 or so depending on where they come from.
Anyway, when that money comes along, I have all the rest of the parts needed for building the amps.
Can't wait for that time.
Anyway, when that money comes along, I have all the rest of the parts needed for building the amps.
Can't wait for that time.
Duo said:
How are you coming up with the $324.80 figure?
If you're using 40 transistors per amp, and you're making two amps, that's 80 transistors. At the 10-99 piece pricing of $1.98, that comes to 80 x 1.98 or $158.40. If you mean you're using 40 PAIRS of transistors per amp, then at the 100 piece pricing, that comes to 160 x 1.54 or $246.40.
So what accounts for the extra $166.40 or $78.40?
se
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