maybe offtopic by now but...
Just a thought but those transformers macbeth has seem just about perfect for building one or two hiraga monster amps. could be a nice experiment, it's a nice little amp.
greetings,
J. Zoutendijk
Just a thought but those transformers macbeth has seem just about perfect for building one or two hiraga monster amps. could be a nice experiment, it's a nice little amp.
greetings,
J. Zoutendijk
Kilowatt,
If you account for power factor and amplifier efficiency, the total power draw could easily peak at between 15 and 20kW ...
Also 5 devices per channel in parallel even with water cooling is seriously pushing the limits if you will be operating near full power for more than the briefest of moments.
NU_NRG,
You will lose a reasonable amount of energy in heat but you should still get enough power to be useful for something.
If you account for power factor and amplifier efficiency, the total power draw could easily peak at between 15 and 20kW ...
Also 5 devices per channel in parallel even with water cooling is seriously pushing the limits if you will be operating near full power for more than the briefest of moments.
NU_NRG,
You will lose a reasonable amount of energy in heat but you should still get enough power to be useful for something.
Yeah, there's five devices in parallel, but that's not all. There are also 2 in series, and therefore 20 devices per channel when the opposite polarity ones are added. This is the same number and the same type of devices that Anthony Holton uses for his 1KW amp, rated 1050W, and I will only be pushing 900W, so they'll hold up fine.
Think I ought to bump it up to 22 or 24 devices/channel? Even though, Anthony made 1KW with 20 and it worked fine.
Matt, do these transformers have a center tap? Or are you going single ended? A good floating ground would draw as much again as the amp.
Matt, do these transformers have a center tap? Or are you going single ended? A good floating ground would draw as much again as the amp.
Yes Kilowatt given that you are using water cooling you could use 6 devices in parallel giving a total of 24 devices per channel this would make me feel a little more secure.
transformers
The transformers are center tapped. While the power supply is on (in the power supply unit the transformer is taken from, not the audio power supply that I'm working on) they measure 17 Vrms (each, and there are 2 taps) with a fluke 76 meter.
The transformers are center tapped. While the power supply is on (in the power supply unit the transformer is taken from, not the audio power supply that I'm working on) they measure 17 Vrms (each, and there are 2 taps) with a fluke 76 meter.
AudioFreak,
thnx for the feedback, but is there any way of keeping the xformer from dissipating that much? soldering the 2 cores together?
Kilowatt,
what slew rate do you intend your amp to have?
Anyone,
what is the lowest slew rate should I consider for a sub amp? 3v/ms enuff?
Thnx for the feedback
-Simon
thnx for the feedback, but is there any way of keeping the xformer from dissipating that much? soldering the 2 cores together?
Kilowatt,
what slew rate do you intend your amp to have?
Anyone,
what is the lowest slew rate should I consider for a sub amp? 3v/ms enuff?
Thnx for the feedback
-Simon
I'd like to have about 8V/ms, but it will be hard to ahieve. For an amp that must swing over 300W, I wouldn't recommend any less than that (based on Randy Slone's book). Now, for a sub amp, maybe you could get away with 3V/ms, but perhaps someone smarter than me could add more info.
Kilowatt,
and 300V not 300W
NU_NRG,
Nothing you can really do. Assuming both transformers are identical, it's just the inherent inefficiency of a single transformer squared. DO NOT try to join the 2 cores!
and 300V not 300W
NU_NRG,
Nothing you can really do. Assuming both transformers are identical, it's just the inherent inefficiency of a single transformer squared. DO NOT try to join the 2 cores!
me likes warnings...
AudioFreak- Not that i don't believe you, but i've seen some of those over the years... whats the big danger? Over fluxing of the cores?
kilowatt- thanks for your feedback, btw sorry I got off topic with that question...
-Simon
AudioFreak- Not that i don't believe you, but i've seen some of those over the years... whats the big danger? Over fluxing of the cores?
kilowatt- thanks for your feedback, btw sorry I got off topic with that question...
-Simon
120->12->12->120
I've seen this done in tube circuits fairly often (using 12V filament transformers) but only for small amps and preamps that only need 120-150 V or with a doubler twice that.
In his case he has a 480 VA (less with the extra transformer losses) isolation transformer.
As to sucking the juice out of the wall, it was done all the time with 5-tube radios, and small console hifis. My 5-buck amp started just that way. I added a 120V isolation trafo from a ground fault isolator to make it safe when i rebuilt it -- sort of at the opposite end of the spectrum from the kilowatts beast at a healthy 1 and a bit watts.
I think it would be more fun to build an amp using the 40A 12+V Rails, than 4A 120V rails.
dave
I've seen this done in tube circuits fairly often (using 12V filament transformers) but only for small amps and preamps that only need 120-150 V or with a doubler twice that.
In his case he has a 480 VA (less with the extra transformer losses) isolation transformer.
As to sucking the juice out of the wall, it was done all the time with 5-tube radios, and small console hifis. My 5-buck amp started just that way. I added a 120V isolation trafo from a ground fault isolator to make it safe when i rebuilt it -- sort of at the opposite end of the spectrum from the kilowatts beast at a healthy 1 and a bit watts.
I think it would be more fun to build an amp using the 40A 12+V Rails, than 4A 120V rails.
dave
interesting idea...
Would it be possible to acheive stable, high power amp with low impedance loads?
A subwofer amp that could drive .25Ohm loads at 500W ???
what do you all think?
-Simon
Would it be possible to acheive stable, high power amp with low impedance loads?
A subwofer amp that could drive .25Ohm loads at 500W ???
what do you all think?
-Simon
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