I'm using a Pass Aleph 4. Plenty of information on here on how to build one.
Good starting point is http://www.kk-pcb.com although I wouldn't use his pcbs.
100W Class A is a serious investment. With all Class A projects you will need massive PSU and heatsinks.
That took some finding but here is Dad's thread on building this beast. He's no longer with us but his legacy lives on.
http://www.diyaudio.com/forums/pass-labs/172276-aleph-4-strickly-diy-project-build.html
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I have 15 watt class A, 2 100 watters, a 180 watter (actually a 220 watter) and a 280 watter.
I've got B&W 703's and a very nice pair of small bookshelf speakers from a local Taiwan company.
The 15 W sounds remarkably capable on my 703's and they make a great pairing for acoustic and light jazz.
But the big amps sound more relaxed in the nicest possible way.
I'd love to hear the class A on a really efficient set of speakers because it has a wonderful silky sound.
I am planning another amp. A really big one. Probably early next year. 4 kVA transformer is quite expensive, even in Taiwan. It will be my mid- life crises amp, like that guy over on the tube forum, although a am a little past mid life now - I just like soldering and sh1t. He he
I've got B&W 703's and a very nice pair of small bookshelf speakers from a local Taiwan company.
The 15 W sounds remarkably capable on my 703's and they make a great pairing for acoustic and light jazz.
But the big amps sound more relaxed in the nicest possible way.
I'd love to hear the class A on a really efficient set of speakers because it has a wonderful silky sound.
I am planning another amp. A really big one. Probably early next year. 4 kVA transformer is quite expensive, even in Taiwan. It will be my mid- life crises amp, like that guy over on the tube forum, although a am a little past mid life now - I just like soldering and sh1t. He he
I bought a 3kVA 110V site transformer.
Handy for 110V site tools while building my house.
Hardly gets used now, just collecting dust at the back of the garage.
It has a 55-0-55Vac secondary that would make for a very high power amplifier.
Secondhand they are relatively cheap.
SOLAR
100W RMS into 8-ohms, 200W RMS into 4-ohms
Limit the Class-A power to ~10W for modest normal heat, and use "perfect Class-AB bias" to minimize high-power distortion.
When you design a few amplifiers you quickly learn that the best transistors( lowest noise, highest gain, most linear) have reasonable rated limits in voltage, current, and power, with the best circuit topologies.
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"I bought a 3kVA 110V site transformer.
Handy for 110V site tools while building my house.
Hardly gets used now, just collecting dust at the back of the garage.
It has a 55-0-55Vac secondary that would make for a very high power amplifier.
Secondhand they are relatively cheap."
Need screen and belly band and it has to be wound for audio. The core is oversized as well.
Handy for 110V site tools while building my house.
Hardly gets used now, just collecting dust at the back of the garage.
It has a 55-0-55Vac secondary that would make for a very high power amplifier.
Secondhand they are relatively cheap."
Need screen and belly band and it has to be wound for audio. The core is oversized as well.
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only one of my transformers had a screen.
I could not measure any improvement in any performance parameter.
None of my transformers have a belly band.
I don't seem to have intractable hum problems.
"it has to be wound for audio"
What does this mean?
Why are these "extras" required for audio?
What is the problem with an oversized core?
Presumably since it is for industrial use the primary winding and core are appropriate to the voltage and frequency in the UK.
I could not measure any improvement in any performance parameter.
None of my transformers have a belly band.
I don't seem to have intractable hum problems.
"it has to be wound for audio"
What does this mean?
Why are these "extras" required for audio?
What is the problem with an oversized core?
Presumably since it is for industrial use the primary winding and core are appropriate to the voltage and frequency in the UK.
Funny questions to provoke funny answers.
But it is clear, the more the better. What a real man really needs is too often determined psychologically.
I used to live close to an airforce base, and had the "opportunity" to listen to the jet engine frequently at few hundred meters away, as well as occationly at a distance of less than 20 meters
.It is said that is the loudest sound that you could hear on this planet, maybe thunder could be louder? By none of the two I like.
The old home is where I wanted to get away from.
Then I decided I never need any system that give me more than 130db SPL. Otherwise it is a torture other than a pleasure.
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it is not related to my choice of amp power.you misunderstood me mate.
The discussion is related to amp power, speaker efficiency, the SPL limit, etc. But I am definately not for a Class-D beast or any thing not realistic for a home hi-fi use.
So, I am actually on same level as yours.
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An amplifier cannot be considered independent of the loudspeakers it is used with, the room they are in and how loud you play (making the OPs question meaningless).
Probably as important as how much power is how gracefully the amplifier clips and how well it recovers from clipping.
Large power amplifiers bring all sorts of issues and compromises to retain reliability and sound quality (or purchase price) suffers accordingly.
In my home with the speakers i typically use (many of those) i find my PP EL34 amp in tridode (20W) sufficient. Sometimes i will flip it into pentode (40w) but usually because it suits the speaker better not because the extra 3dB power is needed. If i find this insufficient volume wise, time to hook up helper woofers and bi-amp.
dave
Probably as important as how much power is how gracefully the amplifier clips and how well it recovers from clipping.
Large power amplifiers bring all sorts of issues and compromises to retain reliability and sound quality (or purchase price) suffers accordingly.
In my home with the speakers i typically use (many of those) i find my PP EL34 amp in tridode (20W) sufficient. Sometimes i will flip it into pentode (40w) but usually because it suits the speaker better not because the extra 3dB power is needed. If i find this insufficient volume wise, time to hook up helper woofers and bi-amp.
dave
Cos we've reached a point, where a further increase in power won't give
you any advantage.
Assumed, this is a serious question:
Not enough. Way more than enough !!!
Like others, I easily achieve above 100 dB with a 25 W amplifier.
If you really need more than 200 W, you probably have a rather huge listening
room, poorly designed speakers or you're suffering from a profound hearing loss.
To appreciate the answer of 42,
You'll need to be aware of the "Hitchhikers guide to the galaxy".
My own opinion, I built a diy 100W amp, and yes it's more than enough, but when I turn it really loud, I can easily turn it into the region where it distorts.
I then built a amplifier that gives 180W and when driven to the loudest I feel I'll ever need, it doesn't distort.
This made me happy, psychologically at least,
And funny enough I've never played this amp that loud since I tested it.
Lol, but if any of my friends asks me what power amp to build, I tell them 100W or do,
100V caps are expensive here, 63V are cheaper
You'll need to be aware of the "Hitchhikers guide to the galaxy".
My own opinion, I built a diy 100W amp, and yes it's more than enough, but when I turn it really loud, I can easily turn it into the region where it distorts.
I then built a amplifier that gives 180W and when driven to the loudest I feel I'll ever need, it doesn't distort.
This made me happy, psychologically at least,
And funny enough I've never played this amp that loud since I tested it.
Lol, but if any of my friends asks me what power amp to build, I tell them 100W or do,
100V caps are expensive here, 63V are cheaper
Off the shelf transformers usually run hot - they use as small a core as possible. They are noisy (I've bough t 3 1KVA transformers - 2 from RS and another from I cannot recall right now). I've used the quietest one in the e-Amp, and one as a step up for my Marantz and the other is in a box. The two not installed in amps are not usable for high end audio in my view.
The 2KVA I had specially wound by Airlink in the UK is the quietest transformer I have. It cost be an arm and a leg, but it runs cool, and Iif i put my ear on the chassis it's completely silent (Ovation 250 amp). The e-Amp is quiet, but not that quiet. The custom wound 500 VA I had done in Taiwan is also very good.
There's enough discussion on the forum about screens and belly bands for me not to have to justify including these if you do a custom build transformer. For very little incremental costs, the benefits are worth it.
I try to design and build amplifiers I am happy to pitch against anyone, including commercial brands, in terms of sound and solid engineering. I don't have the resources to do some of the high end case work, but the electronics and PSU deliver the goods.
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