Wel inrun now 88dB sensitive fullrange drivers from an 8w class A amp, the ACA amp sold as kit on this forum and it goes loud enough for me in this space. And yes i can still touch the heat sink without burning myself. My class ab1 tube amp actually produces more heat than that ACA
And on sound, it’s the only way to sound as subjective good with solid state as tubes for me.
And on sound, it’s the only way to sound as subjective good with solid state as tubes for me.
I'm not badmouthing class A, they're just not appropriate for my passive speaker use. Big speakers, heavy rock, big room.
I'm interested in them for my first active speakers.
However by my reckoning to provide sufficient power I'd need 10 units, 2 for the tweeters and 4 each for mid and bass.
That's too expensive, both to build and run.
That's what I was asking about. The units I was looking at are not really 30w. They are more like 15w. So they'd have to be bridged, and then it gets too rich for my blood.
I might, possibly, use one for the tweeters. That's the two units. And it's cheapest to buy them pre built, in the case, rather than mess about.
I don't need to read it, I wrote it. Class A runs hot and uses a lot of input power for a given output.
It does, on the other hand, produce the best performance.
Which is why if this were REALLY 30 watt modules, they might be viable for my project.
They are clearly not though. Might do for the tweeters.
It does, on the other hand, produce the best performance.
Which is why if this were REALLY 30 watt modules, they might be viable for my project.
They are clearly not though. Might do for the tweeters.
For larger speakers you may be better off with a slightly higher biased (or not) class ab than those knock-off Pass boards.
Not sure bridging is a very sustainable way to go either, are many stories of how things went wrong after doing that.
There are several decent boards on eBay that have threads to help support their implementation here. Try symasym, ljm mx50, np140.
Not sure bridging is a very sustainable way to go either, are many stories of how things went wrong after doing that.
There are several decent boards on eBay that have threads to help support their implementation here. Try symasym, ljm mx50, np140.
Based on this thread, you’re not serious about committing to class A amplification. The expense incurred during the building process isn’t all that different from class AB (not for the way I build), and if this is your hobby and passion, then the quality of your build shouldn’t be allowed to be compromised by limiting choices to the cheapest eBay offerings.
You seem to care about the quality. In my view, if you’re building something and doing all the work to go from passive to active speakers, then it’s worth putting the money into building it right the first time. Your future self will thank you.
You already know the difference in operating costs, and this is the other side of the deal. I think you’ve decided that this point weighs heavily on your final decision that multiple class A amplifiers will add significantly to the utility bill.
I think very good class AB amplifiers would give you what you need without introducing an ongoing expense.
reply to #27
Or....you discover that the heatsink(s) can't cope with the extra average dissipation. I used to get a regular number of over-cooked Japanese amps after the summer holiday season, where "fiddle-fingers" had cranked up the idling bias to some arbitrary level but neglected to check how much hotter it was going to get when approaching max. power before clipping.
Sure, in typical home use and with earlier models, that probably never would have happened but party time is the acid test and those later, wispy thin, convoluted sheet alumininium heatsinks seem to have little margin for excess.
Or....you discover that the heatsink(s) can't cope with the extra average dissipation. I used to get a regular number of over-cooked Japanese amps after the summer holiday season, where "fiddle-fingers" had cranked up the idling bias to some arbitrary level but neglected to check how much hotter it was going to get when approaching max. power before clipping.
Sure, in typical home use and with earlier models, that probably never would have happened but party time is the acid test and those later, wispy thin, convoluted sheet alumininium heatsinks seem to have little margin for excess.
If you want both the highest performance and lowest utility cost: Bruno's Purify amps run cool and run rings around any class A attempt.
Looking for a PURIFI EVAL1 Amplifier Stereo Kit? - SoundImports
Jan
Looking for a PURIFI EVAL1 Amplifier Stereo Kit? - SoundImports
Jan
Fully agree about the cool running. When you're right, you're right. As for the rings, are you sure it is not tinnitus?
I have a friend who built one and after years of trials he found an old germanium class B amp with interstage transformer that sounded exactly identical to his 50kg Hiraga on his rubanoid speakers while he can hear 18kHz...
I'm not a musician aged less than 25 years old and I don't understand why I would want their opinions.
If I can't hear it, why do I care?
And FWIW in my audio career I worked with many young musicians who only heard superficially. If I pointed out a flaw that I heard, they would struggle. Hearing deeply is a learned skill. Prof Goode used to take us under the old iron bridge and listen to all the strange creaks and twangs as car rolled over.
A valid point. OTOH, as Nelson says, you need to put in at least 10,000 hrs serious listening to be able to say anything serious. That's hard before you're 25 ;-)
And as PRR said above.
At any rate, it cuts both ways of course, in any comparative listening setup.
Jan
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