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Buddha
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Which 2A3c SET amp for my Apogees?

OK, I got the SET bug.

Today's the day I hook up my new SET 2A3c amp.

The amp is three watts per channel, well, four with 10% THD.

I'll be using it with some Apogee ribbons. The Apogee dips to one ohm resistance, and is 86dB 'sensitive.'

So, if 1 watt gives me 86 dB, but the amp output doubles its output with every halving of the resistance, then...

My four watt amp should give me 8 watts at four ohms, 16 watts at two ohms, and 32 watts at one ohm.

Therefore...

I should get 89 dB for two watts, 92dB for four watts, 95 dB for 8 watts, 98 dB for 16 watts, and 101 dB for those 32 SET watts into one ohm.

With the gentle clipping behavior of tubes, I should be able to rock the party!

Thank goodness for physics.

Jan Vigne
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Re: Which 2A3c SET amp for my Apogees?

This is the Lirpa model Amp C32A?

jackfish
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Re: Which 2A3c SET amp for my Apogees?

I think you get a 3dB increase with two speakers as sensitivity ratings are for one speaker, about a 4dB increase with the speakers in a room rather than an anechoic chamber, but also lose 6dB as distance doubles.

Monty
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Re: Which 2A3c SET amp for my Apogees?

Interestingly enough, I've been checking out these guys for the last couple of days.
Decware and Wright-Sound .

I recently cleaned out a lot of stuff through Audiogon and have been checking
out some new directions and these guys caught my eye.

rabpaul
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Re: Which 2A3c SET amp for my Apogees?

Nobody else noticed that its Lirpa 1st?

Elk
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Re: Which 2A3c SET amp for my Apogees?


Quote:
Nobody else noticed that its Lirpa 1st?


Of course. But After teasing him about his Lowthar thread I had to leave this one to run its course.

Buddha
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Re: Which 2A3c SET amp for my Apogees?

Yup, it was a "holiday" post.

Next year, we should plan ahead and work as a group...

Elk
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Re: Which 2A3c SET amp for my Apogees?

Buddha, your posts were great! Each required knowledge of the speakers involved and their characteristics.

I kept wondering where the crossover and multiple drivers are in your Lowthars . . .

Buddha
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Re: Which 2A3c SET amp for my Apogees?

I got some good Lowther action at the Asylum.

Next year, I'll introduce a tweak.

KBK
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Re: Which 2A3c SET amp for my Apogees?

Too bad. I'd of told you to actively amplify/cross your DX3's the same way I've actively crossed my DX2's.

SAS Audio
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Re: Which 2A3c SET amp for my Apogees?

"So, if 1 watt gives me 86 dB, but the amp output doubles its output with every halving of the resistance, then...

My four watt amp should give me 8 watts at four ohms, 16 watts at two ohms, and 32 watts at one ohm."

Not quite Buddha. Looks like about 92db or so will be the loudest, but I don't think that is necessarily a problem if easy listening is one's goal.

One ohm will cause the distortion figure to be much higher than 10% and power output will actually be lower at 1 ohm than at 8, assuming the amp has no 1 ohm tap.

Cheers.
Steve

tonepub
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Re: Which 2A3c SET amp for my Apogees?

I highly doubt you will be able to use an SET of any kind with your Apogees, those babies want current! I've had precious little luck ever driving mine with any kind of tube amplifier....

linden518
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Re: Which 2A3c SET amp for my Apogees?


Quote:
I highly doubt you will be able to use an SET of any kind with your Apogees, those babies want current! I've had precious little luck ever driving mine with any kind of tube amplifier....


Yeah, don't know about SETs, but probably Atma-Sphere MA2 MkIII monoblocks would do it, no, at 220 wpc? Triode, but push-pull. Or the MA3 at 500 wpc. Who needs a car when you can have hulking tube monoblocks that put out 500 wpc? Oh my God, I've turned into a DUP.

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