Krell KSA Amps and the Apogee Scintilla, which newer Krell models can drive a 1 ohm load?

darkmatter

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I have always been fascinated by the combination of Krell KSA & The Apogee Scintilla and in the late 1980s and into the 1990s this was a combination I wanted to own.

Things have moved on but am sure that in fine fettle would still be a worthy combination.

My question relates to Krell amps only and have wondered which generation of Krell power amplifiers is the most load tolerant and capable of driving a one ohm load?

My guess would be in the original fan cooled KSA & KMA series all up to the newer fin cooled KSA 250.

in the mono series up to KMA 400 & MDA 500

Reference series in particular the KRS 100 and 200 probably the most load tolerant of all the Krell amps? Loved the KRS-200 driving Divas as I heard at the 1987 Penta show,

later on the Krell KAS possibly the 2 and latterly the big EVOLUTION ONE ? maybe some of the other EVO models?

I think even my little S550i could be capable? Ken Kessler made mention of this in one if his reviews, the lab report indicated it is a powerhouse.

Investigating later models I am not so sure that the FBP series could do it, may be the 402e could, but not the others in that later Evo series, excepting the EVOLUTION ONE ?

Simon
 
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Direct Drive

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Loved the KRS-200 driving Divas as I heard at the 1987 Penta show,
Agreed. I remember that show and room. Couldn't afford the the Apogees so settled for Maggie's.
KSA series were remarkable. Still hanker.
 

BruceD

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Indeed I'd revel in the sonics of that combination in the 80's at an esteemed gentleman's residence in Wimbledon.
KK was frequent visitor as well--we nearly always got around to discussing Watches as well,at one time or another!

Good times,
BruceD
 

Direct Drive

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KK loved the Krell Sintilla combo.
To quote:
Over the years I've had such remarkable pieces. In fact, if you look at what I've had over the years its quite frightening! The longest-serving system I ever had was Krell monoblocks with Apogee Scintillas
But the biggest review of my career was the three-way we did on the Apogee Scintilla [HFN, Sep '85], which was me, Atkinson and Colloms. That was just a phenomenal piece.
Bill Beard provided me with a special pair of mono P100s good for 200W and able to drive 1 ohm, while Martin reckoned that, 'the Krell KSA-100 was the minimum safe bet.' True, you could with some effort, re-wire your Scintillas at home for 4 ohm operation, but with a 6dB loss in voltage-rated sensitivity. At 1 ohm, MC estimated the sensitivity to be 73dB/1W, noting that, 'Consideration also needs to be given to the peak current demand of the Scintilla at 1ohm. Taking an average impedance of 0.9ohms, a Krell KMA-200 on full song will provide up to 60V peak. Assuming minimal cable losses, the Scintillas will draw peak currents of over 60amps. Now you can see why blockbuster amplifiers of Krell current capacity are required for 1ohm working.

Link to KK review: KK Sinctilla Review Sept
On the basis of this review I got a Beard P101 which was the monoblock P100 in a single enclosure. Runs hot!
Anyway I think any amp being considered for Apogees would have to be heard with them.KK Sinctilla Review Sept 1985
 
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spiritofmusic

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I'm sure I saw a long photo essay at the time showing Douglas Adams of HitchHikers' Guide To The Galaxy fame running Scintillas on Krells.

And wondering why he didn't own a Linn/Naim system like I aspired to Lol.

Geddy Lee of Rush also ran Scintillas/Krells...on a mid 80s Philips cdp!
 

bonzo75

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I was very impressed by the scintilla Christoph had made by Henk, certainly the finest apogee heard after Henk's grands. Christoph's neighbouring friend now owns this

 
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User211

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KK loved the Krell Sintilla combo.
To quote:




Link to KK review: KK Sinctilla Review Sept 1985
On the basis of this review I go a Beard P101 which was the monoblock P100 in a single enclosure. Runs hot!
Anyway I think any amp being considered for Apogees would have to be heard with them.

The bolded bit.

I think Scintillas are insane. As Graz says you need a 1.2 Kilowatt amp to drive them to full potential.

So find a Krell with that power output stable at 1 Ohm and you have your answer.

The chances that Krell will actually sound good is another question.

That said you could explore other options if you don't require anything more than mediocre volume levels.

Darkmatter do you own a pair of Scinnies?
 

User211

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Another issue is that on paper some amps look like they fit the power requirements.

But the issue is that whilst they do, they cannot keep it up for long, and will end up over heating when driving at high volume for extended periods.

From experience the more output the amp can manage in pure class A I think the more it is likely to be able to withstand a good thrashing for an extended periods.
 

Direct Drive

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Another issue is that on paper some amps look like they fit the power requirements.

But the issue is that whilst they do, they cannot keep it up for long, and will end up over heating when driving at high volume for extended periods.

From experience the more output the amp can manage in pure class A I think the more it is likely to be able to withstand a good thrashing for an extended periods
So true. Paper specs are not enough. Proof is in the pudding!
 
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Alrainbow

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Another issue is that on paper some amps look like they fit the power requirements.

But the issue is that whilst they do, they cannot keep it up for long, and will end up over heating when driving at high volume for extended periods.

From experience the more output the amp can manage in pure class A I think the more it is likely to be able to withstand a good thrashing for an extended periods.


Bench testing or paper tells the tale Justin, maybe bad or poor testing metrics or interpretation is more at fault here ..
 

Alrainbow

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I Prefer to see independent test results than spec sheets from manufacturer
 

Alrainbow

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The bolded bit.

I think Scintillas are insane. As Graz says you need a 1.2 Kilowatt amp to drive them to full potential.

So find a Krell with that power output stable at 1 Ohm and you have your answer.

The chances that Krell will actually sound good is another question.

That said you could explore other options if you don't require anything more than mediocre volume levels.

Darkmatter do you own a pair of Scinnies?


These amps are so old now a full recap and Biased to spec is a necessity ..
 
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christoph

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The bolded bit.

I think Scintillas are insane. As Graz says you need a 1.2 Kilowatt amp to drive them to full potential.

So find a Krell with that power output stable at 1 Ohm and you have your answer.

The chances that Krell will actually sound good is another question.

That said you could explore other options if you don't require anything more than mediocre volume levels.

Darkmatter do you own a pair of Scinnies?
The Lamms M1.1 drove the Scintillas effortlessly while sounding VERY good.
The Krell KSA 100 Mk2 drives them now at the new owners place.
I much prefer the Lamm M1.1 over the Krell KSA 100 Mk2.
I tried dozens of amps for the Scinnies like for example the Musical Fidelity KW750 or two Sphinx Project 14 in bi-amping apart from the original Krell KSA 100 Mk2 but the Lamms sounded best.

But the thread starter explicitly wanted NOT to read about any non Krell amps :rolleyes:
 
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christoph

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cjfrbw

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I have heard Scinnies with H20 amps in California and with older Conrad Johnson SS MF bipolar transistor amps.
They sounded good, but I still preferred my SET driven Stages in my listening room.

Since the OP asked for Krell opinions only, I just HAD to talk about something else.
 
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christoph

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No not at present, but in the next couple of years we are looking to move to a bigger house so maybe I will have the room to justify a carefully refurbished pair
But why the only Krell policy?
As I said earlier, I owned Scinnies for decades and tried dozens of amps with the Lamms being my clear winner
 
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darkmatter

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The Lamms M1.1 drove the Scintillas effortlessly while sounding VERY good.
The Krell KSA 100 Mk2 drives them now at the new owners place.
I much prefer the Lamm M1.1 over the Krell KSA 100 Mk2.
I tried dozens of amps for the Scinnies like for example the Musical Fidelity KW750 or two Sphinx Project 14 in bi-amping apart from the original Krell KSA 100 Mk2 but the Lamms sounded best.

But the thread starter explicitly wanted NOT to read about any non Krell amps :rolleyes:

Never say never but want to explore suitability of the newer generations of Krell amps first :rolleyes:
 
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christoph

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