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

darkmatter

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For info / background the current amps that I use are a Krell KSA100 a Krell S550i integrated (edit just re-found the review of the 550i and note KK comments on fist & last page) a powerhouse according to the measurements but I personally have no clue how it would sound with the scintillas KK seems to hint at approval?
I have several other amps not suitable for use with Scintillas.
I sold my 700cx to fund my latest big loudspeaker design and build, so will be looking to replace the 700cx with a suitable replacement in a couple of years.
 
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christoph

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For info / background the current amps that I use are a Krell KSA100 a Krell S550i integrated (edit just re-found the review of the 550i and note KK comments on fist & last page) a powerhouse according to the measurements but I personally have no clue how it would sound with the scintillas KK seems to hint at approval?
I have several other amps not suitable for use with Scintillas.
I sold my 700cx to fund my latest big loudspeaker design and build, so will be looking to replace the 700cx with a suitable replacement in a couple of years.
Is your KSA 100 still original?
Make sure you find an able technician to have a proper look at it and probably be prepared to have it overhauled :eek:
 
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christoph

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darkmatter

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Sorry for OT but can you elaborate some on this matter? :cool:

I design and build my own loudspeakers (crossovers and cabinets) and my current project which is in early stages will be a large 3/4 way system -6dbs @ 18Hz in room and quite sensitive. With those parameters comes size the bass enclosure is likely to be around 10 cu ft
 
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darkmatter

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Wonder if the Krell 600 or 900 Evo monos can drive the 1 ohm Scintilla.

Purely out of interest I am working on a list of amps which can drive them will post it here tomorrow
 
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User211

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The reason I said the more class A an amp can manage is this. They are designed to run hot.

So if I run my Accuphase M-60 monos hard so I regularly see 450 odd Watts being pumped into my Duettas, they go into thermal shutdown via some trip switches that can be reset when it cools down.

If I run my Luxman M-800A so it's about full output i.e. about 300 Watts in class A/B but the first 120 Watts in class A I can never cause it an issue. Ever. No matter how many hours it would seem.

So it isn't so much about power output as it is being able to maintain it.

That said high power class D will run cooler than traditional amps so should be less troubled but to really know you have to have experience and all I know about is some Hypex NC700 in Merrill monos that sounded dreadful. Steer clear!!!

Actually that's not quite true Rowland 301 monos at 600 Watt were OK and sounded OK.

And an NC400 DIY implementation.

There's a thread on the Apogee forum Graz raised a while back about amps that can do the job.
 

darkmatter

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christoph

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User211

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Turns out I was quite active in this thread on the Apogee Forum :D
Yeah. You've been around for a bit Christoph!;)

What surprises me is Graz claiming that Krell works and in later times declaring you need 1.2KW!:);)

I guess he's learnt over time, too. Or maybe that model really does output a lot into one Ohm. Dunno without checking.
 
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christoph

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Yeah. You've been around for a bit Christoph!;)

Are you hinting that I'm an old geezer? :p ;)

What surprises me is Graz claiming that Krell works and in later times declaring you need 1.2KW!:);)

I guess he's learnt over time, too. Or maybe that model really does output a lot into one Ohm. Dunno without checking.

If those Krells are doubling down with lower impedance, then there will be a lot of watts in the end ;)

Btw. My Lamms produce over 1 KW into 1 ohm according to stereophile (?) measurements :cool:
 
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darkmatter

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Are you hinting that I'm an old geezer? :p ;)



If those Krells are doubling down with lower impedance, then there will be a lot of watts in the end ;)

Btw. My Lamms produce over 1 KW into 1 ohm according to stereophile (?) measurements :cool:

Be interested to read the test report for the Lamm amps, do you have a link?
 

darkmatter

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Yeah. You've been around for a bit Christoph!;)

What surprises me is Graz claiming that Krell works and in later times declaring you need 1.2KW!:);)

I guess he's learnt over time, too. Or maybe that model really does output a lot into one Ohm. Dunno without checking.

I know the KSA 200 is capable of approx 3kw into 0.5 ohms maybe the same for the KSA250?
Not sure if the later generation Krells are as load tolerant?
 
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christoph

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Be interested to read the test report for the Lamm amps, do you have a link?
I have looked for it but found nothing, sorry...
Probably it was NOT in Stereophile.

I remember that one magazine measured 1KW into 1 Ohm but I also remember that they achieved that NOT on the 1 to 6 Ohm setting but strangely on the 8 to 16 Ohm setting.
Maybe @ddk can say why the high impedance setting puts out more watts into 1 Ohm than the low impedance setting.
 

Alrainbow

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The Switch on the lamm lowers PSU voltage for more current if i remember correctly, current stability is whats necessary at one ohm not huge power . numbers like when driving 8 ohm loads ..
 

Alrainbow

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The KSA-300s with its 5Kva PS seems capable of driving a 1 ohm load?


Any past Krell to my understanding Can drive 1 ohm loads , the sonics differentiate them so i was told at 1 ohm expect a revolving door until you get the sonics desirable ..

BTW make sure they are recapped and properly biased at Krell ..
 

User211

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Any past Krell to my understanding Can drive 1 ohm loads , the sonics differentiate them so i was told at 1 ohm expect a revolving door until you get the sonics desirable ..

BTW make sure they are recapped and properly biased at Krell ..
But not necessarily at the desirable 1.2KW level Al.

This is a Scintilla. It's joke hard to drive properly.
 

Alrainbow

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Do the current calculation at 1 ohm for 1kw Justin , very unlikely you will be using that much current on your scinnies ..

10-20 amp Im thinking per channel thats 40 amps both channel, should be more than enuff , (ok maybe ms peaks a bit more) . Most early big krells can deliver that on music signal no issue , as they are rated into 1 ohm RMS the newer ones rated RMS into 2 ohms , but i do believe their big enuff to drive 1 ohm on music peaks, the sonics delivered will be the difference from model to model.

Im looking for an FPB600 CX to play around with so can add more to the convo then ..
 
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