Apogee Scintilla Power

Has anyone used Merrill Veritas Class D monoblocks to drive Scintillas?

The Duetta signatures aren't that hard to drive, only the full range and the scintilla are the amp killers.

I know I’m very late to the discussion, but I have a pair of Duetta II Signatures that I’m driving out to Bill Thalmann @ Music Technology in Springfield, VA next week for a complete new rebuilt including Wilson caps. Unfortunately Bill is soon retiring. My dad bought these beauties brand new in ‘88. They fried two Counterpoints and an anemic Hafler early on. Since then they have always run on a BAT tube preamp and solid state amp set up. I’m currently running a BAT VK-5i tube preamp and VK-600 with bat pack solid state amp beast. They sound incredible, no loss of details and presence even at very low volume levels. I’ve always used the Symo speaker cables Jason Bloom recommended to my dad and don’t plan to change them. 

Sure would have loved to have heard those 2 VHC's on Scintillas. The ultimate match. 

If you ever get a chance to audition the Classe DR3 VHC I mentioned earlier in the thread, do so (hard to find as less than 200 made). The pair I have were driving the heck out of Scintillas when I bought the amps.

Run in stereo they put out 40 watts into 8 ohms.  Run as a pair of bridged amps, the put out 500 watts into 1 ohm.

"...Not sure the BHK’s can handle the 1ohm load..."   

Arnie Nudell on the BHK Signature Amplifier - Bing video

Not sure the BHK’s can handle the 1ohm load but have not asked PS Audio directly. Certainly that would be a great option with some hybrid magic. Would love to hear if anyone confirms a thumbs up. PS Audio also has some really great class D amps now. Never heard them but folks seem to really like them...

Heard anything about the PS BHK Signatures? 

Thanks for your update to the thread about using the H2O amps and Fire preamp. No doubt this is a proven, winning combination for Scintillas (and sounds like your D-Sigs as well). I am currently using my Plinius SA250iv on my D-Sigs and it is really good. Can’t wait to try the Plinius on my Scintillas when they are done with refurbish. I still think about getting Henry to build me new S250’s but just don’t have the money. And I have money into my Motif MC10 preamp (which is a giant killer) and moving to the Fire Preamp would mean a change here. If he would build it I bet a new Henry Ho build would be even a step further with what he has learned along the way. I am really curious what the new Emotiva mono-blocks sound like. Doing some research it appears they may be able to handle the Scintilla load. Agree on the Duetta Signatures. While many will debate the older ribbons are better, etc. I can say that with new ribbons, XO work, etc., my D-Sigs are quite good. 

If your still considering amps here was my path.  I have the Duetta Signatures and struggled with amps after upgrading from Stages.  I was using my VTL 300 monoblocs with the CJ Premier 10.  Sounded great until I tried the H2O amps from Henry Ho. Use a pair of 250 stereo amps for bi-amp set up. Really made a difference.  Then I tried the Fire preamp and am totally happy with combination.  Tons of power, dynamic range and very detailed, great soundstage etc.  I also mated the Apogees with a pair of Vandersteen Subs and bass is very smooth and quick.  Hope this helps.  The Apogees now need to go to Rich for a total rebuild.  Nothing wrong with them but would love to hear them with new crossovers, wiring, ribbons, caps etc.   They are a special speaker.

Among your best choices below Boulder pricing is going to be the Sanders line, especially the Magtechs.


http://www.sanderssoundsystems.com/products/amplifiers/amplifiers-more-information

I genuinely don’t know of any amp that has a more overbuilt output stage than his do, nor anyone besides Krell who attempts full power supply regulation in mega amps besides the Magtechs.

The amps are especially built by ex-Threshold people at Coda but for the incredibly hard to drive demands of ESL's which reach 1/3 of an ohm at the top of the spectrum.

Since these are all available for home audition, I strongly recommend you take him up on his offer.



Best,

Erik

Probably a few Threshold models would work.

There were very few power amps that could drive into 1 ohm back in the day. They included the Adcom GFA-555, and Classe DR3 and DR3 VHC. the rare Belles 'A', the Krell KSA 80 and 100 and a couple more.  The original speaker review by Cordesman in Stereophile details the requirements.

I am most likely to consider the last two amplifiers mentioned above and below, as they are the most recent, and probably superior in audio performance.

Consideration will also be given to them provided they can drive the 1 ohm load of the Apogee Scintilla.

I have specified this parameter, just in case I decide to scratch the itch I have had since the late 1980s (teenage!!) to try out a pair of these loudspeakers in my main system.

Krell FPB750mcx or Krell Evolution 900

Simon

Apogee Scintilla - List of Krell Amplifiers that can drive them

Krell KSA50 (Just)

KSA100,

KMA100,

KMA200,

KRS-100

KRS-200

Krell KSA 80 (Just with protection setting adjustment)

KMA 160,

KSA200,

KMA 400

KSA150,

KSA250,

MDA 300,

MDS 500

Krell Audio Standard (KAS)

Possible KSA100s

Possible KSA200s

KSA300s

FPBs possibly

Evolution series a Possibly?

I am going to investigate the suitability of the following to drive a 1 ohm load

Krell FPB 750mcx and Krell Evolution 900

For my 700cx replacement, I may be considering

Krell KRS-200 too old? serviceable?
Krell KMA400 these run very hot so I question longevity and serviceability
Krell MDA500 again these run hot and question longevity and serviceability

I am most li8kely to consider the last two as they are the most recent and on performance grounds provided they can drive a 1 ohm load.

Krell FPB750mcx or Krell Evolution 900

As a matter of interest I have been compiling a list of amplifiers that will drive 1 ohm loads in particular the Apogee Scintilla. 

This is one speaker that I have always wanted to own but not easy as I am UK based, as they say owning a pair of Scintillas or Divas i9s an itch I would like to scratch!!

Question
What is this "Scintilla Mod" that you mentioned that was done to your  Sunfire?
I have a Cinema Grand Signature and always wondered if it could drive some Scintillas. Not like I'd ever get that opportunity, but I digress..

westerlm OP
I have recently picked up a Plinius SA250 MkIV that is being refreshed and turned into a Reference. Has proven to operate steady at 1ohm load handling scintilla dips down to .85ohms with high power and current.

This "could" be the one for you, Plinius usually use mosfet in their output which sag not increase into 2ohms
But it "seems" for this SA250 they may have used bi-polar (bjt) in this model, but! not complimentary npn/pnp but just npn for top and bottom rails.
Maybe they meant N channel only top and bottom (not npn) and it is Mosfet, then that would explain this comment when tested into 2ohms " the amplifier is clearly less comfortable with the 2 ohm load" which means not so good with your Apogee’s 0.9ohm loading


Still it can give a good wattage increase for every halving of impedance
320W into 8 ohms
480W into 4 ohms
740W into 2 ohms (single channel driven)

Cheers George

Great feedback. Confirmation as well as some new thoughts.

For my Apogee Duetta Signatures the Mc MC7270 (with autoformer) works pretty well but my CJ MF2500a (bipolar) is fantastic. Using it in a bi-wire configuration is most coherent. Using it with my CJ Premier 11a on high end in gain matched (26db), passive bi-amp set up is also VERY good with tube magic on the MRTW ribbons just a bit lagging with some attack transients (ie.guitar strings, piano, etc.).

For my Apogee Scintilla's the Mcintosh MC7270 runs out of gas. It can definitely handle the load fine with autoformers. The CJ MF2500a works well on the high end MRTW ribbons but does heat up. The CJ Premier 11a cannot play anywhere with the, Scintillas. The Sunfire 300's with Scintilla mod speak for themselves. I have recently picked up a Plinius SA250 MkIV that is being refreshed and turned into a Reference. Has proven to operate steady at 1ohm load handling scintilla dips down to .85ohms with high power and current. Operates in class A and class AB for some flexibility and energy savings. We shall see how it goes. Plinius, will be done in a month but Scintilla rework is a few months out for the ultimate test. When that happens I will get some feedback out for anyone that may be interested. Thanks again for  all the feedback.

westerlm
Apogee Scintilla Power

The Apogee Scintilla are only 79db so you’ll need "at least" 150watt/8ohm to get them going.
But they go down to 0.9ohm right through the lower bass and also 1.2ohm around 1-2khz in the upper midrange.
http://www.lippaudio.org/old/MySystems/Scintilla/impedance.html

So this says, that the amp should come "close" to doubling it’s wattage for each halving of impedance from 8ohms right down to 2ohms. Look at big amps with bi-polar (bjt) output stages. eg Krell KSA250 or similar ect ect ect
Anything else "may sound OK" but will be a compromise, especially tubes, and won’t get the best from them.

EG:
150w/8ohm
300w/4ohm
600w/2ohm

Cheers George

Several excellent options not previously mentioned: Roger Sanders Magnatech, or his earlier Innersound Electrostatic amplifier or one of the Coda amplifiers. Any of these can dump very very large quantities of very high quality current into your apogees without breaking a sweat, at very (IMHO) reasonable prices.

Musical Fidelity AMS-100 in a modern amp 

we sold Apogee and Acoustat and Jim’s amp is a decent match for sure. The big CJ with autoformers also works w magic midrange 

I don’t have it anymore, but back in the 90’s, I drove my Apogees with a McIntosh MC-2300.  It ran them easily I might ad.  The Mac was rated safe to a half ohm, if I’m remembering correctly.

The  only headache were Macs silly speaker screw terminals.  But some well made spade lugs took car of that.

The 2300 could drive the Scintillas to silly volume.  You will be surprised at how good the bass response can be, when driven by a strong amp.

PS. BTW, with the right amps (such as the Gryphon Refs) the speaker cables ("shotgun" configuration, made by the Siltech OEM) have a 4 ft. length (de-mystifying the theory of the maximum 2 ft. long cables). Now, to understand the capability of the Gryphon dual monos, I have to emphasize that, even at 25% of the bias setting, they are able to drive the 1 Ohm Scinnes, in a satisfactory manner (better anyway than a pair of Bryston would be capable of; I've hd Bryston 7b's, before the Gryphon). Of course, I'm usng them at 100% bias setting. The only drawback with the Gryphon is the extra $100 extra burden on the power bill, monthly!...:)

Great question! After all, more than 30 years passed already since the birth of the Scintilla and, in terms of the amps driving them, there are few news. I've read that Dan d'Agostino, Nelsson Pass and Bob Carver are known for using Scinnies as a benchmark difficult speakers to drive in their labs, and so forth they offered solutions to drive them. Somebody mentioned Wollcot Audio. Many years ago, Henry kndly offered to shp me a par of his monoblocks in order to both demystify the fact that tubes mght not be able to drive the 1 Ohm Scinnies and also to add one more page to the already stellar history of his brand. Since his amps were rated for 2 Ohms minimum (if memory serves me well) and we weren't sure if they'll stand the dropped impedance load of the Scinnies, I've respectfully declined the offer (in spite of the fct that Mr. Wolcott took upon himself any possible negative consequences of that "experiment"). A similar story, happened with Ms. Eva Manley, who offered to modiffy a pair of Manley Neo-Classic 500's, down to a 2 Ohms outputs, in order to try driving the 1 Ohm Scinnes. Somebody talked me out of it, by nssting that those tubes would be very short lived, consideing the load (now, thinking it over, my guess is that it not necessarily true). For years now, I'm driving the 1Ohm Scinnes with a pair of Gryphon Reference Ones, 150w/8Ohms, pure class A each (1200w/1ohm and 2400w/0.5Ohms -with peaks to 5000w-! Yeah, that means control and definitely he Scinnes needs and benefits from it, regardless of other opinions. Triode tubes are in the DAC and in the pre-amplifier. Marvelous sound overall, since I've never heard better. A pair of self-powered Velodyne sub-woofers (sacrilege, heh!?...;) compliments nicely the setting, since supplies the necessary extra bass response which was lacking in the 30-60Hz area. Class D, extremly fast, good quality bass, never lags behind. The only questionable "improvement" I may think of would be to add extra tubes, weather the Gryphons sound is extremely "analog" (no dryness, no solid state "nasty" characteristics, that's Fleming Rasmussen's quest, mark and legacy!). As I just happen to have a friend who carries Jadis in his system,  might borrow his JA80's monoblocks (they have a 1 Ohm tap and deliver 90watts/ 8Ohms, each) to see how would they work with the Scinnes, by either replacing or complementing the Gryphons monos. BTW, did anybody tried to drive 1 Ohm Scnnies with Jadis monoblock amps? Any inputs? Thank you.

Thanks for the advice and there is quite a bit of old discussion around Krell, etc. Looking for reliability and more modern approach. SS or tubes. Maybe Pass Labs. Great but expensive. 

Sorry, as noted in the opening of this thread the Scintillas are not for sale (or the subs I needed before the Scintillas that have been repurposed in friends systems) or my Duetta Signatures, or my Dynaco A25’s or my Polk SDA’s or my Klipsch LaScala’s and old BGW and Crown stuff and.....a long list of audio brilliance in its own way....what a great hobby.....or should i say great affliction. 

 Actually maybe I do have a problem should have a sale.....:).

The only thing i “bet” is that some people may like my stereo system and some may not...and depending on my mood and the barometric pressure i can tend to vary on my satisfaction level as well......:)

Hi,
Krell KMA-100, with short lengths of Siltech speaker cable was a very good result back then.
Sell the Scintillas unless you have placed a bet with yourself.

Good point on the Class D. Whatever Henry Ho created with his H2O amplifiers he definitely designed them to work with 1 ohm Scintillas. Cannot speak to the exact design elements. 

Control, was the wrong term regarding tubes on the ribbons.  I can say that when I biamp my Apogee Duetta signatures I use my CJ Premier 11a on the high end and it is an unbelievable combination. I wish the Premier 11A sounded as good on my, Scintillas. The Scintillas have a more complex ribbon for the high end which includes additional ribbons for midrange. Maybe just not enough power at 70wpc. Still have not given up with this approach for, Scintillas. Obviously with biamping with passive crossovers everything has to be gain matched.

Class D has to use a filter at the output to get rid of the switching noise. This filter has to be designed to accommodate a certain impedance. Pretty sure that 1 ohm is not a consideration. Most are set up for 4 ohms. Its not that the amp may not be able to drive the load, simply that the filter isn't set up to do its job on such a low impedance.

Having heard this speaker with tubes, 'control' isn't the issue. 

Thanks for the Wolcott tip! While i am certainly a tube fan with some really great sounding older CJ tube amps i am going to try to make SS work for the Scintillas. Certainly much debate around which is better and attributes for each i value. The apogee ribbons really do respond to control which is why the H2O class D of Henry Ho’s is so highly regarded. I read somewhere that Bob Carver has some new tube designs set up for hard loads (like 1 ohm Scintilla). Something tells me this could be a really good option if within reach financially. 

There are a couple of Wolcott Presence amps on ebay (do a search) one is a stereo amp rated at 120 watts($3500) the other one are mono amps rated at 220 watts($3600) Ive heard that they work great with panel speakers but never listened to them except at a show (CES).Something to check out, TISH

Its really important to keep your speaker cables as short as possible when dealing with a 1 ohm load!! If ever there was an argument for balanced operation and monoblocks, this is it because you really don't want to have speaker cables be over about a foot or so unless they're 4 gauge or larger. The actual speaker connectors are important too as you simply don't want any DC resistances in series with the amplifier output.

Thanks for the additional input. DR-3’s definitely on the list.

Great thought on the autoformers. What is interesting is that my Mc MC7270 has autoformers and a 1 ohm connection did not sound great with the, Scintilla’s. Sounds great with many other speakers. Would love to try the Zeros. Not cheap. 

Other than the one ohm load, that speaker is otherwise reasonably efficient and easy to drive. The only time I heard a pair was at a reveiwer's house with our 100 watt MA-1 amplifiers using a set of autoformers to accommodate the load. There was plenty of power and it sounded quite nice.

So if you wanted to use tubes, you could get a set of ZEROs (www.zeroimpedance.com) to help the amp out with the load.

Jason Bloom often demoed the Scintilla with either a pair of mono Classe DR-3's or a stereo Classe DR-3VHC

Acoustat TNT! Excellent amp, now forgotten!

I had those back in the day.   The sun fires will drive them pretty well. Big soundcraftsmen amp is what you want for something cheap to run them.  Like a 5002      If you can find a used krell  fbp series those will make the scintilla sing.

Thanks for the feedback. Yes, the Sunfires will stay in the collection for now. There is a 600 as well. I think the 300 is 1200w at 1ohm. Quite remarkable. Will check out Magnus and TNT. 

I tried a McIntosh MC7270 and it did not get close to the Sunfires. The Mc has a 1ohm connection terminal that is achieved through the autoformer. Ran fine, cool, etc. but did not have the punch of the SF.

Scintilla’s for $900 a deal for sure. But most likely would have required some work. Could have cost you 5-6K in the end, without a fancy finish. Based on what i have heard (which may be limited) worth it. Of course my Dynaco A25’s i picked up at goodwill for $35 sound pretty sweet...:). 

Keep the Sunfires. 

If you don't want to go money-crazy with brands like Block, look into Magnus. They have some really powerful and well built amps that have been well reviewed. Then there's Mac of course, but I realize that is a polarizing subject... 

Damn! I could have had those Scintilla's for about $900! Alas ...

Keep the mono-ed Sunfires! Those are great amps, for sure! Anything else will only be a marginal advance, if that! Honestly! And if I remember correctly, didn't Bob Carver make a Sunfire 600 Signature? Today's "boutique" amps are way overpriced and built to attract the gullible and neurotic!

How about Jim Strickland's big TNT amp that he designed to drive his paralleled Acoustat electrostats? 250 watts @8ohms and double that as the impedance drops! I have one in my collection. Now I wish I had bought that pair of second-hand Scintilla's offered to me years ago!