Apogee Scintilla - Information about the Efficiency wanted

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Concerning the data sheet about
Scintilla
I read follow:
Sensitivity @ 3m: 79dB (without the associated output voltage resp. output power)

About the German test report (magazine "AUDIOPHILE")
http://apogee-acoustics.de/download/Audio_2011-02_Apogee-DE.pdf
and "HIFI-STARS"
http://apogee-acoustics.de/download/Apogee_small_HS_11.pdf
there is no advice regarded that.

About
Apogee Scintilla Mark IV - AUDIO
I read follow:
max SPL (highest possible value): 93 db (without distance and without the associated output voltage)


about the old datasheet
Apogee Scintilla info
I read:
110db @ 4 Meters using a 100 watt Stereo Amplifier.
Here is the Question follow: 100 watt @ 1 ohms ??

Who can give me more exact values in this case - thank you very much.

BTW - the URL
The Scintillating Apogee - Hi-Fi News September 1985
and the German site
Audiophile Manufaktur | Lautsprecher
provides several informations, but not the wanted.
 
The old scinnies are 1 and 4 ohms, so we have apx. 85db at 1 Ohm, using a stable amp doing 100 w into 8, but 800 into 1 ohm.
This is measured with usual method.
Since they are dipoles there is somewhat more.
Peak level is apx. 105dB with one pair in a room of apx 50m2 if the amp can deliver 35 amperes.

The german speakers are different and a strange clone and absolutely not related to

Apogee Acoustics Website

On this hp you will find almost any info available.

There are new models like the synergy, which is really much better and newer speaker,looks scintilla like from size and ribbon arrays, but very different made.
They have Neodymium Magnets and so on, result is 94/dB 1 W / 1m into 3+ Ohms, works with any amp. More than 150Kg each

Heard them 6 weeks ago down in Oz. Oh Boy, if you like listening Music effortless, naturally timbre and dynamics, and of course lots of space, give them a try.
Take care, you will get addicted.
 
I owned Apogee Scintillas for several years. I bi-amped each speaker with a Krell KMA100 monoblock to direct drive the M-T ribbons using the 1-ohm ribbon load connection, and one side of a Krell KSA250 to direct drive the 1 ohm bass panel. The sound was wonderful. The Scintillas were my first dipole speaker and convinced me that dipole radiation helped compensate for some of the limitations of the stereo recording process and room effects.

The Scintilla's M-T ribbon design is worth study. There is just one magnet cavity with a corrugated Al midrange ribbon in the center of the gap, and narrow T-ribbons along the left and right sides, both in-front and behind the midrange foil. This approximates cardiod radiation. (See below diagram)

T.....T
MMMM
T.....T


The 110db SPL in the owner's manual is a near field measurement.

In the near field a linesource response slopes downward at a 3 dB per doubling of distance (10 dB per decade) rate, while the far field the response declines at a 6 dB per doubling of distance (20 dB per decade) rate.

I sold the Apogee Scintillas and purchased the original Full Range Apogee speakers, which we still have in our living room.
 
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good informations - thank you. Which version of the Scintillas you have heard on your KSA250? There are different versions - one version with very low impedance (0R5) and an other with 3R or 4R (more amplifier friendly).

What about the option for the use of an matching transformer (for the low impedance version, lowest value 0R5) ?
In this case I start this thread yesterday:
http://www.diyaudio.com/forums/pass...ph-1-2-vs-x-xa-xs-series-imp-transformer.html
 
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The low impedance version is declared to be 1 ohm, lowest value with x-over is 0,88 Ohm in bass, without x-over 0,72 ohms, measured with Ohmmeter, in use its a little bit higher.

The 4 ohm version is apx 3,8Ohm.

You will need a huge transformer for doing 1200 watts or more into 1 Ohm on the secondary side. Amorphous core is mandatory....
 
The low impedance version is declared to be 1 ohm, lowest value with x-over is 0,88 Ohm in bass, without x-over 0,72 ohms, measured with Ohmmeter, in use its a little bit higher.

The 4 ohm version is apx 3,8Ohm.

You will need a huge transformer for doing 1200 watts or more into 1 Ohm on the secondary side. Amorphous core is mandatory....
Yes - some time ago I heard from someone, that Audio Consulting - go to
News
offers such transformers on demand.
Unfortunately I don't find informations on the web.
 
Hi Tiefbassuebertr

I build a lot of ribbons and use resitors transformers and amps to direct drive the ribbons.
As for best to worst sounding order 1 amp 2 resistor 3 transformer.
I find the difference to direct drive the ribbon with an amplifier and a transformeer huge.
Build an amplifier like the F5 turbo but with 2sk170/2sj74 IRF610/IRF9610 and the Sanken 2SC3264/2SA1295 each 4 pieces and they deliver about 50A to 0,1 Ohm and sound good.

Rob
 
Which version of the Scintillas you have heard on your KSA250? There are different versions - one version with very low impedance (0R5) and an other with 3R or 4R (more amplifier friendly).
QUOTE]


My Scintillas had the 4-ohm bass panel. My Full Range Apogees have a 2-ohm bass panel.

I agree with Rob, "As for best to worst sounding order 1 amp 2 resistor 3 transformer. I find the difference to direct drive the ribbon with an amplifier and a transformeer huge."

It is not difficult to build a solid state amp that can safely drive a 0.5 ohm load with good efficiency and great sound. The output stage power supply is designed for low voltage (say 10-12V) operation. For extremely low resistance ribbons a series resistor up to 0.5 ohms is added, and the loss in efficiency accepted. Modern NdFeB magnet ribbons are typically 95-105 db/watt efficient, so the power loss in the series padding resistor is modest.

I have built SS amps with 5V output power supplies that can safely drive 0.1 ohm ribbons, but they did not measure as well nor sound as clean as when I added a series resistor to pad up the final load to 0.2 ohms. From my experience, a 0.2 ohm ribbon+resistor amplifier load is the lowest I would use. I used a triple-emitter-follower (3T) output stage with several Sanken 2SC2837 2SA1186 output transistors, each with 0.1 ohm emitter resistors.
 
Watch here

Bachmann Elektronik AG - Rüti ZH - Schweiz

He is an audiophile, he makes his own tube amps an so on and i have my special transformers for my Apogee Full Range from him, custom made.

Die sind wirklich gut :)

Thank you very much for this information - I will contact them and ask.
Can you post a picture of your transformer ?

Hi Tiefbassuebertr
I build a lot of ribbons and use resitors transformers and amps to direct drive the ribbons.
As for best to worst sounding order 1 amp 2 resistor 3 transformer.
I find the difference to direct drive the ribbon with an amplifier and a transformeer huge.
Build an amplifier like the F5 turbo but with 2sk170/2sj74 IRF610/IRF9610 and the Sanken 2SC3264/2SA1295 each 4 pieces and they deliver about 50A to 0,1 Ohm and sound good. Rob
I think, this is strongly dependend from the transformator resp. from the kind of core material.
Each manufacturer has their own recipe and specifies the order of priorities different. Thus there are very large sound differences between various ordinary output transformers for tube output stages, which are available from a wide range of manufacturers.

At which transformer you have observe this ? Was it a cost-effective solution or an ultimate solution?
 
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Hi Tiefbassuebertr

I make my own transformers en a wel known manufactor helped me to get the best out of it.
If you measure the transformers there is nothing wrong with it large bandwidht and low los.
But still the sound difference is huge like I told before.
I only use it for the mid high ribbon not for the bass panel.
Do wat you like and tell us later what you think.

Rob
 
Hi Tiefbassuebertr

I make my own transformers en a wel known manufactor helped me to get the best out of it.
If you measure the transformers there is nothing wrong with it large bandwidht and low los.
But still the sound difference is huge like I told before.
I only use it for the mid high ribbon not for the bass panel.
Do wat you like and tell us later what you think.

Rob
In which respect you perceive the mentioned sound difference by your listening test and which amp model you have in use therefore?

In general it is for me completly clear, that each additional device in the signal pad have an influence regarded the sound. A good known example therefore is a scaly or burnt-off relay contact for DC protect in series to the loudspeaker. Even without relay and with a capacitor in the signal pad you will get an influence to the sonic character (this is my favorite approach to avoid mechanical contacts, despite the present and mostly unwanted high pass character). Basically a directly dc coupled connection between amp out and speaker input saves lowest signal loss (at best with only very short cable connection, directly solder, i. e. without terminal and plug) - this is clear.

One user of Apogee Scintilla uses four power stereo amps in "Mono-Bridged" mode and Bi-Amp mode since a short time.
The model is "SA-Reference" from Plinius Audio - go to
http://www.pliniusaudio.nzld.com/documents/downloads/plinius_sarefbrochure.pdf
and
http://www.pliniusaudio.nzld.com/documents/downloads/plinius_sarefmanual.pdf
Output power at 8 ohm load impedance is 1000 watts (and thus theoretically 16000 watts at 0R5 load impedance but the 10 amp fuses prevents this in real live, of course).
The output stages (8 pairs power BjT devices in parallel mode/each amp) runs with a voltage of +/- 86 volts switchable for class A (2200mA, 275mA/each pair) and class AB (320mA, 40mA/each pair).
Sound quality is exceptionell good, the user says, the best amplifiers ever heard.
But I told him, that the reliability is very low and the likelihood that occur very expensive damage is very high, particularly in such cases, when high sound pressure levels are trying to achieve.

This is the reason to start this thread. Concerning the max SPL of this Apogee planar radiators unfortunately I have no comparison to good known loudspeakers with cone transducers (thus the various mentioned SPL values offer no evidence for me and therefore are no helpful). Also there are no information about the maximal input power rating of this model (for the most cone speakers usually published).

There are only two options for good reliability in the case of further use of this amplifier model:
1) the use of four impedance matching transformers
2) power amp modify in such way, that the supply voltage is halved or quartered (+/-43 volts or +/-21,5 volts) and the idle current accordingly doubled or quadrupled. Basically easy (only reducing the resistors for reference current through the CCS), but in real life much more efforts than matching transformers. From this view I would prefer the first possibility.

If the disadvantage by sonic quality (by use of the matching transformer) is only present at low level aera below 150 Hz, it does not matter, because for this frequency range an additional subwoofer will come later (include an additional high pass filter).
 
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Sorry, a pic of my transformers will not help you, since they are moulded/hermetically sealed in a plastic box, size apx 10cm x10cm x 10cm, rated with 250 Watt, for the tweeter they transform 3 into 1 ohm, for the Mid 3 into 0,2ohms ( good for 35 amperes), you just can see the wires.
It seems to be very small for such a current. Are there a very special core in use?
 
The ultimate solution would be the GTE Trinity amp, which can do 1 Ohm. But more a theoretical option, when looking at the price.
mean you the amplifier from follow URLs ?
TRINITY Electronic Design GmbH
GTE - Trinity Mono-Endstufen
http://www.trinity-ed.de/pdf/MKII100.pdf
http://img.photobucket.com/albums/v53/eliot/munich09/hiend040.jpg
http://marcs-hifi-blog.audiodoo.de/wp-content/uploads/gte-trinity-3.jpg
http://www.trinityamps.com/ForumGallery/trinity/Doc_Files/TrinityAmps_Builder_Guide_3.921.pdf
Unfortunately there are no price lists mentioned and in the tests there are also no price informtions.
Nevertheless - a good advice at all. A large amount of output transistors in parallel mode is also from my view a very good solution.
 
I owned Apogee Scintillas for several years. I bi-amped each speaker with a Krell KMA100 monoblock to direct drive the M-T ribbons using the 1-ohm ribbon load connection, and one side of a Krell KSA250 to direct drive the 1 ohm bass panel. The sound was wonderful. The Scintillas were my first dipole speaker and convinced me that dipole radiation helped compensate for some of the limitations of the stereo recording process and room effects.

The Scintilla's M-T ribbon design is worth study. There is just one magnet cavity with a corrugated Al midrange ribbon in the center of the gap, and narrow T-ribbons along the left and right sides, both in-front and behind the midrange foil. This approximates cardiod radiation. (See below diagram)

T.....T
MMMM
T.....T


The 110db SPL in the owner's manual is a near field measurement.

In the near field a linesource response slopes downward at a 3 dB per doubling of distance (10 dB per decade) rate, while the far field the response declines at a 6 dB per doubling of distance (20 dB per decade) rate.

I sold the Apogee Scintillas and purchased the original Full Range Apogee speakers, which we still have in our living room.
Line , could you explain the midrange setup a bit more , what's the advantage of the t-ribbons , this would appear to me to be more harmful than good ...advantages ...?

Agree with those who feel transformers to be the worst , I have found resistor to be the best with .8 being the optimum for sonics , lower for drive....

The low impedance version is declared to be 1 ohm, lowest value with x-over is 0,88 Ohm in bass, without x-over 0,72 ohms, measured with Ohmmeter, in use its a little bit higher.

The 4 ohm version is apx 3,8Ohm.

You will need a huge transformer for doing 1200 watts or more into 1 Ohm on the secondary side. Amorphous core is mandatory....

Not really they will not require more than 500 watts at 1 ohm , if you measure the current and voltage being used u will see this ...

Hi Tiefbassuebertr


I build a lot of ribbons and use resitors transformers and amps to direct drive the ribbons.
As for best to worst sounding order 1 amp 2 resistor 3 transformer.
I find the difference to direct drive the ribbon with an amplifier and a transformeer huge.
Build an amplifier like the F5 turbo but with 2sk170/2sj74 IRF610/IRF9610 and the Sanken 2SOC3264/2SA1295 each 4 pieces and they deliver about 50A to 0,1 Ohm and sound good.

Rob

Output impedance with 4 pr might have issues with direct drive ....
 
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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.