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-   -   Apogee Scintilla - Information about the Efficiency wanted (http://www.diyaudio.com/forums/planars-exotics/216483-apogee-scintilla-information-about-efficiency-wanted.html)

tiefbassuebertr 19th July 2012 04:20 PM

Apogee Scintilla - Information about the Efficiency wanted
 
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/..._Apogee-DE.pdf
and "HIFI-STARS"
http://apogee-acoustics.de/download/...mall_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.

Groove-T 19th July 2012 04:44 PM

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.

LineSource 21st July 2012 05:35 AM

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.

tiefbassuebertr 21st July 2012 08:14 AM

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-...ansformer.html

Groove-T 21st July 2012 09:31 AM

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....

tiefbassuebertr 21st July 2012 01:42 PM

Quote:

Originally Posted by Groove-T (Post 3099524)
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.

Groove-T 21st July 2012 01:59 PM

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 :)

Rob Dingen 21st July 2012 03:10 PM

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

LineSource 21st July 2012 05:46 PM

[QUOTE=tiefbassuebertr;3099480]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.

tiefbassuebertr 21st July 2012 06:54 PM

Quote:

Originally Posted by Groove-T (Post 3099680)
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 ?

Quote:

Originally Posted by Rob Dingen (Post 3099738)
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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