in one of your links, I saw the amp priced at 52,500 euros. Not sure if that is for a mono set or stereo pair.
Lowering the voltage would be his best option , saves the amp and better sonics at that load. Now how to combat the increases in distortion by the amplifier due to the very low load , more class-a bias ? more feedback ?
Full power...! 
No we tested at our listening avg , the scinnies was that of a friend who had custom build amplifiers , he listens loudly 90-93db avg din , his amps were rated @600 /1ohm the designer told me they would not require more Than that , the fact that he never tripped his 15 amp speaker fuses was a clue ..
On my ribbons I have measured voltage at an avg din of 86db impedance 1 ohm and agree with his assessment . Even when pushed at higher levels I very rarely ever blow the 10 amp speaker fuses and when measured I was using 7V rms into the midrange ribbon (1ohm) at normal listening levels ...
Of course if you want to exceed 100db consistenly then I would suggest double that ,(600) figure and those who do most times damage the bass ribbon ..
Regards ,
No we tested at our listening avg , the scinnies was that of a friend who had custom build amplifiers , he listens loudly 90-93db avg din , his amps were rated @600 /1ohm the designer told me they would not require more Than that , the fact that he never tripped his 15 amp speaker fuses was a clue ..
On my ribbons I have measured voltage at an avg din of 86db impedance 1 ohm and agree with his assessment . Even when pushed at higher levels I very rarely ever blow the 10 amp speaker fuses and when measured I was using 7V rms into the midrange ribbon (1ohm) at normal listening levels ...
Of course if you want to exceed 100db consistenly then I would suggest double that ,(600) figure and those who do most times damage the bass ribbon ..
Regards ,
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not very experienced personally with them, but... putting a resistor in series with the bass ribbon will definitely increase the Q and decrease the DF... probably making for a warmer sounding bass?
Also, I was under the impression that amorphous cores were best at HF, and lacked inductance at LF, so were less than optimum for LF applications...
_-_-bear
Also, I was under the impression that amorphous cores were best at HF, and lacked inductance at LF, so were less than optimum for LF applications...
_-_-bear
Yes bear, thats why my trafos should work only for mid and high.
No res. in series with woofer, the scintilla has a full and rich bass, some people found it to much and you need a real huge resistor.
a.wayne, i had krell mda 300 driving scinnies, and twice my main fuse in the appartment rated at 50 Amperes at 230 Volt were blown when i gave full power with some mid bass impulse.
BTW, the MR itself is only 0,06- 0,07 Ohms, then there are some wires, connectors and a preresistor (foil type). So if you had real 7 V on the MR, how many amperes ???
On the other hand, since i am a certified apogee woofer installer, after installation of new woofers i do some tests with amps minimum 1200 Watt into 1 ohm and its for woofer test especially.
No res. in series with woofer, the scintilla has a full and rich bass, some people found it to much and you need a real huge resistor.
a.wayne, i had krell mda 300 driving scinnies, and twice my main fuse in the appartment rated at 50 Amperes at 230 Volt were blown when i gave full power with some mid bass impulse.
BTW, the MR itself is only 0,06- 0,07 Ohms, then there are some wires, connectors and a preresistor (foil type). So if you had real 7 V on the MR, how many amperes ???
On the other hand, since i am a certified apogee woofer installer, after installation of new woofers i do some tests with amps minimum 1200 Watt into 1 ohm and its for woofer test especially.
After a closer look to the frequency response from second URL by post #1 (from German test magazine "AUDIOPHILE") I am very confused. This is a MK-IV version. What happens here (go to the attachment for higher resolution)?
Actually one need a special additional device for equalization (similar like a RIAA equalization for record players), independend of the fact, whether a impedance matching transformer is in use or not. I doubt, that it is possible with passive components in front of or behind the transformer (perhaps a foil capacitor of 47mF resp. 47.000uF and a low impedance 30 mH inductor is necessary only for remove the low frequency peak by 35 Hz).
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tiefbassuebertrager
There exists no scintilla MK 4.
Like i wrote before, the german thing is a clone and has nothing to do with the real apogee! Actually lawyers are involved to clean up this mess!
The measurings shows a peak at apx 35 Hz, which is part of every apogee woofer, but: The real challenge with apogee is the woofer tuning, which is not done correctly with this clone, for sure! How to do it, is still our certified installer secret.
This peak( if done well) should not be equalised, since this kind of woofer is a dipole, is very depending from placement( distance to rear wall) and not a box and if executed well, the apogees have a kind of bass, which we apogee fans appreciate very much. No boxy sound, but full and rich bass and dipole mid/highs....
The rest of the frequency response is not very scintilla like, since its a clone! Not a real good one IMHO.
The impedance response is not visible here, but originally its demanding the most power in the transit area woofer/MR around 300 Hz and below.
Adding a resistor will change the woofer sound very much due the altered Q and need a lot more amp power just to produce heat. 600 Watt Resistors are a challenge to. Some folks believe resistors do no not change the sound, other ones are convinced they do.
Count me in the second ones.
This impedance thing with the scintilla seems to keep all folks in red alert mode, but it is a problem since more than 25 years and it will not go away. Its stupid to make a clone with the same problems, IMHO!
Thats why Apogee Acoustics in Australia comes with new models, impedance higher than 3 Ohms and efficiency apx. 95dB/ 1 W 1m. Use every amp you like, basta.
There exists no scintilla MK 4.
Like i wrote before, the german thing is a clone and has nothing to do with the real apogee! Actually lawyers are involved to clean up this mess!
The measurings shows a peak at apx 35 Hz, which is part of every apogee woofer, but: The real challenge with apogee is the woofer tuning, which is not done correctly with this clone, for sure! How to do it, is still our certified installer secret.
This peak( if done well) should not be equalised, since this kind of woofer is a dipole, is very depending from placement( distance to rear wall) and not a box and if executed well, the apogees have a kind of bass, which we apogee fans appreciate very much. No boxy sound, but full and rich bass and dipole mid/highs....
The rest of the frequency response is not very scintilla like, since its a clone! Not a real good one IMHO.
The impedance response is not visible here, but originally its demanding the most power in the transit area woofer/MR around 300 Hz and below.
Adding a resistor will change the woofer sound very much due the altered Q and need a lot more amp power just to produce heat. 600 Watt Resistors are a challenge to. Some folks believe resistors do no not change the sound, other ones are convinced they do.
Count me in the second ones.
This impedance thing with the scintilla seems to keep all folks in red alert mode, but it is a problem since more than 25 years and it will not go away. Its stupid to make a clone with the same problems, IMHO!
Thats why Apogee Acoustics in Australia comes with new models, impedance higher than 3 Ohms and efficiency apx. 95dB/ 1 W 1m. Use every amp you like, basta.
I suspect Apogee had 4 reasons behind the Scintilla M-T ribbon design:
1) KEY.. Reduce cost by having only one magnet gap for both the M and 4xTs.
2) Reduce comb filtering by having Ts on top of the M. In the Full Range Apogee the 0.5" wide T was crossed at 10Khz with a 6db/octave slope to the 2" wide midrange, and even physically adjacent this M-T just met a 1-Lambda spacing and not 1/4 Lambda ideal goal.
3) M and 4xTs put 4xT aluminum foil in series to increase the resistance + SPL_area and hence give an easier amplifier load.
4) I suspect the Apogee engineers like the sound of the M-4T cardiod radiation and decided that they could both reduce cost and also provide greats sound even with a simple low order Xover. There were several positive reviews for the Scintillas which describe how coherent the M-T sounds.
If money is no object, I think a separate M and T ribbon is superior with the proper crossover frequencies and slopes. I would use a line array of 3-4 dipole woofers in place of the Apogee style flat planar bass panel. A steep slope like LR8 between the bass-mid helps remove the M-ribbon bass bounce seen on Apogees. LR4 between the M-T is superior to the 6db slope used in Apogees.
Back-in-the-day Krell crossovers with 18db/octave slopes often replaced the original 6db/octave Apogees. The 18db/octave is the steepest possible with one buffer amp stage.
Interesting facts.
This German hifi magazine does definitely not help to clear up this mess.
The Full Range Apogee Speakers are in our living room, so I use Krell equipment and MIT Music Hose cables as part of the decoration.
Each 3-way Full Range is bi-amped with one Krell KSA250 located just behind the speaker. A Krell KRX-1 electronic crossover with 18db/octave at 200Hz is used for for bass-MT outputs to each amp. One KSA250 channel direct drives the 2 ohm bass panel, and the second channel drives Apogee's M-T interface box which is ~4 ohms. This interface box contains a large toroidal step up transformer for the 0.1 ohm M-ribbon, plus resistors to step up the tweeter ribbon resistance to ~4 ohms, plus a 6db/octave passive L + C Xover at 10Khz. This is a very robust setup for the Full Range.
I have built DIY amps which direct drive the 0.1 ohm midrange ribbon and 2 ohm tweeter ribbons. Direct drive always produces greater dynamics and detail, but it is also easier to damage a ribbon by human error. I wish everyone could hear a large M-T ribbon speaker with direct drive amplification to understand how magical this technology can be.
I would be very interested in You DIY amps.
I have a pair of 1 Ohm Scintillas myself and at this time I drive them with a Yamaha PC2602M amps with no problem what so ever.
I think I get about little over 800W out at the peaks before the clip-lamp starts to tell me that the amp is giving 1% distortion.
Please mail me if You feel like letting me in on the design!
Cheers!
I have a pair of 1 Ohm Scintillas myself and at this time I drive them with a Yamaha PC2602M amps with no problem what so ever.
I think I get about little over 800W out at the peaks before the clip-lamp starts to tell me that the amp is giving 1% distortion.
Please mail me if You feel like letting me in on the design!
Cheers!
ask there:
http://www.diyaudio.com/forums/pass...etry-nelson-pass-still-concept-amplifier.html
Perhaps from there you will find an excellent approach for your requirements.
check out also this thread:
http://www.diyaudio.com/forums/solid-state/154690-direct-drive-amplifier-diy-ribbon.html
http://www.diyaudio.com/forums/pass...etry-nelson-pass-still-concept-amplifier.html
Perhaps from there you will find an excellent approach for your requirements.
check out also this thread:
http://www.diyaudio.com/forums/solid-state/154690-direct-drive-amplifier-diy-ribbon.html
Help from LineSource on Apogee Full Ranges
LineSource--I read your thread below and would like to communicate with you more about the Apogee Full Ranges for learning purposes. Could you send me a PM, please? Thanks!
Kip
LineSource--I read your thread below and would like to communicate with you more about the Apogee Full Ranges for learning purposes. Could you send me a PM, please? Thanks!
Kip
Yes--I still do, DeltaStar! In fact, even though I am on a journey to finally set up my Apogee Full Ranges, I still am awed by the Scintillas and listen to them every day.
When I restored them in 2007, I only had to replace two caps since the rest were in great shape. I did pot the larger inductor, though.
I hope LineSource will reply to me--I'm really looking for some advice in how best to set up and drive the Full Ranges.
Thank--
Kip
When I restored them in 2007, I only had to replace two caps since the rest were in great shape. I did pot the larger inductor, though.
I hope LineSource will reply to me--I'm really looking for some advice in how best to set up and drive the Full Ranges.
Thank--
Kip
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