well
in my proposition one woludn't need more then around 5 Watt of amplifier power that is around 71V at the speaker terminals (/1024 Ohm)
and it would be during short peaks, on average it would be closer to 0.5W maximum that is around 22V at the speaker terminals
can 22V or a very short blow of 71V kill a person?
in my proposition one woludn't need more then around 5 Watt of amplifier power that is around 71V at the speaker terminals (/1024 Ohm)
and it would be during short peaks, on average it would be closer to 0.5W maximum that is around 22V at the speaker terminals
can 22V or a very short blow of 71V kill a person?
One thing with an OTL....is that the output Z is usually not low enough with a lot of paralleled tubes..... You also need to account for feedback in lowering the output Z to get it lower than the speaker Z you plan on driving...this way getting the damping you need....
Now the input sensitivity to the output stage decreases with feedback...this means using a larger driver voltage to the output stage valves...
Chris
Now the input sensitivity to the output stage decreases with feedback...this means using a larger driver voltage to the output stage valves...
Chris
100 ohm speaker for OTL
I'm not sure if this thread is still active. But for what it's worth I've experimented with this idea for a couple of years. I am planning to run 8X audax HM130Z12s with 8 X TM025F1 tweeters in a semi line source.
That way I can configure it for either 4 ohms for solid state, 16 ohms for my vintage tube amps and 64 ohms for OTL. The only holdup in the project (I have the drivers and box calcs ready to go) is I keep changing my mind between open baffle and some sort of curvy vented box design.
I am planning to build a 6336A circlotron amp sometime. But in the mean time I have a luxman MQ36 which is rated at 25wpc into 16ohms .
In some literature Lux also rate it at 40wpc into 50ohms so I figure it should be quite happy with a 64 ohm load.
You can't go too far though. I talked to Bruce at Transcendent about my planned 64 ohm speakers and he advised his amps didn't like such a high impedance and recommended 32 ohm as a maximum.
John Corneille
PS I'd love to hear from anyone who has built a 6336A circlotron amp. john@cameraexchange.com.au
I'm not sure if this thread is still active. But for what it's worth I've experimented with this idea for a couple of years. I am planning to run 8X audax HM130Z12s with 8 X TM025F1 tweeters in a semi line source.
That way I can configure it for either 4 ohms for solid state, 16 ohms for my vintage tube amps and 64 ohms for OTL. The only holdup in the project (I have the drivers and box calcs ready to go) is I keep changing my mind between open baffle and some sort of curvy vented box design.
I am planning to build a 6336A circlotron amp sometime. But in the mean time I have a luxman MQ36 which is rated at 25wpc into 16ohms .
In some literature Lux also rate it at 40wpc into 50ohms so I figure it should be quite happy with a 64 ohm load.
You can't go too far though. I talked to Bruce at Transcendent about my planned 64 ohm speakers and he advised his amps didn't like such a high impedance and recommended 32 ohm as a maximum.
John Corneille
PS I'd love to hear from anyone who has built a 6336A circlotron amp. john@cameraexchange.com.au
been there, done that...
enjoyed the bag of chips... best speaker I've ever built, purpose built for circlotron otl.
graaf said:
hello again!
what happened to this speaker project?
Is it completed or under development or was it abandoned?
best,
graaf
ps.
this thread is always active
at least it will be as long as I will be active
enjoyed the bag of chips... best speaker I've ever built, purpose built for circlotron otl.
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graaf said:
hello again!
what happened to this speaker project?
Is it completed or under development or was it abandoned?
Under development. There are some interesting things that I hadn't considered (in my naiveté). Never did a line array before, only a line source ESL. The drivers I got were lovely for the purpose, 4" paper cone units sourced from China. They were the woofer/midranges for the well-regarded NHT Super Zero. What's special about them is the very smooth midrange behavior and gentle rolloff, a key to the Super Zero's design. However, once I measured them, I found that the rolloff began too soon and that they just could not be run without tweeters. Back to the drawing board. I have been VERY unhappy with the sound of arrays with separate woofers and tweeters, the lobing is very evident when the tweeters are lined up, and when one or two tweeters are used, the discontinuity in polar pattern is audibly bothersome to me.
I'm happy for any suggestions on integrating tweeters into this, but what I've been playing with (fortunately, I've got about a hundred of these drivers, so I can kill a few) is various whizzer mods. Haven't got the right one yet, so I'm open to suggestions there, too.
I like projects like this where I start out not really knowing what I'm doing, then finding out I really don't know what I'm doing. That's when I feel that I can actually make progress rather than tread water.
Re: Re: been there, done that...
They were Parts Express buyouts, no longer available. They were built in three days as a proof of concept excercise of the least expensive drivers I could find. 49 cent midranges, 70 cent tweeters. $400 total for the pair, complete. They roll off at 80 and 18000. I crossed over at 4000, used active electronic before tubed mono-blocks. 16 ohm resistive in a complex series/parallel 6 group power tapered arrangement ala James Griffin's NFLAWP.
graaf said:
wow! thanks!
beautiful and impressive!
what is the combined impedance?
what are the drivers? tell me more!
best,
graaf
They were Parts Express buyouts, no longer available. They were built in three days as a proof of concept excercise of the least expensive drivers I could find. 49 cent midranges, 70 cent tweeters. $400 total for the pair, complete. They roll off at 80 and 18000. I crossed over at 4000, used active electronic before tubed mono-blocks. 16 ohm resistive in a complex series/parallel 6 group power tapered arrangement ala James Griffin's NFLAWP.
great!SY said:
I am afraid it cannot be done, at all, especially if one wants to have retain those 100 Ohm of combined impedance in the endSY said:
I seriously believe that You really need a fullrange driver more suitable for use in such a "one way" line array
a driver that really goes beyond 10 kHz, preferaby with frequency response on axis rising towards highs
my advice - sell those "Super Zero" drivers and get something more suitable, for example something like this: http://www.tymphany.com/tg9fd-10-04-0
BTW these are the drivers used by Russell in his IDS25 array, I believe
some independent measurements: http://www.hifisound.de/oxid/out/oxbaseshop/html/0/test_pdf/VIF-1111918.pdf
they are VERY impressive
quite remarkable drivers, in the league of Jordan JX's
after my advice a friend of mine gave them a try in an "Ambiance Acoustics California"-style 2x2 array with surprisingly good results
after equalization of course (active digital in his case)
best,
graaf
I think that the impedance issue can be gotten around, but the frequency response is indeed a problem. I'm hoping that some cobbed-together addition to the drivers will get me to the "good enough" point. If not, well... it's not like I'm short of speakers in the house.
The Vifas look nice, but a floor-to-ceiling array will be totally out of my price range.
The Vifas look nice, but a floor-to-ceiling array will be totally out of my price range.
SY said:
fortunately there are cheaper alternatives, for example those drivers offered by German Intertechnik under the tradename of Gradient (which are rebranded Teslas I believe): http://www.lautsprechershop.de/pdf/gradient/gpm100tv.pdf
they go beyond 10 kHz and they have nice, reponse rising towards highs - almost 10 dB difference between lower midrange and the highs around 10 kHz - which makes them very suitable for arrays, such a rising frequency respone means less equalization needed
in Germany their price is around EUR 14.90, three times less than Vifas:
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/gradient_en.htm
best,
graaf
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