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Old 29th October 2006, 09:10 AM   #101
Bgt is offline Bgt  Netherlands
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BTW your NCD's sound really fine, tough to tell the difference with the 400AD. Trying to find them with different music. Some extra burn in hours will help I guess.(have about 100 now)
Think the neighboorhood will start complaning about SPL
Forgot its sunday
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Old 29th October 2006, 09:23 AM   #102
t. is offline t.  United Kingdom
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Quote:
Originally posted by Bgt
BTW your NCD's sound really fine, tough to tell the difference with the 400AD. Trying to find them with different music. Some extra burn in hours will help I guess.(have about 100 now)
Think the neighboorhood will start complaning about SPL
Forgot its sunday


Thing is Bert I'd expect the NCD to sound a lot better mainly because they cost more than the UCD.
I'll admit my UCD's are sounding soo good at the minute, if I was too upgrade I'd want a noticeable improvement
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Old 29th October 2006, 10:16 AM   #103
IVX is offline IVX  Russian Federation
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Bert, 6V@500khz ripple is too much for a ribbon tweeters, which have very little inductance. If you will use claimed features e.g. "The switching frequency is adjustable in the range of 330 to 1000 kHz.", then will >9V@330 ripple, or about 20W@4Ohm continuously. BTW, how implemented interface with ATtiny13, i see no display and no buttons for software control of the switching frequency?
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Old 29th October 2006, 10:33 AM   #104
IVX is offline IVX  Russian Federation
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Quote:
Originally posted by Bgt

Lars, sorry, my fault
Because I had to switch from 0-1V RMS to 1-10V RMS to get full output the DC content of the generator had to be adjusted.
When I did that it was ok, will make another photo now.
On the UCD I get the output to clip with a level less than 1V RMS.
The NCD needs more. This shouldn't be? 45db should be enough to get full output under 1V RMS?

Hmm..Where you found any words about 45db gain? I see only that -"Input Level 0.9V RMS (200W 8Ohms)" so 40VRMS/.9VRMS=44.4(4) times, but not db's, it's equal 20log(44.4)=33db.
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Old 29th October 2006, 11:53 AM   #105
soongsc is offline soongsc  Taiwan
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I think the 45db came off the NCD site. I saw it too.
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Old 29th October 2006, 12:08 PM   #106
Bgt is offline Bgt  Netherlands
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Originally posted by soongsc
I think the 45db came off the NCD site. I saw it too.
correct
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Old 29th October 2006, 12:11 PM   #107
Bgt is offline Bgt  Netherlands
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Originally posted by t.




Thing is Bert I'd expect the NCD to sound a lot better mainly because they cost more than the UCD.
I'll admit my UCD's are sounding soo good at the minute, if I was too upgrade I'd want a noticeable improvement
T, I look at it from a technical&sonic viewpoint, difference in way of designing/sound. If its no better, than yes, cheaper is better.
The UCD's are very robust also.
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Old 29th October 2006, 12:14 PM   #108
Bgt is offline Bgt  Netherlands
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Originally posted by IVX
Bert, 6V@500khz ripple is too much for a ribbon tweeters, which have very little inductance. If you will use claimed features e.g. "The switching frequency is adjustable in the range of 330 to 1000 kHz.", then will >9V@330 ripple, or about 20W@4Ohm continuously. BTW, how implemented interface with ATtiny13, i see no display and no buttons for software control of the switching frequency?

IVX, how can 500khz do anything with a speaker???? I just cannot imagine this will translate to consumption in the tweeter. Mine is not hot after 4 days of 24h playing.
I don't know about ribbons.
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Old 29th October 2006, 12:17 PM   #109
Bgt is offline Bgt  Netherlands
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Originally posted by IVX



Hmm..Where you found any words about 45db gain? I see only that -"Input Level 0.9V RMS (200W 8Ohms)" so 40VRMS/.9VRMS=44.4(4) times, but not db's, it's equal 20log(44.4)=33db.
You must be right, I think I measured about 1.2V rms for full output for me 100V on the scope. Is about 155Watts.
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Old 29th October 2006, 12:23 PM   #110
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Originally posted by Bgt


correct

Just someone has mismatching with times/db, so your UcD must be little bit louder indeed
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