Bgt said: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
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?
Bgt said:
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.
t. said:
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.
You must be right, I think I measured about 1.2V rms for full output for me 100V on the scope. Is about 155Watts.IVX said:
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.
An externally hosted image should be here but it was not working when we last tested it.
2v/div and 0,5uS/div.
An externally hosted image should be here but it was not working when we last tested it.
UCD 400
0.2V/div 0,2us/div so is about 475khz.(this 1 is the amp. with groundlift resistors, 1 transf. and 2 supply rails, BTW the UCD dual/mono has exactly the same ripple
)So UCD has 1V ripple and NCD nearly 6V.
t. said:
Thanks Bert, Its fine if you don't own either amp, you can just pick one but if you already own say UCD it may be a waste to buy something else if it does not sound better
Enjoying reading your updates Bert
Well T, I own them all but I like to try/investigate(and sell them eventually).
I mean its nice people/designers/DIY's have opinions when they test them but I always want proof. Someone else's truth does not need to be mine.
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