MCD-255 amp - diyAudio
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Old 23rd January 2008, 08:25 PM   #1
Bgt is offline Bgt  Netherlands
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Location: NL, Voorschoten
Default MCD-255 amp

Very nice sound

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mods
LM4562 as input IC now
shortcut on coupling cap. offset now 30mv on both channels, was 5.
output relais on MCD pcb shortcut, using a speaker protection pcb now. Is more sensitive and looks at more variations on the speaker lines, either neg. or pos.
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Bert
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Old 23rd January 2008, 09:02 PM   #2
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Good work!

I'd be interested in a comparison vs. the UcD400 amp, if possible.
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Old 23rd January 2008, 09:56 PM   #3
Bgt is offline Bgt  Netherlands
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its more on the UCD180's power level. It uses 2x30V AC like the UCD180.
But it has to break in first. After 30 hours I will compare.
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Bert
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Old 23rd January 2008, 10:33 PM   #4
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Oh, yes, it's the "smaller" MCD amp.
I'll stay tuned.
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Old 25th January 2008, 11:54 AM   #5
fumac is offline fumac  China
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good job Bgt

you find an special way to install the modules
you attention that the place of the mosfet.
but the heat sink of mcd-255 is just 3mm ,
we Proposal that the best way is install to the bottom board as heat sink (if using the Aluminum bottom board )

but if your job will ok for home using ,

about the opamp, we used the dip transposon, so is very easy to replace the bb2134 with any OPs.

LM4562 is a very good op, 0.00003%


hi TheShaman
we also have high power version.

rg
fumac
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Old 27th January 2008, 01:42 AM   #6
jkeny is offline jkeny  Ireland
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Hi Fumac,
Looks like some excellent work on this "next generation" of class D amplifier!

Can amplifier modules be purchased?
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Old 27th January 2008, 08:48 AM   #7
Bgt is offline Bgt  Netherlands
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Fumac, the amp stays really cool. Should not be a problem.
BTW the "mosfet side" is closest to the amp. side pieces.
Sound is very..................very nice
Positioning of the modules is done for symmetry.
Crosstalk at 20khz is>100Db at full power/8Ohms/>80W/ch.
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Bert
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Old 27th January 2008, 01:32 PM   #8
fumac is offline fumac  China
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Quote:
Originally posted by jkeny
Hi Fumac,
Looks like some excellent work on this "next generation" of class D amplifier!
Can amplifier modules be purchased?
hello jkeny, not to talk about saling here, just mail to me
thanks
fumac


Quote:
Originally posted by Bgt
Fumac, the amp stays really cool. Should not be a problem.
BTW the "mosfet side" is closest to the amp. side pieces.
Sound is very..................very nice
Positioning of the modules is done for symmetry.
Crosstalk at 20khz is>100Db at full power/8Ohms/>80W/ch.

hi Bgt,
i'm so happy that you really like the sound from MCD-255
I do care about any modules out to the world,
all this modules is my babies.
i like them running at a good state, Healthy, and long life .
this time is winter, so the temperature is not hot.
but at summer , the temperature will rase up,
a high temperature of house will cause the more higher temperature of mosfet,
because the RDS(on) will higher when the temperature is higher,
and the RSD higher will cause more power loss into the mosfet....
this is a bad loop
so take care

about Crosstalk
if you use one transformer to one modules, Crosstalk will be best

rg
fumac

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Old 28th January 2008, 04:23 PM   #9
jkeny is offline jkeny  Ireland
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Hi Bert,
Finished break-in yet? How do these amps compare? - would love to hear!
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Old 29th January 2008, 11:43 AM   #10
Bgt is offline Bgt  Netherlands
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jkeny,

will try to do that this weekend
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Bert
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