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Old 23rd April 2010, 04:24 PM   #1491
housing is offline housing  Hong Kong
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Quote:
Originally Posted by Mas Penk View Post
I don't really know about the sonic difference but I hear no Difference...

About the filter I read somewhere that filter should be R=1K C=47nF... CMIIW
Yes, the data sheet says so.
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Old 23rd April 2010, 04:41 PM   #1492
adamus is offline adamus  United Kingdom
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Quote:
Originally Posted by housing View Post
Hello Andrea,

What value of the output capacitor and Rload are you using? What's the minimum voltage of the output capacitor? Is 200V OK?

Regarding the jumper on the DAC board, is it correct to hard wire pin 1 & 3 and leave pin 2 untouched?

Thanks for your response in advance.

housing
200v is not ok.

you should always spec the output cap to be B+ with an extra margin. you need 300v or more caps. if something goes wrong you want the output cap to survive. You do not want 260v going to your next piece of kit!

Andrea is using a different operating point for the CCS. Using a CCS allows you to pick different operating points due to the horizontal load line created (Constant Current, so horizontal). The plate voltage is then just set by the grid bias.

for normal (not using the extra CCS PCB) then the 90v plate voltage is more suitable.

Last edited by adamus; 23rd April 2010 at 04:45 PM.
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Old 23rd April 2010, 05:07 PM   #1493
housing is offline housing  Hong Kong
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Quote:
Originally Posted by adamus View Post
200v is not ok.

you should always spec the output cap to be B+ with an extra margin. you need 300v or more caps. if something goes wrong you want the output cap to survive. You do not want 260v going to your next piece of kit!

Andrea is using a different operating point for the CCS. Using a CCS allows you to pick different operating points due to the horizontal load line created (Constant Current, so horizontal). The plate voltage is then just set by the grid bias.

for normal (not using the extra CCS PCB) then the 90v plate voltage is more suitable.
Hello Adam,

Thanks for your explanation. I think I understand now.
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Old 23rd April 2010, 11:34 PM   #1494
Pocoyo is offline Pocoyo  Indonesia
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Default AD 1865 N-K Group buy

Very sorry for a little distortion

For anyone who wants get The Real AD1865N-K
Please Order in this Group buys, just need 8 pcs order for 30

Ad 1865 n-k Let's do it again ?

Thank you
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Old 24th April 2010, 07:37 PM   #1495
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Default Irfp240pbf

Hi, mouser, digikey, newark, farnell are out of stock. Can I use IRFP250PBF instead IRFP240PBF ?


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Old 24th April 2010, 09:21 PM   #1496
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Originally Posted by ksnider1 View Post
Hi, mouser, digikey, newark, farnell are out of stock. Can I use IRFP250PBF instead IRFP240PBF ?


RS components
code 541-0660
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Old 24th April 2010, 10:14 PM   #1497
Salas is online now Salas  Greece
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Quote:
Originally Posted by ksnider1 View Post
Hi, mouser, digikey, newark, farnell are out of stock. Can I use IRFP250PBF instead IRFP240PBF ?


No, too high Ciss and gfs to match the other side. Look for IRFP244, IRFP340.
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Old 24th April 2010, 11:37 PM   #1498
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If the Salas HV regulator is used, how many I need ?

I guess I cannot put the rc filter for channel separation after the regulator.

Thanks,

Davide
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Old 25th April 2010, 04:37 AM   #1499
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Originally Posted by Salas View Post
No, too high Ciss and gfs to match the other side. Look for IRFP244, IRFP340.
Thanks pop music, Salas, I have to order some missing parts for my other projects. I found IRFP244PBF on mouser. I will let you know how it works out in few days.
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Old 26th April 2010, 05:24 AM   #1500
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Originally Posted by audiodesign View Post
Fred,
where you don't see "filters and bypass caps" ?
Andrea,

Sorry, I meant L1 and L2 was omitted as well as C4, C5, C9 and C10.

Would this heater power supply for the phono preamp applicable to the DACend? The 2.2ohms resistors and the bridge rectifier are too hot, can't stand it. This might be better that the original one. Please advise.
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Last edited by fredlock; 26th April 2010 at 05:27 AM. Reason: additional comment
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