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Old 24th October 2009, 01:44 PM   #311
Salas is offline Salas  Greece
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Quote:
Originally Posted by korben69 View Post
BOM V4.3 (minor changes) :

1 - 4700uF caps rated to 35V : safer + extended lifetime.
2 - Led : both refs for Farnell/Mouser are pointing devices that shows typical Vf : 1.8v at 20mA.

Reports are welcome for update
Nice BOM. You just forgot to write 35V instead of 25V on footnote (1) too.
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Old 25th October 2009, 04:40 AM   #312
grufti is offline grufti  United States
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Salas, I just looked at the DCB1S prototype build pictures that people have posted and it seems that most builders used caps larger than 100uF/25V in the regulator section. 100uF/25V caps are tiny and most proto builders' caps look physically much larger.

What is the effect of using let's say 470uF instead of 100uF in the shunt regulator, if there is an effect at all that you are aware of?
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Old 25th October 2009, 11:37 AM   #313
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Thanks for the reply all.

I have read somewhere that the original b1 uses a coupling capacitor and that the Salas version doesn`t. I guess its best to stick to the original one then, as I will be using it with a firstwatt F5, which is DC coupled.

Perhaps I can just build the normal one, and add the shunt supply to it. Or build salas`with a coupling capacitor. I need to dig a bit deeper in all the treads to find out what would be the best for me.
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Old 25th October 2009, 11:44 AM   #314
Salas is offline Salas  Greece
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Quote:
Originally Posted by grufti View Post
Salas, I just looked at the DCB1S prototype build pictures that people have posted and it seems that most builders used caps larger than 100uF/25V in the regulator section. 100uF/25V caps are tiny and most proto builders' caps look physically much larger.

What is the effect of using let's say 470uF instead of 100uF in the shunt regulator, if there is an effect at all that you are aware of?
100uF is best if you want to follow my tuning. It can work with bigger. No technical problem for 99% of capacitor makes. I understand that some people maybe have good quality ones in different values that they will want to listen to for subjective effects. But I recommend they use 100uF first to know the original tuning. Use your best quality for the one across the 5 leds. The effect is they imprint some signature, especially the latter one. I prefer 100uF in this one as a subjective whole, and I have some simulation indications about the charging shape of the shunt Mosfet's gate Idrive that may exist and correlate in practice or not. Because I had been investigating that back when I did it. Its a ''tuned'' device at least for one person's views and ears. But its elastic. Can play.

Regards.

P.S. If someone uses a very low ESR bigger cap and hears any whistling noise from tweeters, soft or louder, don't worry much, you got it oscillating. Back to 100uF Pana FC, if your oscillation wasn't that bad. Else paypal for some new tweeters.
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Old 25th October 2009, 11:56 AM   #315
Salas is offline Salas  Greece
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Quote:
Originally Posted by rikkert1978 View Post
Thanks for the reply all.

I have read somewhere that the original b1 uses a coupling capacitor and that the Salas version doesn`t. I guess its best to stick to the original one then, as I will be using it with a firstwatt F5, which is DC coupled.

Perhaps I can just build the normal one, and add the shunt supply to it. Or build salas`with a coupling capacitor. I need to dig a bit deeper in all the treads to find out what would be the best for me.
Can't give you any warranties that your build ain't going to collapse at a point and drive DC to a de facto direct coupled and not output protected amp like the F5. Or that you will not never ever have a faulty source connected. On the other hand nobody says that the amp will never fail itself for instance. If you use just one capacitor in the chain, and that will be between buffer and F5, you will be safeguarded though. Using a shunt over a normal B1, I don't know if it matches this one, never tried. Uses 2 caps BTW.

Cheers.
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Old 25th October 2009, 12:14 PM   #316
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i also have f5 and i have to use a buffer before the amp..i should put capacitor to the output of both symmetrical and normal B1.so it doesnt change anything for sound quality?
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Old 25th October 2009, 12:23 PM   #317
Salas is offline Salas  Greece
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Its the less harm you can have for the sake of safety.
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Old 25th October 2009, 12:49 PM   #318
billyk is offline billyk  United States
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I used the same value 100uF but upped the voltage to 50v that's why the looked bigger in my build. They are Silmic II and are what I had at the time.
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Old 25th October 2009, 01:12 PM   #319
Salas is offline Salas  Greece
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I endorse Silmic II there.
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Old 25th October 2009, 07:46 PM   #320
adamus is offline adamus  United Kingdom
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any other mouser relays that would work? they are on back order.

edit - they have the 5v in.

Last edited by adamus; 25th October 2009 at 07:48 PM.
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