Studio Reference Amplifier

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#630
I'm curious if anyone has built the SR50 with the pcb by Drowranger in post #361? I like the bigger, spread out pcb but there is no follow up on it since August 2011. Just wondering if anyone tested it as there were many suggestions and revisions. Thanks.
 
#631
Dear Mr. Apexaudio,
I use one my regulated psu 10 to feed my amp (using 2 pairs of toshiba 5200, 20mV bias set up on R 0,22 Ohm 5 W). 32 Vac from 5A EI resulted 40Vdc.
After plays 5 songs, the bridge dioda (50 A) will be warm tends to hot, zener dioda is 8V.
If I set bias for 5mV, bridge dioda only warm after playing more than 20 songs.
May I have your advice to solve the problem?
Thank you so much.
Best Regards.
Arif
 
#632
Hi Mr Arif,
I guess it is still normal condition, did you put a small heatsink on that bridge rectifier?
I found that our local bridge diode can't handle its ratted current, that bridge dioda without plastic case is better.
I use that marked MIC RU AC KBPC3510 on traffo 32 VAC 10ABE*T on my AX, only warm witout heatsink 😀
How about your new PCB SR200 V2, do you already worked on it?

Regards
 
#633
JOHN BALI said:
Hi Mr Arif,
I guess it is still normal condition, did you put a small heatsink on that bridge rectifier?
I found that our local bridge diode can't handle its ratted current, that bridge dioda without plastic case is better.
I use that marked MIC RU AC KBPC3510 on traffo 32 VAC 10ABE*T on my AX, only warm witout heatsink 😀
How about your new PCB SR200 V2, do you already worked on it?

Regards
Click to expand...
Hi John Bali....How are you?
I see, maybe because of the diode built quality. I use the Mexico one...maybe needs to be put heat sinking on. I used the MIC before but some friends told me that Mexico is the better one.
I order the pcb, never build that one (lack of capability..hi hi hi) ... I am still thinking about what color I will take for that pcb and the pcb maker still full of tasks. So I have to be patient waiting for my pcbs.
Thanks for your input...
Best Regards..
 
#634
Dear John Bali,
sorry my mistake, wrong posting on local diy forum, the right one is I set bias 1 V on r10Ohm instead of fuse. I tried to set up to 1,2 up to 1,3 but the HS was too small. So the amp will hot soon. For the safety reason I prefer to have 1V bias setting.
Best Regards.
 
#635
Arif Budiyanto said:
Dear John Bali,
sorry my mistake, wrong posting on local diy forum, the right one is I set bias 1 V on r10Ohm instead of fuse. I tried to set up to 1,2 up to 1,3 but the HS was too small. So the amp will hot soon. For the safety reason I prefer to have 1V bias setting.
Best Regards.
Click to expand...
Hi, I'm fine thanks.
I have use Mexico diode, they are hotter. I have 2 grade, one of them marked JPN but not really good diode. They only good at lower voltage...
for bias I will say
No, 1 volt on 10 ohm resistor will be 333mA per output tranie (very hot :h_ache:)
Apex suggest 30-60mA per output.
Now let see what the other comment 🙂

shreya said:
Hello Andrew

I mean in sr200 amplifier

capacitors voltage must be?
Click to expand...
Hi Shreya,
I was ask similar question but nobody answer it yet.
JOHN BALI said:
Hi Apex,
For C1, C8, C9, C10, C11 it is also 50V or higher?
if we use max +/-75VDC, what is the minimum allowed(safe) for these caps rating?
Click to expand...
I guess 50V ratted caps will be okay, except on
C8 220nF, C9 22nF, C10 & C11 100pF
I don't know the safe ratting of these caps, maybe they fail if we use 50V ratted caps since total from rail will be more than 100V 😕
So anybody give us some clue, please...

@Arif Budiyanto, what your caps ratting that you used?

Regards
 
#636
Arif Budiyanto said:
Dear Mr. Apexaudio,
I use one my regulated psu 10 to feed my amp (using 2 pairs of toshiba 5200, 20mV bias set up on R 0,22 Ohm 5 W). 32 Vac from 5A EI resulted 40Vdc.
After plays 5 songs, the bridge dioda (50 A) will be warm tends to hot, zener dioda is 8V.
If I set bias for 5mV, bridge dioda only warm after playing more than 20 songs.
May I have your advice to solve the problem?
Thank you so much.
Best Regards.
Arif
Click to expand...

Use fast diode instead bridge like in post #52
 
#637
Dear Apex,
that will be more time to source the fast diode, hard to find in my local city.
any fast diode will work? Any diodes type that recommended?

and sorry if this one just a silly question
but please your guidance because I'm not sure yet
JOHN BALI said:
I guess 50V ratted caps will be okay, except on
C8 220nF, C9 22nF, C10 & C11 100pF
I don't know the safe ratting of these caps, maybe they fail if we use 50V ratted caps since total from rail will be more than 100V 😕
So anybody give us some clue, please...
Click to expand...

Thanks in advance
 
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