Hi Salas,
I still have concerns about my R-Core transformer with the relation to its output voltage. My big heat-sink is hot and I'm reaching 55-65 Deg Celsius.
Voltage adjustment is not simple since it is very sensitive to the temperature.
I touch big heat-sink with my figure and V increase by incriments of 0.5V every 1-2 sec.
I assume I need new R-Core with lower output.
As I wrote in the past, I use R-Core with 26V output which give me about 42V rectified RAW DC (2 of 0-115V primaries paralleled (0 to 0, 115V to 115V), but I have 119V-121V from my receptacle, not 115V). This is why my R-Core has 31-33V output instead of designed 26V.
My target to get out from BIB is 24V, so which output will you recommend from R-Core: 18V or 20V?
You mentioned the manual that BIB shout receive at least 5V more then it output target and 7-10 is even better.
18V output is on border of target+5V recommendation, and 20V output is hard for find. 24 output is too much...
What max current should be in transformer's secondary (does 0.5A enough)?
I still have concerns about my R-Core transformer with the relation to its output voltage. My big heat-sink is hot and I'm reaching 55-65 Deg Celsius.
Voltage adjustment is not simple since it is very sensitive to the temperature.
I touch big heat-sink with my figure and V increase by incriments of 0.5V every 1-2 sec.
I assume I need new R-Core with lower output.
As I wrote in the past, I use R-Core with 26V output which give me about 42V rectified RAW DC (2 of 0-115V primaries paralleled (0 to 0, 115V to 115V), but I have 119V-121V from my receptacle, not 115V). This is why my R-Core has 31-33V output instead of designed 26V.
My target to get out from BIB is 24V, so which output will you recommend from R-Core: 18V or 20V?
You mentioned the manual that BIB shout receive at least 5V more then it output target and 7-10 is even better.
18V output is on border of target+5V recommendation, and 20V output is hard for find. 24 output is too much...
What max current should be in transformer's secondary (does 0.5A enough)?
Attachments
Last edited:
How to lower extra current and probably extra voltage? My BHL uses in averrage 20mA and 50mA is the max for 2 channels.
My voltage IN to BIB is about 42V (from RAW DC supply) and I need 24 out from BIB. Please let me know. Thank you.
Use 12R R101. This will take it from 195mA to ~135mA. A generous reduction in dissipation at those voltage levels with a decent spare current margin still. The largish Vin-Vout is not a problem when the heat is managed, to the contrary it makes the input CCS MOSFET less capacitive (better). The sink now gets 7.6W, after the new setting it will get 5.1W. Try with a cheap 1 or 2W resistor first to evaluate if satisfactory.
Thanks a lot again. I'll try and I'll report.
Men, you never rest!
It is a deep night in Greece and you do not sleep...
Amazing support!!!!!!!!!
Hi Salas,
I tested with 12R and it seems working better and temperature is down a bit. So, I'll install Caddock 930, same type as I used previously, but with 12R value now. Do I need to sink it too? My first 8R2 Caddock was warm (about 40 dec C) during operation.
Another aspect (but I'm no sure if I can use $ compare here), I see Partsconnexion sale Caddock 930 for $7.95 and Digikey is $4.45. It might help some guys located in USA to buy these resistors with cheaper price.
Last think.
I have some level of shshshsh sound in high volume (its starts to be audible from 50% of my volume level and up). Is it normal?
If not, then is it related to GND (currently, it is not connects BIB "0" to chaises) or I should try to increase Zobel cap value (4.7uF currently), or 301 value (currently is 220uF 50V Elna RFS)?
Please let me know.
-No need of sink for that resistor it will be even cooler than in the previous value.
-At how many C is the sink now?
-You mean hiss noise, like an old tape sorta? If its not the phono itself and it surely acquired it recently with the PSU experiment, only then you should worry about it.
If so, put a 100uF/50V capacitor across the sense wires at the reg's connector or across the phono's +V/GND receiving points. Wherever most effective. If there are any small value film or oil caps there across the rail, remove them. Keep a tight power wires loop both in width and length. Have them twisted. Check that stuff first and then check GND.
-At how many C is the sink now?
-You mean hiss noise, like an old tape sorta? If its not the phono itself and it surely acquired it recently with the PSU experiment, only then you should worry about it.
If so, put a 100uF/50V capacitor across the sense wires at the reg's connector or across the phono's +V/GND receiving points. Wherever most effective. If there are any small value film or oil caps there across the rail, remove them. Keep a tight power wires loop both in width and length. Have them twisted. Check that stuff first and then check GND.
Hi Salas,
Thank you again for a quick reply.
- I'll measure the temperature after installation of new Caddock (12R).
Should get it this Friday.
- The noise is a hiss same to what you described with the old tape. It is not a phono, since I used AA alkaline batteries prior BIB and little hiss was also there, but significantly lower in sound and its frequency was higher.
- I'll try 100uF 50V electrolytic at BIB side of sense first (it is easier access for me) and I'l let you know.
- I twisted tightly "+" and "0" of power wires and also "+" and "0" of sense wires. However, these pairs quite loose with the relation to each other.
Do I need to twist power and sense together too? Or how to twist 4 wires aesthetically?
Thank you.
Last edited:
Its picking something then. If the sense cap proves it makes a difference it points to that.
Needs an oscilloscope actually to really say, but anyway.
Twist power and sense also after they are twisted between own types.
After you will evaluate all those things make some experiment with GND as well if still picking. You should try match the previous level of hiss. If there are no weird interactions the Bib brings no hiss to phonos normally.
Needs an oscilloscope actually to really say, but anyway.
Twist power and sense also after they are twisted between own types.
After you will evaluate all those things make some experiment with GND as well if still picking. You should try match the previous level of hiss. If there are no weird interactions the Bib brings no hiss to phonos normally.
Thank you for directions. I'll test it this weekend since I'm traveling now 
.
Beside that, can you please help me with MC portion since I also suspect my MC PSU. I built it based on LT317 and advised by you voltage divider (1K/10K) with 2 1000uF 50V Elna electrostatics and the emitter follower BC550C.
I might made mistake there with the adoption of the concept or types of components. I'm attaching schematics with components types. Can you see PSU portion for any potential errors in structure and types of my components?
In other words, what would you do/use in PSU if you will use LT317 for MC?
Thank you.
.Beside that, can you please help me with MC portion since I also suspect my MC PSU. I built it based on LT317 and advised by you voltage divider (1K/10K) with 2 1000uF 50V Elna electrostatics and the emitter follower BC550C.
I might made mistake there with the adoption of the concept or types of components. I'm attaching schematics with components types. Can you see PSU portion for any potential errors in structure and types of my components?
In other words, what would you do/use in PSU if you will use LT317 for MC?
Thank you.
Attachments
Last edited:
The LT317's output noise gets strongly filtered by the capacitance multiplier formed around Q4. There lies no strong cause for hiss from the 12V rail. R1 & R3 are contributing noise nonetheless, but original to the MC input design. If it was milder for hiss before, then other changes should have done that. The ones of possible noise pick up or instability we talked about to investigate by some cabling rearrangement, extra capacitors, GND changes.