Just finished finetuning the "normal" 48dB riaa.
After long testing periods involving much caps changes I finally have the "almost" perfect sound.
I can not stress enough that a variation of 10p in the 47n or 16n caps can make all the difference.
Tomorrow I will compare it with a Goldenote phono preamp in my friend´s house...
After long testing periods involving much caps changes I finally have the "almost" perfect sound.
I can not stress enough that a variation of 10p in the 47n or 16n caps can make all the difference.
Tomorrow I will compare it with a Goldenote phono preamp in my friend´s house...
Star grounding
A friend left me his camera so can post the photo Star Ground, I'm sorry for quality.
I selected to do the star ground in R2 15 ohms, so can avoid all incoming noise from the cart & cables
Sorry no Rs, still I'm waiting the resistors to do it.
I verified the Phono RIAA gain & it's so high that's almost saturing the integrated Rotel RA-02 in Aux input so only can move the volume level till 9h00 & the volume level start at 6h00.
A friend left me his camera so can post the photo Star Ground, I'm sorry for quality.
An externally hosted image should be here but it was not working when we last tested it.
I selected to do the star ground in R2 15 ohms, so can avoid all incoming noise from the cart & cables
Sorry no Rs, still I'm waiting the resistors to do it.
I verified the Phono RIAA gain & it's so high that's almost saturing the integrated Rotel RA-02 in Aux input so only can move the volume level till 9h00 & the volume level start at 6h00.
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A friend left me his camera so can post the photo Star Ground, I'm sorry for quality.
An externally hosted image should be here but it was not working when we last tested it.
I selected to do the star ground in R2 15 ohms, so can avoid all incoming noise from the cart & cables
Sorry no Rs, still I'm waiting the resistors to do it.
I verified the Phono RIAA gain & it's so high that's almost saturing the integrated Rotel RA-02 in Aux input so only can move the volume level till 9h00 & the volume level start at 6h00.
When you will do remote sensing you must take the -Sense and Force ground cables to star then. Better move the B+/Ground connector near there.
Well, you asked for 63dB gain...
A friend left me his camera so can post the photo Star Ground, I'm sorry for quality.
An externally hosted image should be here but it was not working when we last tested it.
I selected to do the star ground in R2 15 ohms, so can avoid all incoming noise from the cart & cables
QUOTE]
Hi Merlin
Do mean you cured the hum with this star gnd layout ?
(I want to do something like that...
I believe it could be a best practice.... I am thinking about a double layer pcb including this star gnd layout... would you post a schematic (even a drawing over salas schematic would do).
Regards
Ricardo
PS: We are really in high end territory now !
When you will do remote sensing you must take the -Sense and Force ground cables to star then. Better move the B+/Ground connector near there.
Well, you asked for 63dB gain...
Ok I will do with gnd cables for Rs, about move the B+/Ground will try also, thks.
No problem for 63dB gain, I don't use the amp Rotel
Still don't have the resistors, next monday is holidays in Catalonia so I wait till next tuesday minimum to receive the resistors
Star Ground
Hi Ricardo, here the drawing with Star Gnd, as said before Salas instead mine position is better near the B+/GND connector, now for me will be more ease move the connector.
Hi Ricardo, here the drawing with Star Gnd, as said before Salas instead mine position is better near the B+/GND connector, now for me will be more ease move the connector.
An externally hosted image should be here but it was not working when we last tested it.
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Merlin, most probably a proper star ground configuration don't need too many wires (or pcb tracks). IMO you can group components sharing the same potential. I.e. R2 and C10 can be linked togheter and then routed to star ground.
Here are the possible groups: Rloadx alone; D4 alone; R2&C10; C2,C3&R5; C5&R6; C6&R7, R8 alone; C9&V1 (star point). Thus you can reduce the wires from 13 to 8.
Another way is to group the signal ground all together (Rloadx, R2, C10, C2,C3, R5, R8) in bus and refer it to star ground. Moreover, D4 alone, C5&R6; C6&R7, C9&V1 (star point). Now from 13 to (only) 5 links.
Ricardo: I'm working on a similar pcb One side, can be etched at home.
Here are the possible groups: Rloadx alone; D4 alone; R2&C10; C2,C3&R5; C5&R6; C6&R7, R8 alone; C9&V1 (star point). Thus you can reduce the wires from 13 to 8.
Another way is to group the signal ground all together (Rloadx, R2, C10, C2,C3, R5, R8) in bus and refer it to star ground. Moreover, D4 alone, C5&R6; C6&R7, C9&V1 (star point). Now from 13 to (only) 5 links.
Ricardo: I'm working on a similar pcb
One side, can be etched at home.
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Massimo, I am grateful for your advice (believe me I dislike use more cable than necessary & solder more than necessary), wich one of both will be the best star grounding.
Ricardo, possible a pcb with two layers: one ground plane & the other side components solder will help to reduce more the noise due to the fact that ground plane possible do a beneficial effect like shield for EMI/RFI, I'm not sure but if yes you can do at home in one only pcb etched with 2 sides: the side where are the components can be ground plane and here all gnd must be connected and the other side like always the solder components side or viceversa. Probably it is the best solution against noise. IMO the Star GND point only for P2P.
Will be perfect if somebody can design an Universal pcb with two layers & after create a possible GB.....Of course I don't have knowledge to do it but I'm offer all mine support.
Ricardo, possible a pcb with two layers: one ground plane & the other side components solder will help to reduce more the noise due to the fact that ground plane possible do a beneficial effect like shield for EMI/RFI, I'm not sure but if yes you can do at home in one only pcb etched with 2 sides: the side where are the components can be ground plane and here all gnd must be connected and the other side like always the solder components side or viceversa. Probably it is the best solution against noise. IMO the Star GND point only for P2P.
Will be perfect if somebody can design an Universal pcb with two layers & after create a possible GB.....Of course I don't have knowledge to do it but I'm offer all mine support.
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