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Old 2nd September 2010, 12:32 AM   #2021
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Quote:
Originally Posted by Salas View Post
I was wondering if you were about to crank it up for 3A per side or something.
No. But I sure could use a better stove than the one we have now. Hmm...
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Old 2nd September 2010, 12:40 AM   #2022
Salas is offline Salas  Greece
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Don't get ideas now, it will turn into an F5 size sinks. I just wondered bcs all this time you did not say anything about 15mF caps. And by knowing your tendencies...
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Old 2nd September 2010, 07:07 AM   #2023
westend is offline westend  United States
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Originally Posted by AndrewT View Post
shielded twisted pair.

Where do you connect the individual shields?

Are you using the twisted pair to carry the flow of both R & L?
Where does the Return current go?
What about crosstalk?
I connected the shields at one end, they are strapped to ground. R & L are carried by two of the three individual, jacketed wires. I have experienced no cross talk with this cable (at least not audible). If you follow the link posted above, it will show that this cable is specified for AV and other high bandwidth applications.
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Old 2nd September 2010, 09:43 AM   #2024
AndrewT is offline AndrewT  Scotland
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Originally Posted by westend View Post
I connected the shields at one end, they are strapped to ground. R & L are carried by two of the three individual, jacketed wires. I have experienced no cross talk with this cable (at least not audible). If you follow the link posted above, it will show that this cable is specified for AV and other high bandwidth applications.
you have a problem.
You have not told us how the signal circuit maintains the flow and return of the signal.

It appears from your description that the right signal flows along the red wire. The left signal flows along the white wire. The third core is unused. The shield is connected (grounded) at one end only.

Where is the return route for the signal circuit?

It must be a circuit. The signal cannot flow unless you provide a return route.
I think you have told us that you hear music. If that is the case then there is a return route. Do you know where that route goes?
I suspect you never thought about it.
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Old 2nd September 2010, 06:22 PM   #2025
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Originally Posted by wushuliu View Post
No. But I sure could use a better stove than the one we have now. Hmm...
And for sure better sound. My stove loves to buzz
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Old 2nd September 2010, 06:45 PM   #2026
westend is offline westend  United States
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Quote:
Originally Posted by AndrewT View Post
you have a problem.
You have not told us how the signal circuit maintains the flow and return of the signal.

It appears from your description that the right signal flows along the red wire. The left signal flows along the white wire. The third core is unused. The shield is connected (grounded) at one end only.

Where is the return route for the signal circuit?

It must be a circuit. The signal cannot flow unless you provide a return route.
I think you have told us that you hear music. If that is the case then there is a return route. Do you know where that route goes?
I suspect you never thought about it.
Sorry, skipped over that. The third conductor is used.
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Old 4th September 2010, 05:59 PM   #2027
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Quote:
Originally Posted by Malka07 View Post
Thank you all, for your suggestions with my hum problem...I am going away on holiday to Cornwall tomorrow and so wont be able to try the suggestions out for a while...but i didnt want people thinking i wasn't grateful...today i moved the large toroid to the right and vertically mounted it, also vertically mounted the small toroid, and i also tuck in the ac primary's into the metal grooves in the chassis all using Blu Tac

Click the image to open in full size.

The Hum, on the right speaker has almost disapeared, very very quite now...move the ear 6 inches from the speaker and the hum cant be heard. The hum on the left speaker has also got quieter, but not as quite as the right speaker...Buzz remains the same on both speakers.

Well im off on holiday see you all in a week.

Alon
Hi Alon,

to verify your hum problem, i connected my pcb between my Tube-I-zator and my pre amp.
The Vin comes from the 15V line of my TDA1541A DAC-Shunt.
Absolute silence... So it is a problem in your setup.

Click the image to open in full size.
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Old 5th September 2010, 02:18 PM   #2028
Malka07 is offline Malka07  England
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Quote:
Originally Posted by dvb-projekt View Post
Hi Alon,

to verify your hum problem, i connected my pcb between my Tube-I-zator and my pre amp.
The Vin comes from the 15V line of my TDA1541A DAC-Shunt.
Absolute silence... So it is a problem in your setup.

Click the image to open in full size.
Hi Oliver,

Do you use just the Optivol? or do you use Optivol with the Dcb1? On a side note...i found using the salas shunt at 5v(deleting Optivol power supply section) to sound best...i also tried salas shunt at 8v into optivol power supply, but this was not as good.

Alon
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Old 5th September 2010, 05:02 PM   #2029
Malka07 is offline Malka07  England
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I have just realised, that the hum changes with the volume...so hum gets louder when volume is turned up...and lower when turned down.

Oliver i noticed on the Optivol board there is a 7th hole next to the potentiometer...is this used for earthing the pot case?

Alon
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Old 5th September 2010, 07:20 PM   #2030
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Im going to be using my own power supply (+-12v 1amp 3mv ripple shunt) that i built for my other parts of the amp.

Is there anything i need to change since i will be air wiring it?

Also on the output fets. If i dont care about dc off set (all my amps have 1 cap at either the driver or power stage), what are the benefits of having them current matched?
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