Hi all diyers ! I have built 2 different examples of the Balanced Bride Of Zen. One for myself and one for Copenhagen Hifi Club.
Both of them uses the Twisted Pear " Darwin inputselector". On this inputselector there is 100 kohm from phase to ground by the relays at the input and as well at the output.
Both of them have massive hum when connected in Balanced mode to a balanced power amplifier.
When RCA is used there is no problem. I do not use the pots at the output.
Can anybody help ?
Greatings from E. Sæterdal Copenhagen.
Both of them uses the Twisted Pear " Darwin inputselector". On this inputselector there is 100 kohm from phase to ground by the relays at the input and as well at the output.
Both of them have massive hum when connected in Balanced mode to a balanced power amplifier.
When RCA is used there is no problem. I do not use the pots at the output.
Can anybody help ?
Greatings from E. Sæterdal Copenhagen.
Could be a lot of different things, but ground loops and
oscillation are where you start.
Is there a power transformer in the preamp?
Is it near the circuit?
Are you sure the circuits really have the same ground?
Are there Gate stopper resistors on the Gates of the devices?
Is there some output resistors in series with the outputs?
oscillation are where you start.
Is there a power transformer in the preamp?
Is it near the circuit?
Are you sure the circuits really have the same ground?
Are there Gate stopper resistors on the Gates of the devices?
Is there some output resistors in series with the outputs?
Could be a lot of different things, but ground loops and
oscillation are where you start.
Is there a power transformer in the preamp?
Is it near the circuit?
Are you sure the circuits really have the same ground?
Are there Gate stopper resistors on the Gates of the devices?
Is there some output resistors in series with the outputs?
I have not tried to measure it with Scoop. Maybe my input impedance is to high. I have done really many preamps in my life so I do not think there is any loops. Maybe there is a problem with the extra ground on the selector.
There is a transformer but I am sure its not a problem. No hum in single ended mode.
I use Gate stoppers. I use 500 ohm at the output.
Are you using XLR connector or twin RCA for inputs?
And you did not answer my last question.
Take the transformer out of the box and run it from a couple
of feet away and see what happens.
The very first try was with the transformer in a seperate box.
I use XLR for inputs and RCA and I use a Darwin Relay selector. There is 100 kohm resistors on the selector both at the input and the output to ground.
The input impedance is 22 kohm and 50 kohm in the 2 Preamps. At the ouput there is 100 kohm on the board to ground and 100 kohm on the selector print.
R 15 is 500 ohm and 160 ohm.
I use XLR for inputs and RCA and I use a Darwin Relay selector. There is 100 kohm resistors on the selector both at the input and the output to ground.
The input impedance is 22 kohm and 50 kohm in the 2 Preamps. At the ouput there is 100 kohm on the board to ground and 100 kohm on the selector print.
R 15 is 500 ohm and 160 ohm.
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In series with the output there is 500 ohm Vishay Bulk Foil SMD. And 100 kohm Vishay 1 W Bulk Foil to ground.
In series with the input 1,5 kohm Vishay Bulk Foil 100 kohm 1 Bulk Foil to ground. Gate stopper is 330 okm Carbon.
I am a little afraid about those Vishay resistors because I have bad experience with Ruepoint resistors. They made some circuits unstable. Now I am sitting changing the resistors from input to ground to Takman 22 kohm metal film. Also I change the R 15 to 200 ohm Takman from 500 kohm Vishay.
In series with the input 1,5 kohm Vishay Bulk Foil 100 kohm 1 Bulk Foil to ground. Gate stopper is 330 okm Carbon.
I am a little afraid about those Vishay resistors because I have bad experience with Ruepoint resistors. They made some circuits unstable. Now I am sitting changing the resistors from input to ground to Takman 22 kohm metal film. Also I change the R 15 to 200 ohm Takman from 500 kohm Vishay.
Thank you, I'm in this.
Anyway I appreciate the work of the Danes in audio.
Perhaps it is enough if I refer to Poulsen's work here.
Furthermore, some of my work during the Danish firm had contact, such as COWI.
Or nowadays Widex and Interacoustics.
Oh, and one of my favorite composers, Diderik Hansen Buxtehude.
Wacky Gyuri
Anyway I appreciate the work of the Danes in audio.
Perhaps it is enough if I refer to Poulsen's work here.
Furthermore, some of my work during the Danish firm had contact, such as COWI.
Or nowadays Widex and Interacoustics.
Oh, and one of my favorite composers, Diderik Hansen Buxtehude.
Wacky Gyuri
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It is true. It's always satisfying to find your mistakes and then
you know the universe is reasonable.
It's always satisfying to find your mistakes and then you know the universe is reasonable.
That has to be the all time best quote I've ever read.
That has to be the all time best quote I've ever read.
do not underestimate Papa . he had ...... and will have few more , even weirder .
you remember "one hand clapping" ?
that previous one is good ...... but also too long
or , to paraphrase Gyuri :
"all ends ; but some sentences ends sooner "
My god this did not solve my problem. Also I am quite sure the R 15 have been mounted correct earlier . In the other Balanced Bride Of Zen I have made for a Hifi club the problem is the same, just have not discovered before now because we have never used it balanced. In this the R 15 was mounted correct all the time. I have been fighting with this problem for 2 years ( not working on it all the time ). I have used very exspensive parts. The cost of the output caps alone is around 1800 dollars. So I am very sad it do not work.
Maybe I should try to reduce the output impedance. I must admit that I have changed the position of the output caps and the output resistors. The resistors is before the caps. This should not change anything ???
Maybe I should try to reduce the output impedance. I must admit that I have changed the position of the output caps and the output resistors. The resistors is before the caps. This should not change anything ???
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First off, the problem you describe is unlikely to have anything
to do with the cost of the parts.
At this point, you are the one who has to play detective, since
there's nothing about the design that encourages noise issues.
So put on your detective hat, and let us know when you have
found it.
to do with the cost of the parts.
At this point, you are the one who has to play detective, since
there's nothing about the design that encourages noise issues.
So put on your detective hat, and let us know when you have
found it.
First off, the problem you describe is unlikely to have anything
to do with the cost of the parts.
At this point, you are the one who has to play detective, since
there's nothing about the design that encourages noise issues.
So put on your detective hat, and let us know when you have
found it.
Of course the problem is not because of the cost.
Anybody that have more patience ?
After the regulation I have 10.000 uf Sidereals followed by no resistors to the board where the resistors are short circuited. On the board there is 2x220 uf. and 2x 33 NF.
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