Doing experiments with interlink (signal) cables I noticed I was not able to find the the optimal one. Even trying more expensive one. Browsing on the net I discovered very interesting solution - an active cable, by author called AudioBuffer - http://www.pha.inecnet.cz/macura/buffer_en.html. Not expensive, simple circuit. What do you think about?
Hi!
Looks nice, although I I use an OPA134, I would also use it as a balanced line driver (since this is what OPA134 is for).
Of course, then you will need to use the corresponding de-balancing circuit (don't know the OPA nr right now), unless you have balanced inputs on your amplifier...
But sometimes I will check it out (I have some of those OPAs lying around...)
Bye,
Arndt
Looks nice, although I I use an OPA134, I would also use it as a balanced line driver (since this is what OPA134 is for).
Of course, then you will need to use the corresponding de-balancing circuit (don't know the OPA nr right now), unless you have balanced inputs on your amplifier...
But sometimes I will check it out (I have some of those OPAs lying around...)
Bye,
Arndt
Cradle22 said:
I think you are mixing up the letters: the balanced driver is the DRV134. The OPA134 is a regular opamp.
Carlos
it's only a buffer...
Hi,
Is the op-amp really needed?
Don't think so.
Only if you need the gain, in case of a headphone amp.
The buf634 alone has 250 ma current drive, not 200 as it says on that link.
Hi,
Is the op-amp really needed?
Don't think so.
Only if you need the gain, in case of a headphone amp.
The buf634 alone has 250 ma current drive, not 200 as it says on that link.
Gainf of the BUF is lower than 1 ( about 0.9) i.e. you need gain stage to correct it. Unless you accept attenuation of the signal.
BUF634
Koy,
You have a point there.
But on the datasheet you can see:
GAIN:
RL = 1k, VO = ±10V 0.95 0.99 [ [ V/V
RL = 100, VO = ±10V 0.85 0.93 [ [ V/V
RL = 67, VO = ±10V 0.8 0.9 [ [ V/V
I suppose that above 1kohm load it's unity gain...
Koy,
You have a point there.
But on the datasheet you can see:
GAIN:
RL = 1k, VO = ±10V 0.95 0.99 [ [ V/V
RL = 100, VO = ±10V 0.85 0.93 [ [ V/V
RL = 67, VO = ±10V 0.8 0.9 [ [ V/V
I suppose that above 1kohm load it's unity gain...
Carlosfm,
yes, the opamp is needed. It estimates the overall behavior of the circuit, the BUF634T is there to
1) deliver enough current to drive matched cable,
2) to eliminate capacitive load
3) to minimize thermal feedback on OA chip
It results in considerably better sound. Though it might seem not making sense, it really does. The best way is to try it.
yes, the opamp is needed. It estimates the overall behavior of the circuit, the BUF634T is there to
1) deliver enough current to drive matched cable,
2) to eliminate capacitive load
3) to minimize thermal feedback on OA chip
It results in considerably better sound. Though it might seem not making sense, it really does. The best way is to try it.
Carlosfm,
there is a load of 50 Ohm + 50 Ohm, i.e. 100 Ohm. The terminating resistor of 50 Ohm is a must. Omitting it all the effect disappears.
there is a load of 50 Ohm + 50 Ohm, i.e. 100 Ohm. The terminating resistor of 50 Ohm is a must. Omitting it all the effect disappears.
I have finished this active cable published above. Some pictures are at http://koy.hi-end.org/Audio/Bastleni/AudioBuffer.html. To be right it works. And nice. The cheaper device you have the more difference you can hear. I tried OAP134, 602 and 627. 602 was the best sounding opamp. But you have to check it out. I am afraid I can stop with "cablemania".
I like the concept and look of the project....but it would be nice if we could understand the article in English
You guys can't be serious. An opamp+buffer to make for cable deficiencies?! A high price in transparency. Could you a make a buffer for a power amp as well so we'll eliminate speaker cable sound?
I've tried driving interconnects with high quality line transformers and having an input transformer at the power amp end. If the transformers are sufficiently transparent you can easily hear the cable sound. If otoh your buffer is not quite so transparent you may succed in masking the cable sound at best.
cheers
peter
I've tried driving interconnects with high quality line transformers and having an input transformer at the power amp end. If the transformers are sufficiently transparent you can easily hear the cable sound. If otoh your buffer is not quite so transparent you may succed in masking the cable sound at best.
cheers
peter
I have made my own Line drivers in the past when equipment has been a distance apart from each other,mostly in pro applicationswhen the line level was forced to be near power cables etc...I have had good luck with Lf353`s even.there are so many different ways you can do it....I have even powered the circuit off the Phatom power in a Balanced Line circuit
Cheers!! The DIRT®
Cheers!! The DIRT®
CABLES?
Hi,
Need to run transmission lines over ten miles, do you?
Nuts...
There are better ideas than that out there, ever tried polarising the shielding?
Some people, ya know...😉
Hi,
Need to run transmission lines over ten miles, do you?
Nuts...
There are better ideas than that out there, ever tried polarising the shielding?
Some people, ya know...😉
I am an electronic engineer and I would not believe in the effect of this circuit if I did not build it. For everyone who doubts I suggest: try it and then make a judge.
Analog Devices makes the SM2141/SM2142 Balanced Line Driver/Receiver chips, which have really good specs. These could be used to achieve the same effect as driving the shield, but with far less noise.
I based alot of my designs off RANE app notes...they make great proffesional gear and have a good knowledge base
I don´t like to persuade anybody but ...
Idea of active cable is more than 20 years old. As I am informed Idea was developed to the applicable form by Pavel Dudek. He manufactured it under name Sound Refiner and sold hunderds pieces. Reviewers was keen for it. Some about on english version www.gmx.cz - "Wire Combat - a Great Test of Interconnects"
Similar device is now manufactured in the Netherlands ( I hope, Iål try to dig the URL address out of my mind) in price about hunderds EU. You can give a taste the sound with Audiobuffer almost for free comparing to original price.
Idea of active cable is more than 20 years old. As I am informed Idea was developed to the applicable form by Pavel Dudek. He manufactured it under name Sound Refiner and sold hunderds pieces. Reviewers was keen for it. Some about on english version www.gmx.cz - "Wire Combat - a Great Test of Interconnects"
Similar device is now manufactured in the Netherlands ( I hope, Iål try to dig the URL address out of my mind) in price about hunderds EU. You can give a taste the sound with Audiobuffer almost for free comparing to original price.
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