Black Stuart
MOT: Deep Sound Cables
- Joined
- Aug 25, 2006
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This is a really simple and cheap mod to try. Most people who do it, stay with it. Most who do it rate it as equal or better than a stepped attenuator, it's certainly a damn sight cheaper and a lot less work and solder connections.
I first used it in my World Audio Design Mk1 h/amp and though I knew from numerous postings by mates on the old WAD forum that it was very effective, like anything in life - you have to experience things for yourself.
Quite simply it removes layers of mush (that you did'nt know existed) and there is just so much more clarity as a result. What it will not do is change the balance of your piece of equipment.
I can do no better than reproduce the explanation from this month's copy of Hi-Fi World made by Peter Comeau, the man who designed so many great speakers for Heybrook's and Mission in the past.
Petercom - "Talking of volume controls brings us on to the upgrade options. There has in recent years, been considerable interest in using an L-pad switched volume control instead of the ubiquitious potentiometer.
The common sense approach is that passing the signal through two high quality resistors and a switch is better than through the vagaries of a potentiometer track and wiper. In practice the subjective difference is small and perhaps not worth the considerable expense of the L-pad attenuator. However there is another way of acheiving much the same object - the shunt attenuator.
Here the volume control is fed from a high value resistor and the potentiometer connected as a shunt to ground. The signal passes only through the resistor - the pot. then justs acts as a variable resistor to ground as part of the L-pad. It is tempting to think that any old pot. can then be used, because the signal is not passing through it, but in fact the pot. is in parallel with the input stage so any noise due to the pot will appear on top of the input signal. Use a quality pot. like the Alps however and your main improvement is that the signal in this arrangement is affected only by the quality of the series resistor.
There is a downside or course, there always is! This arrangement gives a 6dB loss of signal level. For most sources this won't be an issue."
In practice I can say that it is not a problem, in my h/amp it just means I have to turn the volume control a little higher.
Earlier I said "it will not change the balance of your equipment - it won't but by using different types of resistor you can change the character. You should notice better cleaner bass, far more seperation of instruments etc. Whatever the rating of your pot, you should aim to use resistors of about 90% of that value ie. 50K pot. use a 47K resistor. 1/2W resistors are fine. There is a lot of crap talked about carbon Rs - if you listen mainly to CD think about using quality carbons, it may soften the sound a bit. Then there are Tantalum, which I use or Vishay (can create a hard sheen) whatever.
Where your pot. connects to the PCB or tag boards, just solder in series to signal and ground. If you are happy with this mod (and the chances are you will be very happy, if the legs on the resistors are long enough and the connection close to the pot. you can remove the existing wires altogether and solder the resistor legs directly from pot. to PCB/tagboard.
In no way can this upset your pre-amp/amps - just be careful with the soldering iron inside your amps - suck and see.
Stuart
I first used it in my World Audio Design Mk1 h/amp and though I knew from numerous postings by mates on the old WAD forum that it was very effective, like anything in life - you have to experience things for yourself.
Quite simply it removes layers of mush (that you did'nt know existed) and there is just so much more clarity as a result. What it will not do is change the balance of your piece of equipment.
I can do no better than reproduce the explanation from this month's copy of Hi-Fi World made by Peter Comeau, the man who designed so many great speakers for Heybrook's and Mission in the past.
Petercom - "Talking of volume controls brings us on to the upgrade options. There has in recent years, been considerable interest in using an L-pad switched volume control instead of the ubiquitious potentiometer.
The common sense approach is that passing the signal through two high quality resistors and a switch is better than through the vagaries of a potentiometer track and wiper. In practice the subjective difference is small and perhaps not worth the considerable expense of the L-pad attenuator. However there is another way of acheiving much the same object - the shunt attenuator.
Here the volume control is fed from a high value resistor and the potentiometer connected as a shunt to ground. The signal passes only through the resistor - the pot. then justs acts as a variable resistor to ground as part of the L-pad. It is tempting to think that any old pot. can then be used, because the signal is not passing through it, but in fact the pot. is in parallel with the input stage so any noise due to the pot will appear on top of the input signal. Use a quality pot. like the Alps however and your main improvement is that the signal in this arrangement is affected only by the quality of the series resistor.
There is a downside or course, there always is! This arrangement gives a 6dB loss of signal level. For most sources this won't be an issue."
In practice I can say that it is not a problem, in my h/amp it just means I have to turn the volume control a little higher.
Earlier I said "it will not change the balance of your equipment - it won't but by using different types of resistor you can change the character. You should notice better cleaner bass, far more seperation of instruments etc. Whatever the rating of your pot, you should aim to use resistors of about 90% of that value ie. 50K pot. use a 47K resistor. 1/2W resistors are fine. There is a lot of crap talked about carbon Rs - if you listen mainly to CD think about using quality carbons, it may soften the sound a bit. Then there are Tantalum, which I use or Vishay (can create a hard sheen) whatever.
Where your pot. connects to the PCB or tag boards, just solder in series to signal and ground. If you are happy with this mod (and the chances are you will be very happy, if the legs on the resistors are long enough and the connection close to the pot. you can remove the existing wires altogether and solder the resistor legs directly from pot. to PCB/tagboard.
In no way can this upset your pre-amp/amps - just be careful with the soldering iron inside your amps - suck and see.
Stuart
