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Anybody here terminate DH Labs BL-1 cable?

I want to make sure I'm terminating these correctly.
They have 2 conductors, a drain wire and a shield.

For unbalanced RCA termination, 1 wire for signal, 1 wire for ground, and combine the drain on the ground wire?
Is that correct? Or is the drain only used for balanced connections?

Thanks,
Itsik
itsikhefez
erik_squires
5,268 posts
 
Sorry Aux, it doesn't add up like that unless you mean your + and - each have a pair of 20 AWG conductors. :)

Just like with speaker cables. A single pair of 14AWG does not add up to a 12 AWG. :)

Erik
auxinput
1,538 posts
 

When I used the BL-Ag I was doing a single-ended RCA cable.  RCA only has one signal conductor, the other is just ground (not negative like an XLR).  Using just one of the 23awg conductors in BL-Ag for the main signal wire (and doing the ground/floating drain solution) was not enough for good sound.  It wasn't until I combined the two 23awg together for the signal wire that it really opened up the imaging/soundstage.  The drain wire was just soldered to ground on each end of the RCA cable.  The drain/ground wire does not necessarily need to be the same gauge as signal.  The ground wire on the RCA doesn't actually carry a signal - it just connects to the ground plane on both source/target circuits.

As far as my own cables are concerned, they are all balanced XLR anyways.  I use two sets of braided 20awg solid-core, so each XLR conductor (positive/negative/ground) has two 20awg wires (6 wires total in the cable).  This proved to be better than just using one braid of 20awg (3 wires total).

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almarg
8,673 posts
 
Auxinput 10-27-2016
The ground wire on the RCA doesn’t actually carry a signal - it just connects to the ground plane on both source/target circuits.
Although of course for a current to flow a complete circuit must be present, and therefore the current corresponding to a signal sent from one component to another must also return to the component which provided the signal. In the case of an RCA cable the return path will usually be the shield if the cable does not provide a separate return conductor. Some fraction of the return current will also follow a different return path if one is present, as would be the case if a ground loop exists. And if the cable includes a shield and a separate return conductor, and if both of them are connected to the RCA ground sleeve at both ends, the return current will divide up between the two paths in inverse proportion to their resistance.

I’m sure you realize all of this, but I thought I’d point it out since others reading the thread may not.

Best regards,
-- Al

erik_squires
5,268 posts
 
Um, assuming there are no ground loops, and perhaps no other ground path, then the shield would absolutely become part of the circuit. Consider devices without a ground pin, otherwise yes, current would be distributed exactly as stated above.

If I’m paying for pure silver conductors, or fancy litz, etc. with an aluminum foil shield and AL drain, then I would want to avoid having any current in that shield at all. To do that I must avoid connecting the drain at both ends.

Now, what you may like to listen to is another story. :)

Best,

Erik
auxinput
1,538 posts
 

@almarg - thinking about this, you're right.  There may be a little bit of current going back and forth on the RCA shield/ground, since this connects to the electrical ground on both source/target circuits.  However, the primary driver of the audio signal is the main signal wire - as it is the only one connected to the input/output legs of the operation amplifier circuits.

@erik_squires - I understand what you're saying.  In a perfect world, it would probably be better ground the shield on only the source end to act as a ground/drain for any EM.  I'm just posing an alternate method for experimentation.  I never had any problem connecting shield on both end of the RCA cable.  In the end, I suppose it's up to whoever is building the cable to decide on isolated drain/shield versus a larger signal conductor with less resistance.

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