[Brettio]

Thank you James for taking the time to write that out for us.  Outside of the time with my family, reading that and learning from you is the highlight of what's been a pretty good day.

[witchdoctor]

and don't forget the Power Conditioner 

http://bryston.com/PDF/brochures/BIT_BROCHURE.pdf

[witchdoctor]

GETTING WIRED

There is not a day that goes by where I do not get asked what cable Bryston recommends with our amplifiers. Hopefully the following will assist you in weeding through some of these complex issues.
Part of the problem is that there is an awful lot of marketing going on and not much science in some cases. The 'elaborate packaging' of these interconnects and speaker cables may make you feel warm and fuzzy but the electrical characteristics are still the primary issue of concern. Simply stated the geometry (where the plus is relative to the minus) of a cable determines the inter-relationship between the measured performance of a specific cable. These measured performance criteria are called the 'Primary Constants'. They are R-resistance, L-inductance, C-shunt capacitance and G-shunt conductance. You can play around with all the different types of exotic packaging and add-on appendages you like but ultimately the measured performance (primary constants) tell the tale.

Bryston does not think cables should be 'voiced' to sound a specific way. The best cable is NO cable at all so we contend that the best cable is the cable that changes the signal the least.

COAX INTERCONNECT CABLES
An analogue Preamp/Amplifier connection is a 'high impedance interface' therefore; you are looking for low measured Capacitance. An interconnect cable acts like a capacitor in the signal path so the better that capacitor the better the interconnect. We use an interconnect wire with (very low capacitance) and the RCA connectors are made for us in Switzerland. The RCA cables 'make and break ground' first and last when connecting and disconnecting. This prevents ugly pops and bangs from going through your system with the possible negative results.

XLR INTERCONNECT CABLES
The XLR cables we use are also very low in capacitance. Actually the XLR cable we are currently using is in fact low noise balanced microphone cable with 100% shield coverage against RF. The advantage of Balanced XLR cables is that they have a noise canceling effect know as 'common mode noise reduction'. This helps prevent noise and hum from affecting your system. With today's complexity of audio and video surround systems this is a big plus, so if you 'got em-use em'.

DIGITAL INTERCONNECT CABLES
With 'Digital' interconnects things are a lot different. The wavelengths of digital signals are 'very short' (same for FM) so the lengths and terminations are much more critical than with the analogue signals previously discussed. When the wavelength of the signal the cable is used for approaches 1/30th of the length of the cable then transmission line effects start to appear and much more attention has to be paid to the connection and termination. If not then reflections and cancellation of data is a real possibility. For instance the AES/EBU digital connection on the back of all Bryston products should be used with a cable having an impedance of 110 ohms.

VIDEO CABLES
Video cables also operate at very high frequencies - typically 5-6 MHz for Composite and S-Video and 8-30 MHz for Component Video depending on the scan rate and resolution. So again understanding the wavelengths of the signals and interfaces involved is important.

SPEAKER CABLES
The Amplifier/Speaker interface is a 'low impedance' connection. Therefore, in a speaker cable you are looking for low 'self inductance' (because inductance rolls off the top end) as opposed to 'low capacitance' required in the RCA or XLR analogue interconnect. For speaker cables we use a stranded 9 gauge linear crystal copper with 'Heavily Gold plated' Spade lugs or Expandable Banana plugs specially made for Bryston.

A/C POWER CABLES
When you plug your power cord into the wall outlet you are in 'SERIES' with all the wire on the other side of the wall all the way back to the power source. The small length of power cord from the wall to the amp is insignificant compared to the miles of wire it is connected to. As long as the power cord can deliver the current and voltage required to drive the amplifier to full power it is as good as it can get.

There are 4 basic things to remember about these issues:

1.   The connection should be of similar metals (preferably gold) and be airtight. If not airtight it will break down molecularly over time and begin to rectify or produce a diode effect on the signal.
2.   With all the RF floating around today the better the 'Shield' on the interconnect the less intrusive the RF will be.
3.   The connection between your analogue Source components (Preamplifier, CD Player, Tuner, DVD Player etc.) is a 'High Impedance' connection and the interface between your power amplifier and your speakers is a 'Low Impedance' connection. So, the requirements are totally different for optimizing these interfaces.
4.   Digital and Video cables are much more susceptible to reflection/phase/cancellation problems because of their short wavelengths relative to cable length.
As you can see from the above, no surprise that people hear differences in cables when connected to the variety of equipment in the market today. Given the differences in input and output impedance's between transistor and tube gear, the lack of understanding of the high impedance and low impedance interfaces, the world of RF, and the digital/video connection issues no wonder we have these differences of opinion.

RECOMMENDATIONS
I highly recommend keeping the speaker wires as short as possible and utilizing XLR balanced lines if available. Given the choice of long interconnects and short speaker leads or short interconnects and long speaker leads - choose long interconnects (preferably Balanced) and short speaker leads. With digital and video cables finding out the sending and termination requirements is very important due to the very short wavelengths relative to cable lengths involved.

The cables Bryston recommends represent a scientific approach to these issues and are the cables we use in all our professional studio installations. All of these cables are available from 'Bryston in the Products list.

Its so nice to get a straight answer for once. Some of your competitors right here on AC are absolutely out of their league when asked a question like this.

[Bendingwave]

Keeping watch TV

I dont watch tv you are delusional   

[Jozsef]

James old boy,

I had a big smile on my face reading the long response you posted about cables.

I didn't know that the AES/EBU cable functioned as a resonant transmission line. May I assume that the connectors also having the correct characteristic impedance is not critical? I remember crunching the numbers for 75 ohm CATV cable to verify that the connectors really don't matter. It turns out they don't. So, what should I look for in the way of a cable that I can terminate myself? Is there an RG designation that might be easy to get?

[James Tanner]

Hi Jozef

Well there are plenty of experts that disagree - connectors and proper termination does matter.

james

[Jozsef]

Hi Jozef

Well there are plenty of experts that disagree - connectors and proper termination does matter.

james

I'm afraid I'm still confused. As i understand it, proper termination, meaning constant impedance, would depend on the specific application, just as you explained for the various analog connections. I was asking because I'm not aware of 3 pin XLR having an impedance spec but it seems to be the standard AES/EBU connector. I mentioned CATV as an example of connector impedance being non critical because many years ago I did not quite trust the experts and so I investigated it. It turns out that with F connectors, any mismatch in that analog situation simply results in a miniscule signal level drop.

Since we're talking now of digital, are there pitfalls to avoid or do I just get a piece of 110 ohm cable and solder on the XLRs?

[witchdoctor]

I'm afraid I'm still confused. As i understand it, proper termination, meaning constant impedance, would depend on the specific application, just as you explained for the various analog connections. I was asking because I'm not aware of 3 pin XLR having an impedance spec but it seems to be the standard AES/EBU connector. I mentioned CATV as an example of connector impedance being non critical because many years ago I did not quite trust the experts and so I investigated it. It turns out that with F connectors, any mismatch in that analog situation simply results in a miniscule signal level drop.

Since we're talking now of digital, are there pitfalls to avoid or do I just get a piece of 110 ohm cable and solder on the XLRs?

It all depends on your taste. I find the digital cable to be the most important cable in the entire system. Any information constricted by the digital cable never makes it through the system. The only pitfall to avoid depends on the sensitivity of your hearing and equipment. If they are not so sensitive just plug and play. If you are more discerning make one cable and then order two that have a 30 day return policy. For example Emotiva has an el cheapo cable at around $15 while Mapleshade has a premium cable at around $200. The specs and geometry couldn't be more different. Compare it with your DIY and see what you think. Then take one for the team and post your findings.

https://www.amazon.com/Emotiva-XDRCA-Digital-Coaxial-Interconnect/dp/B008O37ICI?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B008O37ICI

http://shop.mapleshadestore.com/Clearview-Excalibur-Digital-Ribbon-Interconnect-with-PLUS-Upgrade/productinfo/EDRIC-PL/

[Armaegis]

I'm afraid I'm still confused. As i understand it, proper termination, meaning constant impedance, would depend on the specific application, just as you explained for the various analog connections. I was asking because I'm not aware of 3 pin XLR having an impedance spec but it seems to be the standard AES/EBU connector. I mentioned CATV as an example of connector impedance being non critical because many years ago I did not quite trust the experts and so I investigated it. It turns out that with F connectors, any mismatch in that analog situation simply results in a miniscule signal level drop.

Since we're talking now of digital, are there pitfalls to avoid or do I just get a piece of 110 ohm cable and solder on the XLRs?

It's all a little bit of a crapshoot... Digital cares about the characteristic impedance (not the same as regular impedance) in both the cable and the connector, otherwise you potentially get reflections within the line. Whether that creates a perceivable effect in the audio band is not something I wish to debate here. It is also worth noting that characteristic impedance has more to do with the physical construction/manufacturing of the cable and connectors themselves. I do not know of any boutique or hifi cable manufacturer who can create true 75ohm cabling on their own; it is not something you can accomplish with mods or braiding etc.

With coaxial cable (and properly crimped RCA or BNC termination; most of your boutique connectors do not fit the bill), you can maintain proper 75ohm characteristic impedance all the way through.

With AES, you can have 110ohm cable, but the connectors do not maintain the characteristic impedance. However, you do get balanced transmission lines and transformer isolation. Whether that creates a perceivable effect or improvement vs coax is another debate.

[Jimmy71]

Hi Jozef

Well there are plenty of experts that disagree - connectors and proper termination does matter.

james

James in your site you write 12 awg speaker cable and in the post here you write this For speaker cables we use a stranded 9 gauge linear crystal copper with 'Heavily Gold plated' Spade lugs or Expandable Banana plugs specially made for Bryston which is the correctone                                               Thanks Dimitris

[James Tanner]

James in your site you write 12 awg speaker cable and in the post here you write this For speaker cables we use a stranded 9 gauge linear crystal copper with 'Heavily Gold plated' Spade lugs or Expandable Banana plugs specially made for Bryston which is the correctone                                               Thanks Dimitris

Hi JImmy

Our cable is 4 wires twisted together so if you bi-wire it is a 12 gauge and if you use all 4 wires it is 9 gauge.

james

[Jimmy71]

Hi JImmy

Our cable is 4 wires twisted together so if you bi-wire it is a 12 gauge and if you use all 4 wires it is 9 gauge.

james

James I have the 4 B3 CAN YOU PLEASE TELL ME DO YOU PREFER SPADES OR BANANA  AND DO YOU HAVE ANY PICS OF SPEAKER CABLE THANKS

[James Tanner]

Hi

Pic of the cables



The main issue with connectors is you do not want any corrosion or rectifying effects to occur over time.  So you want a Gold to Gold connection and you want it to be as airtight as possible. I use expandable Banana connectors on the speakers and Spades on the amps and make sure they are tighten securely.

james