On my first BIII SE 9038 Pro build (headphone amp) I used Otto II and Cronos boards connected to the DAC via I2S using my usual pure silver single core wire (cheaply obtained from jewelry suppliers)

Sounded great! But I wondered whether these Hirose thingies would sound even better - so I shelled out around $150 to Element14 for the connectors (as short as I could get) and plugged them in.

Opinion: Absolutely awful! Like someone put a pillow full of steel wool over the sound. Ripped them out after a few minutes as they sounded so bad.

What on earth is the attraction to these things? They appear to be sonic poison - or did I get the wrong type perchance?

Hi Brian.

I used to assume that too, but now know it not to be true after my own experiments building a headphone setup based on the BIIISE Pro 9038. I played around extensively with various USB and I2S connectors and there were very clear audible differences between the various materials and constructions used - particularly so for I2S.

The question is: Is the connection passing the digital signal without any transmission errors. For example, it is recommended to use solid-core network cable instead of multi-core to minimise data transmission errors when the cable runs are long.

As you well know, computer systems cope with the inherent unreliability of data transmission over the wire via error detection and re transmission protocols - but re-transmission doesn't work so well for real-time data transfer. Transmission errors will create artifacts in the music which can be heard if there are enough of them.

So your u.fl cable hypothesis would only be true if they transmitted the I2S data without any transmission errors :-).

My I2S 'experiment':

Setup was Amanero/Cronos to OttoII to BIIISE Pro 9038 I2S connections + MCLK connection from Cronos to DAC.

I usually use multicore Arduino hookup cables with dupont connectors to quickly wire things up for initial testing. These work of course, the connections are solid onto the header pins, but the sound is quite grainy and a bit harsh. Interestingly, the graininess was less when I directly connected the Cronos to the DAC instead of the extra hop (and extra set of connectors) via the OttoII.

I then replaced the multicore Arduino cables with .7mm solid 99.99% pure silver with cotton sleeving (low dielectric) with dupont connectors crimped and soldered on. The difference was apparent. The graininess all but vanished and inner detail/enjoyability improved markedly. A no-brainer improvement.

Next I replaced all connections with .u.fls I purchased from element 14 (which are multicore possibly made out of steel strands). I tested continuity - all ok - but the sound degradation was substantial - significantly worse sounding than the cheapo Arduino hookup cables, as the sound was not simply grainy but muffled! Particularly noticeable was the loss of top-end detail.

I progressively switched individual cables around to see if there was some kind of fault in one of the ufls, but all that happened was that the sound became progressively better the more u.fls I replaced with solid core silver.

USB 'experiment'

I replaced an ordinary USB cable (which sounded perfectly OK) with a handmade one using solid core silver. Similar effect to the I2S experiment, just a bit more subtle - any 'graininess' more-or-less vanished. Adding a USB filter (Audioquest Jitterbug) further improved the sound on either cable by removing some harshness/glare. Silver wire + filter resulted in a pleasing detailed but natural sound.

The home-made silver USB cable was not perfect however, pushing up the transmission rate above 96Khz caused crackling - so there was obviously something wrong with its construction for higher speed transmissions.

In conclusion: Do digital connectors make a difference? Absolutely IMHO!

Cheers,

Poss