[Thetaburn]

On a somewhat related note, everybody will tell you to use the sine wave connection...... Everybody except me that is. I find the square wave sounds noticeably better at least for my C18/U18/A22 combination

I found square wave is sharper and clearer.
Sine wave smoother but slightly less resolution.

 

[Jake2]

Afterdarks 50 Ohm red BNC cable is the best 50 Ohm cable Afterdark has when I got mine. It claims to make a reference sound. It's fairly affordable starting around $200. There are many expensive 75 Ohm cables but not so many decent 50 Ohm cables.

I bought my Tubulus Concentus used for less than 50 percent of it's original cost or I wouldn't have one. Seems like nice cables can be had for a great deal. Most of my stuff is used and I've never had an issue with a single thing yet.

What do you mean by dual clocking? Do you mean a different clock for each?

Nice deal on the Concentus I2S. And I’m sure your Afterdark clock cable (not to mention the clock!) is quality, likely similar level to the HT DC III. By dual clocking I just meant clocking the DAC and DDC with the same master clock. I can only speak for my DAC as there’s a lot of variables, including whether the DAC is in NOS or oversampling mode, the design and performance of its clock synthesiser etc. Email response from Gustard referred upthread is that when synchronous inputs are used in NOS or DSD Direct mode there’s no benefit from an external clock… but that scenario, I2S + NOS/DD was my most typical use case with the U18, and there definitely was a benefit. Others, but not all with Gustard DACs have found the same thing. Similar findings with Audio-Gd DAC and DDC users.

 

[phoneslave86]

Nice deal on the Concentus I2S. And I’m sure your Afterdark clock cable (not to mention the clock!) is quality, likely similar level to the HT DC III. By dual clocking I just meant clocking the DAC and DDC with the same master clock. I can only speak for my DAC as there’s a lot of variables, including whether the DAC is in NOS or oversampling mode, the design and performance of its clock synthesiser etc. Email response from Gustard referred upthread is that when synchronous inputs are used in NOS or DSD Direct mode there’s no benefit from an external clock… but that scenario, I2S + NOS/DD was my most typical use case with the U18, and there definitely was a benefit. Others, but not all with Gustard DACs have found the same thing. Similar findings with Audio-Gd DAC and DDC users.

This makes sense why HQplayer was such a downgrade for me (DSD 512, PCM 768k, 2x and all the good filters tested). It never came anywhere close to the sound of lossless Flacs for me. If there was no benefit from the clock that would make some real sense. Really was a massive gap in every way compared to playing downloads at 1x.

Yea Afterdark said the red BNC cable is the best 50 Ohm that they had. It's kinda nice because it wasn't too terribly expensive. That 50 Ohm HT DC III, wow that is a nice looking 50 Ohm cable, best looking 50 Ohmer I've seen. Need to find someone who has compared it to the Red BNC to see if it's worth it.

 

[phoneslave86]

I found square wave is sharper and clearer.
Sine wave smoother but slightly less resolution.

Ya never know till you listen. Squarewave is more compatible with quite a few things and probably does sound better in those cases. That said both squarewave and sinewave clocks come at many levels and forms. I'd imagine a lower end sinewave clock is going to sound worse than a really nice squarewave clock. The high end sinewave clock blew away my mid level King squarewave clock from afterdark. I loved my squarewave King though, it was worth every penny too. The sinewave clock revealed quite a bit deeper into tracks, more finesse, more clarity and it also showed me all kinds of noise/interference in my system I had no idea was there with the squarewave clock. The day I got my sinewave clock I had to move both wifi routers in the room as well as my gaming PC away from my system. I had never even known anything was interfering directly. It all shifted away into the inaudible range just by moving things pretty much that day which improved the sound even more and I had no idea to do that before. It was basically a free upgrade that had been sitting there the whole time (removing inaudible noise uncovers more audible music). Also, I could hear transformer hum for the first time after the sinewave clock (outside of the audible level).

 

[macsoo]

I think about adding U18 to my setup to be able to use I2S in Gustard A26 as I hear it's better than Coax input. I believe it might be so after hearing improvement on LAN vs Coax, but with Tidal playing on build in streamer from time to time I get sound skipping which is unacceptable even when the SQ is better.
So my idea is to switch from Allo Digione (w/ coax) build on Raspeberry Pi 4, and go with just RPi and use USB output to send signal to U18. I got good low noise LPU which stays.
But my concern how much the quality of USB output matters if I use U18? Does it at all? If U18 has galvanic isolation and does some signal processing, do I need have good USB souce? I've read somewhere that RPi's USB port can be noisy.

Another thing that might be next step for me is to stay with Allo Digione and add master clock - LHY OCK2. Anyone has idea what can bring more good U18 or LHY OCK2?
With time I may go for both U18 and OCK2 if it's the optimal setup, but for now I can get one.

 

[Thetaburn]

Ya never know till you listen. Squarewave is more compatible with quite a few things and probably does sound better in those cases. That said both squarewave and sinewave clocks come at many levels and forms. I'd imagine a lower end sinewave clock is going to sound worse than a really nice squarewave clock. The high end sinewave clock blew away my mid level King squarewave clock from afterdark. I loved my squarewave King though, it was worth every penny too. The sinewave clock revealed quite a bit deeper into tracks, more finesse, more clarity and it also showed me all kinds of noise/interference in my system I had no idea was there with the squarewave clock. The day I got my sinewave clock I had to move both wifi routers in the room as well as my gaming PC away from my system. I had never even known anything was interfering directly. It all shifted away into the inaudible range just by moving things pretty much that day which improved the sound even more and I had no idea to do that before. It was basically a free upgrade that had been sitting there the whole time (removing inaudible noise uncovers more audible music). Also, I could hear transformer hum for the first time after the sinewave clock (outside of the audible level).

A gaming PC is bad for audio.
Music streamers are so much better for audio.

 

[richie60]

I think about adding U18 to my setup to be able to use I2S in Gustard A26 as I hear it's better than Coax input. I believe it might be so after hearing improvement on LAN vs Coax, but with Tidal playing on build in streamer from time to time I get sound skipping which is unacceptable even when the SQ is better.
So my idea is to switch from Allo Digione (w/ coax) build on Raspeberry Pi 4, and go with just RPi and use USB output to send signal to U18. I got good low noise LPU which stays.
But my concern how much the quality of USB output matters if I use U18? Does it at all? If U18 has galvanic isolation and does some signal processing, do I need have good USB souce? I've read somewhere that RPi's USB port can be noisy.

Another thing that might be next step for me is to stay with Allo Digione and add master clock - LHY OCK2. Anyone has idea what can bring more good U18 or LHY OCK2?
With time I may go for both U18 and OCK2 if it's the optimal setup, but for now I can get one.

I've read somewhere that RPi's USB port can be noisy.

This wouldn't apply to the RPI4, only previous versions which shared the Bus with the Ethernet port. I use an RPI4 with a Linear Power Supply running Ropieee XL into the Gustard U18 with good results, no noise detectable.

Can't say how this compares to any other streamer, but I can sit on the fence and watch as manufacturers release streamers every month, touted as the next best thing. I am in no rush to 'upgrade' yet.

 

[phoneslave86]

My U18 transformer sometimes was getting very noisy and usually would have a moderate hum when it was warm (you could hear from a foot or two away, at it's very worst from farther away). After adding an AlieX Flux-50 it's been just silent since. Can barely hear it if I put my ear to it now, even when it's really warm. I had other equipment that was humming too. These things really help the equipment quiet down from what I can tell. Sound improvements are great too. Putting these things on everything for sure.

 

[kumar402]

My U18 transformer sometimes was getting very noisy and usually would have a moderate hum when it was warm (you could hear from a foot or two away, at it's very worst from farther away). After adding an AlieX Flux-50 it's been just silent since. Can barely hear it if I put my ear to it now, even when it's really warm. I had other equipment that was humming too. These things really help the equipment quiet down from what I can tell. Sound improvements are great too. Putting these things on everything for sure.

Hum is mostly due to ground loop or due to DC in the power. May be you have some SMPS plugged in nearby.

 

[phoneslave86]

Hum is mostly due to ground loop or due to DC in the power. May be you have some SMPS plugged in nearby.

Oh it shouldn't be ground loops. The whole system is isolated and grounded with Puritan Routemaster which grounds each piece of equipment to a universal star grounding point. Transformers are known to buzz/hum when they overheat and also if you have noisy enough or fluctuating power it can make them do that too (stressful to capacitors and transformers). I'm pretty abusive and run my system pretty much all day every day and it gets hot sometimes in this room so I think it's mostly because of heat. It's now just silent even when it's really warm for the first time ever. I want to say it's bad power too as I have pretty nasty wall power here but I've got it all on a AVR UPS + PSM136 as well and the sound is pretty good even when the power is bad so I'm just not sure. The Flux-50 did lower the noise floor further on some things more than cryo cables did on their own as well.

 

[milkdudd]

I've been using a DH labs HDMI cable between my U18 and my A22 DAC with spectacular results. I haven't been listening as much as usual the last couple of months so perhaps there's more to this improvement in sound than just the cable. I use USB Audio Player Pro and I know they update it from time to time and I listen to Qobuz, perhaps they've also made some changes. So far my findings from best to worst HDMI cable (I hate calling any of them worst) are DH labs, Blue Jeans, AV Play. For a couple of years I've wanted the Tubulus but I haven't been able to justify the $500 charge. The DH Labs is only $70 (I got it on sale for $21 so a no brainer). I wish someone who had the Tubulus could try the DH Labs and let us know how they compare. Soon I'll do a quick A-B comparison of the DH labs and Blue Jeans to confirm whether or not it's the cable that made my improvement. Anyway here's a link to it if anyone's interested

https://silversonic.com/products/video-cables/hdmi-2-0-silver/

 

[Gotgi19]

On a somewhat related note, everybody will tell you to use the sine wave connection...... Everybody except me that is. I find the square wave sounds noticeably better at least for my C18/U18/A22 combination

Today I had the time and made the switch from sine to square wave on my U18/C18/R26- system. Same experience. Almost day and night.

 

[phoneslave86]

Today I had the time and made the switch from sine to square wave on my U18/C18/R26- system. Same experience. Almost day and night.

Some devices are not sinewave compatible or able to take advantage very much. Squarewave is much more universal works much better with many common devices as well, like computers ect.

 

[Thetaburn]

Has anyone had an issue where on the U18 only the i2s output work but the Coax and Optical output does not?

When I messaged the seller (Shenzhen Audio). Support team said to update the firmware on the U18 and the X26pro seperately if the devices are connected to the same PC....
There is an U18 firmware???

I could rollback the firmware on the x26pri and see if that fixes things I guess......

 

[TheRealDz]

Has anyone had an issue where on the U18 only the i2s output work but the Coax and Optical output does not?

When I messaged the seller (Shenzhen Audio). Support team said to update the firmware on the U18 and the X26pro seperately if the devices are connected to the same PC....
There is an U18 firmware???

I could rollback the firmware on the x26pri and see if that fixes things I guess......

I had that issue, but could not resolve it, so I returned the unit. I did not try to update the firmware.