A novel way to massively improve the SQ of computer audio streaming

[tims]

Anyone please let me know if this switch (D-link DGS-105) is OK to get the clock mod done by SOtM?

 

https://www.amazon.com/dp/B00JRCC7VC/ref=twister_B073XHJBCG?_encoding=UTF8&psc=1

 

Thanks

[limniscate]

33 minutes ago, tims said:

Anyone please let me know if this switch (D-link DGS-105) is OK to get the clock mod done by SOtM?

 

https://www.amazon.com/dp/B00JRCC7VC/ref=twister_B073XHJBCG?_encoding=UTF8&psc=1

 

Thanks

Yes, that's the switch that they modded for me.

[austinpop]

Clock Distribution and Termination

 

I wanted to update this thread with some information I have gleaned from recent discussions with Kenji Hasegawa-san of Cybershaft, May from SOtM, as well as @zephyr24069, who has provided me very valuable advice with regards to clocks.

 

Important Considerations with Clock Distribution

 

With all the interest in the SOtM sCLK-EX and master reference clocks, it's important not to lost sight of the basic tenets of clock distribution. At the frequencies of interest here, in the 10-54 MHz range, a clock cable acts as a transmission line. Transmission lines are defined by their characteristic impedance. For the SOtM, Mutec, and Cybershaft being discussed here, they are designed to use cables with 50 or 75 ohm characteristic impedance. It is also necessary for clock cables to be terminated at both ends, with the correct impedance (50 or 75 ohm). Proper termination is necessary to minimize reflections, which occurs on the transmission line if there is an impedance mismatch.

 

Point to Point

 

We have almost exclusively been discussing point to point clock connections in this thread. Examples of this are:

1. Cybershaft clock <-> tX-USBultra master clock input via 50 ohm BNC
2. Mutec Ref 10 <-> Mutec MC-3+ USB via 75 ohm BNC
3. sCLK-EX clock point <-> modded component (switch, router, sMS-200, etc) via 50 ohm SMB

In all these cases, it's important to know that the source and target connections are internally terminated. In scenario 1, for example, the Cybershaft output is terminated with a 50 ohm impedance, as is the master clock input of the tX-USBultra. I have confirmed this with both Cybershaft and SOtM. The Mutec Ref 10 uses an internal distribution amp to provide 8 independent clock outputs, but each of these is internally terminated, and expects a properly terminated target as well.

 

In case you are wondering, SOtM handles the termination internally when you send them components to mod. For each sCLK-EX clock point, both the source and the target are appropriately terminated.

 

But what about the case, where you're a cheapskate like me, who doesn't want to spring for multi-output clocks like the Ref 10 or the upcoming SOtM sMS-OCX10? Can I use a single high-quality clock like the OP-14 and drive multiple outputs?

 

This is where things get interesting.

 

Daisy Chaining

 

Yes, you can daisy chain, but you have to consider the entire length of the cable across the chain as a single transmission line, and you must have termination on each end equal to the characteristic impedance of the cable. For this to work, you have to have devices whose inputs can be selectively configured to be terminated (i.e. have an input impedance of 50 or 75 ohms as needed), or unterminated, in which case the input impedance of the input is very high. In the quote from Kenji below, he calls this "Hi-Z."

 

Regarding distribution of clock T plugs, it is possible under certain conditions.

For example, in the case of a daisy chain

 

1.

Clock output(50ohm) ------T--------T--------T-(50ohm)Terminator

                                      (Hi-z)   (Hi-z)    (Hiz)

                               Device1   Device2   Device3

2.

Clock output(50ohm) ------T--------T- non

                                     (Hi-z)   (50ohm) 

                                  Device1   Device2 

 

( Hi-z = High impedance) 

Be sure to have one 50 ohm impedance at the end and the other relay point must be Hi-z.

Therefore, T plug can be used only when the clock input can be set to Hi-z.

For reference, I attach a connection diagram of CH presision CH and D1. Please be aware that each relay point is Hi-z.

If, for example, there are 50 ohm points in two places, the impedance will be 25 ohm, the current will overload and destroy the output circuit of clock due to long-term use.

SOtM tX - USBultra can not set the input impedance to Hi - z. So SOtM tX - USBultra does not use T plug in the situation.

Also, due to the use of T plugs, noises of each device can interfere and clocks that can be transmitted can not be transmitted. I do not recommend using T plug.

The best way to distribute the clock is to use an ultralow noise distribution amplifier.

However, I could not find a low-cost ultra low noise distribution amplifier of less than $ 1000 from the world market.

We are developing to sell low-cost distributors by next spring.

 

Pay particular note to his point about overloading the output circuit of the clock due to it "seeing" a lower impedance than designed. The second consequence of not paying careful attention to termination is that impedance mismatches cause reflections, that degrade the signal integrity of the clock, which negates the whole point in the first place.

 

The other point to note is that he discourages the use of daisy chaining, and promotes the use of an ultra low noise distribution amplifier. I got the same feedback from May and I believe (although I'd have to check) Mutec also discourages daisy chaining. With the Ref 10, it's self evident due to the provision of 8 clock outputs!

 

So what does this all mean

1. Don't daisy chain, if at all possible. Even without the other complications, daisy chains necessitate longer cable lengths, which degrades clock quality
2. If you must, design your chain to ensure that all devices in the chain can be configured to be unterminated, and that there is proper termination of the right impedance on both ends, using tees and terminators.
3. At least for the SOtM Ultra components, SOtM does not currently provide a way to switch between terminated and unterminated. I'm pretty sure that upon request, they can configure a device whichever way you want it.

For me, this means that if I get to the point where I have more than one component with a master clock input that I want to drive, I'll want to spring for a Ref 10 or OCX-10. Ouch!

[tims]

1 hour ago, tims said:

Anyone please let me know if this switch (D-link DGS-105) is OK to get the clock mod done by SOtM?

 

https://www.amazon.com/dp/B00JRCC7VC/ref=twister_B073XHJBCG?_encoding=UTF8&psc=1

 

Thanks

Whoops!  Sorry, that should have read:

Anyone please let me know if this switch (ZyXEL GS-105S v2 5-Port) is OK  to get the clock mod done by SOtM?

Not the D-link DGS-105.  The ZyXEL switch is OK?

 

[auricgoldfinger]

1 hour ago, austinpop said:

So what does this all mean

1. Don't daisy chain, if at all possible. Even without the other complications, daisy chains necessitate longer cable lengths, which degrades clock quality
2. If you must, design your chain to ensure that all devices in the chain can be configured to be unterminated, and that there is proper termination of the right impedance on both ends, using tees and terminators.
3. At least for the SOtM Ultra components, SOtM does not currently provide a way to switch between terminated and unterminated. I'm pretty sure that upon request, they can configure a device whichever way you want it.

 

Terrific post!  Thanks for taking to time to share this valuable information with everyone.

[marce]

On 05/11/2017 at 12:20 PM, ElviaCaprice said:

Not looking for a lecture on clocks.  We already know empirically that the sCLK-EX clock replacement improves audio performance immensely.  Keeping an eye out for better mobos to perform better once the clocks have been replaced.  Probably handle the power within the mobo better for audio purposes is what I would be on the lookout for.  Smaller is better, 12V DC input.  Ability to have or add one PCIe lane, actually 2 would be better. 

Just thought, @marce, with all your technical experience would have a thought on such a mobo.  Didn't hurt to ask.  Sometimes you can overthink the process.  Practicality comes into play here.

!

[marce]

As I pointed out in my previous post, you have to measure a clock line and pick a termination that matches the line, distributing high speed clocks is not that straight forward if you want to maximise signal integrity and in your cases achieve minimum jitter... Using a generic line and resistor will go some way, but especially for the higher frequencies is tailoring any termination to the full line, which does require some direct observation of the signal.

Clocks can be distributed using a clock distribution amplifier, it does not need to be a $1000 device, there are chip distribution IC's.

Daisy chaining can be horrendous to get right, again direct observation and simulation is the best option if you want to be sure the clock that is at your device pins still has low jitter...

 

[auricgoldfinger]

1 hour ago, marce said:

Using a generic line and resistor will go some way, but especially for the higher frequencies is tailoring any termination to the full line, which does require some direct observation of the signal.

 

How does one directly observe the signal?  Please be specific with links to any instruments or other devices mentioned. 

[marce]

A scope will usually suffice, that is the general tool for looking at waveforms...

Generally adding a resistor to a line will swamp the lines mismatches making for good signal transfer, when you get into the high frequencies though things can get a bit fun... The illustration I put up was a 16MHz clock going 8.5mm, just to show what can happen to clocks.

 

[jabbr]

23 hours ago, austinpop said:

 

Yes, I do. I could write a short treatise on proper termination, impedance matching, and the importance of clock cable length. Oh wait - if you bother to actually go back to the index and look, I’ve done that before, as have others.

 

Are you here to participate and contribute to the subject of this thread? If so, welcome!

 

But if you are here to lecture us, and try to convince us that we couldn’t possibly be hearing what we are hearing, then please move along. Nothing to see here.

 

The fundamental premise of this thread seems to be that bridging on a PC has "massively" better "SQ" than going through an ethernet switch. Not only does this massively go against my own personal experience but I really have no idea what the fundamental difference between switch and PC hardware is supposed to be that might create such a difference. 

 

For example, my NAA box, the Solid-Run Clearfog is designed to be used as a network appliance/switch/router. This device has an SFP port which accepts direct fiber input and serves as my NAA (connects to my DAC). Alternately the device which had been my NAA now runs XXHE and this also has a direct fiberoptic input. This connects to my NOS1a G3. I have several of the ASRock Q1900M motherboards, all LPS, including one of Paul Pang's "reclocked" which was a complete waste of money (for me). I have extensive personal listening experience. 

 

I have all sorts of network equipment, and at least via fiber, none of my switches have any sonic signature. Not on my system. I won't make that claim for copper (but am not currently using copper so perhaps different factors apply)

 

I have no doubt that you are hearing what you hear, although I would be very hard pressed to say that I've ever heard an ethernet switch to have a "massive" effect on "SQ" so don't be surprised that I am skeptical. 

 

In any case I use LPS and batteries as standard power supplies in everything close to my audio. 

 

My own network switches if anything improve the sound on my own system which I am quite pleased with. I see zero improvement going direct renderer to NAA or direct to NAS ... but that's my own equipment and I can't say that yours doesn't sound different.

 

Now if you are interested in upgrading clocks, for ~$20 the Crystek: http://www.crystek.com/crystal/spec-sheets/clock/CCHD-575.pdf  and I'd recommend using this (or similar from NHT) perhaps with a small adapter board, to directly replace the clock on the board, without cables, or connectors. Of course the power supply is absolutely critical.

 

Consider me a data point. Of course if your goal is only to hear subjective impressions that validate your viewpoint, then of course your conclusions will be what they are.

[elan120]

22 minutes ago, jabbr said:

Now if you are interested in upgrading clocks, for ~$20 the Crystek: http://www.crystek.com/crystal/spec-sheets/clock/CCHD-575.pdf  and I'd recommend using this (or similar from NHT) perhaps with a small adapter board, to directly replace the clock on the board, without cables, or connectors. Of course the power supply is absolutely critical.

Just out of my own curiosity, were you refer to the network switch clock or DAC clock?  In case you did refer to switch clock such as 24MHz clock, can you point me to a retail place that carry the item?  All of the online retailers I know don't carry 24MHz or 25MHz oscillators, and you will need to purchase in bulk quantities from OEM.

[Lebouwsky]

13 hours ago, jabbr said:

 

The fundamental premise of this thread seems to be that bridging on a PC has "massively" better "SQ" than going through an ethernet switch. Not only does this massively go against my own personal experience but.....

 

Unfortunately my experience is the same as @jabbr. Although I would not call my system ultra high end, it’s far from mediocre. When I implemented the bridged mode I thought I could hear an improvement, but now switching back and forward I cant distinguise them anymore.

 

I’m from the “trust your ears camp”, but I also learned that a change in my system can only be called an upgrade after a longer period of listening. I think jumping to fast in conclusion is my pitfall in this hobby. I can imagine more peolple recoignize themselves in this enthousiastic behaviour. 

 

[sandyk]

Just now, Lebouwsky said:

I’m from the “trust your ears camp”, but I also learned that a change in my system can only be called an upgrade after a longer period of listening. I think jumping to fast in conclusion is my pitfall in this hobby. I can imagine more peolple recoignize themselves in this enthousiastic behaviour. 

 

 Ideally, you should listen for a reasonable period of time until you are fully used to the sound, then if possible reverse the change/modification. You will then normally hear the difference immediately , if indeed there was one, but not always an improvement!

[Cooler]

As Jcat started to sell their Jcat net cards with clocks, i immediately bought one for my music PC. And for now I use it in bridged mode. First lan port for ultraRendu and second one for router. With two working lans it consumes more than LPS-1 can provide, so i use HDPlex LPSU for Jcat card and music PC.

 

But I spent some time with linux configuration and i found the way how to fully isolate ultrarendu from internet/router.

With that I want to achieve 3 aims:

 

1. Less noise from Jcat itself and from external devices to Jcat card

Actually the only reason, why we need access to internet for ultrarendu (to make it visible for external devices) is to give to it an IP address.

For that we built bridge, which is a wrong way. As we mix signals from external very noisy devices (router/switch) with clean (what we are trying to have) signals internally in one card.

And i dont want to connect directly router to Jcat card even through pink faun lan isolator or any other isolator.

 

And another issue is that Jcat card consumes more current and: heats more, more noisy etc and as a result has worse SQ.

Once we use one port, we will get better SQ itself from Jcat card and in addition we will cut noise from router, which is getting into Jcat card.

 

2. Use LPS-1 as PSU, which is better than HDPlex

Once we use only one port on Jcat card, it will consume less or near 1A, which can provide LPS-1. 

 

3. Possible use music PC without internet at all 

Roon wont work for now, but HQPlayer still works. Maybe later Roon will add offline license validation, then we can use Roon offline, maybe partially offline, i mean to have some online validation once in a week or day, i will write to them with this idea. But then the issue is a control, but i can live with some small screen, which connected to music PC, which i can turn on and turn off (one of the ways to control).

 

So for now, i have working ultrarendu without internet on linux, i provide IP for it locally from PC its connected, i installed there DHCP server with different subnet comparing to my router.

And i use one Jcat card port only. Win-win!  

 

The only issue i have is the internet connection, for that i use builtin lan on motherboard and i still fighting with configuration. Internet doesnt work properly, so i cant use Roon so far  

 

I may share configuration later, once i have working solution. If someone already have this working, let me know pls!

[Lebouwsky]

1 hour ago, Cooler said:

3. Possible use music PC without internet at all 

Roon wont work for now, but HQPlayer still works.

Funny because I experimented with this too. HQ player runs on a w10 server (ssd) with dual lan bridged, sms200 is directly connected to server. I use a screen and an optical mouse to control hq player, works fine for me. I can unplug ethernet from server and hqplayer still sees the sms200 as a NAA device.

 

Some observations:

 

* music stored on a separate nas (far away from audio system) which hqplayer w10 server can acces, sounds just as good (maybe even slightly better) then music stored locally on the ssd w10 server when using hqplayer.

 

* music stored locally on ssd using hqplayer sounds just as good with the ethernet cable plugged or unplugged.

 

* the ssd on the server scatters high frequency noice which I’m sensitive for and can spot quite easally.

 

Based on this I’ll keep the ethernet pluggen in so I can acces nas. First of all this make life more conveniant (central point of all kinds of data/ files in house network).

 

Second, now I can experiment with small 32 or 64 gb sdcard or usb stick  and install w10 / hqplayer on it. The goal is to remove the noisy ssd entirely. This is something w10 supports. I only upsample pcm to 192/24, so this doesn’t require a fast server.

[ElviaCaprice]

The fundamental premise of this thread has become the sCLK-EX and how it's clocking versatility and excellent SQ upgrades has changed the outlook for all audio components from servers to fixers. 

@CoolerI don't use Roon, but somehow it escaped me that it is incapable of working offline, which I always do with my audio server.  Another reason I would stick with JRiver on my sCLK-EX server.

If you want to remove SSD noise, go with 5V HDD encased and powered separately from outside the PC, in my case a NUC.  It's 5TB and partitioned to run the OS and audio DATA.

 

To be honest, ever since I've had the modified sCLK-EX NUC, I've noticed that hard drive noise and any optimizations have no noticeable effect on SQ.  An onboard SSD would probably be fine for the OS. 

[Lebouwsky]

I thought ssd always comes with high frequency noise, no matter how you power it, but maybe it’s just an assumption.

 

Nonetheless, I never noticed the same noise coming from an usb stick or sdcard. Trust me,  my ears can tell, I can spot things like telephone chargers and stand-by tv’s from quite some distances. Dog whistles even hurt. Compared to your suggestion, it saves money and 2 extra boxes.

 

Is this off topic from your perspective @ElviaCaprice, or did I misunderstood your hint (if last then sorry for that)

[lmitche]

8 minutes ago, Lebouwsky said:

I thought ssd always comes with high frequency noise, no matter how you power it, but maybe it’s just an assumption.

 

Nonetheless, I never noticed the same noise coming from an usb stick or sdcard. Trust me,  my ears can tell, I can spot things like telephone chargers and stand-by tv’s from quite some distances. Dog whistles even hurt. Compared to your suggestion, it saves money and 2 extra boxes.

 

Is this off topic from your perspective @ElviaCaprice, or did I misunderstood your hint (if last then sorry for that)

You are on topic, no worries. Post away.

[ElviaCaprice]

See above, my changes to the posting.  I currently am not using the SSD, because the HDD suffices for my need in speed, OS, and it's already in place.  No need to add an extra SSD to the mini port and require more power usage of the mobo.  Although I doubt I could hear a difference because of the sCLK-EX.

[Forehaven]

4 hours ago, Cooler said:

As Jcat started to sell their Jcat net cards with clocks, i immediately bought one for my music PC. And for now I use it in bridged mode. First lan port for ultraRendu and second one for router. With two working lans it consumes more than LPS-1 can provide, so i use HDPlex LPSU for Jcat card and music PC.

 

But I spent some time with linux configuration and i found the way how to fully isolate ultrarendu from internet/router.

With that I want to achieve 3 aims:

 

1. Less noise from Jcat itself and from external devices to Jcat card

Actually the only reason, why we need access to internet for ultrarendu (to make it visible for external devices) is to give to it an IP address.

For that we built bridge, which is a wrong way. As we mix signals from external very noisy devices (router/switch) with clean (what we are trying to have) signals internally in one card.

And i dont want to connect directly router to Jcat card even through pink faun lan isolator or any other isolator.

 

And another issue is that Jcat card consumes more current and: heats more, more noisy etc and as a result has worse SQ.

Once we use one port, we will get better SQ itself from Jcat card and in addition we will cut noise from router, which is getting into Jcat card.

 

2. Use LPS-1 as PSU, which is better than HDPlex

Once we use only one port on Jcat card, it will consume less or near 1A, which can provide LPS-1. 

 

3. Possible use music PC without internet at all 

Roon wont work for now, but HQPlayer still works. Maybe later Roon will add offline license validation, then we can use Roon offline, maybe partially offline, i mean to have some online validation once in a week or day, i will write to them with this idea. But then the issue is a control, but i can live with some small screen, which connected to music PC, which i can turn on and turn off (one of the ways to control).

 

So for now, i have working ultrarendu without internet on linux, i provide IP for it locally from PC its connected, i installed there DHCP server with different subnet comparing to my router.

And i use one Jcat card port only. Win-win!  

 

The only issue i have is the internet connection, for that i use builtin lan on motherboard and i still fighting with configuration. Internet doesnt work properly, so i cant use Roon so far  

 

I may share configuration later, once i have working solution. If someone already have this working, let me know pls!

Perhaps this?  https://www.bestbuy.com/site/insignia-usb-3-0-to-gigabit-ethernet-adapter-white/3510527.p?skuId=3510527&ref=212&loc=1&ksid=95130a68-941a-4abe-8066-f596ea5cf046&ksprof_id=401&ksaffcode=pg264881&ksdevice=c&lsft=ref:212,loc:2&gclid=EAIaIQobChMIkcCV556v1wIVyIV-Ch3oGQcJEAYYASABEgKVavD_BwE

[austinpop]

2 hours ago, lmitche said:

You are on topic, no worries. Post away.

 

+1

 

Perfectly on topic, @Lebouwsky. 

[Cooler]

@Forehaven Guys, you misunderstood me. I have bridge solution now, i have jcat net card with two lan ports and also +1 lan on motherboard. 3 lans in total. I dont need more lans, but i want:

1. Use only 1 lan of Jcat card, i explained why

2. I want to use motherboard lan just for Roon work, but maybe i will go with offline solution (but just for tests, i like Roon and use Tidal)

3. I dont want to use a bridge mode. I want to isolate ultrarendu from external network, as it doesnt need network to work, only Roon needs network to communicate with remote controls.

 

I expect SQ improvements from this next level configuration

[ElviaCaprice]

3 hours ago, Lebouwsky said:

Is this off topic from your perspective @ElviaCaprice, or did I misunderstood your hint (if last then sorry for that)

 

As others stated, you are fine.  My hint was in regards to another poster who seems to want to diminutize the importance of this thread and the sCLK-EX.

[Johnseye]

On 11/6/2017 at 5:34 PM, austinpop said:

Clock Distribution and Termination

 

I wanted to update this thread with some information I have gleaned from recent discussions with Kenji Hasegawa-san of Cybershaft, May from SOtM, as well as @zephyr24069, who has provided me very valuable advice with regards to clocks.

 

Important Considerations with Clock Distribution

 

With all the interest in the SOtM sCLK-EX and master reference clocks, it's important not to lost sight of the basic tenets of clock distribution. At the frequencies of interest here, in the 10-54 MHz range, a clock cable acts as a transmission line. Transmission lines are defined by their characteristic impedance. For the SOtM, Mutec, and Cybershaft being discussed here, they are designed to use cables with 50 or 75 ohm characteristic impedance. It is also necessary for clock cables to be terminated at both ends, with the correct impedance (50 or 75 ohm). Proper termination is necessary to minimize reflections, which occurs on the transmission line if there is an impedance mismatch.

 

Point to Point

 

We have almost exclusively been discussing point to point clock connections in this thread. Examples of this are:

1. Cybershaft clock <-> tX-USBultra master clock input via 50 ohm BNC
2. Mutec Ref 10 <-> Mutec MC-3+ USB via 75 ohm BNC
3. sCLK-EX clock point <-> modded component (switch, router, sMS-200, etc) via 50 ohm SMB

In all these cases, it's important to know that the source and target connections are internally terminated. In scenario 1, for example, the Cybershaft output is terminated with a 50 ohm impedance, as is the master clock input of the tX-USBultra. I have confirmed this with both Cybershaft and SOtM. The Mutec Ref 10 uses an internal distribution amp to provide 8 independent clock outputs, but each of these is internally terminated, and expects a properly terminated target as well.

 

In case you are wondering, SOtM handles the termination internally when you send them components to mod. For each sCLK-EX clock point, both the source and the target are appropriately terminated.

 

But what about the case, where you're a cheapskate like me, who doesn't want to spring for multi-output clocks like the Ref 10 or the upcoming SOtM sMS-OCX10? Can I use a single high-quality clock like the OP-14 and drive multiple outputs?

 

This is where things get interesting.

 

Daisy Chaining

 

Yes, you can daisy chain, but you have to consider the entire length of the cable across the chain as a single transmission line, and you must have termination on each end equal to the characteristic impedance of the cable. For this to work, you have to have devices whose inputs can be selectively configured to be terminated (i.e. have an input impedance of 50 or 75 ohms as needed), or unterminated, in which case the input impedance of the input is very high. In the quote from Kenji below, he calls this "Hi-Z."

 

Regarding distribution of clock T plugs, it is possible under certain conditions.

For example, in the case of a daisy chain

 

1.

Clock output(50ohm) ------T--------T--------T-(50ohm)Terminator

                                      (Hi-z)   (Hi-z)    (Hiz)

                               Device1   Device2   Device3

2.

Clock output(50ohm) ------T--------T- non

                                     (Hi-z)   (50ohm) 

                                  Device1   Device2 

 

( Hi-z = High impedance) 

Be sure to have one 50 ohm impedance at the end and the other relay point must be Hi-z.

Therefore, T plug can be used only when the clock input can be set to Hi-z.

For reference, I attach a connection diagram of CH presision CH and D1. Please be aware that each relay point is Hi-z.

If, for example, there are 50 ohm points in two places, the impedance will be 25 ohm, the current will overload and destroy the output circuit of clock due to long-term use.

SOtM tX - USBultra can not set the input impedance to Hi - z. So SOtM tX - USBultra does not use T plug in the situation.

Also, due to the use of T plugs, noises of each device can interfere and clocks that can be transmitted can not be transmitted. I do not recommend using T plug.

The best way to distribute the clock is to use an ultralow noise distribution amplifier.

However, I could not find a low-cost ultra low noise distribution amplifier of less than $ 1000 from the world market.

We are developing to sell low-cost distributors by next spring.

 

Pay particular note to his point about overloading the output circuit of the clock due to it "seeing" a lower impedance than designed. The second consequence of not paying careful attention to termination is that impedance mismatches cause reflections, that degrade the signal integrity of the clock, which negates the whole point in the first place.

 

The other point to note is that he discourages the use of daisy chaining, and promotes the use of an ultra low noise distribution amplifier. I got the same feedback from May and I believe (although I'd have to check) Mutec also discourages daisy chaining. With the Ref 10, it's self evident due to the provision of 8 clock outputs!

 

So what does this all mean

1. Don't daisy chain, if at all possible. Even without the other complications, daisy chains necessitate longer cable lengths, which degrades clock quality
2. If you must, design your chain to ensure that all devices in the chain can be configured to be unterminated, and that there is proper termination of the right impedance on both ends, using tees and terminators.
3. At least for the SOtM Ultra components, SOtM does not currently provide a way to switch between terminated and unterminated. I'm pretty sure that upon request, they can configure a device whichever way you want it.

For me, this means that if I get to the point where I have more than one component with a master clock input that I want to drive, I'll want to spring for a Ref 10 or OCX-10. Ouch!

 

I don't think this was mentioned in your post, but I just confirmed with May that only 1 connection to a master clock for all taps on a single sCLK-EX board is required.  I'm opting for the 50 ohm connector for the board I'm using for my mods.  I'm hoping it gives me more versatility, although it will eliminate the Ref 10 as an option for me.  The new SOtM master clocks can have either impedance.

[austinpop]

1 hour ago, Johnseye said:

 

I don't think this was mentioned in your post, but I just confirmed with May that only 1 connection to a master clock for all taps on a single sCLK-EX board is required.  I'm opting for the 50 ohm connector for the board I'm using for my mods.  I'm hoping it gives me more versatility, although it will eliminate the Ref 10 as an option for me.  The new SOtM master clocks can have either impedance.

 

Yes, correct - the master reference clock input for sCLK-EX is for the entire board, so only one is needed. It makes sense, because the sCLK-EX implements an internal reference oscillator, that feed the frequency generators for the 4 output frequencies. The master clock input is replacing, or overriding, the internal reference oscillator.

 

Also, you don't need to eliminate the Ref 10 as an option. The Ref 10 has 8 total outputs, of which 6 are 75 ohm, and 2 are 50 ohms.