Master Clock for your EtherREGEN

[Exocer]

44 minutes ago, DarqueKnight said:

I cannot speak for anyone else's EtherREGEN, but mine, and my ears, much preferred the BG7TBL's square wave input. Switching to the BG7TBL's 75 ohm sine wave input caused a loss of bass detail, diminished tactile sensation, and diminished imaging properties. Inserting the filter caused a further reduction in sound quality, particularly in bass detail.

 

While my results with the Mini-Circuits filter were not positive, I would not discourage anyone from trying it, especially if you have a high quality sine wave clock. Results will vary based on your clock and cables.

Many thanks for your tests! I am feeling less FOMO for going with the 3 Square wave output BG7TBL...

 

My takeaways from your experience are:

 

1. Sine + Filter at device input while objectively better may not actually "sound" better in practice to everyone.

2. Square outputs straight from the BG7TBL actually sound good as-is if not better than the Sine output from the same clock with filter at input on some systems.

3. Better looking wave does not always translate to better sound (?)

4. While the waves produced by certain cables may look similar, the sound characteristics may still differ more than the measured wave output would suggest.

 

Please do correct any of the above if it is incorrect.

Since cables shouldn't matter as much for the sine wave outputs, did you notice zero variance in SQ between the cables used on the sine wave outputs?

 

I had planned to try a sine wave BG7TBL but I may just end up going with an Afterdark Square wave output clock as an upgrade and be done with it. Will have to get a nice cable though 😁

 

[GMG]

53 minutes ago, DarqueKnight said:

Figure 12. Square wave pulse waveform with Prosig cable

Is it expected that the cheapest cable will have what appears to be the closest wave form to an actual square?

[DarqueKnight]

4 minutes ago, GMG said:

Is it expected that the cheapest cable will have what appears to be the closest wave form to an actual square?

 

It is not what I expected, but it is what it is.

 

7 minutes ago, Exocer said:

My takeaways from your experience are:

 

1. Sine + Filter at device input while objectively better may not actually "sound" better in practice to everyone.

2. Square outputs straight from the BG7TBL actually sound good as-is if not better than the Sine output from the same clock with filter at input on some systems.

3. Better looking wave does not always translate to better sound (?)

4. While the waves produced by certain cables may look similar, the sound characteristics may still differ more than the measured wave output would suggest.

 

Please do correct any of the above if it is incorrect.

 You summarized my experiences nicely.

 

8 minutes ago, Exocer said:

Since cables shouldn't matter as much for the sine wave outputs, did you notice zero variance in SQ between the cables used on the sine wave outputs?

 

I noticed less variance in the cables with the sine wave outputs, but I attributed that to the sine output, of this clock, facilitating less detail to begin with.

[LowMidHigh]

13 minutes ago, GMG said:

Is it expected that the cheapest cable will have what appears to be the closest wave form to an actual square?

 

Oddly enough, many high-end cables are often not built to spec. In addition, there's an issue of attenuation. Pro cable manufacturers publish those figures; fancy ones omit them. So it's difficult to know which cable would yield better results. The superb test shown above does just that.

 

I am impressed by the nearly perfect square of the standard cable. 

[soares]

57 minutes ago, DarqueKnight said:

I have received my Mini-Circuits filters. The people at Mini-Circuits were a pleasure to deal with. The order was placed mid-morning and it was shipped early afternoon the same day. It arrived three days later by FedEx.

 

Figure 1. The filters arrived in a sturdy box with copious amounts of protective paper padding.

 

Figure 2. Two of the BLP-10.7-75+ 75 ohm filters and one of the BLP-10.7+ 50 ohm filters were ordered. I have one BG7TBL with three 75 ohm square wave outputs and another BG7TBL with a 75 ohm square wave output, a 75 ohm sine wave output, and a 50 ohm sine wave output.

 

Figure 3. I did not pay attention to the filter size on the spec sheet. I expected them to be smaller.

 

Figure 4. I also received this accessory for my Tektronix TDS 2012 oscilloscope. It is a 75 ohm feed through termination for impedance matching of 75 ohm cables to the scope's 1 M-ohm input impedance.

 

Figure 5. Three 75 ohm BNC cables. Bottom to top: Prosig PSG00542 RG-59/U coaxial cable, 2 meter length. This cable came with my dCS Puccini U-Clock word clock, cost $5, Revelation Audio Labs Prophecy Cryo-Silver with Oyaide BNC connectors, 1.5 meter length, made in 2009, cost $349, Revelation Audio Labs Prophecy Cryo-Silver with Furutech BNC connectors, 1 meter length, made in 2015, cost $449.

 

Figures 6 through 8 show the waveform and amplitude distortions that occurred due to the impedance mismatch between the cables and the scope. The BG7TBL had been on for over 24 hours prior to taking measurements.

 

Figure 6. Square wave pulse train waveform with Prosig cable, impedance mismatch.

 

Figure 7. Square wave pulse train waveform with RAL 2009 cable, impedance mismatch.

 

Figure 8. Square wave pulse train waveform with RAL 2015 cable, impedance mismatch.

 

Figure 9. Square wave pulse train waveform with Prosig cable, impedance matched.

 

Figure 10. Square wave pulse train waveform with RAL 2009 cable, impedance matched.

 

Figure 11. Square wave pulse train waveform with RAL 2015 cable, impedance matched.

 

Figure 12. Square wave pulse waveform with Prosig cable.

 

Figure 13. Square wave pulse waveform with RAL 2009 cable.

 

Figure 14. Square wave pulse waveform with RAL 2015 cable.

 

The RAL 2015 was the best sounding of the BNC cables.

 

Figure 15. Unfiltered sine wave from 75 ohm BG7TBL output.

 

Figure 16. Sine wave from 75 ohm BG7TBL output with 75 ohm Mini-circuits filter.

 

Listening Evaluations

 

Figure 17. EtherREGEN with Mini-Circuits 75 ohm filter at its clock input. Both the EtherREGEN and the BG7TBL clock were powered with separate TeraDak DC-30 linear power supplies.

 

I cannot speak for anyone else's EtherREGEN, but mine, and my ears, much preferred the BG7TBL's square wave input. Switching to the BG7TBL's 75 ohm sine wave input caused a loss of bass detail, diminished tactile sensation, and diminished imaging properties. Inserting the filter caused a further reduction in sound quality, particularly in bass detail.

 

While my results with the Mini-Circuits filter were not positive, I would not discourage anyone from trying it, especially if you have a high quality sine wave clock. Results will vary based on your clock and cables.

Thank you for sharing your results.

Here it was exactly the opposite. I was really surprised with your findings.
Would you consider selling me the 75ohm version?  Just to compare results to the one I got.

Thank you. 
Jorge

[GMG]

Is there anyway to find out which output is square and which is sine without measurement equipment?

I ordered the clock with 2 square and 1 sine but it came unmarked. 
the seller is trying to find out but I doubt that I will get a very reliable answer...

[DarqueKnight]

6 hours ago, soares said:

I was really surprised with your findings.

Would you consider selling me the 75ohm version?  Just to compare results to the one I got.

 

I will keep both of them, thank you.

 

1 hour ago, GMG said:

Is there anyway to find out which output is square and which is sine without measurement equipment?

 

Yes, if you know what to look for on the circuit trace side of the board. I don't.

 

The top side of the boards are identical. Shown below is the square-sine-sine board on left and the square-square-square board on right:

 

 

Below is a high resolution image of the circuit trace side of the square-sine-sine board on left and the square-square-square board on right. The seller should be able to find out from the manufacturer what the circuit trace differences are between the square and sine outputs. It is difficult to tell just by looking. Click on the picture to expand it to full size:

 

 

[R1200CL]

@DarqueKnight

I studying my clock below this week. Mine has some modifications none of yours seems to have. Did you purchase the EtherRegen version from Ham Radioshop ?

[DarqueKnight]

Yes, the triple 75 ohm output BG7TBL was purchased from Ham Radio Shop. The 75-square, 75-sine, 50-sine output BG7TBL was purchased from TZT Shop. Both via AliExpress.

 

The printed circuit boards of both units are identical. Both have the same board number (06109A_Y743-200719) and date (2020-07-19).

[R1200CL]

One of us can’t have what we expect to have.......

But you did measure yours, so I suppose you have as said. 

[PYP]

Are there 75 ohm high-quality external splitters?  I have two eRs.  The Cybershaft feeds one (has one sine wave output), but perhaps it can feed both eRs.   

 

Not sure if that defeats the moats, however.  

 

Should get the 75 ohm mini-circuits filter on Monday.  Interested if my setup will respond positively or negatively.  

[soares]

1 hour ago, PYP said:

Are there 75 ohm high-quality external splitters?  I have two eRs.  The Cybershaft feeds one (has one sine wave output), but perhaps it can feed both eRs.   

 

Not sure if that defeats the moats, however.  

 

Should get the 75 ohm mini-circuits filter on Monday.  Interested if my setup will respond positively or negatively.  

With thanks to ambre:

https://www.adark.co/collections/cybershaft/products/cybershaft-limited2-ocxo-10mhz-op14-op20

[DarqueKnight]

3 hours ago, R1200CL said:

@DarqueKnight

I studying my clock below this week. Mine has some modifications none of yours seems to have.

@R1200CL

 

Your BG7TBL uses a different OCXO (Frequency Communications) than mine (Symmetricom). Your board version number is different also.

 

Yours: 06109A_Y742-200719

 

Mine: 06109A_Y743-200719

[PYP]

45 minutes ago, soares said:

With thanks to ambre:

https://www.adark.co/collections/cybershaft/products/cybershaft-limited2-ocxo-10mhz-op14-op20

Thanks, Jorge.  But a bit pricey and 50 ohm input.  Was thinking more along the lines of this, but in 75 ohm version: https://www.adark.co/collections/cybershaft/products/cybershaft-50ω-10mhz-變壓器型-2分配器-cyb-ds01

 

This may NOT work even if it exists because of leakage gremlins working from one eR to another.  Nasty bugs.

 

To avoid that, would probably mean adding an additional clock and LPS.  I'm already past my own threshold for complexity and adding more boxes might result in the back of my rack looking like your setup.  We mustn't have that!!! 

[ambre]

21 minutes ago, PYP said:

Thanks, Jorge.  But a bit pricey and 50 ohm input.  Was thinking more along the lines of this, but in 75 ohm version: https://www.adark.co/collections/cybershaft/products/cybershaft-50ω-10mhz-變壓器型-2分配器-cyb-ds01

Have a better look it's 50 or 75 Ohm high quality distributor 4x whatever you choose per output selectable 

[FIndingit]

If you have two sq wave outputs and one sine, the middle one is guaranteed to be sq wave. 

[PYP]

17 minutes ago, ambre said:

Have a better look it's 50 or 75 Ohm high quality distributor 4x whatever you choose per output selectable 

I was looking at the 50 ohm input (single input on the upper left), which is a mismatch with my Cybershaft's 75 ohm output.  

 

[One and a half]

3 hours ago, PYP said:

Are there 75 ohm high-quality external splitters?  I have two eRs.  The Cybershaft feeds one (has one sine wave output), but perhaps it can feed both eRs.   

 

Not sure if that defeats the moats, however.  

 

Should get the 75 ohm mini-circuits filter on Monday.  Interested if my setup will respond positively or negatively.  

The BNC connectors are not connected to the chassis or thumbscrew of the EtherRegen,  so they float. So if the splitter is floating you won't compromise the moat.

Perhaps long term to consider the Mutec REF 10 or MC3+USB for clock source?

[JohnSwenson]

Now is a good time to write about what I found in the BG7TBL box that Alex sent me.

 

First off what is inside:

 

OCXO produces sine wave, this goes into a standard CMOS logic gate, which makes an attempt at converting the sine to square. This signal then feeds three more CMOS gates, one for each output. Outputs with sine have a multi-pole passive filter to get rid of most of the harmonics from the square waves. Square wave outputs just feed the CMOS gate output directly to the BNC jack.

 

An important thing to note is that standard CMOS outputs (such as these) cannot even come close to supplying enough current to feed a properly terminated  50 or 75 ohm input. The output impedance is also usually in the range of 10 to 20 ohms, which is not going to match anything.

 

So neither the sine nor square are actually close to outputting what they should, no matter what cable you use. If you get a good looking square wave out of one it is pure luck.

 

Look at the pictures of the square wave in a previous post, on the falling edge you can actually see a glitch where the falling actually goes back up, then back down. This is caused by an impedance mismatch on the board itself.

 

The 50 or 75 ohm output don't actually change the impedance coming out of the board, just the connector.

 

Given all this it is a wonder some people find this to improve things.  Given all the impedance mismatches the length of the cable is going to play an important part with square waves.

 

Getting a decent sound improvement out of this box is more a matter of luck than technical "goodness"  of any cables or connectors.

 

John S.

 

 

[R1200CL]

10 minutes ago, JohnSwenson said:

Getting a decent sound improvement out of this box is more a matter of luck than technical "goodness"  of any cables or connectors.

Well, I really doesn’t hope the same applies to the AfterDark clock you have. 

[Superdad]

3 minutes ago, R1200CL said:

Well, I really doesn’t hope the same applies to the AfterDark clock you have. 

No it does not.

[soares]

1 hour ago, PYP said:

I was looking at the 50 ohm input (single input on the upper left), which is a mismatch with my Cybershaft's 75 ohm output.  

 

Same problem here. Perhaps you could contact Adrian from AfterDark. I also order a 75 Ohms clock and I am in the same situation if I ever will to connect another device... 🙂

[PYP]

1 hour ago, One and a half said:

Perhaps long term to consider the Mutec REF 10 or MC3+USB for clock source?

Thanks.  When I thought there would be one eR in my system, I ruled out the REF 10.  Now there are two, but it still seems like a waste of great gear and money.  Nothing else in my system uses an external clock.   If my DAC did use a clock, I would seriously consider it.  

[PYP]

30 minutes ago, soares said:

Same problem here. Perhaps you could contact Adrian from AfterDark. I also order a 75 Ohms clock and I am in the same situation if I ever will to connect another device... 🙂

Well, I should let everything settle in once I add the filter.  And I don't want to gild the lily.   

[soares]

52 minutes ago, PYP said:

Well, I should let everything settle in once I add the filter.  And I don't want to gild the lily.   

I was surprised with the SQ upgrade I experienced. The voices are really incredible.