Buffalo GS20xx - Bypass 12V stage via 3 external PSs

[tims]

Hi tgb

Thanks for starting this thread. 

I'm waiting for my gs2016 from Japan and will have to replace the 100v mains supply and feed 12vdc directly to the pcb to get it up and running. 

Any idea if the 12v input is strictly necessary or can it be lower as the 3.3 / 1.5 / 1VDC regulators surely don't need a 12v input. 

Or maybe there are other regs on the board that need the 12v?  

Thx.

[tims]

3 minutes ago, zerung said:

Sometimes a picture speaks for itself. Or not in this case.

 

A group of us are doing this.

 

There will always be a debate on 'discrete and not' LPS power. This takes the former route. The intervention of sub-intervention in the power path is another issue worthy of debate. Your intervention is welcome from that point of view (Which we are not doing). The sonic result will be interesting for sure-to know.

 

The clock in the switch is another point for debate. Which you have decided not to partake in (Perhaps wisely?).

Using a high quality clock on my Ether Regen gave my network a turbo boost - perhaps should state - completely calmed the network down and pushes the music thru in its most ethereal state (Pun intended) ....So it is, that I am doing the same for my Buffalo switch.

 

Yes, many have decide not to add clock and implement the best power they can provide into their system. Like you, and I understand that is wonderful too!

Hi Zerung

With you say there was a large boost to SQ your 12v LPS power supply compared with the stock switching supply?  How would you describe the changes?

[tims]

My two GS2016 will hopefuly arrive soon.  To get them going I need to remove the 100vac switching PS and replace them with a 12v linear supply direct to the pcb's but I've only got one 6 amp linear PS available for both switches. 

Will this be detrimental to SQ by a loss of galvanic isolation due to sharing the power supply with both switches?

Thanks

 

[tims]

5 hours ago, RickyV said:

So I Frankensteined this today and it works,😀.
 

 

So I had to fall back to a smps to deliver the power, lower right corner.

From 7.5V I dropped it to 3.6V, that heatsink gets 60 degrees C. From this 3.6V I fed a 1A 3.3V module and a 2A 1.5V module. I used 2A module because dissipated heat/ power. 
The 1V, 5A was still a problem I started out with 4V on the input but that the regulators got about 80 degrees C, too hot. Than I tried it one diode, dropping 0.8V that dropped the temperature to 60 degrees C, still to hot. Than two diodes dropping 1.6V so now the 1V/5A regulator has 2V on its input and is about 50 degrees C now.

The heatsink’s from the first regulator and the diodes get about 60 degrees C. Even the smps get 43 degrees C.

So now that everything is working I will put it, temporary, in my system upstream of my Etherregen, connected by fiber.

So now I have to figure out what I need for a power supply. 
7.5Vx 5A= 37.5W    37.5W/3.6V= 10.4A at 3.6V ???

 

 

Hi Ricky

Could you please give more details about the stacked modules you are using to get the 1.5v and 1v supplies?

Are they 1 amp LDOVR modules? I don't get how you actually stacked them like that.

[tims]

May not be of interest but here are a couple of LDO regs that offer <1v output voltage and 5A output:

"The LT3070 from Analog Devices has 5-A output with 0.15-V maximum dropout. Maximum input is 3 V; output voltage is adjustable from 0.8 to 1.8 V."

and

"The MIC69502 from Microchip Technology has 5-A output with 0.5-V maximum dropout. Maximum input is 5.5 V; output voltage is adjustable from 0.5 to 5.5 V"

from

https://www.electronicdesign.com/power-management/power-supply/article/21808454/5-ldo-regulators-with-high-output-current

[tims]

Hi tbh

 

Thanks for your continued work with the switch'es power supply.  I've been following your posts in forum-hifi.fr (via google translate) and read that the 1v supply works with 5v (on the 12v input) with the other voltages (3.3v and 1.5v) being fed separately. 

However, without the separate supplies for 3.3v and 1.5v,  do you think a linear 5v PS (feeding 3.3, 1.5 and 1v) would sucessfully boot the switch?

If so, I guess the 5v supply would need to output at least 4 or 5 amps?

I know that this single linear 5v supply supply would not be as good separate supplies for 3.3 and 1.5v but it would have to be better than the 12v switching supply that comes with the switch.

[tims]

Hi guys

 

Off topic, but in case you don't know there is a GB for a SOTA clock developed my Andrea Mori and others that's meant to match the Pink Faun OCXO clock (https://www.diyaudio.com/forums/digital-line-level/261651-tempered-master-clock-building-low-phase-noise-jitter-crystal-oscillator-54.html#post6344203).

I have two GS2016 switches that I plan to upgrade the clocks and my order will cost €206 plus shipping (and tax if you're in the EU) - seems a 'no brainer' to me and there's plenty of interest.

 

If you're interested here is the link to the group buy:

https://www.diyaudio.com/forums/group-buys/291925-tempered-master-clock-buy.html

 

My order (to replace the clocks in my two switches) is:
1 x 6.2500 MHz AT-cut
1 x TWTMC-PXO-AIO-SF
1 x TWTMC-PXO-AIO-XFMR
1 x TWTMC-STS-FSDO-F

 

If you need other info, go to https://www.diyaudio.com/forums/digital-line-level/261651-tempered-master-clock-building-low-phase-noise-jitter-crystal-oscillator-68.html, to ask questions but if you're interested better hurry as the GB closes soon.

[tims]

1 hour ago, Soul Analogue said:

Thank you for the information

 

Unfortunately the diyaudio posts do not mention the output type of the clocks....

the buffalo only takes lvcmos.... and it does not work with cmos output clock signal..

This was bought up here:

https://www.diyaudio.com/forums/digital-line-level/261651-tempered-master-clock-building-low-phase-noise-jitter-crystal-oscillator-57.html#post6368666

 

"Hi Andrea.
If a Buffalo BS-GS2016 switch only works with LVCMOS output clocks, is there problems to use any of Yours clocks?"

*

"No problem, you can use all the new oscillators since they need to be followed by a sine to square converter that's LVCMOS output"

 

[tims]

1 hour ago, Soul Analogue said:

Hi, wonder why you choose AT cut rather than SC cut?

so what I would be interested to get 3 sets to achieve 25mhz....

one set to get 24.576mhz and one set to get 33.8688mhz

For 25Mhz, choosing the AT cut crystal was the only one that had any chance of reaching the MOQ.