Uptone Audio Regen

[jexby]

Hm would this be another potential power source for the Regen?

 

http://ifi-audio.com/portfolio-view/accessory-ipower/

[reverendo]

Hm would this be another potential power source for the Regen?

 

Accessory – iPower

 

curious in regards to price

[Ipoci]

...

b) Below about 9V since we want the REGEN to be usable by those people whose DACs are entirely bus powered, and if one of those DACs draws the 500mA USB-spec allowed max., then the 4V drop from 9V to 5V is going to generate 2W of heat on a regulator with no heat sink. (If not using an entirely bus-powered DAC--say just powering your USB input, then a 12V or greater supply could even be used, though there is no need.)

 

--Alex.

 

Hi Alex, I've a wonderful ( and unused ) homemade LPS built with Belleson regulator in it ...

 

What's the expected current requirement of the REGEN when feed by DC 12V ?

 

Belleson is rated at 2A maximum, I hope to have enough horsepower to run it.

 

Have a nice day, Massimiliano

[bibo01]

This is a term I coined to refer to the power and ground noise a receiver generates when reading a packet of data. For example in USB (and Ethernet) data comes in packets with a fair amount of space between packets. The receiver chip doesn't do much of anything in-between packets, this doesn't generate much noise on supply planes. But when a packet comes in the receiver goes into high gear processing the data that just came in, this processing generates a lot of highly variable current draw from the board which generates a fair amount of noise on the supply planes.

 

This noise comes in bursts, which is the packet frequency. For example USB high speed has packets at 8KHz, which is in the human hearing range. This noise can modulate processes in the DAC (such as the main clock oscillator and the DAC conversion to analog) producing subtle distortions which are in the audio range.

 

John S.

Interesting explanation.

In the presence of a galvanically isolated USB interface like JLSound where clocks are on the isolated side and there are two separate ps (one for xmos chip and one for oscillators), can that "fair amount of noise on the supply planes" still be relevant? If yes, how?

The two separate PS share ground.

If we measure noise on both PS, what kind of measured value should we aim for in order to leave DAC unaffected?

[RichB]

curious in regards to price

 

Speaking as a USA iFi Audio dealer, I have not received any info yet on availability or how much the iPower will cost. It's a new product from them.

[RichB]

Hm would this be another potential power source for the Regen?

 

Accessory – iPower

 

The specs on the iPower web page show that it can be had in 9V version which can supply up to 1.5A (so about 14 watts), which from what Alex has posted is more than enough power capability (probably overkill) to power the Regen.

[firedog]

Really interesting device. Depending on price, I can see myself buying a few.

[Superdad]

Hi Alex, I've a wonderful ( and unused ) homemade LPS built with Belleson regulator in it ...

What's the expected current requirement of the REGEN when feed by DC 12V ?

Belleson is rated at 2A maximum, I hope to have enough horsepower to run it.

 

Hi Massimiliano:

 

The REGEN has two ultra-low noise regulators (the wonderful TI TPS7A4700), one for 3.3V for the USB hub chip, and one for 5V for forwarding clean VBUS to the DAC for those that require it.

 

As you know we will be including a 7.5V/2.93A/22W SMPS that I selected as best "sounding" for the price. The REGEN could actually take as much as 20VDC but we advise against that. Even 12V is high for our goals. Please refer to this post where I explain the range and heat dissipation issues: http://www.computeraudiophile.com/f10-music-servers/uptone-audio-regen-22803/index6.html#post401661

 

So if you chose to use a 7V supply with the REGEN and an entirely bus-powered DAC (500mA max., just as you say), that's a 2V drop to 5V for the USBVBUS, so 1w of heat to dissipate which is no problem at all. We are trying to keep the regulator for the 5VBUS from having to dissipate much more than 2.5W since it does not have a heatsink and is in a sealed enclosure.

 

On the other hand, if you have a bus-powered DAC drawing the full 0.5A allowed by the USB spec and you use a 12V PS, then the drop to get to 5V is 7V; 7V*0.5A=3.5 watts--perhaps a bit more than I would feel comfortable with. Probably okay, but I'd rather go to 9V or below.

 

If you don't need any bus power at all--or for sure only just for initial handshake--then you really don't have to worry. I think our USB hub chip draws less than 50mA at 3.3V, so it would be pretty hard to overheat that second regulator. (even 15V dropped to 3.3V will, at 50mA be only about 0.6w)

 

As you can see, current capability for the REGEN's PS is really not the issue. The only reason I chose such a high wattage PS to include is that I found that size to be the sweet spot quality and output capacitance for current delivery--bass was better than on the little cheap ones, and MUCH better, and with clearer highs than on any of the available inexpensive linears (only wall warts; all the factory tabletop linears are unregulated units). Go figure…

[Ipoci]

Hi Massimiliano:

 

... if you chose to use a 7V supply with the REGEN and an entirely bus-powered DAC ... On the other hand, if you have a bus-powered DAC …

 

Thanks for details. At this point in time .... I don't have a DAC ! ... Ah ah ah ... My last dac departed few months ago and I'm still waiting to be fascinated by one of the smart solutions that should pop up in the upcoming months.

 

Have a nice day, Massimiliano

[Superdad]

Interesting explanation.

In the presence of a galvanically isolated USB interface like JLSound where clocks are on the isolated side and there are two separate ps (one for xmos chip and one for oscillators), can that "fair amount of noise on the supply planes" still be relevant? If yes, how?

The two separate PS share ground.

If we measure noise on both PS, what kind of measured value should we aim for in order to leave DAC unaffected?

 

Hi Gianluca:

 

I am sure John will chime in with a proper technical explanation, but allow me to point out a few things--

a) The purpose of the REGEN is create a USB signal with better signal integrity and impedance than what is at the end of your USB cable from your computer or streamer;

b) Galvanic isolator chips (some of which are much better than others--all of which generate their own jitter and should be reclocked afterwards), as used on many USB>I2S boards and in the last couple of years in decent DACs, all come AFTER both the USB PHY and the USB processor;

c) The "packet noise", "logic induced modulation", whatever you want to call it--is still happening on the USB input board, and despite the presence of isolator chips, the extra voltage spikes, activity, and noise generated will still have an effect on the sound. That's because those galvanic isolators are good at galvanic isolation, but the signal itself gets embedded with tiny stuff (John will have to expound and correct here). Also, I seem to recall that the isolators are good at some frequencies and not others.

 

In addition, to use the JLSounds board as an example (I have one myself, uninstalled as of yet), they have the audio clocks on the board, and as you say, some sharing of PS planes may occur. (And if one does the better thing and feeds a better DAC master clock back into the board, it appears that he ran out of isolator channels and the clock would not go through the isolators. He also chose to use the RF transmitter/receiver type of isolator. Not only do those Silicon Labs isolators have about 3.5 times the jitter of the ones John likes, but there may be some RFI emitted.)

 

As a separate example, John when to great lengths in the design of the USB input of the recently releases BottleHead DAC to insure isolation, immunity, etc. He used all the right tricks with regards to PHY, processor, multiple isolated regulators, clocking, and the best galvanic isolators and reclock flops--all placed and ordered for optimal results.

And guess what? USB cables, computer stuff, and the REGEN all still make a difference!

 

So sorry, when Chord just announced that its newest two DACs--the about-to-ship 2Qute and Hugo TT--have galvanic isolators in their USB input path that make choice of USB cables and power supplies irrelevant, forgive me if I don't act surprised if users discover otherwise.

[Superdad]

Hm would this be another potential power source for the Regen?

 

Accessory – iPower

 

Hey, I love the idea of an SMPS wall-wart designed to perform better. Would be fine with the REGEN if you set it for 9V. The regulators we use are quite exceptional, so it remains to be seen if a difference will be heard just due to lower SMPS ripple. We should not get wildly excited about their 1uV noise spec though--they are honest and show in a footnote that is an average measured in the audio band. That's not the range where SMPS are noisy.

 

Rich B.: please find out the price for this from iFi. I am hoping they will retail for about $30 +/-.

 

Cheers,

ALEX C.

[jtwrace]

So for those of us with. JS-2 that do not need bus power what voltage is really recommended?

[Superdad]

So for those of us with. JS-2 that do not need bus power what voltage is really recommended?

 

Jason: Anything from 6-12V is fine. If you use your new JS-2 (shipping to you ahead of schedule BTW; my ex-areospace assembly lady I hired is a fast learner!), then set one of its outputs to 7V. Higher voltages are a waste as it just gets dropped to 5V and 3.3V and wasted as heat (though there are often good things to be said for having warm devices; John thinks people like the effect of putting putty on clock oscillators because it gets them a bit warmer--not because of the vibration damping effect it may or may not have).

[pl_svn]

Alex... will the second cable that came with my JS-2 fit the Regen?

 

oh... and don't waste your time sending me a "news" email: just send me straight away a PP invoice

[Superdad]

Alex... will the second cable that came with my JS-2 fit the Regen?

 

oh... and don't waste your time sending me a "news" email: just send me straight away a PP invoice

 

Francois-Paul: Both of the cables you got were my custom, large gauge, Oyaide/Belden pieces with 5.5mm x 2.5mm plugs at both ends. The REGEN's jack is a 5.5mm x 2.1mm, but plugs with 2.5mm holes generally work fine with 2.1mm jacks (0.4mm is not a very big difference). I do also stock the nice Oyaide plugs in the 2.1mm size, or you can get a 2.5mm>2.1mm adaptor plug (Bix Power sells a lot of such items: C Series Connectors , but I am sure you can find a source closer to France.)

 

The reason everyone will be getting an e-mail is not for the news, but for the web ordering page. I am really trying to avoid doing REGEN orders via individual e-mail--too time consuming and I am already buried in e-mail!

[JohnSwenson]

Interesting explanation.

In the presence of a galvanically isolated USB interface like JLSound where clocks are on the isolated side and there are two separate ps (one for xmos chip and one for oscillators), can that "fair amount of noise on the supply planes" still be relevant? If yes, how?

The two separate PS share ground.

If we measure noise on both PS, what kind of measured value should we aim for in order to leave DAC unaffected?

 

Very good question. The isolation helps but is not nearly the panacea many people think. Lets travel through the system and look at both the power and signal and what happens to them as we go through the system.

 

So lets start with a USB receiver with bursts of high frequency noise on both the power and ground planes. This PG (power/ground) noise will modulate the data being sent to the isolators. It will slightly increase jitter and the amplitude of the pulses will vary with the noise.

 

This noisy power also goes into the driver side of the isolator. The signal going across the barrier (light, EM waves, magnetic field etc) gets modulated by this PG noise as well. The PG noise also changes the threshold of the input receivers, adding jitter to the signal.

 

On the other side of the barrier we have a couple things happening, the varying signal level, caused by the PG noise in the driver, also causes the receiver current to change, even with no signal applied. Thus the receiver causes PG noise on the "clean side" directly related to the PG noise on the "dirty side" It is definitely attenuated, but not by nearly as much as most people expect. Then we also have traditional logic noise caused by the fact the output is a normal logic signal, every time the output changes it creates noise on the PG planes on the clean side. The jitter on the signal created by the PG noise on the dirty side is still there PLUs jitter introduced by the isolation scheme. This jitter changes the spectrum of the logic noise on the PG planes on the clean side.

 

So then we feed the signal through a reclocking flop, which is supposed to get rid of all that jitter on the input. Well it helps, but no reclocking flops are completely effective. The PG noise at the flop still causes jitter to show up on it's output, PG noise changes the threshold where the flop detects the "switch" of the clock, thus increasing jitter on the output.

 

The result of this chain is that PG noise on the "dirty side" can still make it through to the "clean" side. It IS attenuated, but not completely gone.

 

Cascading such stages can theoretically help, but in order for that to work the reclocking clock has to get fed back through the isolators which significantly degrades the clock so it turns out cascading doesn't help much. (a two stage cascade does make things better, but not by a huge amount)

 

On the issue of PS supply noise THAT is a whole story in itself which needs to get tackled separately.

 

John S.

[DZetye]

Please email me the link to the ordering page, Alex. Thanks

[Superdad]

Woo-hoo!! Five first article production samples just in from our USA board house! Below is a pic. The fifth one is playing in my system and sounds dynamite--slightly better than the prototypes, probably because the 4-layer board stack up of the production matches what John did the impedance matching too (versus his proto-board house's layer stack).

 

Cranking the SHM-SACD of the Pentagle's first album, al long time favorite. Oh this sounds sooo good.. Oh shoot--I have to call the board house to approve them running the rest.

 

Ciao,

--Alex C.

 

[Solstice380]

Tell them it's a rush order!!!

[jtwrace]

Tell them it's a rush order!!!

 

No $hit!

[Superdad]

No $hit!

 

Chill guys. The rest ship Tuesday but the cases don't ship from Japan until April 3rd. I have plenty to prepare before then.

 

Very happy to report that my first assembler hire (she did assembly for a small local aerospace contractor for 14 years) has been super easy to train on JS-2 assembly this week. Even better is that our musical tastes in the shop are reasonably compatible (I'll stretch her range over time).

[jtwrace]

The REGEN's jack is a 5.5mm x 2.1mm, but plugs with 2.5mm holes generally work fine with 2.1mm jacks (0.4mm is not a very big difference).

Yeah, I'm a bit too retentive about this stuff. I prefer to use matched connectors; there's a reason. Please make mine match! ;-)

[pl_svn]

(I'll stretch her range over time).

 

99% sure you already do know/have this one too but... one never knows: "Re-Covers" by Albert Kuvezin and Yat-Kha

[BobSherman]

Chill guys. The rest ship Tuesday but the cases don't ship from Japan until April 3rd. I have plenty to prepare before then.

 

Very happy to report that my first assembler hire (she did assembly for a small local aerospace contractor for 14 years) has been super easy to train on JS-2 assembly this week. Even better is that our musical tastes in the shop are reasonably compatible (I'll stretch her range over time).

 

How about some Mose?

 

[EuroDriver]

Woo-hoo!!

Oh this sounds sooo good..

 

[ATTACH=CONFIG]17652[/ATTACH]

 

Getting excited, EuroDriver's tail is wagging !