Pro-Ject Pre Box S2 Digital: MQA HW decoding at reasonable cost

[MagnusH]

Quote

2. USB input is in use: Unit can be powered directly from computer via USB input. In this case is highly recommended to disconnect Power 5V DC cable from the unit - power disturbances from two power supplies could affect sound performance

That part of the manual is wrong (confirmed by John Westlake who designed this DAC). If you use an external power to the micro connection, the power is taken from there and not from the big USB A connection. A first step which gives a little boost to SQ is to buy an iFi Power 5V which costs around $60.

If playing from a PC I would also suggest some USB tweak, or use optical. To much electronic noise coming from the PC over a straight USB connection (I use mine with toslink).

[left channel]

5 hours ago, RicaNeaga said:

Hello! Just bought this DAC, and I've read several posts on this topic regarding power supply. Can you please recommend the best choice for a power supply?

 

To be more specific, I want to connect it to my PC via the USB port (for Tidal & MQA), however I found this in the user guide:

 

 

So what choices do I have? Is really an external power supply out of the question when using the USB port for PC connectivity? I've seen many thinking of buying ''chinese linear power supply'' - are these better than a iFi Audio iPower 5v and can these be used concurrently with a PC USB connection? Can you recommend some specific linear power supply that are below a 100 euro price limit?

 

Thank you in advance  

 

8 minutes ago, MagnusH said:

That part of the manual is wrong (confirmed by John Westlake who designed this DAC). If you use an external power to the micro connection, the power is taken from there and not from the big USB A connection. A first step which gives a little boost to SQ is to buy an iFi Power 5V which costs around $60.

If playing from a PC I would also suggest some USB tweak, or use optical. To much electronic noise coming from the PC over a straight USB connection (I use mine with toslink).

 

@RicaNeaga John Westlake further recommended only a linear power supply or battery bank, and Pro-Ject has since announced products that meet those requirements: https://www.project-audio.com/en/category/hifi-electronics/s2-line/power-s2-line/

 

The iFi iPower is a switching PSU, not linear, however @MagnusH and others say it does produce an improvement in sound quality. For that matter even the included switching PSU, which John does not recommend (for technical reasons I can point you to if interested) actually does provide an improvement to my ears. But to meet John's requirements, I did upgrade to an $11 linear wall-wart. Others have selected higher-end linear PSUs from China and elsewhere, and are very happy with them.

Whatever you choose, I've found that using external power provides the most notable improvement, with USB anti-jitter etc. cleaners providing a small additional boost in sound quality.

[audiobomber]

I have an Audiolab 8200CD, also designed by John Westlake. The unit has internal power supplies, does not use power from the USB cable. I found that blocking the USB 5V pin improves the sound, making voices in particular sound more cohesive. This may be worth a try with the Pro-Ject box.

 

Initially I just blocked the USB A connector's 5V pin with electrical tape. I am now using an iFi Audio iDefender, which severs the 5V feed and helps with grounding if you have a problem (I don't). This is an inexpensive tweak and well worth a try.

 

PS My last CD player was another Lakewest design, the Cambridge IsoMagic/DacMagic. John helped me upgrade the power supply to amazing effect. I'm patiently waiting for the FDAC.

[left channel]

49 minutes ago, audiobomber said:

I have an Audiolab 8200CD, also designed by John Westlake. The unit has internal power supplies, does not use power from the USB cable. I found that blocking the USB 5V pin improves the sound, making voices in particular sound more cohesive. This may be worth a try with the Pro-Ject box.

 

Initially I just blocked the USB A connector's 5V pin with electrical tape. I am now using an iFi Audio iDefender, which severs the 5V feed and helps with grounding if you have a problem (I don't). This is an inexpensive tweak and well worth a try.

 

PS My last CD player was another Lakewest design, the Cambridge IsoMagic/DacMagic. John helped me upgrade the power supply to amazing effect. I'm patiently waiting for the FDAC.

 

@audiobomber @RicaNeaga unfortunately the S2D does not work that way. It seems to require power on the USB line just to detect the existence of that input, even when it has external power.

[RicaNeaga]

1 hour ago, MagnusH said:

If playing from a PC I would also suggest some USB tweak, or use optical. To much electronic noise coming from the PC over a straight USB connection (I use mine with toslink).

What USB tweaks? Can you please be more specific?

 

1 hour ago, left channel said:

But to meet John's requirements, I did upgrade to an $11 linear wall-wart. Others have selected higher-end linear PSUs from China and elsewhere, and are very happy with them.

Whatever you choose, I've found that using external power provides the most notable improvement, with USB anti-jitter etc. cleaners providing a small additional boost in sound quality.

USB anti-jitter? Is iFi Audio iDefender 3.0 enough or do you have other recommendations?

 

And ok, after your recommendations I'll go straight to buying a linear power supply, however I have no clue on which to choose in the 50 - 150 euro price bracket. I live in Europe / EU, and this one can be found in France, and also on ebay found several options (this, this, this, this and this). Do I have to look at a certain specification (like ''regulated'') at that linear power supply? Can someone point to a specific model that is the best option (preferably to cost ~ 100 euro)?

 

Thanks again and sorry for the noob questions :D 

[franz159]

I have the audiophonics, powering a Raspberry and an Allo Boss Dac separately.

Very happy about the results!

[RicaNeaga]

Thanks. After some digging, I found out that in this price range one of the differences is the transformer used - a green chinese made one, a blue Talema (imported to China from the Czech Republic) one (that on ebay is even considered as a direct replacement for the green one by some chinese sellers for a 15$ extra), and probably the best option is the toroidal transformer (like some high end DACs have inside). The Audiophonics seems like a chinese rebrand, with a chinese transformer (green) inside.

 

I think I'm going to buy one with a Talema blue transformer, I don't want to spend extra for the toroidal one, since you consider even the green transformer to produce (in a certain board) an ok result, however I cannot decide on the power needed - there are 15W versions (that are capable of 2.0A / 2.1A) or 25W versions in that price range, that are capable of 3.5A / 4A for the 5V line.

 

Does the Pro-Ject Pre Box S2 Digital benefit somehow from the higher amperage on the 5V line? Probably not, since the default DC included in the box is a 1A one, however I just wanted to be sure. Thanks again  

[Taz777]

44 minutes ago, RicaNeaga said:

Thanks. After some digging, I found out that in this price range one of the differences is the transformer used - a green chinese made one, a blue Talema (imported to China from the Czech Republic) one (that on ebay is even considered as a direct replacement for the green one by some chinese sellers for a 15$ extra), and probably the best option is the toroidal transformer (like some high end DACs have inside). The Audiophonics seems like a chinese rebrand, with a chinese transformer (green) inside.

 

I think I'm going to buy one with a Talema blue transformer, I don't want to spend extra for the toroidal one, since you consider even the green transformer to produce (in a certain board) an ok result, however I cannot decide on the power needed - there are 15W versions (that are capable of 2.0A / 2.1A) or 25W versions in that price range, that are capable of 3.5A / 4A for the 5V line.

 

Does the Pro-Ject Pre Box S2 Digital benefit somehow from the higher amperage on the 5V line? Probably not, since the default DC included in the box is a 1A one, however I just wanted to be sure. Thanks again  

 

I have a third Chinese-made Talema (blue) 25VA based LPS on the way. Very happy with the two that I already have.

 

The amperage will be fine as long as it equals or exceeds 1A. I would go for the 25VA (25W) one as that will have decent reserves of current. The current capability is what the LPS could provide to the equipment that it powers. It is not necessarily what will be supplied. getting the 25VA one may mean that the LPS runs a bit cooler and you may have options to use it in the future for equipment that needs a bit more power. However, you'll be fine with the 15W one too.

 

Be aware that on eBay, you sometimes have to send a message to the seller immediately after the purchase stating the input voltage you require (e.g. 110V or 230V reflecting the mains voltage in your country) and the output voltage (e.g. 5V, 9V, 15V etc), so read the advert carefully!

 

You may also want to check that you already have the correct cable to connect your DAC to the LPS. Some of the Chinese LPS's that I've seen come with a 5.5m (2.1mm centre) lead that suits DACs like a Topping D50, DX3 Pro, etc.

 

The Pre Box S2D needs a micro-USB at the external 5V power input jack. Check that the LPS has a 5V USB output jack - some don't. If it does then you can use a standard USB A to micro-USB cable. If it doesn't then you'll need to get a cable with the correct connectors on each end (i.e. the correct connector for the LPS 5V output jack and a micro-USB connector for the S2D).

 

One final thing to bear in mind is that the LPS's from the Chinese sellers on eBay rarely come with a mains cable (i.e. am IEC 'kettle' cable power lead). You may have one lying around at home.

 

I bought several of item number 273289214752 and this cable is superb for my Chinese-made LPS's. It's fairly short at 1.5m, soft and flexible, and a good balance in terms of price between a cheap IEC cable expensive 'audiophile' ones.

[arcman]

If one purchased the power BOX s2, how would one hook to the Prebox. Does the Poer Box come with cables?

[left channel]

1 hour ago, arcman said:

If one purchased the power BOX s2, how would one hook to the Prebox. Does the Poer Box come with cables?

 

It would connect to the the 5V USB outlet on the Power Box. You'll have to ask a dealer or Pro-Ject what cables come with the Power Box — the website, data sheet, and manual do not offer that information — but a male USB A to male micro USB cable is easy enough to find.

[RicaNeaga]

10 hours ago, Taz777 said:

You may also want to check that you already have the correct cable to connect your DAC to the LPS. Some of the Chinese LPS's that I've seen come with a 5.5m (2.1mm centre) lead that suits DACs like a Topping D50, DX3 Pro, etc.

 

The Pre Box S2D needs a micro-USB at the external 5V power input jack. Check that the LPS has a 5V USB output jack - some don't. If it does then you can use a standard USB A to micro-USB cable. If it doesn't then you'll need to get a cable with the correct connectors on each end (i.e. the correct connector for the LPS 5V output jack and a micro-USB connector for the S2D).

 

Thanks, although there's an option like this one - MicroUSB to 5.5/2.1mm DC Barrel Jack Adapter - I'm inclined to buy this LPS (79$ toroidal with micro-USB power cable) instead of probably the best one (on the long term, 99$, suitable for any upgrades to any other DAC) and also instead of probably the wisest choice (57$, cheapest talema LPS also with USB).

 

I'm going to think for it another day, maybe you'll have different opinions, and then I'm going to order one of those chinese LPSes.

 

Also, since I have active monitors that are very sensitive to any electrical noise, most likely I'm going to use iDefender3.0 directly linked also to the LPS, so the DAC will be fed only via the USB port (with both data and power), I think this would be the best option, however I'll also test the LPS linked directly to the DAC.

 

In the end, I'm also considering to buy only for testing iPurifier3 (and most likely just return it before 30 days have passed since its acquisition), probably only iDefender would make a day/night difference, but I'm very curious if the sound would  really be ''cleaner'' also with iPurifier (the complete link would be PC - iDefender & LPS - good USB cable - iPurifier - DAC). Hopefully in about a month I'll solve this puzzle and you can be sure I'll write here my findings.

 

Thanks again and feel free to judge those LPSes above  

[audiobomber]

48 minutes ago, RicaNeaga said:

PC - iDefender & LPS - good USB cable - iPurifier - DAC 

iFi recommend a USB 3.0 cable with the iDefender and iPurifier3. I'm using a cheap Belkin USB 3.0 cable in my headphone system with an iPurifier2.and Korg DAC and it sounds very good. IME, the iFi treatments are system dependent, so make sure you listen critically after break-in. 

 

"The better, faster USB3.0 connection equals even better sound quality."

https://ifi-audio.com/products/idefender3-0/

 

 

 

[RicaNeaga]

7 hours ago, audiobomber said:

iFi recommend a USB 3.0 cable with the iDefender and iPurifier3. I'm using a cheap Belkin USB 3.0 cable in my headphone system with an iPurifier2.and Korg DAC and it sounds very good. IME, the iFi treatments are system dependent, so make sure you listen critically after break-in. 

"The better, faster USB3.0 connection equals even better sound quality."

https://ifi-audio.com/products/idefender3-0/

 

Thanks, however the iPurifier3 has only ''USB2.0 High Speed output port''. Also the DAC has USB2.0 ports. So is really USB 3.0 a must in my case?

 

LE: Also found two cables available in my country - KáCsa KCS-UA-B and Roland RCC-3-UAUB.

[free0704]

Hello. With connected Pro-Ject Pre Box S2 Digital windows 10 does not go into idle mode and the monitor does not turn off. Are there any solutions to this issue?
 

[Taz777]

15 hours ago, RicaNeaga said:

 

Thanks, although there's an option like this one - MicroUSB to 5.5/2.1mm DC Barrel Jack Adapter - I'm inclined to buy this LPS (79$ toroidal with micro-USB power cable) instead of probably the best one (on the long term, 99$, suitable for any upgrades to any other DAC) and also instead of probably the wisest choice (57$, cheapest talema LPS also with USB).

 

I'm going to think for it another day, maybe you'll have different opinions, and then I'm going to order one of those chinese LPSes.

 

Also, since I have active monitors that are very sensitive to any electrical noise, most likely I'm going to use iDefender3.0 directly linked also to the LPS, so the DAC will be fed only via the USB port (with both data and power), I think this would be the best option, however I'll also test the LPS linked directly to the DAC.

 

In the end, I'm also considering to buy only for testing iPurifier3 (and most likely just return it before 30 days have passed since its acquisition), probably only iDefender would make a day/night difference, but I'm very curious if the sound would  really be ''cleaner'' also with iPurifier (the complete link would be PC - iDefender & LPS - good USB cable - iPurifier - DAC). Hopefully in about a month I'll solve this puzzle and you can be sure I'll write here my findings.

 

Thanks again and feel free to judge those LPSes above  

 

The TeraDak one should be fine - it uses a different transformer depending on your country's mains voltage. I just don't like the way it's put together internally, but that's probably just a cosmetic thing.

 

The Talema one looks good (your 'wisest choice'). It's also usefully has two 5V outputs so makes connectivity a little easier.

 

The Nobsound one is essentially a bench power supply with variable voltage. Might be useful if you want to power DACs with a different inout voltage in the future, but I'd be petrified of accidentally turning the voltage knob and blowing the DAC!

[RicaNeaga]

14 minutes ago, Taz777 said:

 

The TeraDak one should be fine - it uses a different transformer depending on your country's mains voltage. I just don't like the way it's put together internally, but that's probably just a cosmetic thing.

 

Yes, I also don't ike it, however for me (Europe - 230V) it comes with a toroidal transformer, that probably suffices any other board design flaw/ capacitor's brand etc

 

Thanks again

[audiobomber]

8 hours ago, RicaNeaga said:

 

Thanks, however the iPurifier3 has only ''USB2.0 High Speed output port''. Also the DAC has USB2.0 ports. So is really USB 3.0 a must in my case?

 

LE: Also found two cables available in my country - KáCsa KCS-UA-B and Roland RCC-3-UAUB.

The iPurifier3 has USB 2.0 output but USB 3.0 input. The 2.0 end connects to the DAC, the 3.0 end connects to the cable. I don't know the cables you linked. Roland is a well-respected pro audio brand but the cable you have shown is not USB 3.0. iFi say the speed of the 3.0 connection provides better noise processing. 

 

I bought this cable. I was very pleasantly surprised by the sound quality, warm and smooth. It may be available from Amazon in your country. At this price, it's worth a try?

 https://www.amazon.com/gp/product/B003IRLYG6/ref=ppx_yo_dt_b_asin_title_o05__o00_s00?ie=UTF8&psc=1

 

The Belkin replaced a dual head USB 2.0 cable, with power leg fed by a battery supply. This setup is much more convenient than a battery I needed to recharge, and even better sound quality. The freebie USB 3.0 cable that iFi supplied with my iOne DAC did not sound very good, so it's not just the 3.0 spec that matters.

[left channel]

8 hours ago, free0704 said:

Hello. With connected Pro-Ject Pre Box S2 Digital windows 10 does not go into idle mode and the monitor does not turn off. Are there any solutions to this issue?
 

 

That is related to a Windows 10 setting. I can't remember what fixes it, but try turning off "fast startup". If not, try other power settings. Or try using a different USB port on the same machine.

[Mark Dirac]

I recall someone saying that this annoyance is caused by Pro-Ject's driver for the IR HID stuff, that is, for Pro-Ject's W10 driver which handles the S2D receiving IR commands from its remote control and then sending those commands to the PC over USB. This person claimed that by disabling the driver (listed as "HID") in W10's device manager, that the annoyance is solved. (Although, of course, the remote control will then cease controlling the PC.)

[left channel]

1 hour ago, Mark Dirac said:

I recall someone saying that this annoyance is caused by Pro-Ject's driver for the IR HID stuff, that is, for Pro-Ject's W10 driver which handles the S2D receiving IR commands from its remote control and then sending those commands to the PC over USB. This person claimed that by disabling the driver (listed as "HID") in W10's device manager, that the annoyance is solved. (Although, of course, the remote control will then cease controlling the PC.)

 

I would try that if nothing else works. Most need not go that far.

[free0704]

1 hour ago, Mark Dirac said:

I recall someone saying that this annoyance is caused by Pro-Ject's driver for the IR HID stuff, that is, for Pro-Ject's W10 driver which handles the S2D receiving IR commands from its remote control and then sending those commands to the PC over USB. This person claimed that by disabling the driver (listed as "HID") in W10's device manager, that the annoyance is solved. (Although, of course, the remote control will then cease controlling the PC.)

Yes, I found the HID device, which belongs to Pro-Ject, turned it off, the monitor now goes out. The console now controls only the volume. Thank!

[left channel]

 

3 minutes ago, free0704 said:

Yes, I found the HID device, which belongs to Pro-Ject, turned it off, the monitor now goes out. The console now controls only the volume. Thank!

 

Crazy that one would have to disable such a key feature of the product. If there is no other way to fix this on some systems, Pro-Ject should issue a driver update.

[free0704]

3 минуты назад левый канал сказал:

 

 

Сумасшедший, что нужно было бы отключить такую ключевую функцию продукта. Pro-Ject должен выпустить обновление драйвера.

I have a foobar that is completely controlled from the smartphone. The main problem is found, it is always possible to turn the remote control back on.

[Mark Dirac]

I reckon that in the last few days we've been discussing three very distinct possible improvements to the S2D:

1. Noise injected via the power USB
2. Noise injected via the signal USB
3. Jitter in the (USB) signal

I believe that the S2D handles (2) and (3) particularly well, and it may be difficult to achieve improvements here. A large number of enthusiasts made £50 contributions to John Westlake to develop new techniques for controlling jitter, and John has proudly announced that many of the  developments were incorporated into the S2D.

 

From comments John has made over the years, I believe that his only concern with switching power supplies is not noise generated by the switching process, but common mode noise loops arising from the RFI suppression capacitors which are fitted to switching PSUs to control their EMI tendencies. Linear supplies do not need these capacitors. 

 

I have always suspected (no evidence) that this is why the manual confusingly talks about not using the supplied wall-wart when connected via (signal) USB - because if the S2D is connected to its PC/phone/streamer via USB, then there is more opportunity for common mode noise loops though the capacitors in the wall-wart, than there would be using optical or co-ax.

 

 

 

[RicaNeaga]

2 minutes ago, Mark Dirac said:

I reckon that in the last few days we've been discussing three very distinct possible improvements to the S2D:

1. Noise injected via the power USB
2. Noise injected via the signal USB
3. Jitter in the (USB) signal

I believe that the S2D handles (2) and (3) particularly well, and it may be difficult to achieve improvements here. A large number of enthusiasts made £50 contributions to John Westlake to develop new techniques for controlling jitter, and John has proudly announced that many of the  developments were incorporated into the S2D.

 

From comments John has made over the years, I believe that his only concern with switching power supplies is not noise generated by the switching process, but common mode noise loops arising from the RFI suppression capacitors which are fitted to switching PSUs to control their EMI tendencies. Linear supplies do not need these capacitors. 

 

I have always suspected (no evidence) that this is why the manual confusingly talks about not using the supplied wall-wart when connected via (signal) USB - because if the S2D is connected to its PC/phone/streamer via USB, then there is more opportunity for common mode noise loops though the capacitors in the wall-wart, than there would be using optical or co-ax.

 

So, related to the discussion above, do you think that for this DAC only the iDefender3.0 can give obvious results (like in my case, when using active studio monitors and very likely problematic power supply), while the iPurifier3 can have less ''audibly'' results? Thanks