My (very) mini review of the Singxer SU-1 DDC

[sig8]

I have some questions about upgrading SU-1 (I bought my unit from Tim):

 

1. I am already powering the main board with LPS-1 (SU-1 PS is completely by-passed, no 120v to SU-1).

2. I have second LPS-1 powering USB connected to SU-1 (I have a W4S Recovery between PC and SU-1, and I power W4S with LPS-1 #2). I do not think I need to upgrade the power supply, but I might be wrong.

3. What are the other upgrades? Who can do it? I don't think my soldering/unsoldering skills are up to it, based on what I read here. Is it a kit from Tim and/or you need to send the unit to Tim.

 

Thanks.

[enser]

Short of discrete voltage regulators I'd be hard pressed to think of any more needed changes for good power...

[elan120]

12 minutes ago, sig8 said:

I have some questions about upgrading SU-1 (I bought my unit from Tim):

 

1. I am already powering the main board with LPS-1 (SU-1 PS is completely by-passed, no 120v to SU-1).

2. I have second LPS-1 powering USB connected to SU-1 (I have a W4S Recovery between PC and SU-1, and I power W4S with LPS-1 #2). I do not think I need to upgrade the power supply, but I might be wrong.

3. What are the other upgrades? Who can do it? I don't think my soldering/unsoldering skills are up to it, based on what I read here. Is it a kit from Tim and/or you need to send the unit to Tim.

 

Thanks.

I have done "1." above short while ago and was very pleased with the result, and then couple weeks later, decided to do "3." by replacing the 3.3V voltage regulator (LD1086) and the 5 large electrolytic caps (will change again to better suited low ESR caps this weekend) on the main board, and liked the result even more.  While waiting for the new ISORegen/LPS-1 to be delivered in order to insert it in front of SU-1 (your W4S location), I added a 5V voltage regulator while upgrading the 5V internal cable that goes from blank plate (LPS-1 input) to main board, and changed the LPS-1 output from 5V to 7V as something to play with, and liked the result again.  My upcoming mod plan in addition to replacing the 5 caps again, will be a different 3.3V voltage regulator just to see what difference that will make.  These are the steps I took at this point hopefully there are some ideas for you to try.

 

The main board voltage regulator and the electrolytic capacitors mod have been done by individual owners, myself included, based on the inputs here, but certainly can be done by anyone handy with soldering skills like another member or Tim from Kitsune.

[bluesaint]

Just came back from @Energy 's place and with his help, the voltage regulator and caps were all replaced.  

Don't want to base my feedback on limited listening, but I change on top of my existing LPS-1 mod made an noticeable incremental difference.  oh and @tboooe your board just arrived at his place too hah.

[Ric Schultz]

All connectors suck.  Why don't you hardwire the power supply directly to the pins on the board instead of having a connector on the unit and another cable?  It WILL sound better hardwired.  Connectors add noise and distortion. 

[Energy]

1 hour ago, Ric Schultz said:

All connectors suck.  Why don't you hardwire the power supply directly to the pins on the board instead of having a connector on the unit and another cable?  It WILL sound better hardwired.  Connectors add noise and distortion. 

 

Why don't we just skip the DC input connector and hardwire it into the board.

Or hardwire our cables directly into our headphone's drivers.

Or bring the circuit breaker into our listening room.

 

Because it's not convenient. 

 

If he has plans on selling his SU-1 in the future, switching back to the stock power supply won't be as difficult when using modular cables. As long as the DC waveform is precise and current is correctly delivered, then I can't see why a soldered connection will any sound better.

 

Yes, multiple connections do add noise similar to what happens within metals such as copper that isn't smelted into a uniform crystal. These multiple pieces of metal known as grains are all condensed into one solid looking structure that we all see are actually only partially touching and have empty spaces (boundaries) between them filled with impurities (such as gases). These boundaries do produce capacitative charge and discharge which can translate to distortion. This part of the circuit however is not sensitive to contact fluctuations. If for example one were to use a connector or socket for certain areas like regulators or oscillators then yes, it may cause oscillation and tamper with performance in which case direct soldering will be more ideal.

 

And finally, like I do say with pretty much every subjective topic, if you want a peace of mind and can personally hear a difference, go for it.

 

Cheers,

Timothy

[granosalis]

I'm going to replace the stock voltage regulator with the Belleson Superpower SPZ17. I have already replaced all the capacitors and power supply is external using Bel Canto VBS1 and SBooster ulltra 5V as filter. 

Look forward to see the difference with the new VR.

[granosalis]

I can not believe in my ears. The difference is so obvious, no doubt at all.
The Belleson Voltage regulator is an impressive dynamic ignition to the system. Bass extension and artculation is also incredibly improved.
This is the most effective - single electronic component mod - I ever heard. 

 

Ciao,

Giuseppe

[Energy]

I'm glad you liked it. 

 

But why are your capacitors like that? Having long leads is not recommended especially for (and nearing) discrete voltage regulators. My best guess is that you were trying to use "audiophile" capacitors for a DIGITAL circuit and what looks like Nichicon KZ. 

 

Higher material composition capacitors work best in ANALOG circuitry. Digital circuits on the other hand work better with low ESR capacitors (such as solid type polymer) as it provides quicker charge/discharge, lower output ripple, stability for power control loops, etc. The circuit only calls for higher ESR in various concerns such as regulator stability but other than that, you're more likely degrading more than upgrading your unit. From a technical standpoint I reckon the stock Panasonic FC would perform better in this circuit than the current KZ for two reasons.

 

1. The Panasonic FC should already have lower ESR than the KZ

2. Adding additional length to leads increases resistance (ESR) 

 

Σ₪ergψ 

Σ₪ergψ

[granosalis]

Ciao Energy,

Thanks for the clarification. I'm not a technician so I can't comment. The improvement from the stock capacitors are evidente (wa no name capacitors, not Panasonic in my very ealry model) and I like the analog and relaxed effect that now my SU1 have. 

[ted_b]

I am noticing that all these mods to the SU-1 seem to have immediate sq effect, all positive.  Are all you guys saying that there is no break-in for these new caps, regulators, etc?  That they immediately sound great?  I ask cuz this flies in the face of what I have experienced with any new mod or introduction of new parts in the signal path over my audio life.  Now I am not saying that you need to take a step back before you go two steps forward, but simply saying that there is a period of time where the real potential is not yet realized.  Kind like a new remodel job at home....you can clearly see the benefits but the place smells of paint for a few days (not the best analogy, sorry).

 

For example, my recently upgraded KTE SU-1.  The detail retrieval, speed, tautness and overall clarity is quite amazing, but there is an ever-decreasing bit of rawness or edginess that will undoubtedly recede to nothing over the next 100-150 hours or so.  It's always been this way, and yet I have not heard ONE EXAMPLE of that in these mod stories.  Weird.

[pkane2001]

29 minutes ago, ted_b said:

Are all you guys saying that there is no break-in for these new caps, regulators, etc?  That they immediately sound great? 

 

Speaking for myself, I'm really not sure why a voltage regulator or an external power supply would need a prolonged break in period. Out of force of habit, I usually leave the components on for a period of time before listening, usually about an hour to give the equipment a chance to reach nominal operating temperature. This is helped by my amplifiers that really do take 1 hour to warm up, so I have no choice but to wait

 

When I did the regulator mod and connected an outside 5v supply, I did the same thing. The changes were pretty obvious after the first hour. I can't say that I heard the quality of the sound change since then in any significant way.

 

[T-Bone]

4 hours ago, Energy said:

Σ₪ergψ

Now we're getting fancy!  Cool sig 

[scan80269]

4 hours ago, ted_b said:

I am noticing that all these mods to the SU-1 seem to have immediate sq effect, all positive.  Are all you guys saying that there is no break-in for these new caps, regulators, etc?  That they immediately sound great?  I ask cuz this flies in the face of what I have experienced with any new mod or introduction of new parts in the signal path over my audio life.  Now I am not saying that you need to take a step back before you go two steps forward, but simply saying that there is a period of time where the real potential is not yet realized.  Kind like a new remodel job at home....you can clearly see the benefits but the place smells of paint for a few days (not the best analogy, sorry).

 

For example, my recently upgraded KTE SU-1.  The detail retrieval, speed, tautness and overall clarity is quite amazing, but there is an ever-decreasing bit of rawness or edginess that will undoubtedly recede to nothing over the next 100-150 hours or so.  It's always been this way, and yet I have not heard ONE EXAMPLE of that in these mod stories.  Weird.

I don't think people are claiming no incremental SQ improvement with time for these mods, but the step-function jump in SQ immediately after one of these mods (especially the LPS-1 one) is anything but subtle, which is what people are inclined to report.

 

I'm not familiar with the break-in time with conductive polymer capacitors, or at least how these would compare with traditional aluminum electrolytic capacitors.  If folks are hearing incremental SQ step-ups after days or weeks, by all means post a follow-up to this thread.

 

One thing I know about the SU-1 is that the downstream side consumes barely over 0.5W of power, and hardly any component has perceptible heat, so the whole box runs quite cool and the time to reach thermal equilibrium should be a matter of minutes.  That should just about leave capacitor and cable break-in as the factors that can take a bit of time.

 

I'm not quite done with mods for my SU-1, and have only logged a few hours of post-mod listening so far.

 

[bluesaint]

43 minutes ago, scan80269 said:

I don't think people are claiming no incremental SQ improvement with time for these mods, but the step-function jump in SQ immediately after one of these mods (especially the LPS-1 one) is anything but subtle, which is what people are inclined to report.

 

I'm not familiar with the break-in time with conductive polymer capacitors, or at least how these would compare with traditional aluminum electrolytic capacitors.  If folks are hearing incremental SQ step-ups after days or weeks, by all means post a follow-up to this thread.

 

One thing I know about the SU-1 is that the downstream side consumes barely over 0.5W of power, and hardly any component has perceptible heat, so the whole box runs quite cool and the time to reach thermal equilibrium should be a matter of minutes.  That should just about leave capacitor and cable break-in as the factors that can take a bit of time.

 

I'm not quite done with mods for my SU-1, and have only logged a few hours of post-mod listening so far.

 

It will take 90min or so for SU1 to reach thermal equilibrium.  Credit to folks on superbestaudiofriends.  See the following time chart. 

 

 

 

 

[ted_b]

57 minutes ago, scan80269 said:

I don't think people are claiming no incremental SQ improvement with time for these mods, but the step-function jump in SQ immediately after one of these mods (especially the LPS-1 one) is anything but subtle, which is what people are inclined to report.

 

I'm not familiar with the break-in time with conductive polymer capacitors, or at least how these would compare with traditional aluminum electrolytic capacitors.  If folks are hearing incremental SQ step-ups after days or weeks, by all means post a follow-up to this thread.

 

One thing I know about the SU-1 is that the downstream side consumes barely over 0.5W of power, and hardly any component has perceptible heat, so the whole box runs quite cool and the time to reach thermal equilibrium should be a matter of minutes.  That should just about leave capacitor and cable break-in as the factors that can take a bit of time.

 

I'm not quite done with mods for my SU-1, and have only logged a few hours of post-mod listening so far.

 

Each of your points makes perfect sense.  And thanks for the other comments; yes a DDC like the Su-1 should have very little of the classic break-in that a component with an analog stage would likely have...my bad. Thx.

[enser]

9 hours ago, Energy said:

I'm glad you liked it. 

 

But why are your capacitors like that? Having long leads is not recommended especially for (and nearing) discrete voltage regulators. My best guess is that you were trying to use "audiophile" capacitors for a DIGITAL circuit and what looks like Nichicon KZ. 

 

Higher material composition capacitors work best in ANALOG circuitry. Digital circuits on the other hand work better with low ESR capacitors (such as solid type polymer) as it provides quicker charge/discharge, lower output ripple, stability for power control loops, etc. The circuit only calls for higher ESR in various concerns such as regulator stability but other than that, you're more likely degrading more than upgrading your unit. From a technical standpoint I reckon the stock Panasonic FC would perform better in this circuit than the current KZ for two reasons.

 

1. The Panasonic FC should already have lower ESR than the KZ

2. Adding additional length to leads increases resistance (ESR) 

 

Σ₪ergψ 

 

Σ₪ergψ

This is truth... Digital circuitry is super sensitive to parasitic capacitance, lead inductance and voltage losses (of course rfi/emi as well). I'd say in place of electrolytics for bypass/decoupling in digital use, try SMD caps if you can. ESR is almost a non-issue at this point. However, to be more practical in tweaking- in place of KZ, FC etc I would recommend TDK MLCC - C0G (NP0) dielectric (http://www.mouser.com/Search/ProductDetail.aspx?R=FK20C0G1H104Jvirtualkey52130000virtualkey810-FK20C0G1H104J) . These are quite stable across temps and great for this scale of circuit.

[Energy]

10 hours ago, ted_b said:

I am noticing that all these mods to the SU-1 seem to have immediate sq effect, all positive.  Are all you guys saying that there is no break-in for these new caps, regulators, etc?  That they immediately sound great?  I ask cuz this flies in the face of what I have experienced with any new mod or introduction of new parts in the signal path over my audio life.  Now I am not saying that you need to take a step back before you go two steps forward, but simply saying that there is a period of time where the real potential is not yet realized.  Kind like a new remodel job at home....you can clearly see the benefits but the place smells of paint for a few days (not the best analogy, sorry).

 

For example, my recently upgraded KTE SU-1.  The detail retrieval, speed, tautness and overall clarity is quite amazing, but there is an ever-decreasing bit of rawness or edginess that will undoubtedly recede to nothing over the next 100-150 hours or so.  It's always been this way, and yet I have not heard ONE EXAMPLE of that in these mod stories.  Weird.

 

The KTE version is simply a capacitor change and voltage regulator replacement of the LM2940CT-5 (150µV) in the stock power supply. This improves on output noise and ripple rejection ratio and can easily be heard more so than the LD1086 replacement (although it is not far behind).

 

The addition of the UpTone LPS-1 performs similar to the KTE edition in terms of output noise (~4µV) but what it really gains is better speed (electrical bursts) which is important in certain circuits that are ever-changing and calls for quick power. The most important feature of this unit however is it's ability to fully isolate AC mains from it's DC power distribution circuit. This means no AC currents can seeps through the power supply that could potentially affect your SU-1 and make it's way into the DAC even after the signal has been reclocked.

 

Together these three benefits make for an immediate difference over the stock SU-1 or even the KTE.

 

Now since most of the parts on the reclocking side of the SU-1 (after the ISO7641FM digital isolators) run on +3.3V from the LD1086 voltage regulator, it is advised to have one that works optimally as it directly affects the XILINX XC9572XL programmable logic that is tied to the crystal oscillators that controls the clocks. The stock power supply feeds this important regulator with 5V and certain short coming components on the board. Like the stock voltage regulator on the power supply it too does not measure well coming in at 100µV. The discrete version of this regulator everyone here is attempting to replace it with offers lower output noise to those important components and better input rejection from the source voltage and in turn lets the Crystek CCHD-575 oscillators (clocks) work in a domain that less affected by noise thus it is able to produce a signal less affected by jitter.

 

8 hours ago, T-Bone said:

Now we're getting fancy!  Cool sig 

 

You caught me Terry . I was playing around with alt codes at work due to boredom. 

 

5 hours ago, bluesaint said:

It will take 90min or so for SU1 to reach thermal equilibrium.  Credit to folks on superbestaudiofriends.  See the following time chart. 

 

This is awesome to know, thanks for sharing! I'll share something too! 

 

For anyone who wants a Singxer SU-1 for cheap: Singxer SU-1 (For Sale) on Head-Fi

[pkane2001]

1 hour ago, Energy said:

The KTE version is simply a capacitor change and voltage regulator replacement of the LM2940CT-5 (150µV) in the stock power supply.

 

I'm curious: what would be an example of a lower noise replacement for the stock 5v regulator? I still can't bring myself to pay for a power supply that costs as much as SU-1

 

[limniscate]

What I would like to know is whether a molded SU-1 is better than the new SOtM dx-USB Ultra. I've heard the tX-USB Ultra with sMS-200 Ultra and a modded switch, and the improvement was astounding. 

[elan120]

34 minutes ago, pkane2001 said:

 

I'm curious: what would be an example of a lower noise replacement for the stock 5v regulator? I still can't bring myself to pay for a power supply that costs as much as SU-1

 

in addition to Belleson and Sparkos that you already know, I like LT3045 quite a lot.  Get the one with LM78xx pin out and it will be a direct plug-in replacement.

[pkane2001]

1 hour ago, elan120 said:

in addition to Belleson and Sparkos that you already know, I like LT3045 quite a lot.  Get the one with LM78xx pin out and it will be a direct plug-in replacement.

Thanks for these, @elan120! Do you know what current SU-1 draws? The stock regulator is rated for 1A. I would assume that I should pick a replacement rated for 1A, as well.

[elan120]

9 minutes ago, pkane2001 said:

Thanks for these, @elan120! Do you know what current SU-1 draws? The stock regulator is rated for 1A. I would assume that I should pick a replacement rated for 1A, as well.

Hi @pkane2001, I did not measure the current consumption for the entire SU-1, but I did measure the current draw from LPS-1 to 5V main board input, and that is 110~115mA.  The current draw for the 5V main board likely will be less than 150mA, so the 3 choices mentioned earlier, including LT3045 will work just fine.

[LoryWiv]

12 hours ago, bluesaint said:

It will take 90min or so for SU1 to reach thermal equilibrium.  Credit to folks on superbestaudiofriends.  See the following time chart. 

 

 

Seems like this would be a compelling reason to leave the SU-1 on 24/7. Is there any downside to doing so?

[scan80269]

7 hours ago, LoryWiv said:

20 hours ago, bluesaint said:

It will take 90min or so for SU1 to reach thermal equilibrium.  Credit to folks on superbestaudiofriends.  See the following time chart. 

 

 

Seems like this would be a compelling reason to leave the SU-1 on 24/7. Is there any downside to doing so?

There is really no downside.  SU-1 doesn't even run warm.  Its power consumption on the upstream and downstream sides are both in the 0.5W ballpark, and it's one of the least power hungry piece of audio gear I've come across.  Ironically for a stock SU-1, the internal LPS probably wastes more power than all the internal electronics.