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

[[email protected]]

11 minutes ago, elan120 said:

One question about using the heat sink on your regulator, how well in terms of thermal transfer is your regulator using a heat sink such as what your link show?  I plan to use your regulator in other area where heat sink is needed, but not sure how well in thermal transfer is your regulator with the back side of PCB against heat sink with thermal compound in between

Hi
thank you for your feedback, thermal resistance for Rth for the board itself ~30C/W (Junction-to-case + PCB + Insulator), to calculate Junction temp you need to add Rth(H-A) Heatsink-to ambient. If no heatsink - you can consider copper pour as a heatsink with Rth(H-A) ~ 40C/W

you can use silicon rubber pad Insulator i ship with the board (you can not attach heatsink directly due to Vin/Vout traces at the back), thermal compound does not make big sense (may be few degree), 2oz copper PCB used to spread heat more efficiently.

 

[roberto2]

31 minutes ago, elan120 said:

Hi @[email protected],

 

Good to see you dropping by here.  I am currently using your regulator in my SU-1 to send 5VDC to the main board with outstanding result...

 

Hi elan120,

but you told me it was not good at this place...!

Ar you using this one? The seller is named Alexey. I don't understand...

http://www.ebay.com/itm/LT3045-Ultralow-noise-0-8-VRMS-LDO-linear-regulators-0V-15V-0-5A-78xx-Layout-/252880467320?hash=item3ae0d9b578:g:jSMAAOSwol5YyCO1

[elan120]

11 minutes ago, [email protected] said:

Hi
thank you for your feedback, thermal resistance for Rth for the board itself ~30C/W (Junction-to-case + PCB + Insulator), to calculate Junction temp you need to add Rth(H-A) Heatsink-to ambient. If no heatsink - you can consider copper pour as a heatsink with Rth(H-A) ~ 40C/W

you can use silicon rubber pad Insulator i ship with the board (you can not attach heatsink directly due to Vin/Vout traces at the back), thermal compound does not make big sense (may be few degree), 2oz copper PCB used to spread heat more efficiently.

 

Hi @[email protected],

 

Thank you for the follow up information.  That is helpful.

 

 

 

11 minutes ago, roberto2 said:

Hi elan120,

but you told me it was not good at this place...!

Ar you using this one? The seller is named Alexey. I don't understand...

http://www.ebay.com/itm/LT3045-Ultralow-noise-0-8-VRMS-LDO-linear-regulators-0V-15V-0-5A-78xx-Layout-/252880467320?hash=item3ae0d9b578:g:jSMAAOSwol5YyCO1

 

Hi @roberto2,  I use this regulator in different configuration.  In my case, I removed the stock power supply by using Uptone LPS-1 feeding 7VDC to SU-1, and then using Alexey's regulator to drop the voltage from 7V to 5V feeding the SU-1 main board..

 

In terms of regulator to use, by having more thermal transfer data from him directly, it can be a replacement part to consider, but make sure to follow his instruction in heat sink and application method.

 

My experience with this regulator is quite good, and will be replacing the Belleson 3.3V I currently using on the main board to make a comparison.

[roberto2]

1 minute ago, elan120 said:

Hi @roberto2,  I use this regulator in different configuration.  In my case, I removed the stock power supply by using Uptone LPS-1 feeding 7VDC to SU-1, and then using Alexey's regulator to drop the voltage from 7V to 5V feeding the SU-1 main board..

 

In terms of regulator to use, by having more thermal transfer data from him directly, it can be a replacement part to consider, but make sure to follow his instruction in heat sink and application method.

 

My experience with this regulator is quite good, and will be replacing the Belleson 3.3V I currently using on the main board to make a comparison.

OK now I understand much better!

About the heat sink, does the stock Singxer SU-1 heat sink would be ok for that regulator?

[elan120]

Just now, roberto2 said:

OK now I understand much better!

About the heat sink, does the stock Singxer SU-1 heat sink would be ok for that regulator?

From overall heat transfer standpoint, yes, that will be more than enough, but you will need to check if mounting and hole location will be a match.  Since I don't have my unit here at work, if you need me to measure it, it will have to be later this evening in US.

[scan80269]

3 minutes ago, roberto2 said:

OK now I understand much better!

About the heat sink, does the stock Singxer SU-1 heat sink would be ok for that regulator?

Don't forget to electrically insulate that heat sink from the new regulator.  Standard TO-220 insulation components like plastic washer and thermally conductive silicone pad or mica sheet should do the trick.  The heatsink on the stock SU-1 linear power supply is grounded, so electrical insulation for the regulator is a must.

 

[paulinus]

1 hour ago, elan120 said:

They connect the transformer in series, which drove the voltage up to 14V output before the bridge rectifier.

I think you are wrong, or there are different PCB revisions.

Let us take a look on transformer (pic.1)

I marked pins from right to left. So, in case of series connection, pins 2 and 3 must be connected together.

Now, let us take a look on the other side (pic.2)

As you could see pins 2 and 4 are connected together. It is hard to see, but on component side pins 1 and 3 are connected together as well. 

Looks like secondaries connected in parallel.

[elan120]

1 minute ago, paulinus said:

I think you are wrong, or there are different PCB revisions.

Let us take a look on transformer (pic.1)

I marked pins from right to left. So, in case of series connection, pins 2 and 3 must be connected together.

Now, let us take a look on the other side (pic.2)

As you could see pins 2 and 4 are connected together. It is hard to see, but on component side pins 1 and 3 are connected together as well. 

Looks like secondaries connected in parallel.

Not sure whether there are different PCB versions, but my reading was measured from the regulator input pin with 12.3VDC, and the output show 4.97VDC.

[[email protected]]

22 minutes ago, scan80269 said:

Don't forget to electrically insulate that heat sink from the new regulator.  Standard TO-220 insulation components like plastic washer and thermally conductive silicone pad or mica sheet should do the trick.  The heatsink on the stock SU-1 linear power supply is grounded, so electrical insulation for the regulator is a must.

Few comments
1. Standard TO-220 insulation does not work (mounting hole 3.1mm dia), BUT you can use M3 screw directly, because heatsink mounting hole DC grounded. You need to use insulator only to protect Vin/out traces (but not screw)

2. If you are using existing heatsink please be sure that it does not touch headers (soldered at the back). If radiators mounting hole placed upto 18mm from heatsink bottom - it can be mounted safely, if more - need to use some tricks

 

P.S. And sorry - english is not my native language 

[[email protected]]

14 minutes ago, elan120 said:

but my reading was measured from the regulator input pin with 12.3VDC

how did you measure - with loads or without?

[elan120]

3 minutes ago, [email protected] said:

how did you measure - with loads or without?

With, but low current, only have a 500ohm resistor on hand at the time.

[FIndingit]

I think replacing the caps is a real chore and the danger of ruining the board bigger. Replacing the regulators is easy compared to that. Not to mention that it is doubful whether the outcome is audible compared to the fine Panasonic fcs already there. 

[T-Bone]

22 hours ago, FIndingit said:

I think replacing the caps is a real chore 

I just got done replacing mine; and you are right.  It's a pain in the *ss.    ....at least it was for someone with my "neophyte" soldering skills.  I'm sure a more skilled tech would have blazed through the job.

 

...but at least I didn't "brick" my SU-1.  It's back in my system now and I'm giving it a listen.  

Since there's no way to listen to the changes back-to-back any listening impression would be based purely on memory.  So I can't say whether new caps make an audible difference or not.  

(unlike the regulator swap whose improvements were very apparent)  

It certainly doesn't sound any worse and I enjoyed the challenge.    

[tboooe]

I am should be receiving my board back today after having the voltage regulator and caps replaced.  A BIG thanks to @Energy for doing this for me.  With my less than "neophyte" soldering skills I would have surely smoked my SU-1.  Its been a week since I last listened to my system so we will see if my music memory allows me to notice any difference.  I am thinking the changes may be minor since I already had the LPS-1 powering the SU-1.  

[T-Bone]

2 minutes ago, tboooe said:

Its been a week since I last listened to my system so we will see if my music memory allows me to notice any difference.  I am thinking the changes may be minor since I already had the LPS-1 powering the SU-1.  

I've got the LPS-1 powering my Singxer too and would wager a few bucks that you'll hear an improvement.

In my system the Sparko Labs regulator made a nice change, not as big as the LPS-1, but an improvement.  
I don't think you'll have to "listen hard" to notice the difference.   Enjoy!  

[enser]

34 minutes ago, T-Bone said:

I just got done replacing mine; and you are right.  It's a pain in the *ss.    ....at least it was for someone with my "neophyte" soldering skills.  I'm sure a more skilled tech would have blazed through the job.

 

...but at least I didn't "brick" my SU-1.  It's back in my system now and I'm giving it a listen.  

Since there's no way to listen to the changes back-to-back any listening impression would be based purely on memory.  So I can't say whether new caps make an audible difference or not.  

(unlike the regulator swap whose improvements were very apparent)  

It certainly doesn't sound any worse and I enjoyed the challenge.    

 

This is a good point. I've had similar experiences replacing things like voltage regulators with massive improvement. Think of how much even the top of the line regs cost versus some top of the line caps or even worse, cables.

[Energy]

I was going to make a comment but @T-Bone pretty much said it all. Easy improvement to hear even with LPS-1.

[tboooe]

For those you thinking about making the internal DC cable for the 5V directly to the SU-1 board, I can confirm that a Canare 4S8 starquad cable will fit the connector.  Its tight but you can solder the pair of wires to each pin and jam them into the housing.  The 4S8 needs to be bent a bit but the SU-1 cover will fit.  Is there any difference at all using the 4S8 starquad over the smaller 4S8 or even just a pair of wires??  Who knows but I sure feel pretty studly knowing I have that thick cable in there!

[Energy]

Surprising you got the 4S8 to fit. I used a 4S6 for @bluesaint's SU-1 and it barely went in. It may be because I had the actual insulation of the wires go into the connector along with a layer of 1/16 heatshrink. I think you're peeling the insulation further back than normal to give it a smaller diameter right? Are you using heatshrink over the tinned soldered wires?

[tboooe]

14 minutes ago, Energy said:

Surprising you got the 4S8 to fit. I used a 4S6 for @bluesaint's SU-1 and it barely went in. It may be because I had the actual insulation of the wires go into the connector along with a layer of 1/16 heatshrink. I think you're peeling the insulation further back than normal to give it a smaller diameter right? Are you using heatshrink over the tinned soldered wires?

The housing will accept a pair of 4S8 wire with insulation if they are stacked vertically.  It's a tight fit but it will work.  I did not use additional heatshrinking though I did place a piece of insulation between the pair of wires right at the housing just in case.  

[Energy]

OH! No wonder... I recall I had mine more horizontally positioned. Darn...

[tboooe]

First of all, a HUGE thank you to @Energy for helping to mod my SU-1 with a new regulator and caps.  I've been listening to my system for a few hours now and it sounds amazing!  Based on memory, it seems these mods have increased the soundstage quite a bit.  The music now envelopes more of my listening space both vertically and horizontally.  The other big change which is harder to quantify is that the music is more organic, more real sounding.  Perhaps this is down to hearing more detail or a lower noise floor or placebo???  Regardless, my enjoyment of music has never been higher.  I have an IsoRegen coming and i really wonder how things can sound better.  

[Energy]

You're welcome @tboooe. The expanded sound stage and deafening quietness sure helps to make each produced sound that much more intimate and inviting for the listener.

 

By the way, I had some time to kill today and read up on the Linear Technologies LT3045 LDO Regulator and have some things to say that will clarify on how it performs opposed to the Sparkos Labs SS1117.

 

OUTPUT NOISE: (the lower the better)

At 3.3V the LT3045 is specified to 2.8μV (output noise) whereas the SS1117 is 3.2μV.

The LT3045 is only specified/advertised at 0.8μV if you are using voltages 1.3V or below.

 

RIPPLE REJECTION: (the higher the better)

At 120Hz the LT3045 is specified 117dB (input rejection) whereas the SS1117 is 124dB.

At 10KHz the LT3045 is specified 90dB (input rejection) whereas the SS1117 is 108dB.

 

Having said that, If you currently have the SS1117 Installed, It wouldn't make a lot of sense to replace it with the LT3045. Even though it gains a hair in output noise, it loses in input rejection. If one were to start the mod from scratch, I would recommend the Linear Technologies LT3045 for $22.95 as it's half the price and as better load regulation as well as spot noise. But just to say, I doubt you will be able to hear a difference between the two..

 

Cheers,

Timothy

[pkane2001]

I'm happy to report that I have now a fully super-regulated SU-1

 

I replaced the power supply regulator with Sparkos Labs SS7805 regulator, as well as the supply capacitors with Panasonic FR series. As you may recall, I previously replaced the main board 3.3v regulator with Sparkos SS1117xx.

 

Adding the 5v super regulator resulted in an obvious improvement. Obvious compared to the iFi 5v supply I was using previously. The only way I can describe the change is that the music is now more immersive. The sound stage feels organic and natural, all around me, with more precise soundstage positions without harshness or other artifacts. Very, very nice! In quantitative terms, I would rate this as about 10% improvement in SQ over what I had with the iFi supply and the Sparkos 3.3v regulator, so definitely worth the $60 invested.

 

Installing the new capacitors was pretty easy. Removing the old 5v regulator was quite a bit more challenging, as it was soldered on both sides of the board and all the way through. In the end, I had to remove the heat sink and heat it from above the board to be able to desolder it. Took me about 5 minutes to remove and replace all four capacitors, and another 20 minutes to just unsolder the regulator. Installing Sparkos was pretty easy, I just had to be careful to align the hight with the heatsink before fixing it in place. I put a silicone insulator in between the regulator and the heat sink, as per instructions. 

 

Oh, and I did twist the stock DC cable, although I really didn't believe it would make any audible difference

 

Here's the original power supply with stock regulator and capacitors. Note a drop of solder on top of one of them.  I didn't do it, I swear!

 

 

And here's the supply with changed capacitors and Sparkos regulator, installed in SU-1. The smaller value capacitor had to be bent a little away from Sparkos, as it was nearly touching it:

 

 

I'm very pleased with the changes and am now enjoying anew some of the music that I heard many times before. I did have about 4 hours of warm/up break-in time for the new components before trying it out.

[elan120]

14 minutes ago, pkane2001 said:

I'm happy to report that I have now a fully super-regulated SU-1

 

Outstanding job!  Good to know the improvement over the ifi power supply.