[Occam]

If you really want to confuse the evaluation, in your spare time       , you could compare -
both digital RWA and Boulder SB2s
1.  powered by the RWA SLA powersupply
and similarly
2. powered by the Boulder AC powersupply

this would allow an ascessment of the relative merits specific to both the SB2 mods and those to the specific powersupplies.
This would be enlightening for both the public and Vinnie and Wayne themselves. Rereading your post, I believe you may have done 2. already and found them indistinguishable. If so, would you just do 1?

TIA,
Paul

[angelo]

If you really want to confuse the evaluation, in your spare time       , you could compare -
both digital RWA and Boulder SB2s
1.  powered by the RWA SLA powersupply
and similarly
2. powered by the Boulder AC powersupply

this would allow an ascessment of the relative merits specific to both the SB2 mods and those to the specific powersupplies.
This would be enlightening for both the public and Vinnie and Wayne themselves. Rereading your post, I believe you may have done 2. already and found them indistinguishable. If so, would you just do 1?

TIA,
Paul

i think the RWA mod also change the power connector that goes to the SB2 unit, so it might be difficult to just plug the battery supply to the boulder unit, he can make an adapter i guess.

angelo

[jermmd]

The Bolder unit can not be plugged into the RW battery. The battery can be bypassed though so that both units are run off of AC (power conditioned in George's case). My very brief and inadequate comparison of the 2 units at George's house pretty much reflect his views. With the battery bypassed, my initial impression was that the Bolder unit had a slight edge. This was only on one or two songs and the differences were so miniscule that I'm not sure my impression would be reproducible. I wish I had brought my unmodded SB2 so I could have compared that unit to the modded units. I'm told the difference between the unmodded unit and the modded units is much more dramatic.

[zybar]

If you really want to confuse the evaluation, in your spare time       , you could compare -
both digital RWA and Boulder SB2s
1.  powered by the RWA SLA powersupply
and similarly
2. powered by the Boulder AC powersupply

this would allow an ascessment of the relative merits specific to both the SB2 mods and those to the specific powersupplies.
This would be enlightening for both the public and Vinnie and Wayne themselves. Rereading your post, I believe you may have done 2. already and found them indistinguishable. If so, would you just do 1?

TIA,
Paul

Paul,

I can't easily power the Bolder unit via the RWA battery.  The battery connects to the SB2 via a special umbilical cord.

Maybe somebody who is more technically gifted can pick up the ball from this point and perform some battery vs. AC tests? hint...hint

George

[Occam]

Angelo, Jermmd, Zybar - Thanks for the feedback.....

Vinnie - Dang you for frustrating my curiosity!
Thwarted, yet again.

[Vinnie R.]

Angelo, Jermmd, Zybar - Thanks for the feedback.....

Vinnie - Dang you for frustrating my curiosity!
Thwarted, yet again.

George,

Thanks for taking the time to do the comparison and post the results.

All,

The RWA modded SB2 uses a 3-pin plug (switchcraft) to input 12V, 5V, and GND.  

I replace the internal switching power chip (14V) with the 12V from the battery.  

The stock SB2 only has a 5V input.  I'm pretty certain that the Bolder modded SB2 only uses the 5V input as well, so this will make things difficult in just comparing the SB2s with the same power supply.  

Even more exciting would be an SB2 comparison using the analog outputs fed directly into an amp (using the SB2s built-in digital volume control).     I did not implement analog output mods for Zybar.  He is too happy with his TacT  

In any case, I would not be surprised if some prefer Bolder's SB2 to the RWA, and vice versa.  One is bound to have better synergy with the rest of the system than the other, right?  The differences are probably not 'night and day' obvious, but I'm sure can be heard on a decent system.  

Regards,

[Wayne1]

Nice review, George!

I would like to bring out a couple of points.

First, the unit George has from me is "prototype" mod. It is a digital mod only that had a digital isolation transformer installed. I am thinking that maybe some of the "splashiness" in the highs he has mentioned might be caused by the extra wire running to and from the transformer. The wire could be picking up some of the switching power supply noise from the computer section of the SB2. I have offered to remove the transformer and refund the money he paid for it, if George so desires.

The other little point is that he mentions that there is NO difference between the two UNLESS the RWA is running purely on batteries. That means it has to have the charger AND the AC unplugged from the wall. With the charger plugged in, there is no difference.

This could lead some to forget to plug the chager back in the wall and run the SLA battery down. When an SLA battery does run down below a certain voltage enough times, it cannot be recharged. The battery will have to be replaced.

Mgalusha tried out a similar experiment with his BOLDER Cable modded SB2. He happened to have an 12 v SLA hanging around so he hooked it up to his power supply with a switch. He thought the battery position sounded better than the AC. After more experimentation he found the WHEN BOTH THE AC transformer AND THE BATTERY were connected to the switch, the battery sound a bit better. WHEN JUST THE AC or JUST THE BATTERY were connected, he couldn't tell them apart. This seems to indicate the perhaps the magnetic field from the transformer might be having some affect on the total sound with the battery involved.

Bottom line: Both units sound very good. The mods do improve the sound of the SB2 over the stock unit. The Battery powered SB2 might be a bit quieter ONLY WHEN IT IS POWERED DIRECTLY FROM THE BATTERY WITH NOTHING PLUGGED INTO THE AC. The battery powered unit also requires changing the power connector so no comparison can be made with other power supplies.

The AC powered units sound the same all the time. It uses the standard DC connector so it can be compared to other AC power supplies. No worries about forgetting to plug things in or unplug to get the best possible sound.

I have my personal SB2 modded with Silver Slipstream Bybees in the digital and analog outs. This is a very smooth sounding unit. This is an expensive option. mgalusha had me install Sonicap Teflon bypass caps on his SB2. These take a very long time to break-in, but after a month, his is also VERY smooth.

Thanks again George for stepping up and writing your thoughts on the two SB2 with digital only mods. Hopefully we will hear from others who have received the mods and their thoughts on the SB2 from either Vinnie or myself.

If you have never heard one, please try to contact Red Wine Audio or myself for an audition. I really feel it will be worth it you. I am enjoying my music more and stressing far less about gear  

[polishpowerlifter]

Its nice to see 2 competitors be so upright and genntlemanlike in their business.This to me not only speaks volumes of your professionalism but to your personal charachter as well.I personally appreciate this and wish the best to both of you.Im sure others feel the same.

[zybar]

Wayne and Vinnie,

Thanks for the follow-up posts and acting in such a civilized manner.

I agree with Wayne that there are some issues that need to be taken into consideration before going with a battery as your power source.  However, if those are ok with you, I am finding that the performance was just a little bit better.

I will probably take Wayne up on his offer to further tweak my Bolder SB2 in an effort to improve it.

George

[bixby]

Zybar:

thanks for the primer on how the Squeezebox hooks up to your system.  Am I to assume that any old pc running some ripping software and a cd drive  is all you need on the pc end?

I know my PC has some noise issues, like buzzes through the speakers when I move the mouse.  This was only eliminated when I disconnected the audio cable from the CD drive.  Can I get away with not using a fanless, expensive hush type?

And can I use iTunes to rip & create my wav files?  

And then on to how the signal gets to the SB2.  How do you get the signal to it if you are using the ethernet port for connecting to the internet?  Hub or switch?

And no dropped bits or pauses like with Apple's iPod between tracks issues?

Do I give up my search for my next cd player.  I was really thinking about the Modwright Denon or a Droplet, but If I can get this for lots less?  And what about my system in the bedroom.  Wireless to another SB2 there?

I will go to the SB site and could use some pointers to more primers.  Can it be this easy?  I guess the only issue is ripping all my cds.

cheers
bixby

[mgalusha]

I was not going to mention running the Boulder modded SB-2 from a battery but since Wayne brought it up..

My results are as Wayne described. I wanted to know for myself what the difference would be running from a top notch liner supply vs a battery supply. To accomplish this, I added an input jack for the battery and a toggle swtich. The switch breatks the circuit between the diodes and regulator and connects the battery to the regulator and caps.

Toggling between the two I thought there might be a slight difference but it wasn't clear which was better. Out of curiosity I pulled the AC power cord from the power supply and there was a noticeable and repeatable improvement. It is not a large difference but I find it a little smoother and cleaner. This of course raised the question of why? I knew the AC was completely disconnected when I threw the toggle, so why the difference with the power cord removed?

In an effort to learn more, I connected the power supply to the oscilloscope to see if there was any ripple or other noise in the output. Of course on DC there is zero ripple as one would expect. Running from the AC supply there was a barely measureable ripple. And I do mean barely as I had the scope on the 1mV/division setting (as sensitive as it goes) and saw about .5mV of peak to peak ripple. Very low. The big surprise came when running on DC with the power cord connected vs disconnected. When switching to DC from AC the ripple increased to about 2mV p-p, about 4 times higher than when running from the AC supply. Pulling the power cord removed the ripple.

It appeared that the regulator and or the caps were picking up AC via induction from the transformers field. This seems to be cancelled out when being fed from the transfomer, so perhaps the induced current is 180 out of phase with the input to the rectifiers. I did not try and measure this.

The bottom line is that I find it slightly better when running on the battery with the AC disconnected. That said, I do most of my listening via the linear supply and am very happy with the results. I swiped the battery from my Teres and the improvement it makes on the Teres is not so subtle, so that's where I use it.

George, if you'd like, I can ship you my supply and battery and you can satisfy Paul's curiosity and see how the two units compare completely off the grid. 'Course that means I'd have to listen to more vinyl for a week or two. I think I can make that sacrifice.

Mike

[mgalusha]

Hmm... last post is not showing up... I hate this bug.

[Occam]

...George, if you'd like, I can ship you my supply and battery and you can satisfy Paul's curiosity and see how the two units compare completely off the grid.

While I appreciate your generosity, my curiosity is more than satisfied. These posts have been tremendously informative for me, as a DIY sort of a guy. My questions are a devious method extract conclusions/hypothoses on what exactly is going on, not which vendor's products are 'better'.

Using Wayne's linear supply as an other than intended switching station to go from AC to battery sourced supply was 'unfair'. His choice of a EI core (split bobbin?) was IMO the right one for purposes of minimized noise coupling and bandwidth. Assuming mgalusha was powering the supply via the balanced BPT, I'd tentatively rule out chassis coupled noise leakage, and assume, as he surmised, the ripple was simply induced on the rest of the circuity via a non optimized (jury rigged) implementation when powering that lashed together battery sourced supply. Again, this seems reasonable as ripple was lower in the AC sourced supply.

Many thanks for satisfying my curiosity. Most helpful.

[Vinnie R.]

mgalusha,

Nice post, and thanks for contributing your finidings!  

[ctviggen]

I wonder if you could just shield the transformer, for instance by placing the transformer in a metal box that's grounded?  Does the SB have separate digital and analog grounds?  I'm looking forward to getting one of these.  Can the SB software run two SBs playing different songs at the same time?  Do you run two instances of the software, or control them both from one instance?

[zybar]

I wonder if you could just shield the transformer, for instance by placing the transformer in a metal box that's grounded?  Does the SB have separate digital and analog grounds?  I'm looking forward to getting one of these.  Can the SB software run two SBs playing different songs at the same time?  Do you run two instances of the software, or control them both from one instance?

Bob,

Not sure on the transformer stuff, but I can answer the other questions.

The slim server software can handle multiple SB's connected to it at once (I currently have two running at the same time), but I am not sure what the exact number of concurrent SB's are (I think it is more than a dozen).

You can have each SB play different songs at the same time or have a master/slave relationship where each SB plays the same song (cool feature when comparing different modified SB's).

George

[Occam]

I wonder if you could just shield the transformer, for instance by placing the transformer in a metal box that's grounded?

The incremental induced ripple is (I assume) a magnetic artefact. Shielding, grounded or no, isn't going to do much unless the shielding is magnetically permeable. Aluminum won't do much. Physical distance (inverse square law) or a mu metal/ crs barrier would work a treat.
But it is largely moot, as Zybar's experiment was to kludge an ac ps not physically optimised for battery power. If Wayne was to provide a ps designed for both AC and battery sourced power, I'd assume he would address these layout constraints.

[Paul_Bui]

Am I to assume that any old pc running some ripping software and a cd drive  is all you need on the pc end?

Right, but keep in mind the better PC and CD-ROM drive are, the faster your CD ripping will be.  I first used the PHILIPS D-28 DVD-RW drive (that comes with a desktop Dell PC) to rip CDs and thought it's OK.  But curiously I bought and installed a Plextor PX-716A drive, and oh so pleased with the ripping CDs business.  Faster, smoother, with tons more fucntions and options.  EAC (Exact Audio Copy) programmers use Plextor drives to write and test their software, by the way.

And can I use iTunes to rip & create my wav files?

Why not?  Slim Server software and Squeezebox2 make use of tons of formats, including but not limited to iTunes Apple Lossless, FLAC, WAV, WMA, MP3, etc.  However, I am sure many (I for one) prefer using EAC (free downloadable software) to ripp CDs to FLAC format (true bit, lossless, and hard disk space savings).

In addition, while waiting for Vinnie to complete the SB2 mods I listened really closely to the Shanling SCDT200 player and wondered if I was making a mistake shifting to an unheard device/unknown technology.  The change got to be a leap of faith.  To be sounding this good, the Shanling cost me over $3,500 after purchased new and modified by Underwood Hifi/Part Connexion, I added 4" Mapleshade maple platform and brass cones, expensive power cords (Virtual Dynamics) and power conditioner (Shunyata Hydra), Audio Desk Systeme (to shave and paint the CDs), CD de-magnetizer, audiophile grade AC outlets.  Needless to say, with those painstaking tweaks the Shanling sounded really good.

A few minutes of listening to the Red Wine modded SB2, and I decided to sell the gorgeous sounding and looking Shanling.  There's something very analog about the SB2's sound that was later confirmed with headphone listening, not to mention the convenience of remote control access to virtually unlimited numbers of CDs that you could put on your hard drive(s).

After having my 2nd SB2 modded by Vinnie, I learned yet another few tricks: to be able to have multiple SB2s play either same songs or different songs simultaneously, to "chain" the song folders to expand to multiple hard drives, etc.  It's both fun and sonic rewarding, unlike my past experience with audio.

[zybar]

How do you chain multple HD's in order to have the SB2 think it is just one big folder?

George

[Wayne1]

How do you chain multple HD's in order to have the SB2 think it is just one big folder?

George

That one is really easy. Just add a shortcut in the main music folder to wherever your additional files are.