mick_w;171641 Wrote: > Yes I did test the voltage (spot on 5V), yes I did wire the unit > correctly, and yes I did have it running for over 4 weeks constantly > before I tried the A/B test. > > (I don't want to start a flame either, but running in a power supply > shouldn't really make any difference if its working correctly to start > with...) > > Like I've said above, I couldn't tell the difference even though I > really wanted to believe the linear PS was better. My initial > impressions that the new PS was better was a pure placebo effect. > > Is everyone else on this thread using linear power supplies? and are > you claiming yours doesn't get hot or hum ? (find a really quiet room > and put your ear next to it) > > To reiterate, I wouldn't dare claim the linear power supply mod is just > snake oil, but it my system it didn't make a blind bit of difference; > other (more expensive?) systems might resolve the improvements.
I built, tested, and listened to the SB3 with a very high quality linear power supply based on LT1084, adjusted to exactly 5 volts. Xfrmr was split bobbin, capable of RMs current far exceeding worst case from SB3. Total umbilical wire length was about 2 feet. The rest of supply consisted of 5 6800 10v high quality Elna caps for a total of 34,000 ufd of capacitance. The diode bridge was constructed of high current schottky types, and the final output was bypassed with a high quality film cap. Not that this is the ideal place for a bypass cap, but there it is. The entire thing is encapsulated in a sturdy brushed aluminum case. There is barely any noticable hum when powering SB3 with ear right next to case. Case barely warm...I tested it with dummy loads that drew over an amp for exteneded periods. The supply is working as advertised. Been running for several days, powering the SB3. My system: SB3/Marantz SA8001 -> Acoustic Zen Ref Mat 2 RCA-> Audio Research LS15-> Audience RCA -> Audio Research 100.2 -> Acoustic Zen speaker cable -> Dynaudio Contour 1.8 MKII Room is acoustically treated and my system, in my opinion, is capable of very high resolution/transparancy. 1st off, the Marantz SA8001 SACD player is superior across the board. I was not shocked. I used this as my reference for my tests. I used my favorite Diana Krall and Steve Tyrell cd's, both ripped EAC/FLAC. Stock SB3 -> overall very good sound, but definitely has that mid-fi sonic character: compressed soundstage, restricted highs, a bit small sounding, with an overall electronic haze. Not a slam to SB3, I am comparing it to a pretty good CD player in a high res system. I was hoping the linear would help the top end and create the impression of a bigger stage... SB3 with linear: I can detect no positive difference. I tried with all my songs of the above mentioned ripped cd's. Yes the old switcher was removed. Maybe my ears are full of lead, but i'll be darned if I can actually make out any improvement. In fact, and I plan to prove this by more listening, I think it may actually sound worse with the linear power supply. This was a welborne labs squeezebox upgrade supply in case your wondering. A tad dissapointed...I am. I wish I had my hands on the schematic (i'm not going to crack the SB3 case and reverse engineer it) but i'm sure there is a reason for it. Could be that the switched mode power suppy is a better match due to the digital section and its dynamic current drain... -- dpac996 ------------------------------------------------------------------------ dpac996's Profile: http://forums.slimdevices.com/member.php?userid=9407 View this thread: http://forums.slimdevices.com/showthread.php?t=31758 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
