Glenn2;408758 Wrote: > Finally, I got a proper 7808 (1.5A version) and used that, removing the > zener diode. Both regulators are now properly bolted to the heatsink > (and I applied fresh heat-transfer compound too). > > I also followed afblaster's lead from an earlier post and removed some > of the ventilation slats in the casing (top and bottom) and there's > proper convection in the case now. > > It's been running non-stop for 24 hours now and gets hot but not as > much as originally. > > The main problem still, is that the secondary voltage of the > transformer is just way too high. It's 13V unloaded, dropping to 11.2V > with the Squeezebox playing music over wi-fi. > > Using the 7808 and 7805, I'm sharing the power dissipation equally > across both regulators and both sides of the heatsink. They are both > dropping 3V. > > Ideally, the unregulated voltage would be 8V... or even 7V and you > could use one low drop-out regulator and it would barely get warm. > > As it stands, although my PSU appears to be fixed, I'm still dumping > more power as heat than the Squeezebox is consuming! > > Glenn
The biggest issue I see with this POS PS is the lack of heatsink size and improperly selected transformer. It was like somebody was given a big lot of transformers for free and decided what can we cobble together to make money! For an SB3, the PS of choice so far from testing is the OEM power supply. There are other good power supplies out there, don't get me wrong and assume I am putting them all down as I am not. After testing some of the best designed linear PS for the SB3, the resulting data showed no difference as did the listening tests. The test software shows that the signals are basically identical. So one can buy a $15 Slim Devices PS or pay $259 for a CIA VDC*SB linear PS getting the same results. Granted the Channel Islands PS looks great but I recommend from the test results that you save your money to spend on a good DAC or doing a true upgrade to a Transporter. -- iPhone *iPhone* Media Room: Transporter, VTL TL-6.5 Signature Pre-Amp, Ayre MX-R Mono's, Vandersteen Quatro, VeraStarr 6.4SE 6-channel Amp, VCC-5 Reference Center, four VSM-1 Signatures, Runco RS 900 CineWide AutoScope 2.35:1 Living Room: Duet, ADCOM GTP-870HD, Cinepro 3K6SE III Gold, Vandersteen Model 3A Signature, Two 2Wq subs, VCC-2, Two VSM-1 Kitchen: Squeezebox BOOM Bedroom: SB3, GFR-700HD, Thiel 2.3, Second Boom Home Office: SB3, NAD C370, two VSM-1 Home Gym: SB3, Parasound Vamp v.3, Thiel PowerPoint 1.2 House Portable: SB3, Audioengine A5 Thunderbird: Duet, Mac Mini Expedition: SB3, ToughBook ------------------------------------------------------------------------ iPhone's Profile: http://forums.slimdevices.com/member.php?userid=13622 View this thread: http://forums.slimdevices.com/showthread.php?t=61090 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
