2. home-theater
  3. 1436271195

Lexicon RV-8 query followup-fan noise?

Ok. This was a dud when i bought it secondhand, So ive never actually heard it. Eventually had to get a new power supply from lexicon, at ridiculous cost. (Approx USD700, shipped to NZ, of which person who sold amp to me contributed half). Amp is now up and running. But fan noise from the power supply seems LOUD to me, and is constant, even staying on for ages after you power the unit down. Can anyone who has owned one of these amps tell me-Is this fan noise normal, and im being over sensitive?!

Between this, and the fan on my linn sizmik subwoofer, and in my oppo bdp 95, im going nuts. Whose bright idea was to use fans to cool hifi and HT gear, anyway?! Is it just me? But meeb theres something wrong with lexicon? At least the linn and oppo fans are only on intermittently.....
yourmomm
yourmomm OP
12 posts
 
Yep i was thinking similar....there are some very quiet 80mm 12v fans, so i could just put an inline 24v-12v regulator in, and fit one of these. I see most of them have a third cable (to a resistor?) which i assume is the control? i looked at external pc fan controllers, but these seem to need their own power source? i guess i could run another 12v circuit in parallel from the inlune regulator, but this seems a mission. Anyone know of an external fan controller which works passively? Or is there an easier way to do this that im missing?
yourmomm OP
12 posts
 
Ok i think i got this. According to my research, a 12v fan's speed is dependant on input voltage....So i can buy an ultra quiet 12v fan, then just use 24v-12v regulator from the normal power supply's (24v) power and ground feeds (leaving the fan speed sensor cable disconnected at both ends), and then just a small variable resistor, rated for the power requirements of the circuit, to step down from 12v to 5v, and back up again, depending on how much air i need to actually move to keep the power supply cool? Any advice appreciated here as im no electrician....
yourmomm OP
12 posts
 
Ok. Lexicon state that (curiously) the original spec RV8 did not have a power supply fan at all(!), but confirmed that it is normal that, once the power supply fan WAS added to subsequent models, it stayed on permanently, with no internal speed control. So, if i removed the fan entirely, i would have an original spec RV8!! Albeit with a failure-prone power supply. The only thing i can think is that it was added as a hasty and poorly designed afterthought, to deal with the numerous power supply failures that lexicon had to deal with (including my own, despite it having a fan previously!). These power supply units really seem to be the weak part of the RV8 design, despite costing so much...I'm going to make the fan speed control and 12v fan modification, as well as a soft start circuit for the power supply, and take my chances....who would have thought such an expensive and well reviewed piece of kit needed so much work?!!
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