Just received a replacement amp as my first one had the fan spinning all the time.
However the replacement is doing the same thing.
According to SD support the fan should only spin once at power on and then shut off until the unit needs cooling.
I’ve sent another question into SD support to see if the fan behaviour has been changed so that it is spinning constantly on the current batch of amps.
Or is it that there is a faulty batch and I’ve received another faulty one?
The serial numbers are 4 digits different on the 2 amps.
If if anyone has a PowerStage 170 can you let me know how your fan operates on the amp?
Comments
Ha! Many years ago Sony brought out a range of "Micro Hifi" and the amp, punchy wee thing, 50Wpch iirc, had a thermostatic fan. The customer complained that it was noisy when it kicked in and so a phone call to Sony elicited a mod kit.
I fitted it in the punter's bedroom and the "mod" was that now the fan ran ALL the time! Needless to say, we got the kit back and lost the sale.
Many electronics designers view cooling fans as a design failure, often prompted by the bean counters not being prepared to stump up for big enough heat sinks or enough OP devices. Maybe back in the earlier design stage that fan should have been controlled? THEN they had burn outs!
I spent a good 3 weeks taking temperature measurement from the heat sink of an amp's power controller just to make sure it was getting the right cooling..SANS fan!
Dave.
I’ve sent another message to SD support and to their UK distributor to see if they will confirm it either way. Fan adjustment or faulty batch.
It it does sound pretty good.
And the fan is quiet and unobtrusive at the moment.
Fans can fail and which will cause (usually expensive) failure of the rest of the kit as well.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Could I ask a massive favour? When SD come back to you, would you mind letting me know by DM so that I can recheck the thread? I'm not on here that much and the topics move fast!
I don't mind if they wind up a bit when cranked - as long as they can't be heard above the louder playing, bur for low level playing or late nights / recording etc it's a nightmare.
I had the wonderful Mesa Prodigy 4:88 once. 265W all valve.
Sounded amazing (as it should have done for the money) - but the fan was stupid. Looked to be a 4 inch item, it was loud and whiny. Made it impossible to use at TV listening levels.
I thought about having the fan replaced for a "silent" version but in the end I traded it for a Demeter 800W amp that was fanless - never overheated either - just properly designed in the first place.
I don't get the obsession with making the case as small as possible - it just causes heating issues. And then for many small amps the design means they can't be racked either.
Just stick them in 1 or 2u rack sizes with proper cooling. Maybe have a fan for when the amp is working in the top third of the output - at that volume there will be a noisy drummer anyway. Otherwise let them run silently as they should.
I want to hear the notes - not the fan.
I’m so bored I might as well be listening to Pink Floyd
I replaced it with a low-noise Papst fan, and the fastest speed was then about the same as the slowest had been before, and the slowest was inaudible even at late-night bedroom volume - so much so that when I first turned the amp on I thought it wasn't working at all. Admittedly this fan cost £15, and the original was probably worth about a tenth of that.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Yes, fans can be cheap and noisy or pricey and quieter but they all suffer from the same problem..Muck.
Even without fan sucking or blowing an amp will develop a "crust" on every exposed surface. The solution is of course to fit a fan and filter the air going in but you then rely on the punter cleaning/changing the filter!
Most fans on most of the gear I have seen do not have filters so they just clag up themselves. Even a mm of muck on the blades has a drastic effect on a fan's efficiency but then they rarely get cleaned until they gum up completely and something blows.
Dave.
It's a QSC PA power amp which had been installed in a club for many years before the smoking ban. It had essentially been operating as an air cleaner for the club...
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
@Clecko I will dm you the details of the 2 units I’ve had and when SD get back to me.
I’ve seen the insides of PCs that look very similar to that amp @ICBM and even with filters on the intake fans it still doesn’t stop the muck getting in. Just means it’s a very fine layer of dust that still coats every surface of the components.
Going to to organise a return again for this second unit, but I won’t be requesting another replacement.
I’m just not happy with a constantly spinning fan waiting to clog up in a year or 2.
However on the PS700 the fan is still temperature controlled and will only spin when cooling is required.
Ive just purchased a PS 200, and the fan is always on, AND emits considerable noise…
These things are great for powering home cinema systems, monitor speakers and such but might not have been designed living in such a small box. Personally if I owned one I would want the fan on constantly.