Power Amp (Sunfire) - Turn on options help

[Brian_74]

I'm in the process of re-cabling my setup. $100 worth of F6 braided sleeve into which I'm bundling all my IC's, power cables, etc (power separate from IC of course ) It looks so much cleaner already.

I've currently had my Sunfire configured for signal sensing Auto turn-on. However, I still get an audible thump when turning on my AVR (poor man's pre-pro). It turns off silently, but the thump is something that has always bothered me a bit. Should I be concerned about the turn-on thump?

For those with Sunfires, how do you have yours setup? Do you just leave it on all the time? 12V trigger? I've tried the trigger turn-on via my Belkin PF60 output and I still get a thump when turning things on.

If you guys say the thump is no big deal, I'll probably stick with the auto signal sensing turn-on. I'm open to suggestions and advice!

 

[TomD]

Interesting, I have the same amp and i get the thump when shutting down. The manual mentions this when bi-amping, but I haven't checked into it just yet.

I shut all my equipment down then turn off the conditioners. When powering up, the conditioners are turned back on then each component. When I am away, or if there is a threat of lightning, the conditioners are unplugged.

 

[Gordon Gray]

Brian,

If set to auto turnon, something in the preamp section might be on, which will magnify the amp turn on transient.

With my system, I get a very small "thump" when I power up my amp with my preamp in the "full mute" mode.

If the preamp is out of mute, the turn on thump is quite loud.

So you may want to try muting / turning completely off the preamp before you fire up the amp.

Good luck.

GG

 

[Horchem1972]

Sunfire thump

I have always had a thump with every Sunfire amp I have owned(3).What's interesting is that I have a Carver AV-705X which is dead silent.I wonder why he never incorporated the soft turn on like he did with some Carver models?Anyway,I have never had damage occur on the turn on thump.

 

[JonFo]

Seeing as how I have three Sunfires in my rig, I have to say I never get a thump when powering on preamps. Not with the Meridian nor the new Denon AVP.

I do use an automated power sequencing system to ensure the amps are cycled down before the pre's are shut down, but I've tested with the amps on, and no thumps on shutdown either.

Maybe a power subsystem challenge? Or just 'noisy' pre's.?

 

[timm]

I have a Sunfire Sig Grand and the Sunfire TGIII - no thumps ever. However, I used to have them plugged into a switched outlet on the wall - and every now and then - we would shut down the Pre - and by accident switch off the power at the outlet via a switch on the wall - and I would get a HUGE thump. That has since changed though since I have moved and am not on a switchable plug. But, maybe that gives us some type of clue... I use auto-sensing turn on as well - and after the pre shuts down - it takes about 5 minutes before the amp finally shuts down... and of course when I power up - the amp comes on last...

 

[Brian_74]

Thanks for the replies. Let me clarify that I have NO thump when shutting down--the amp turns itself off after a few minutes, no thump. I have a thump when the auto-sensing turns the amp on. Of course since it needs a signal to detect, the pre (my AVR) is already turned on.

Does anyone just leave the amp on constantly? Would that be a bad idea?

 

[Gordon Gray]

Brian,

You've figured out the problem. Turn your AVR / preamp on after your amp when powering up the system and vice versa when you shut down.

As for leaving amps on all the time. No go with tubes. OK with SS.

GG

 

[TomD]

Just checked the TGA manual (covers TGA-5400 and 5200) and on p17 there is the title Turn-on and turn-off thumps. The paragraph reads "Plug the amplifier into an unswitched AC outlet, and use the AUTO-ON feature. This will allow the amplifier to turn on and off silently."

 

[Brian_74]

Brian,

You've figured out the problem. Turn your AVR / preamp on after your amp when powering up the system and vice versa when you shut down.

As for leaving amps on all the time. No go with tubes. OK with SS.

GG

I have a chicken and egg problem then Gordon. I remotely power on my AVR in order to provide the signal (via Front Preouts) which the Auto-sense feature of the Sunfire uses to turn itself on. I don't have any other way to turn the amp on unless I were to setup a switched outlet bank on my Belkin, and then MANUALLY turn the switch, wait, and then remotely turn on my pre-amp. Hope that makes sense. If the wife had to manually turn on the amp, I'm sure I would hear about it

Tom, I am using the Auto-On feature per the manual, but I'm still getting thumps--I think it's cuz I use my preamp pre-outs as the signal, thus the pre-amp is turned on before the amp in every case.

 

[TomD]

We do not want to cause any difficulties for our wives; bless them for putting up with our obsession.

I am thinking that the preamp is sending a residual signal into the amp, which is enough to cause the amp to turn on prior to being triggered when an audio signal is passed (i.e. CD, DVD). The MLs are an example. They only turn on when an audio signal is received, but I never seen them turn on when the amp and pre are idling. Perhaps the Sunfire is just oversensitive. Thus, without the presence of an audio sound, the thump Is heard.

I also have a Carver amp in my system. As mentioned above, it does not cause any thumping when turned on or off. You would think that the Sunfire is built on the platform of the Carver experience, so I find it surprising that a thump occurs especially when following the manual's procedure. What I can’t explain is why my thump occurs on shut-down but not when fired up. Release of stored current?

 

[Brian_74]

I ended up not changing anything with the way I turn the amp on. I'll just live with the thump until I can upgrade my AVR with a real pre-pro Good enough reason for an upgrade don't ya think?

 

[JonFo]

One solution to this dilemma for anyone having this challenge is to get a power distribution system with a power sequencer integrated. Some of the high-end units offer delay-on and delay-off sequencing specifically to handle this.

Look at units from APC and Belkin.

For instance, this Belkin PureAV power center has all the features needed to mange sequencing. As well as certain power protection filtering.
http://catalog.belkin.com/IWCatProductPage.process?Product_Id=178925


On the higher end, ETC also offers a selection of sequencers:
http://www.etasys.com/Main/Products/PowerSequencing.asp


There is also this power distribution with sequencing (TECHNICAL SQB10 - 10 Outlet Power Sequencer)for just $99 that might do the trick.

I've assembled my own sequencing solution, and I can tell you that good quality relays cost money. So the more expensive systems are going to be more reliable and transfer more current than the cheaper ones.

 

[Brian_74]

One solution to this dilemma for anyone having this challenge is to get a power distribution system with a power sequencer integrated. Some of the high-end units offer delay-on and delay-off sequencing specifically to handle this.

Look at units from APC and Belkin.

For instance, this Belkin PureAV power center has all the features needed to mange sequencing. As well as certain power protection filtering.
http://catalog.belkin.com/IWCatProductPage.process?Product_Id=178925


On the higher end, ETC also offers a selection of sequencers:
http://www.etasys.com/Main/Products/PowerSequencing.asp


There is also this power distribution with sequencing (TECHNICAL SQB10 - 10 Outlet Power Sequencer)for just $99 that might do the trick.

I've assembled my own sequencing solution, and I can tell you that good quality relays cost money. So the more expensive systems are going to be more reliable and transfer more current than the cheaper ones.

Agreed. I have the Belkin unit that you referenced above. It's a great piece. The problem is I don't have another component with DC trigger or switched accessory outlet other than my AVR. So I can't use switched outlet banks on the Belkin to solve my problem. The AVR has to come on first to activate any switched outlets on the Belkin. I don't want to manually switch on the Belkin either, but that would allow me to sequence the power up correctly. I really wish the Belkin came with an IR remote to turn it on.

If anyone knows of another way to do it, please chime in. I know you can buy AC current detecting devices that send out a DC trigger. Again, not the most elegant solution though.

 

[Craig]

Did you double check that your Auto-on switch is in the correct position. It behaves as if its in the On position.

I have the Sunfire Cinema Grand and it automatically turns on/off silently.

It would have to be a really hard thump to do speaker damage. How loud is it? Although any unwanted thump is annoying.

 

[Brian_74]

Thanks for the reply Craig,
The thump isn't too loud, but easily noticeable. And yes, it's probably more annoying than anything. To answer your question, yes, I have the switch in the Auto-on position. The front light turns red when the amp turn off, and thumps when it turns on (blue light).

Is it possible the circuit is somehow malfunctioning?

 

[timm]

why don't you try calling sunfire? In the past - when I have had wierd sounds when I power up or down - switching out my pre-amp has fixed it. I'm not saying it is your pre - that has just been my experience....

 

[TomD]

I changed my turn-on/shut-off routine to try to reproduce your thump when starting up. Now when starting the sunfire from standby (red light) it does not thump but "clicks." Its a much higher frequency single short duration "click" sound, as opposed to a lower frequency thump coming from the woofer. BTW, the aeon i are bi-amped from the sunfire, if that makes a difference.

With the sunfire on standby mode (rear switch in the middle position) and allowing it to shut down by itself (it takes a little while), no thump or click is heard. However, as mentioned in my previous post, if it is manually shut down (blue light to off using the front button), the thump occurs.

Someone suggested that it may be the preamp. I experienced the thump using an older Yamaha 5.1 receiver and its Lexicon MC-12B replacement. Although experienced with only two processors, they are a world apart in terms of their build and yet the thump occurs with either unit.

Just wanted to share this with you. I do not believe that it is an issue based on the thump that I am experiencing, which is much lower in intensity than normal listening levels.

 

[ScottGardner]

I have the Belkin unit... referenced above. It's a great piece. The problem is I don't have another component with DC trigger or switched accessory outlet other than my AVR. So I can't use switched outlet banks on the Belkin to solve my problem.

Yes you can.

The AVR has to come on first to activate any switched outlets on the Belkin.

exactly what we need

I don't want to manually switch on the Belkin either, but that would allow me to sequence the power up correctly.

That will also work

I really wish the Belkin came with an IR remote to turn it on.

Not really nessessary your AVR is IR controlled

If anyone knows of another way to do it, please chime in.

Here we go...

Remember: Amps: OFF first -- ON last:

OFF FIRST: Just the way it was when you FIRST got it. Because you don't want it on while everything else is shutting down and amplifiing every little snap, crackle and pop (or thump).

ON Last: After all the other electronics have settled down and aren't snapping crackling and popping (or thumping) any longer.

The Power Controller (PC) should have at least two kinds of outlets on it: switched and un-switched. And will need an AC-current-sensing-input to control the switched outlets - prefereably delayed.

I read a review about the Belkin PC and from what I read it has the nessessary functionality. In order to use this function though, you must enable it by utilizing the �Remote� button located at the bottom of the LCD screen. I don't have a manual so you'll have to look this up.

I have a Monster PC that is similar and this is how I did it with my since departed Yamaha DSP-A1 (AVR):

1. PC plugged into the wall outlet. (NOT the switched outlet of the AVR. The AVR's switched outlets can only handle 200 watts which is not nearly enough for the PC and everything plugged into it.)

2. AVR plugged into an un-switched outlet of the PC. (So it continues to get power regardless of the state of the PC's switched outlets. The AVR needs to be in stand-by mode so its IR recever and remote will work)

3. AVR switched-outlet goes back into the PC's AC-current-sensing-input. The belkin comes with this special cable but you may need to get another one if it has disappeared.

4. Amps plugged into DELAYED-ON outlets of PC. (Remember Amps ON last)

When the AVR powers up (comes out of stand-by) its switched-outlet tells the PC (via your special cable and its AC-current-sensing-input) to trigger its (PC's) switched-outlets which then provides power to the amps.

When the AVR is put into stand-by it turns its switched-outlet OFF which tells the PC to turn its switched-outlets OFF (but leave its un-switched outlets alone so the AVR can stay in stand-by mode).

The AVR then is indirectly controlling the Amps (and other components) ON and OFF states through the PC which handles the delay-ON (and delay-OFF if necessary for say an active crossover).

The PC switches the delayed-ON outlets off first and delays powering off the other switched outlets but leaves the un-switched outlets alone.

The PC is also providing clean power to itself and the AVR while all of this is happening.

Once you have this setup going the autopower capability of the Sunfire is irrelavant except that the Sunfire will go into stand-by if everything is on but no sound is going through it. (you fall asleep listening to a CD and repeat is not set)