2009 models, soft-start retrofit

Jason T · « **on:** 27 Dec 2009, 02:56 am »

Since were on topic of new circuitry, here is what the soft start's will probably end up looking like

virtue · « **Reply #1 on:** 27 Dec 2009, 03:11 am »

You know how excited I am about these new high-current power supply options. Well, to make them work on the 2009 products, and not fuse the power switch, you're going to need a soft-start circuit. Rather than making you open the unit and start soldering something onto the power switch, we're creating an external unit. You just put it between the amp and your power supply. It's a bit crude looking, but works well. Electrically, it's 100% the same as what we've put inside the new ONE.2 and ONE "classic."

TRADERXFAN · « **Reply #2 on:** 5 Jan 2010, 04:44 pm »

Updated ETA for this soft start please??

virtue · « **Reply #3 on:** 7 Jan 2010, 08:56 pm »

Sorry for any confusion on soft-start timing. They will ship at the same time as the ONE.2 - mid/Feb they arrive together. FYI, every ONE.2 pcb we make has an extra soft-start as a little finger on the board. We populate the soft-start along with the "parent" ONE.2 unit, break it off the "parent" board, and then connect the leads to it. I sourced the leads yesterday for late January delivery to our assembly OEM factory in Taiwan. It's all good.

dboulet · « **Reply #4 on:** 19 Jan 2010, 11:52 pm »

Is the soft-start recommended for those of us using the 130v switching PS on the first-generation amps?

PSB Guy · « **Reply #5 on:** 20 Jan 2010, 01:45 am »

Seth did mention in another thread (http://www.audiocircle.com/index.php?topic=76422.0) that the soft-start helps with on/off wear and tear, so I don't think you can go wrong using one.

Nuuk · « **Reply #6 on:** 20 Jan 2010, 01:37 pm »

Quote from: dboulet on 19 Jan 2010, 11:52 pm

Is the soft-start recommended for those of us using the 130v switching PS on the first-generation amps?

No with that I would just leave a huge gap between the plug and the amp!

Seriously, I think that you meant the 30v SMPS and no you won't need a soft-start with those.

virtue · « **Reply #7 on:** 20 Jan 2010, 03:29 pm »

Guys,

Cornelis got it right. The 90w supply does not have the juice to damage the amp, but the 130w supply could. I upgraded all of the switches before final production (at great cost

and put a nice 2.2uF cap over them to reduce arcing, but no commercial switch that would fit in the box that we could find, is rated for the kind of turrn-on surges that we've seen on the scope (ever notice the "spark" on the back of the unit if you insert the plug after turn-on?) At "time zero" the bulk cap is across the power circuit and functions as a dead-short. Until it's charged, the PSU is shorted effectively, through the power switch.

As noted in the manual, those switches have been known to fuse in the "on" position, sometimes temporarily (but do sometimes permanently), with the 130w supply. Were the supply less powerful, it would handle the current demand surge by simply not delivering current. These new and more powerful supplies, and especially batteries, don't know how to NOT deliver current

Why do I care? Having units fail in customer hands is a lose-lose proposition. Virtue is not cash positive yet and if I have to pay for return shipping on "broken" units within the warranty period, and for American hands to fix those units, it will be prohibitively expensive. So making the soft-start affordable to customers is a win-win. Customers can take their amps to a new level, and I sleep easier knowing that even with the 130w supply, power switches will never fail. Break-even is unclear for me as so far (soft-start subsidy vs. cost to repair failed units) as only 1 in 100 amps fail with the 130w supply CURRENTLY, but I'd rather be safe than sorry, to prevent these switches from ever failing at all.

Second-hand owners don't have full warranty protection, and get the amps at a significant discount, so I ask them to pay for the soft-start circuits, thereby subsidizing those loyalists who held onto their amps - which we like and appreciate.

Seth

dboulet · « **Reply #8 on:** 21 Jan 2010, 01:17 am »

Quote from: Nuuk on 20 Jan 2010, 01:37 pm

Seriously, I think that you meant the 30v SMPS and no you won't need a soft-start with those.

Doh! Ha. Yes, I meant the 30v/130w supply.

Thanks for clearing that up Seth, looks like I'll be ordering a soft-start then.

droht · « **Reply #9 on:** 21 Jan 2010, 05:11 am »

Seth, it is nice to see a manufacturer do what is right as opposed to making a risk management decision based solely on the bottom line. I'm sure you will see a return on this sort of investment in customer satisfaction.

Xcalibur · « **Reply #10 on:** 30 Jan 2010, 05:35 am »

I must've missed something somewhere. I thought the soft start retrofit was for customers who were wanting to use battery power or the new linear PSUs. Now I'm reading that the 130w switching supply can fry the power switch too? Looks like I need to check into the soft start afterall.

dvenardos · « **Reply #11 on:** 30 Jan 2010, 10:09 pm »

If you are using a high current power supply of any type you should get the soft-start module. The tripath chips have graduated from tiny t-amp output to serious levels of output and the soft start is a must.

Quote from: Xcalibur on 30 Jan 2010, 05:35 am

I must've missed something somewhere. I thought the soft start retrofit was for customers who were wanting to use battery power or the new linear PSUs. Now I'm reading that the 130w switching supply can fry the power switch too? Looks like I need to check into the soft start afterall.

virtue · « **Reply #12 on:** 1 Feb 2010, 08:37 am »

To be clear, it's not the Tripath chips that are the root cause of the soft-start "fix;" it's the huge reserve caps we use. If you put a 22,000 uF cap in front of ANY amp on the market, you're going to blow even a switch rated at 8A if you're using batteries or a 10A amp supply, without a soft-start.

As I said earlier, very few of the switches have failed in the field but I do think that more will in the future without the soft-start. My own cousin in South Africa had his switch fail with the 130w supply and he thinks I'm shilling second-rate merchandise.

Anyway, we're moving to a new business and product model with the ONE.2 and Sensation whereby we're encouraging customers to buy high-current PSUs not only from us, but from other vendors as well. We're specifying a max voltage but not max current.

If you want to get in on that game as an original ONE/TWO owner, you need a soft-start, period. If you've got a 130w supply, you're probably not going to see a switch failure. Could you? Yes. Is it covered by warranty? Yes. Would I rather you have the soft-start? Yes. Hope that's clear.

Xcalibur · « **Reply #13 on:** 3 Feb 2010, 04:27 am »

Quote from: virtue on 1 Feb 2010, 08:37 am

If you've got a 130w supply, you're probably not going to see a switch failure. Could you? Yes. Is it covered by warranty? Yes. Would I rather you have the soft-start? Yes. Hope that's clear.

Clear as mud.

Though, just to make it extra soupy mud, you mean it's covered under warranty for the duration OF the warranty right? A person could read this as a statement that this failure is covered by warranty regardless of when the failure happens.

virtue · « **Reply #14 on:** 3 Feb 2010, 04:35 am »

Correct on the warranty. It is finite as bizness-wize, my liability must be finite. However, with care and love and soft-starts, these amps will last generations...

There is a stick buried somewhere in the soft-start carrot