[Jason Stoddard]

Hey guys,
 
To clear things up:
 
1. Lyr has a 20 second relay-switched delayed output and immediate relay mute on turn-off. It's a running change we made in production. 
2. From the start, we've always urged extreme caution with Lyr, and we have never recommended it for high-sensitivity headphones.
3. Relying on any form of protection--relay delays, microprocessor-controlled DC monitoring systems, whatever--can still bite you, when and if there's a failure in the system. And all of them (to us, at least) involve sonic compromise. That's why you'll typically find many of the highest-dollar components out there running naked, so to speak.
 
That said, we now understand that the precautions common to ultra-high-end (where it's well-known that turning on your multi-kilobuck amp before you turn on your multi-kilobuck preamp may involve having a very bad day) simply won't fly with inexpensive gear, so we're making the changes necessary to have our stuff be as user-friendly as possible.
 
Asgards will now ship with the same relay mute as Lyr, when we are back in stock. We will also offer a retrofit relay mute for Asgard and Lyr, for customers who want the convenience, and install it on any current owner's amp for free. I am still conflicted on relays, since it means another contact in the signal path, relay contact degradation over time, and the possible reliability hit (there's a joke in high-end that if something's broken, it's probably a relay.) That said, I think we have identified an acceptably reliable, least-sonic-impact solution.
 
And--to complete the trio--Valhalla's inherently slow turn-on (tube outputs) negates the need for a relay.
 
All the best,
Jason
 
 

 

[fishski13]

Quote:

 
You have turn off you B22 before unpluging your headphones so you don't fry the output transistors but you have to unplug them before turning off your Lry so the "thump" doesn't blow your headphone's drivers.

minor correction: as long as the output transistors in the B22 are not amplifying a signal (volume turned all the down), there is no issue.  the MOSFETs are rated for 17A, and with a typical quiescent current bias of 120mA-160mA, a brief shorting with a TRS is no problem.  if driving a piggy load with the volume up, yes, all bets are off if you short the outputs of an amp capable of 18W in stock build. 
 

 

[fishski13]

Jason,
your customer service is remarkable by any measure.

 

[maverickronin]

Quote:

minor correction: as long as the output transistors in the B22 are not amplifying a signal (volume turned all the down), there is no issue.  the MOSFETs are rated for 17A, and with a typical quiescent current bias of 120mA-160mA, a brief shorting with a TRS is no problem.  if driving a piggy load with the volume up, yes, all bets are off if you short the outputs of an amp capable of 18W in stock build. 

Really?  So its safe if you kill the volume first?
 
I'm not up on the specs of the parts but I've read over most of AMB's page on it and read a few horror stories about people frying their amps that way and others recommending adding the optional resistors talked about on the AMB page or using a locking TRS connector for safety.

 

[upstateguy]

 
Quote:

Really?  So its safe if you kill the volume first?
 
I'm not up on the specs of the parts but I've read over most of AMB's page on it and read a few horror stories about people frying their amps that way and others recommending adding the optional resistors talked about on the AMB page or using a locking TRS connector for safety.

Would you explain this a little further?  I've heard the same from AMB but I never really understood why you have to turn the Sigma's power off first.
 

 

[deadlylover]

Yeah they just recommend you turn the volume down and pull the plug really really quickly.

 
There's no problem if you are using balanced connectors, as they don't cause temporary shorts when plugging in/out.

 

[fishski13]

Quote:

Really?  So its safe if you kill the volume first?
 
I'm not up on the specs of the parts but I've read over most of AMB's page on it and read a few horror stories about people frying their amps that way and others recommending adding the optional resistors talked about on the AMB page or using a locking TRS connector for safety.

i have not heard of of any issue when removing the TRS plug with the pot fully attenuated, and this is what Ti Kan recommends.  personally, it's good practice no matter what amp.  i've done this literally hundreds of time with my own B22.  i've had customers that have pulled the plug with music playing with no issues, but these cans were 'easy' loads.  if the cans draw a lot of juice, or if the TRS plug 'sticks' on removal, sure, shorting a channel to ground with significant current through the output MOSFETs can be a problem. 
 
i think the horror stories are mostly from meets where people don't know better and leave the volume cranked when removing. 
 
 

 

[Clayton SF]

I have a beta22 sigma22 with mute switch on the b22. When the amp is on I've been told to activate the mute before removing the headphones or I'll fry something. This I've known before I got the b22. As with the Asgard I just thought the on/off switch was all that I needed to be concerned about.
 

 

[maverickronin]

i have not heard of of any issue when removing the TRS plug with the pot fully attenuated, and this is what Ti Kan recommends.  personally, it's good practice no matter what amp.  i've done this literally hundreds of time with my own B22.  i've had customers that have pulled the plug with music playing with no issues, but these cans were 'easy' loads.  if the cans draw a lot of juice, or if the TRS plug 'sticks' on removal, sure, shorting a channel to ground with significant current through the output MOSFETs can be a problem. 
 
i think the horror stories are mostly from meets where people don't know better and leave the volume cranked when removing. 

OK then.  That seems to make sense.

 

[fishski13]

Quote:

 

Would you explain this a little further?  I've heard the same from AMB but I never really understood why you have to turn the Sigma's power off first.
 

you should not have a switch on the B22.  by switching the only the O22, it in itself is a 'soft start' circuit of sorts or so that extends the time charge of the B22 caps, slowing down the in-rush current.  slamming the on board caps with a fully 'charged' O22 can lead to premature cap failure.
 

 

[fishski13]

Quote:

I have a beta22 sigma22 with mute switch on the b22. When the amp is on I've been told to activate the mute before removing the headphones or I'll fry something. This I've known before I got the b22. As with the Asgard I just thought the on/off switch was all that I needed to be concerned about.
 

yes, a mute will work too.

 

[BobSaysHi]

Quote:

Jason,
your customer service is remarkable by any measure.

Indeed, truly remarkable.
 

 

[Steve Eddy]

Quote:

Jason,
your customer service is remarkable by any measure.

Well, it does lose a little in avoirdupois pounds versus troy, but gains a little in ounces. But on the whole, yes, quite remarkable.

 
In all seriousness, it is something every manufacturer should aspire to.
 
se
 
 
 
 

 

[kwkarth]

Quote:

Holy crap, that sucks.
 
I always thought it was a bad idea to unplug headphones before turning the amp off, as a TRS plug shorts the output's of an amp for a split second.
 

One should always turn the volume to 0 before plugging in or unplugging a headphone.  The momentary short has no effect on the amp that way.
 

 

[upstateguy]

Quote:

One should always turn the volume to 0 before plugging in or unplugging a headphone.  The momentary short has no effect on the amp that way.
 

Do you plug the headphone in before you turn it on or after?   Does before or after matter if the volume is 0?