Beta 22 Question

[luvdunhill]

edit: +n't

[dreamwhisper]

Oh I ended up buying a GS-1 not a Beta 22. 
Sorry for the confusion.

Is it the power output of the Beta that's the dangerous part?
Did I hurt my GS-1? I've done it once or twice.

Eagerly awaiting your response. :/

Edited December 10, 2014 by dreamwhisper

[RudeWolf]

It's the MOSFET output stage.

[dreamwhisper]

What's in these modules? Any specifics?

This is an all-new module designed in-house. It will be the first non-Gilmore amplification circuitry I have offered in a home amp. It is a 100% discrete design, real Class A circuit. The output consists of a pair of Hitachi MOSFETs designed for audio -- good for a substantial couple of watts in this circuit.

  Edited December 10, 2014 by dreamwhisper

[spritzer]

Nothing to do with mosfets in general.  It's due to the TRS shorting the outputstage to ground

[RudeWolf]

Some output stages are more fickle with this than others. That being said - it's a good idea to turn volume down when swapping headphones or just putting an XLR pigtail on the amp.

Edited December 10, 2014 by RudeWolf

[chiguy]

To add to all of this, there are two resistors on each channel board that can be upped to provide some additional protection against the TRS shorting.  I don't remember the details but they are over at the AMB forums. 

[Remolon]

What I do is to put a mute circuit at the output. There is a switch that direct the signal to the headphones or to ground through a resistor (I use 300R).

[dreamwhisper]

Do you have a link where you can buy something like this?

[HeadphoneAddict]

 

Depending on when this beta was built and how the output is configured I'd first start by saying that you should never hot swap or plug in headphones on a beta²².  That's a good way to release the magic smoke and render the amp useless.  Unless you're talking about an amp configured with a connector other than the usual 1/4" TRS jack.  That jack causes a momentary short on the output when plugging/unplugging headphones that has been known to cause major issues.

 

That said, there should really be an issue powering two headphones at once off of the beta, just that if the sensitivities/load are significantly different it may be difficult or impossible to find a happy listening volume.

 

 

Someone killed Asr's B22 at a headphone meet by hot swapping phones with music playing.  It sucked.

[n_maher]

edit: +n't

Correct, as usual.

[The Monkey]

I still love my Nugget Audio B22.

[K3cT]

I find increasing the quiescent current of the output device from amb's recommendation of 120 - 160 to around 180mA helps warming up the sound. 

[swt61]

I found that plugging in a TRS jack with the unit at a good volume warms everything up.