[amb]

That subject has already been argued to death, a simple search will get you all sides of opinions.

 

[Stillhart]

I'm just looking for a brief summary.  And I don't think it's a simple search, as I wouldn't know what search terms to use.  
 
Anyways, clearly it's a loaded topic for you.  Perhaps someone else can chime in.

 

[jcx]

there are opinions on subjective values
 
and there can be different weightings of issues by different engineers leading to different designs, but taken individually several key claims of "3-channel" "advantages" are simply technically wrong
 
my analysis is engineering based, addresses the incorrect technical claims put forth by the "3-channel" advocates and can be shown to be more accurate in calculation, simulation and measurement
 
 
the Beta22 is good enough that I doubt the "3-channel" flaws are audible problems, or that the one real advantage re PS currents makes any difference either
 
but most of the reasons given for using it are simply wrong and causes me as an engineer intellectual distress when I see so many naïve builders being steered wrong - and clear explanations being attacked by fanboys
 
using Beta22 amps, dual polarity supplies "3-channel mode" wastes money, time, resources for added technical flaws and one never demonstrated improvement in PS rejection for a amp with huge psrr built into the topology
 
 
and yes I do speculate that dual mono, and the requisite "balanced" 4 pin headphone connector rewiring would be the cheaper route to "better" technical performance given real world system limitations
 
 
but even common supply, 2-channel with attention to a "technical ground" - heavy copper, proper wiring to "star point" at the TRS gnd should be fine
 
but 4 pin "balanced" headphone cabling should be better still with the L,R headphone driver's gnd returns routed to each board respectively
 
 
 
and yes search works, but you may want to do it on different forums if you really want independent views - you can see mine here on head-Fi:
 
http://www.head-fi.org/newsearch?advanced=1&action=disp&search=%223-channel%22&titleonly=0&byuser=jcx&output=posts&replycompare=gt&numupdates=&sdate=0&newer=1&sort=relevance&order=descending&Search=SEARCH&Search=SEARCH

 

[Stillhart]

Thanks, I'll do some reading.
 
Anyone want to explain how to do dual mono?  I don't see it as one of the options in the official AMB documentation.

 

[amb]

What jcx proposes is a standard two-channel passive-ground configuration, with an independent power supply for each channel. Also, rather than a standard TRS stereo phone jack (which has 3 conductors with a common ground), you use a different connector that lets you separate the left and right grounds and route them directly to each channel's power supply ground (the "star ground points"). HeadRoom's style of two XLR connectors on their balanced amps, or a single 4-pin XLR connector as found on the AKG K1000 headphones can be used to do this. Of course, this scheme requires you to modify your headphones.

 

[Stillhart]

What jcx proposes is a standard two-channel passive-ground configuration, with an independent power supply for each channel. Also, rather than a standard TRS stereo phone jack (which has 3 conductors with a common ground), you use a different connector that lets you separate the left and right grounds and route them directly to each channel's power supply ground (the "star ground points"). HeadRoom's style of two XLR connectors on their balanced amps, or a single 4-pin XLR connector as found on the AKG K1000 headphones can be used to do this. Of course, this scheme requires you to modify your headphones.

 
Thanks, that makes sense.  So from the headphone's point of view, this acts like a balanced connection?  I mean, as long as the headphones are already wired for balanced, this should work with no further modifications to the headphone?
 
Dual mono seems like an interesting project, but at that point, I'd rather just go balanced.  

 

[amb]

Thanks, that makes sense.  So from the headphone's point of view, this acts like a balanced connection?  I mean, as long as the headphones are already wired for balanced, this should work with no further modifications to the headphone?

The signal won't be differential, but yes, any headphones already modified in this way will work, as long as the connector type and pin assignments are consistent.

 

[Stillhart]

So the insulation/mounting kit for the heatsinks are pretty pricey.  How do I know if I'll need them or not?  "Close proximity" is a very subjective term...
 
Also, any recommendations for RCA jacks?  The Neutrik ones look weird... Rean perhaps?

 

[amb]

If there any risk of the PCB-mount heatsinks touching the chassis, top cover, or some other metal object, then you need the mounting kit.

Search for Cardas GRFA or Vampire CM2F and you'll see some nice RCA panel-mount jacks. There are also many clones or similar available on eBay at much lower prices.

 

[MisterX]

The Rean NYS367-* jacks are actually pretty nice considering they're priced around $2 each.

 

[Energy]

Has anyone done a comparison of their β22 to amplifiers like the Schiit Ragnarok?
 
With declining popularity for the β22, I don't see many opinions circumventing the two.
 
According to user ogodei (source: http://www.head-fi.org/products/schiit-audio-ragnarok/reviews/11797), according to him the GS-X MKII sounds very similar if not the same as the Schiit Ragnarok. In comparison to the GS-X MKII out of my own β22, to my ears I found the β22 to sound almost exactly like it. The only difference was that the β22 was ever so slightly warmer, and i mean barely. I love the GS-X MKII, don't get me wrong. But I've always found them to sound a wee bit cold. They are fantastic for a solid state amplifier, but the added warmth on the β22 just removes that last ounce of digital glare. It just sounds more relaxed and yet somehow manages to add presence. Again, this is very very and I mean, VERY subtle. I've noticed these sonic variations during a direct comparison of the two in BALANCED mode (β22 vs GS-X MKII).
 
Would love to know if anyone else have had experience with these three amplifiers.
I currently own the GS-X MKII, β22 Balanced, and am in the process of purchasing a Ragnarok from a fellow Head-Fi for a comparison.
 
In time I felt the decline of the β22 meant that it was losing in performance, but based on the A/B test's I've done up to this point has proved to me it hasn't. I truly feel like people have gone more towards the path of HeadAmp GS-X MKII or Schiit Ragnarok due to form factor, ease of use, or even hype.. 
 
Comments?

 

[FallenAngel]

  Has anyone done a comparison of their β22 to amplifiers like the Schiit Ragnarok?
 
With declining popularity for the β22, I don't see many opinions circumventing the two.
 
According to user ogodei (source: http://www.head-fi.org/products/schiit-audio-ragnarok/reviews/11797), according to him the GS-X MKII sounds very similar if not the same as the Schiit Ragnarok. In comparison to the GS-X MKII out of my own β22, to my ears I found the β22 to sound almost exactly like it. The only difference was that the β22 was ever so slightly warmer, and i mean barely. I love the GS-X MKII, don't get me wrong. But I've always found them to sound a wee bit cold. They are fantastic for a solid state amplifier, but the added warmth on the β22 just removes that last ounce of digital glare. It just sounds more relaxed and yet somehow manages to add presence. Again, this is very very and I mean, VERY subtle. I've noticed these sonic variations during a direct comparison of the two in BALANCED mode (β22 vs GS-X MKII).
 
Would love to know if anyone else have had experience with these three amplifiers.
I currently own the GS-X MKII, β22 Balanced, and am in the process of purchasing a Ragnarok from a fellow Head-Fi for a comparison.
 
In time I felt the decline of the β22 meant that it was losing in performance, but based on the A/B test's I've done up to this point has proved to me it hasn't. I truly feel like people have gone more towards the path of HeadAmp GS-X MKII or Schiit Ragnarok due to form factor, ease of use, or even hype.. 
 
Comments?

 
Flavor of the month psychology and "newer is better" mentality. That's all I have to say.

 

[vixr]

I soldered every joint of my B22 and Nate Maher built the stepper... From a true DIY perspective? The B22 is the finest thing I've ever built or listened to.

 

[FallenAngel]

I soldered every joint of my B22 and Nate Maher built the stepper... From a true DIY perspective? The B22 is the finest thing I've ever built or listened to.

 
Pretty close to my experience as well. I loved my Beta22 and at over $2000 in parts for my personal build, it was the most expensive thing I've ever built.
In terms of the "hardest" build, the Dynahi tops that list. Damn those custom drilled heatsinks. It also happens to be in the top 2 favorite solid state amps (with the Beta22 as the other obviously).

 

[musedesign]

Hi guys, I finally got round to taking some pics of my B22 amp. It has taken me over a year to get to this point and I thought i'd share my hard work with you all. First of all, a [size=x-large]MASSIVE[/size] thank you to everyone who has helped me with this project especially, Ti (AMB LAbs), MR Majestic, and johnwmclean. I would not have been able to do it without your help and patience!

The amp sounds bloody amazing, really happy with it. Its safe to say its not the easiest amp I have ever built, there is a lot that can go wrong (and did go wrong!) but got there in the end. I will be adding some more pics for those interested on the post pics thread (I didn't want to clutter this thread too much).

 
Dear Fault151,
  Very impressive work !!
 
What headphone jacks did you use on the front ?
 
Thank you !