[Shahrose]

Quote:

 
The B22 is more stable, thermally and electrically. It is better equipped at handling hard loads like speakers (see this), and the parts are easier to find. I would not choose a dynahi over a B22.
 
They're really very similar though, brothers in the head amp world.

 
If only all that translated to better SQ.
 
Quote:

 
Just a quick comment on this as well - no headphone is going to give you any soundstage, at all. The nice thing about headphones is their detail and separation, but when you've heard a good speaker system you realise what "soundstage" is. It's not possible from speakers attached to your ears.

 
Headphones can and do have a soundstage. It's small and intimate compared to speakers obviously, but that doesn't mean no soundstage exists.

 

[iim7V7IM7]

The B22 is more stable, thermally and electrically. It is better equipped at handling hard loads like speakers (see this), and the parts are easier to find. I would not choose a dynahi over a B22.

They're really very similar though, brothers in the head amp world.

I do not plan on using it with speakers. My speakers are active monitors that are hooked directly to my Grace m903. I am also not intending to build either. The Beta 22 would be built by YBM and the GS-X (which I thought was a Dynamid and not a Dynahi) will be built by Justin at HeadAmp. The amp would be used with 300 ohm Sennheiser HD800 headphones.

 

[joeyjojo]

Tough decision then. I went for the B22 for the above reasons. If I were you I'd go on price and features over anything else. I haven't heard any of the dyna-'s so I don't know what the audible differences are.
 
The biggest "pros" of MOSFETS as output stage (from the B22 tech highlights page) are:
 

1. The rugged and stable MOSFETs have no "secondary breakdown" region typical of BJTs, and have a negative temperature coefficient. This allows the amp to be designed without a safe operating area (SOA) V-I limiting circuit nor does it require any thermal compensation to control "thermal runaway" conditions. This also reduces complexity, eliminates any amplitude compression effects associated with such circuitry, and provides maximum sonic transparency.
2. MOSFETs are majority-carrier devices and are faster than BJTs of comparable power ratings, because they do not exhibit the BJT's "hole storage and recombination delay" characteristics.
3. MOSFETs are voltage-to-current amplification devices (contrast to the BJT, which are current-to-current). The gate impedance of a MOSFET is very high and thus simplifies the needed drive circuit. They do have a capacitive gate characteristic but cascoding reduces that considerably, and high quiescent current in the VAS stage provides an abundant charge for high speed drive of the MOSFETs.

 
Edit: I also wouldn't personally order one or the other based on some head-fiers subjective comparison/vague feelings.
 
Quote:

If only all that translated to better SQ.
 
Headphones can and do have a soundstage. It's small and intimate compared to speakers obviously, but that doesn't mean no soundstage exists.

 
Good point, If anybody has done a blind listening test of the two amps it would be quite interesting.
 
I stand by my definition of soundstage, which is the illusion of localised sources of individual sounds/instruments in space. With headphones you certainly get different resolution of instruments from pair to another (better headphones are generally more detailed), but it's still all in 1D (left/right), not in 2D (left/right forward/back).

 

[verber]

Quote:

 
Just a quick comment on this as well - no headphone is going to give you any soundstage, at all. The nice thing about headphones is their detail and separation, but when you've heard a good speaker system you realise what "soundstage" is. It's not possible from speakers attached to your ears.

 
I would agree, in general, conventional headphones won't give the soundstage an excellent set of speakers provides... but there are some headphones that give no sound stage, and others which at least give a sense of the sound stage.  There are two options for headphones that do give a very speaker like sense of soundstage: the AKG K1000 or using a Realiser sound processor with a good set of headphones.
 
--Mark

 

[preproman]

Quote:

 
 I would not choose a dynahi over a B22.
 

 
 
Why?  Please explain.

 

[preproman]

Quote:

 
Just a quick comment on this as well - no headphone is going to give you any soundstage, at all. The nice thing about headphones is their detail and separation, but when you've heard a good speaker system you realise what "soundstage" is. It's not possible from speakers attached to your ears.

 
 
Yes when compared to speakers.  When comparing headphones to headphones some produce a better soundstage than others.

 

[MacedonianHero]

Quote:

Hey Michaelson and Morley used mph (186,350), Think of it this way and your SR009s are a bit closer...

 
But Einstein would use km/h. 

 
Quote:

 
Compared to someting like the Telefunken E88CC they are

 
I certainly wouldn't call the Telefunken E88CCs more "neutral" than the Siemens. They are slightly drier but very similar IME.

 

[joeyjojo]

Quote:

Why?  Please explain.

 
For the reasons above - easier to source components/PCBs, better documentation, thermal/electrical stability at a variety of rail voltages and gain settings, able to power small speakers if necessary. I also like the rationale of the component selection and overarching use of symmetry in the topology. I like TK's general philosophy on DIY and audio (as much as that can be figured out from reading forum posts) and the assistance by forum/email is top notch.
 
If the two can be told apart by ear in a blind test I'd be a little surprised as they're technically very similar. I haven't followed the development of the new one (dynamid?) so not sure if there are big changes there.

 

[iim7V7IM7]

Interesting issue with Sigma/Beta 22....

I am told by the builder that the two units should not be stacked for thermal and EMI/RFI reasons unless you have 3" of space between them. I have always seen people stack them. I have a single space, 23" rack. I cannot see devoting two racks for these units or stacking them with tall spacers.

 

[preproman]

Quote:

 
For the reasons above - easier to source components/PCBs, better documentation, thermal/electrical stability at a variety of rail voltages and gain settings, able to power small speakers if necessary. I also like the rationale of the component selection and overarching use of symmetry in the topology. I like TK's general philosophy on DIY and audio (as much as that can be figured out from reading forum posts) and the assistance by forum/email is top notch.
 
If the two can be told apart by ear in a blind test I'd be a little surprised as they're technically very similar. I haven't followed the development of the new one (dynamid?) so not sure if there are big changes there.

 
 
Sharhrose has both.  Hope he can chime in on the difference in SQ.  
 
I do no for myself the Gilmore amps are more transparent and in a word unforgiving compared to  AMB amps.  The βeta-22 and the M^3 that I have are colored by this I mean more tilted toward the bass.  The M^3 more than the βeta-22 but both more so than lets say a GS-1.  
 
Sharhrose has lived with these amps for a while now.  I'll put $$ on him that he can pick out the Dynahi in a blind test.  I'm sure I could do the same when I had the GS-1 and the βeta-22 together at the same time.
 
Whith that being said.  YES it is hard as heck to source the parts for the Dyanhi - I think I got some of the last boards from lil kight.  I also think Kevin is coming out with another desgin called SS (Super sym) something?     With onboard heat sinks in stead of offboard

 

[joeyjojo]

Quote:

Sharhrose has both.  Hope he can chime in on the difference in SQ.  
 
I do no for myself the Gilmore amps are more transparent and in a word unforgiving compared to  AMB amps.  The B22 and the M^3 that I have are colored by this I mean more tilted toward the bass.  The M^3 more than the B22 but both more so than lets say a GS-1.  
 
Sharhrose has lived with these amps for a while now.  I'll put $$ on him that he can pick out the Dynahi in a blind test.  I'm sure I could do the same when I had the GS-1 and the B22 together at the same time.
 
Whith that being said.  YES it is hard as heck to source the parts for the Dyanhi - I think I got some of the last boards from lil kight.  I also think Kevin is coming out with another desgin called SS (Super sym) something?     With onboard heat sinks in stead of offboard

 
Cheers. Just noticed I recognise your nick from around the place, in particular here. I was looking for that thread the other day so thanks for the reminder.
 
It would be interesting, as they both measure as flat, fast, negligibly distorting, un-phase-shifting etc. as each other. Having never heard them together I can't be sure, but everything is telling me they should be indistinguishable in a level matched blind test.
 
If your impressions are that the B22 is tilted towards the bass, I'd say (again, just from the specs and listening to mine), that the B22 is flat, and whatever you're comparing it to must be lacking bass. Go with your preferences ofc but it's nothing an EQ can't fix.
 
The super sym stuff is interesting. I believe Nelson Pass has a rather broad patent on it, so TK went and asked permission to continue with the B24 as there are some similarities. They were both working independently though so NP said it was fine.

 

[preproman]

Quote:

 
Cheers. Just noticed I recognise your nick from around the place, in particular here. I was looking for that thread the other day so thanks for the reminder.
 
It would be interesting, as they both measure as flat, fast, negligibly distorting, un-phase-shifting etc. as each other. Having never heard them together I can't be sure, but everything is telling me they should be indistinguishable in a level matched blind test.
 
If your impressions are that the B22 is tilted towards the bass, I'd say (again, just from the specs and listening to mine), that the B22 is flat, and whatever you're comparing it to must be lacking bass. Go with your preferences ofc but it's nothing an EQ can't fix.
 
The super sym stuff is interesting. I believe Nelson Pass has a rather broad patent on it, so TK went and asked permission to continue with the B24 as there are some similarities. They were both working independently though so NP said it was fine.

 
 
Yes - that's my other adventure I'm looking into.  Although I'm not a builder and don't even know how to open a case (just joking)  I love DIY and the DIY type stuff - like the "Liquid Gold".  I'm looking for a builder that will build me a B24 Pure Class A style amp.
 
 
 

 

[iim7V7IM7]

Quote:

 
Cheers. Just noticed I recognise your nick from around the place, in particular here. I was looking for that thread the other day so thanks for the reminder.
 
It would be interesting, as they both measure as flat, fast, negligibly distorting, un-phase-shifting etc. as each other. Having never heard them together I can't be sure, but everything is telling me they should be indistinguishable in a level matched blind test.
 
If your impressions are that the B22 is tilted towards the bass, I'd say (again, just from the specs and listening to mine), that the B22 is flat, and whatever you're comparing it to must be lacking bass. Go with your preferences ofc but it's nothing an EQ can't fix.
 
The super sym stuff is interesting. I believe Nelson Pass has a rather broad patent on it, so TK went and asked permission to continue with the B24 as there are some similarities. They were both working independently though so NP said it was fine.

 
I associate perceptions of “warmth” in sound with two things:
 

1. Harmonic distortion of frequency response deviations in reproduction or,
2. A deviation in the balance of frequencies reproduced where either the bass frequencies or high frequencies are attenuated relative to the mid-range effecting how we perceive the sound.

 
In the case of the AMB and Gilmore amps, they both have fantastically linear performance across the audible frequencies so I doubt this is the cause of perceived “warmth”.  The second reason is possible but unlikely. If the Beta 22 presents low frequencies <150 Hz at higher dB level than the GS-X for example, one might perceive the sound as warmer.  Why this would be is an interesting question that I have no explanation for (differences in power bandwidth or something about MOSFETS etc.?).

 

[iim7V7IM7]

Down to Two

I have now narrowed my selection to two amps. One solid state and balanced and the the other tube based and singled ended with balanced outs.

AMB Audio 4-Channel Sigma/Beta 22
or
DNA Stratus 2A3

Both are excellent amps and it will be difficult to decide. Both will require a custom cable with a 4-pin XLR to take advantage of each amps balanced outs. The AMB will require that I use the balanced TRS outs on my m903 and the DNA will use unbalanced outs. The base cost is similar on both.

Upgrades on the AMB like a 2nd PSU in the Sigma 22, a Goldpoint attenuator, transformers will make the AMB about $800 more than the DNA; but that difference will end once I venture into tube rolling with Emission Labs 2A3s or a NOS rectifier.

Given that I own the m903 and while I will use it as a DAC with either amp, I will still have it as a SS headphone amp. Do I add a better SS balanced amp or do I add a tube amp?

What say you?

Bob

 

[purk]

Quote:

Down to Two
I have now narrowed my selection to two amps. One solid state and balanced and the the other tube based and singled ended with balanced outs.
AMB Audio 4-Channel Sigma/Beta 22
or
DNA Stratus 2A3
Both are excellent amps and it will be difficult to decide. Both will require a custom cable with a 4-pin XLR to take advantage of each amps balanced outs. The AMB will require that I use the balanced TRS outs on my m903 and the DNA will use unbalanced outs. The base cost is similar on both.
Upgrades on the AMB like a 2nd PSU in the Sigma 22, a Goldpoint attenuator, transformers will make the AMB about $800 more than the DNA; but that difference will end once I venture into tube rolling with Emission Labs 2A3s or a NOS rectifier.
Given that I own the m903 and while I will use it as a DAC with either amp, I will still have it as a SS headphone amp. Do I add a better SS balanced amp or do I add a tube amp?
What say you?
Bob

 
Can you attend a local meet prior to making decision?  How about buy a used balanced Beta22 to reduce the cost.  There seems to be several used maxed out Beta22 for sale for 1.5 to 2.3k.