[JeremiahS]

Hi Luke, 
 
Sorry, I have not heard the M3 before so I cannot comment too much about it. 
 
However a colleague own the HeadAmp GS-X MK2 which if I am not wrong has the same operating principles as the Dynalo. 
 
I would say that the GS-X MK2 has a rather bright and cold sound signature, very detailed but for me it is hard to enjoy because it has a glare to its sound especially in the treble. I think someone here have made a comparison review between the GS-X MK2 and other top solid-state amps and he also noted this glare issue. 
 
The Beta22 has a neutral-to-warm sound signature. It has solid state control and dynamics but at the same time has a tube-like fluidity to its sound. I think it has a sound characteristic that is not so impressive in the first listen but you come to appreciate in long term. 
 
Another solid state amp that I like is the Luxman P-700u. This is more tube like than the Beta22. 
 
The unit I tested is a fully-balanced build. Hope this helps. 
 
Regards,
Jeremiah 

 

[luke99]

I think its real name is an M cubed, its quite well known design: http://www.amb.org/audio/mmm/  
The amp you are describing is I think the balanced version of the Dynalo I like so much. I get no glare or cold. I find it very transparent and neutral. It has dynamics and good bass. 
Dynamics is an interesting aspect of amplifiers too. I find that too much slam is very engaging at first and sounds lively, but can begin to sound exaggerated or forced and becomes tiresome. I think the Dynalo is in the middle here. I am not good at describing music, but to quote Nelson Pass "We are in the entertainment business". We all like different things. I just wish I didn't have to build everything to hear it 

 

[Jose R]

  Hi Jeremiah,
 
I am quite curious about this amp but when I read warm and tube like I loose interest. I had an M3 and found it too soft and warm for my liking. Is the Beta22 a similar signature?
My next amp will be a balanced dynalo, SE version is excellent so I'm going to try balanced but run it SE until I get cans that I can run balanced. I guess the only way to know what the Beta22 sounds like is build one and see for myself.

There are many ways to build an M3. Unlike the Beta22, which is a discrete circuit, the M3 employs opamps. Thusly, its sound signature can be *customized*, depending on the builder's preferences.
 
An M3 in balanced configuration, with the default AD8610 as the output device, is not soft nor warm.
 
I have not heard a Beta22, but do plan to build a balanced version (I already have the boards) once I am done re-building my SE tube amp.

 

[luke99]

Judging by your avatar you would know I think it had AD8610 opamp but cant remember, I didn't have it long. At the time I think I had ATH-AD700 HP, which wasn't for me, so its hard to know why I decided to get rid of it. I'm not so much into opamp rolling, but I'm quite keen to try the new National opamps in my Sapphire 3.0. That's a very good amp BTW.

 

[Stillhart]

Hi all,
 
I'm starting the planning stage for my B22 build now.  I want to do a relatively simple build for my first one and then potentially to one with all the bells and whistles after.  I plan on doing a 3-board active ground B22 with a Sigma22 power supply.  No speaker taps, no stepped attenuator or selectable inputs or anything like that.  Just a straightforward B22+S22.
 
I have a few questions I was hoping someone might be able to help with:

• Is it possible to get the Epsilon22 backplane board anymore?
• Can anyone recommend a good case for the 3-board beta?  My priority is keeping it compact.  I was thinking of just using the recommended Hammond 1455T220x for the Sigma, but I'm not sure if the 3-board Beta will fit.
• Can anyone recommend a good guide on how to do the case work?  That's really the part I'm most worried about.  I don't want to buy a custom front or back plate, I want to cut my own holes and use a dremel to engrave the lettering as needed (with a simple build, it's probably not even needed!)
• Recommended gain/attenuation level for HE-560, HE-1000, Q701, HD650?

 
Thanks, folks!

 

[Zashoomin]

  Hi all,
 
I'm starting the planning stage for my B22 build now.  I want to do a relatively simple build for my first one and then potentially to one with all the bells and whistles after.  I plan on doing a 3-board active ground B22 with a Sigma22 power supply.  No speaker taps, no stepped attenuator or selectable inputs or anything like that.  Just a straightforward B22+S22.
 
I have a few questions I was hoping someone might be able to help with:

• Is it possible to get the Epsilon22 backplane board anymore?
• Can anyone recommend a good case for the 3-board beta?  My priority is keeping it compact.  I was thinking of just using the recommended Hammond 1455T220x for the Sigma, but I'm not sure if the 3-board Beta will fit.
• Can anyone recommend a good guide on how to do the case work?  That's really the part I'm most worried about.  I don't want to buy a custom front or back plate, I want to cut my own holes and use a dremel to engrave the lettering as needed (with a simple build, it's probably not even needed!)
• Recommended gain/attenuation level for HE-560, HE-1000, Q701, HD650?

 
Thanks, folks!

1.  If amb isn't stocking them anymore you can ask around but one isn't necessary.  
2.  I get my cases from parmetal, but you can also get some from modushop.  If you are going simple though I suggest you do a 1 chassis build, so you will need someting that can fit 4 boards and a transformer.  Just remember that if you are doing a 1 chassis build, twisting the wires is very important.  It will eliminate a lot of the noise in the circuit.  
3.  dunno about a guide, but i would not recommend you use a dremel to engrave the lettering unless you have very strong and steady hands, or you are engraving wood/plastic.  (like you said I don't think its needed either)  
4. the default 8x gain should work wonderfully for everything but IEMs.  

 

[Stillhart]

  1.  If amb isn't stocking them anymore you can ask around but one isn't necessary.  
2.  I get my cases from parmetal, but you can also get some from modushop.  If you are going simple though I suggest you do a 1 chassis build, so you will need someting that can fit 4 boards and a transformer.  Just remember that if you are doing a 1 chassis build, twisting the wires is very important.  It will eliminate a lot of the noise in the circuit.  
3.  dunno about a guide, but i would not recommend you use a dremel to engrave the lettering unless you have very strong and steady hands, or you are engraving wood/plastic.  (like you said I don't think its needed either)  
4. the default 8x gain should work wonderfully for everything but IEMs.  

 
Awesome, thanks a ton!  I have no idea how to figure out the case size needed, but I'm going to work on it a bit and report back.

 

[Zashoomin]

   
Awesome, thanks a ton!  I have no idea how to figure out the case size needed, but I'm going to work on it a bit and report back.

If you are going with a parmetal case you can get a 16x12x(whatever height you deem fit)  will fit everything comfortably with room to spare. You can go smaller than that but it is going to be a tight.  Or you can even order a custom size from them for a reasonable price, but it won't be as cheep as the chassis they stock.   

 

[amb]

The PCB dimensions are documented at the β22 and σ22 websites. You want to arrange the PCBs in the case for optimal signal routing, and place the power transformer as far away from the amp boards as possible. Once you establish the basic layout, then find a case that would fit. You could also go the opposite direction, start with a case and then try to fit everything in, knowing that it may or may not work well, and you may need to go to a different size case. Don't forget to take maximum component height + PCB thickness + standoff height into consideration for case height (internal).

There are lots of example β22 builds at the website gallery, use them as reference and inspiration.

 

[Stillhart]

  If you are going with a parmetal case you can get a 16x12x(whatever height you deem fit)  will fit everything comfortably with room to spare. You can go smaller than that but it is going to be a tight.  Or you can even order a custom size from them for a reasonable price, but it won't be as cheep as the chassis they stock.   

 
Thanks again.  
 
Another noob question:  For the voltage of the PSU, it says to keep it between 24V and 30V, with 24 running cooler and 30 providing more power and voltage swing.  I'm tempted to keep it cooler at the expense of some power since I'm not planning on driving anything particularly difficult.  I believe the B22 has gobs of power so losing a bit isn't going to be a big deal, especially if I'm not driving speakers.  Does this sound about right?

 

[Stillhart]

The PCB dimensions are documented at the β22 and σ22 websites. You want to arrange the PCBs in the case for optimal signal routing, and place the power transformer as far away from the amp boards as possible. Once you establish the basic layout, then find a case that would fit. You could also go the opposite direction, start with a case and then try to fit everything in, knowing that it may or may not work well, and you may need to go to a different size case. Don't forget to take maximum component height + PCB thickness + standoff height into consideration for case height (internal).

There are lots of example β22 builds at the website gallery, use them as reference and inspiration.

 
I'm quite jealous of all the builds with the E22 board.  Any idea if you're going to print more?
 
For now, I'm thinking a 3" height should suffice, but still looking...

 

[amb]

Newer builds now appear at AMB DIY audio forum, either in the β22 amplifier subforum or the "Post pics of your builds" thread under "General DIY discussions". You can also ask questions there.

 

[jcx]

well some questions are welcome there - its actually a feature for a project to have a fully independent forum that reigns in fanboy attacks against even the slightest deviation from the party line
 
just try getting a objective response to questioning the theory, show measurements of "3-channel ground" flaws there

 

[JeremiahS]

  I think its real name is an M cubed, its quite well known design: http://www.amb.org/audio/mmm/  
The amp you are describing is I think the balanced version of the Dynalo I like so much. I get no glare or cold. I find it very transparent and neutral. It has dynamics and good bass. 
Dynamics is an interesting aspect of amplifiers too. I find that too much slam is very engaging at first and sounds lively, but can begin to sound exaggerated or forced and becomes tiresome. I think the Dynalo is in the middle here. I am not good at describing music, but to quote Nelson Pass "We are in the entertainment business". We all like different things. I just wish I didn't have to build everything to hear it 

 
Hi Luke, 
 
I think I can generally agree with you there. I remember testing the Schiit Mjolnir and it has the same "over dynamics" problem you describe there, it got fatiguing real fast with music with lots of saxophone. 
 
Perhaps this kind of signature is aimed at a younger crowd. I am new to headphones and there is a lot of young people, a lot more than your usual hi-fi speaker crowd. 
 
What main headphone you are using by the way? 
 
Regards,
Jeremiah 
 
 

  well some questions are welcome there - its actually a feature for a project to have a fully independent forum that reigns in fanboy attacks against even the slightest deviation from the party line
 
just try getting a objective response to questioning the theory, show measurements of "3-channel ground" flaws there

 
Hi jcx, 
 
What is your opinion on the 3-channel ground? 
 
I remember talking about this with my DIY-er friend and he thinks that it is not really necessary. He is a fan of "monoblock" arrangement and his personal Beta22 is also built in such manner. 
 
He's a bit of artist but I have a lot of respect for him because his Beta22 is seriously awesome sounding. 
 
I hope I can learn more about this. If I remember right, there is a portable amp that I like, the Triad L3 and it's specifically a 3-channel design. 
 
Regards,
Jeremiah

 

[Stillhart]

  snip
 
Hi jcx, 
 
What is your opinion on the 3-channel ground? 
 
I remember talking about this with my DIY-er friend and he thinks that it is not really necessary. He is a fan of "monoblock" arrangement and his personal Beta22 is also built in such manner. 
 
He's a bit of artist but I have a lot of respect for him because his Beta22 is seriously awesome sounding. 
 
I hope I can learn more about this. If I remember right, there is a portable amp that I like, the Triad L3 and it's specifically a 3-channel design. 
 
Regards,
Jeremiah

 
+1 I'm interested in hearing more about this as well.  The 3-channel setup is "recommended" for headphones and "gives many of the advantages of balanced".  Those sound appealing.  What's the down side?