[chengka7]

Craig is building my MKIV right now, and will be finished soon I guess. I actually ordered 445 but it has been delayed due to the redesign, so I switch to 2A3MKIV. I am so excited. 

 

[rydenfan]

So for HD800's is the recommendation the 2A3 or 445? And what are the major differences in SQ between them?

 

[Stapsy]

  I was part of the first run of 4-45s. My amp, #3, was delivered yesterday.
 
Just a note for future 4-45 owners. When you power on the amp, you will hear a truly terrifying noise that sounds like aliens boring into your brain. When I first heard this I was unprepared, and it scared the sh!t out of me. I immediately powered down the amp and contacted Craig who assured me this sound---what he innocently calls "the Star Trek noise"---is 100% normal for this amp. It lasts for about 10 seconds before going away. If you find yourself turning on a 4-45, you too will likely hear this Borg-sticking-dental-equipment-into-your-ears sound. Be prepared.
 
The 4-45 is not a "god amp" (as a certain forum says) but rather a "demon amp" that will strike fear into any other amp in the vicinity with its mighty roar before devouring its soul. When the beast's thirst for audiophile blood is quenched, the noise subsides leaving you with a background as quiet as a tomb.

 
LOL the same thing happened to me.  The sound has developed a certain musicality to it after 3 months.  It is quite comforting to hear the shriek after a long day at work.

 

[Rico613]

   
Indeed, for example, the BA is FULLY BALANCED, in and out, while the 4-45 has balanced outputs, but only RCA inputs !  
 
is this a drawback or it does not make any SQ difference ?
 

This would be a deal breaker for me.  Maybe the redesign will have balanced inputs?

 

[bmichels]

This would be a deal breaker for me.  Maybe the redesign will have balanced inputs?

Well bellow is what Cutrus wrote to me on April 13th:


"The 4-45 is a speaker/ headphone amplifier. It has balanced outputs, but only RCA inputs. Power is 3 watts into 8 ohms.

I am out of stock, new amps are 6-8 weeks away"

 

[Rico613]

I know some people don't have a problem with single ended cables and RCA connections.  In my experience balanced interconnects between the DAC and amplifier make noticeable difference in sound stage and overall sound quality.  There is less of a difference on the outputs, but still noticeable.
 
I'll have to check with Craig.  I wonder if the MKIV is single ended or balanced . . . ?

 

[Stapsy]

It is single ended.  I am not an expert but as I understand the mk4 and 445 are single ended designs.  There would be no point to balanced inputs.  The balanced output is balanced off the transformers.  I haven't noticed a difference when using the 4pin xlr vs 1/4 jack.

 

[purrin]

 
Indeed, for example, the BA is FULLY BALANCED, in and out, while the 4-45 has balanced outputs, but only RCA inputs !  
 
is this a drawback or it does not make any SQ difference ?

 
It's more like a tradeoff. The BA does take balanced inputs, but the balanced inputs are converted to SE via transformers (those two small cylinders marked Cinemag mounted on the back panel of the BA). This is both good and bad. The good is that both legs of the balanced output are actually used. The bad is that we are adding an unnecessary reactive component in the signal path. Some DACs which have balanced output capability, electically sum the balanced signal for the SE output. So in this case, using short (not 30ft. length in studios) patch cables, it shouldn't matter on the 4-45. Other DACs, like the PWD2 I had, sort of cheat and simply use one leg of the balanced for its SE output. Taking the PWD2 for example, I felt the SQ was kind of a wash between the SE (one leg of the balanced) and balanced outputs into the BA. Really too close to call. It's important to understand that the BA is still a SE amp.
 
If you wanted to, you could wire up or have Craig build you a balanced to SE transformer box, but honestly, and depending upon the design of your DAC, it could be a waste of money as good transformers, even small ones, are expensive.
 

 
So I wonder if the 4-45 is just a more powerful BA that is useful only with very hard to drive headphones or... does the 4-45 sound better than the BA with ALL headphones ?

 
Taking out of consideration for any preference toward specific tube types, the 4-45 sounds better than the BA with all headphones across the board in terms of resolution, macro-micro dynamics, layering, separation, clarity, imaging, realism, and immediacy. It's hard to put into words, but "REAL" factor is definitely there, especially now that I've got the complement of tubes in there that I want. The 4-45 is a step up in driver control from the BA when it comes to orthos, but is still a step behind compared to the best solid-state.

 

[purrin]

Marv,

Can you compare the 445 with the Dynahi for some harder to drive cans (orthos particularly). Much as I love my BA and it with the Lampizator really is head and shoulders better than anything else I've heard with the HD800. However, the Dynahi just does well with everything reducing the BA to a bit of a one trick HD800 pony. Even the AD2000 I prefer with the Zana Deux. Does the 445 effectively replace the need for two amps like the D-Hi and BA?

 
Considering that the ZD has quite a unique presentation different from the BA that really does work well with the AD2000: Taking a conservative stance, I'm afraid that you may still find the 4-45 a one trick pony. However, it's possible or even probable that you may find the 4-45 + AD2000 combo as a truly viable alternative to the ZD + AD2000 combo. My initial assessment of the 4-45 being the "God" amp was with the AD2000 after all, not the HD800 or Abyss which I am mostly using with it.
 
The 4-45 (and 2A3mk4) is probably the best EC amp right now for driving orthos. Steps it up a bit from the BA - much less soft. However, the 4-45 is still a notch behind the best solid-state amps for ortho driver control. The 4-45 of course brings other things to the table, but the extent of which orthos can take advantage of these things, i.e. scale appropriately is in question. And then it comes down to personal sensibilities.

 

[Sko0byDoo]

  I know some people don't have a problem with single ended cables and RCA connections.  In my experience balanced interconnects between the DAC and amplifier make noticeable difference in sound stage and overall sound quality.  There is less of a difference on the outputs, but still noticeable.
 
I'll have to check with Craig.  I wonder if the MKIV is single ended or balanced . . . ?

 
Use this if you have to do balanced into SE amp:
 
http://www.ebay.com/itm/Jensen-Transformers-PC-2XR-XLR-RCA-Audio-Converter-Balanced-to-Unbalanced-/400456028519?pt=US_Signal_Amplifiers_Filters&hash=item5d3d0a1167
 
BA has this built-in.

 

[CEE TEE]

^Fantastic rundown, thanks!!  That's a great and concise update on the differences and uses... Short of buying them and trying them all with those phones, it's really hard to get that kind of info. 
 
(Especially since two of those amps are scarce and one isn't even out yet.)
 
BTW, the first time I heard that cool horror/sci-fi sound on start up (if it is the same sound)- I was freaked out too.  jazzfan lent me his EML Mesh-Plate 300B to try in the BA.  At first I wanted to run, but now I think it is one of the coolest/craziest sounds that I have heard.  Unfortunately, my EML Solid Plates and KR PX-4 tubes don't do that.  And, if this is four tubes making that sound instead of two tubes? 
Hopefully someone can record it and post it.

 

[Rico613]

 

  I know some people don't have a problem with single ended cables and RCA connections.  In my experience balanced interconnects between the DAC and amplifier make noticeable difference in sound stage and overall sound quality.  There is less of a difference on the outputs, but still noticeable.
 
I'll have to check with Craig.  I wonder if the MKIV is single ended or balanced . . . ?

 
Use this if you have to do balanced into SE amp:
 
http://www.ebay.com/itm/Jensen-Transformers-PC-2XR-XLR-RCA-Audio-Converter-Balanced-to-Unbalanced-/400456028519?pt=US_Signal_Amplifiers_Filters&hash=item5d3d0a1167
 
BA has this built-in.

Thanks . . not sure it would be necessary but good to know.

 

[bmichels]

   
It's more like a tradeoff. The BA does take balanced inputs, but the balanced inputs are converted to SE via transformers (those two small cylinders marked Cinemag mounted on the back panel of the BA). This is both good and bad. The good is that both legs of the balanced output are actually used. The bad is that we are adding an unnecessary reactive component in the signal path. Some DACs which have balanced output capability, electically sum the balanced signal for the SE output. So in this case, using short (not 30ft. length in studios) patch cables, it shouldn't matter on the 4-45. Other DACs, like the PWD2 I had, sort of cheat and simply use one leg of the balanced for its SE output. Taking the PWD2 for example, I felt the SQ was kind of a wash between the SE (one leg of the balanced) and balanced outputs into the BA. Really too close to call. It's important to understand that the BA is still a SE amp....
 

 
Thanks a lot purrin for those precises informations. very helpfull...  
 
- Based on the above, I am just now a little concern that the 4-45 may nor be the best Amp for my Alpha DOG (& may be soon LCD X) ! What is THE Headphone that offer with the 4-45 the BEST synergy that you know?
 
- Now, do you have a DAC to recommend for the 4-45 (something (SE ?) with which you expect or have experienced GREAT synergy) ? 
 
- And, is a "tube based" DAC a good idea (Lampisator,...) for the 4-45 or will it be "too much tubes" in the line

 

[chengka7]

When I asked Craig what is the best amp for HD800 and HD650, he told me like this：
 
If all you want is a good headphone amp to run HD800, HD650 headphones, the 445 amp is the best sound. Second best is the 445 proto amp that I sent a picture of.
 
And based on the other comment, 445 should work best with HD800. 

 

[bmichels]

  When I asked Craig what is the best amp for HD800 and HD650, he told me like this：
 
If all you want is a good headphone amp to run HD800, HD650 headphones, the 445 amp is the best sound. Second best is the 445 proto amp that I sent a picture of.
 
And based on the other comment, 445 should work best with HD800. 

thanks, but what is the difference between the 445 and the 445 proto ??