[burdie]

HPA-3B : LME49990 vs LME49720ha

High: LME49990 > LME49720 (LME49990 definitely clearer, LME49720 not far behind)
Mid:  LME49990 = LME49720
Low:  LME49990 < LME49720 (bass on LME49990 not solid as LME49720)
The better performance on high for LME49990 cannot 'compensate' the worser bass performance. So I stick to LME49720HA.
 
Volume Knob

I still prefer the volume knob to be one big round shape

 

[keanex]

  Has anyone been able to enable DSD through Audirvana?  I show DSD64 and DSD128 grayed out.

Did you install the drivers?

 

[reeseg]

No drivers necessary on the Mac.  It must be a setting in preferences somewhere.  I did figure out that I should only get DSD 64...but still looking.

 

[lucasseijikc]

Has anyone tried the Matrix M-Stage HPA-3U with the AKG K702s yet?
 
I am considering buying this amp/DAC to pair up with my K702s.
 
I really like the sound to be as neutral as possible, and was wondering if the HPA-3U would be a good match for that.
 
Thanks in advance!

 

[Ultrainferno]

I have just published Dave's review of the "new" HPA-3U on the site. I only had the pleasure to listen to the original M-Stage myself, too bad they aren't this present in Europe. Dave does really like it with his HD650 it seems.

 

[DigitalFreak]

My reviews up folks


http://headphone.guru/the-new-matrix-audio-m-stage-hpa-3u/

 

[raoultrifan]

  HPA-3B : LME49990 vs LME49720ha

High: LME49990 > LME49720 (LME49990 definitely clearer, LME49720 not far behind)
Mid:  LME49990 = LME49720
Low:  LME49990 < LME49720 (bass on LME49990 not solid as LME49720)
The better performance on high for LME49990 cannot 'compensate' the worser bass performance. So I stick to LME49720HA.

 
Hi burdie, 
 
You do realize that you're actually rolling +/-22V OPAMPs with +/-17V OPAMPs (LME49720)? HPA-3B has NJM7818/NJM7918 (JRC actually) power regulators installed and these two are regulating a power voltage of +/-18V, so the two audio dual-OPAMPs from inside HPA-3B and also all output transistors are actually powered by +/-18V; this is why manufacturer choose LME49860, because there are not many OPAMPs out there designed to work 24/7 at +/-18V (36V) voltage (Violectric/Lake People choose LME49860 from the same reason, but also because the sound is very good when used as voltage gain OPAMP). OPA134/2134 might handle +/-18V as well, but this is max. recommended voltage for them, like LME49990.
 
Feel free to use LME49990 if you like them, but at least place a decent heatsink on top (glued with Arctic Alumina or with a good heat transfer tape). Their max. recommended voltage by manufacturer would be +/-18V.
 
As for the LME49720HA, I would strongly recommend you to take them out from HPA-3B, because you'll most likely kill'em slowly...sorry.  
http://www.ti.com/lit/ds/symlink/lme49720.pdf - their max. recommended voltage by manufacturer would be +/-17V, despite their absolute max. voltage of +/-18V. Also, "(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur", so keeping LME49720 for long time at +/-18V would really not be a very good idea.
 
Thank you, 
Raul.
 
P.S.: I like the sound of this headamp: it's strong and powerful and can drive all phones around here, balanced and unbalanced as well. Quite decent construction I'd say and good sounding amp, strongly recomended for its price.
 
L.E.: Adding a couple of pictures with the 2 regulators:
 

 

[raoultrifan]

  Has anyone tried the Matrix M-Stage HPA-3U with the AKG K702s yet?
 
I am considering buying this amp/DAC to pair up with my K702s.
 
I really like the sound to be as neutral as possible, and was wondering if the HPA-3U would be a good match for that.
 
Thanks in advance!

Hi, 
 
It sounds very well on my K701; gain of +10dB should be perfect, but also at gain of +5dB will work just fine. Gain of +20db should not be pressed while listening to K701/K702, unless volume knob is on the left half (between 7 o'clock to 12 o'clock).
 
This little beast headamp can drive perhaps all headphones from the planet. Give it a try if you have the opportunity, but to be honest there's nothing not to like here (MOSFET sound is quite good and neutral).
 
Cheers,
Raul.

 

[burdie]

   
Hi burdie, 
 
You do realize that you're actually rolling +/-22V OPAMPs with +/-17V OPAMPs (LME49720)? HPA-3B has NJM7818/NJM7918 (JRC actually) power regulators installed and these two are regulating a power voltage of +/-18V, so the two audio dual-OPAMPs from inside HPA-3B and also all output transistors are actually powered by +/-18V; this is why manufacturer choose LME49860, because there are not many OPAMPs out there designed to work 24/7 at +/-18V (36V) voltage (Violectric/Lake People choose LME49860 from the same reason, but also because the sound is very good when used as voltage gain OPAMP). OPA134/2134 might handle +/-18V as well, but this is max. recommended voltage for them, like LME49990.
 
Feel free to use LME49990 if you like them, but at least place a decent heatsink on top (glued with Arctic Alumina or with a good heat transfer tape). Their max. recommended voltage by manufacturer would be +/-18V.
 
As for the LME49720HA, I would strongly recommend you to take them out from HPA-3B, because you'll most likely kill'em slowly...sorry.  
http://www.ti.com/lit/ds/symlink/lme49720.pdf - their max. recommended voltage by manufacturer would be +/-17V, despite their absolute max. voltage of +/-18V. Also, "(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur", so keeping LME49720 for long time at +/-18V would really not be a very good idea.
 
Thank you, 
Raul.
 
P.S.: I like the sound of this headamp: it's strong and powerful and can drive all phones around here, balanced and unbalanced as well. Quite decent construction I'd say and good sounding amp, strongly recomended for its price.
 
L.E.: Adding a couple of pictures with the 2 regulators:
 

Hi Raul,
Thanks for your advise. In fact I have consider the regulated max 18V power voltage supplied to the opamps and other components. The max voltage that 49720 can handle if not mistaken should be 17V+0,7V, so that is very close to the 18V supply power. After considering that the power voltage pass through few components/resistor and theoritically voltage should drop a bit, I risk burning the opamps and proceed with the rolling.
However, I have 4 pieces of 49720HA, two of it (with heatsink) are not stable and causing HPA-3B enter into protection mode, i.e. cut off power itself, when gain set at +20db, but it works perfectly when the gain set at +10db or below. The other two 49720HA just work perfectly under +20db. I tried 49720NA (DIP-8) also and let it ran for 2-3 hours and nothing happened.
This protection design (which found on other Matrix product as well) somehow protect the opamps and I really don't like LME49990 as it lacks of bass. 

 

[burdie]

  Hi, 
 
It sounds very well on my K701; gain of +10dB should be perfect, but also at gain of +5dB will work just fine. Gain of +20db should not be pressed while listening to K701/K702, unless volume knob is on the left half (between 7 o'clock to 12 o'clock).
 
This little beast headamp can drive perhaps all headphones from the planet. Give it a try if you have the opportunity, but to be honest there's nothing not to like here (MOSFET sound is quite good and neutral).
 
Cheers,
Raul.

You will be amazed by how well HPA-3B paired with 'balanced' AKG K701, comparing to single ended K701. Please do so if you haven't

 
I did compare HPA3 with WA6 (both in SE mode) with a group of head-fier. Well, HPA3 can drive perhaps all headphones from the planet but it doesn't mean it can drive at good sounding, at least not on Beyer T1 gen 1/gen 2. However, HPA3 do give better sounding than WA6 in few headphones we try, LCD 2.2, K701, K712, DT1770, ATH-R70X etc when the opamps are 49990 and 49720, and all of us ranked HPA3 below WA6 when it equipped with LME49860, as clarity gone with LME49860.

 

[raoultrifan]

Thank you burdie for your thoughts on the LME49720HA and for the "protection circuit" that needs to get "investigated" somehow.
Also, helps reading http://sjostromaudio.com/pages/index.php/miscellaneous/170-how-does-it-sound about LME49860 sound and like I said before Violectric/Lake People guys are building quite nice headamps around LME49860, so I really think that this OPAMP could be a keeper in HPA-3B, unless upgraded with something discrete like Audio-GD or Burson (ofc, able to operate at +/-18V).
 
Thanks a lot for the info about balanced K701; will do this in the next few days. I just finished last night my balanced DT880/600: 2 cables CORDIAL CMK ROAD 250 BK having 2x0.5mm2 copper wires with good shielding inside (outer plastic/PVC was stripped by me because of outer diameter was too big and heavy, so right now cable is very shiny because of the copper shielding being visible; will add some nice sleeving soon, so no worries) + Amphenol 4-pin 100% metallic shielded plug. This evening I'm gonna give'em a spin. BTW, original DT880/600 cable had 1 ohm on each hot wire and 2 ohms for the GND, quite a lot I'd say; the new cable has 0.086 ohms/meter.
 
Raul.

 

[burdie]

  Thank you burdie for your thoughts on the LME49720HA and for the "protection circuit" that needs to get "investigated" somehow.
Also, helps reading http://sjostromaudio.com/pages/index.php/miscellaneous/170-how-does-it-sound about LME49860 sound and like I said before Violectric/Lake People guys are building quite nice headamps around LME49860, so I really think that this OPAMP could be a keeper in HPA-3B, unless upgraded with something discrete like Audio-GD or Burson (ofc, able to operate at +/-18V).
 
Thanks a lot for the info about balanced K701; will do this in the next few days. I just finished last night my balanced DT880/600: 2 cables CORDIAL CMK ROAD 250 BK having 2x0.5mm2 copper wires with good shielding inside (outer plastic/PVC was stripped by me because of outer diameter was too big and heavy, so right now cable is very shiny because of the copper shielding being visible; will add some nice sleeving soon, so no worries) + Amphenol 4-pin 100% metallic shielded plug. This evening I'm gonna give'em a spin. BTW, original DT880/600 cable had 1 ohm on each hot wire and 2 ohms for the GND, quite a lot I'd say; the new cable has 0.086 ohms/meter.
 
Raul.

Many have argued on LME49720/49860 family and mostly think they are identical in both specs and sound, 49720HA merely a metal can version over LME49720NA and LME49860. Many now support LME49990 as claimed it is one of the best spec among many compatible opamps out there.
As of LME49720/49720HA/49860, I still think that the metal can version LME49720HA has the best sounding among the family members..
 
reading from the specs, CORDIAL CMK ROAD 250 BK using bare copper which will be oxidized, why not consider others that using OFC., ultra pure OFC, linear crystal OFC, silver plated OFC, hybrid or silver cable?

 

[raoultrifan]

 
Many have argued on LME49720/49860 family and mostly think they are identical in both specs and sound, 49720HA merely a metal can version over LME49720NA and LME49860. Many now support LME49990 as claimed it is one of the best spec among many compatible opamps out there.
As of LME49720/49720HA/49860, I still think that the metal can version LME49720HA has the best sounding among the family members..

 
I've seen some time ago a pretty good explanation about why metallic and ceramic OPAMPs might sound better, sorry I can't remember where exactly, but the explanation was quite plausable. Meantime, here's a good pool: http://www.head-fi.org/t/521972/lm4562-lme49720-lme49860-do-they-sound-different-to-you. BTW, 6moons says that "

LME49720HA make sense as they are basically the metal can version of the LME49860", but I was sure it's the metal version of LME49720...hmmm, strange.
 

  reading from the specs, CORDIAL CMK ROAD 250 BK using bare copper which will be oxidized, why not consider others that using OFC., ultra pure OFC, linear crystal OFC, silver plated OFC, hybrid or silver cable?

 
Couldn't find a better cable right now, but I wouldn't worry about this too much, because the 2 "hot wires" from inside each cable have 2 decent outer sheets + the outer copper shield + future sleeving. Anyway, cable is really thick (AWG 20), so if oxidation will occur that will happening only to the outside of the copper wires and perhaps after at least 10 years of service. If I will ever find better cables I will probably upgrade them, but right now I bought these because lack of time and because I need right now some balaced headphones to test the new M-Stage headmp.
 
Might worth reading:
http://www.head-fi.org/t/408073/why-oxygen-free-copper-cables-sound-no-different-than-etp-copper
http://www.avsforum.com/forum/89-speakers/1014081-speaker-wire-does-oxygen-free-matter.html
 
P.S.: I have a friend having a small recording studio and he told me these CORDIAL ROAD cables are quite decent, so if his high impedance and very sensitive microphones are sounding OK after a couple of years of intensive usage, I'm preety sure my heapdhones should sound great after at least 10 years with these cables

 

[burdie]

   
 
Couldn't find a better cable right now, but I wouldn't worry about this too much, because the 2 "hot wires" from inside each cable have 2 decent outer sheets + the outer copper shield + future sleeving. Anyway, cable is really thick (AWG 20), so if oxidation will occur that will happening only to the outside of the copper wires and perhaps after at least 10 years of service. If I will ever find better cables I will probably upgrade them, but right now I bought these because lack of time and because I need right now some balaced headphones to test the new M-Stage headmp.
 
 
P.S.: I have a friend having a small recording studio and he told me these CORDIAL ROAD cables are quite decent, so if his high impedance and very sensitive microphones are sounding OK after a couple of years of intensive usage, I'm preety sure my heapdhones should sound great after at least 10 years with these cables

Just for precaution, I have seen stock cable with bare copper of few flagship headphone oxidize in 2 - 3 years time, which including T1 and LCD series,
 
Expecting your thoughts on balanced DT880 on HPA-3B

 

[raoultrifan]

DT880/600 sounds great on HPA-3B. With this new balanced cable soundstage increased and details seem more focused. I really think that moving from single-end to balanced is a real upgrade for anyone, especially if DAC is really-balanced as well.
 
BTW, I'm already thinking in doing few "mods":
- upgrading volume knob with a black anodized aluminium knob as burdie suggested (headamp will look much better)
- adding an EMI/RFI AC noise filter (should take care of any possible AC line hum/noise)
- shielding toroidal transformer with G.O.S.S. (Grain Oriented Silicon Steel)
- replacing WIMA MKS 4 (Metallized Polyster) with JB JFX Premium Film Cap (Polypropylene Film)
- replacing 2SC3421/2SA1358 1A/10W transistors with 2SC5171/2SA1930 2A/20W transistors used in Burson HA-160 (I don't think sound will change, but the heatsinks temp should decrease with at least 5C)
- increasing heatsinks on the voltage-gain transistors (these 4 small heatsinks inside the headamp are incredible hot!)
 
I don't really believe I will have the time to do all of these mods, but at least some of them will probably do sometimes.
 
Thanks,
Raul.