[Chillzone21]

Does it use burr brown?

 

[Pharmaboy]

I have 2 HPA-1s. Bought a mint/used 2012 v.2 model for a gift desktop system I'm setting up for my brother, and when I heard how good it sounded (shockingly musical in my system), I promptly purchased another used one, an extremely mint 2013 v.2 model for myself.
 
I changed the volume knobs on both--the originals are impossible to see and don't feel very good to actually handle/adjust--and ordered the OPA627AP opamp (on browndog adapter) which I'll put in my 2013 HPA-1. It already sounds very nice...just hoping to fine-tune that niceness. 
 
Someone mentioned possibly driving the Fostex TH-X00s with the M Stage HPA-1 a few msgs back in this thread. I have done that w/my TH-X00, and the HPA-1 drives it about as well as any other HP amp on hand (the TH-X00 aren't a difficult load in my experience).
 
Something I should emphasize about the HPA-1 that no one else seems to remark on: it works exceedingly well as a preamp. True, there are only 2 inputs (2 RCA input pairs), which is fewer than the 4-6 inputs found on most full-function preamps. But on the desktop, that's really more than enough. I use the RCA inputs from my DAC, and send the output of the HPA-1 to my powered speakers (Swan M200 MkIII) + sub. The volume control of the HPA-1 works silently & well...no pops or surprises (important w/powered speakers!).
 
In the coming weeks I'll replace my current DAC (Peachtree Audio DAC ITx) with an Audio GD NOS 19, and I'll run it through the HPA-1. That's a huge DAC upgrade, and it tells you how well I regard the HPA-1 as a preamp...

 

[Mad Max]

  I have 2 HPA-1s. Bought a mint/used 2012 v.2 model for a gift desktop system I'm setting up for my brother, and when I heard how good it sounded (shockingly musical in my system), I promptly purchased another used one, an extremely mint 2013 v.2 model for myself.
 
I changed the volume knobs on both--the originals are impossible to see and don't feel very good to actually handle/adjust--and ordered the OPA627AP opamp (on browndog adapter) which I'll put in my 2013 HPA-1. It already sounds very nice...just hoping to fine-tune that niceness. 
 
Someone mentioned possibly driving the Fostex TH-X00s with the M Stage HPA-1 a few msgs back in this thread. I have done that w/my TH-X00, and the HPA-1 drives it about as well as any other HP amp on hand (the TH-X00 aren't a difficult load in my experience).
 
Something I should emphasize about the HPA-1 that no one else seems to remark on: it works exceedingly well as a preamp. True, there are only 2 inputs (2 RCA input pairs), which is fewer than the 4-6 inputs found on most full-function preamps. But on the desktop, that's really more than enough. I use the RCA inputs from my DAC, and send the output of the HPA-1 to my powered speakers (Swan M200 MkIII) + sub. The volume control of the HPA-1 works silently & well...no pops or surprises (important w/powered speakers!).
 
In the coming weeks I'll replace my current DAC (Peachtree Audio DAC ITx) with an Audio GD NOS 19, and I'll run it through the HPA-1. That's a huge DAC upgrade, and it tells you how well I regard the HPA-1 as a preamp...

 
Could be because this isn't a speakers forum. Maybe.
 
Yeah, I've tried it out as a preamp as well and it rocks.  Better bass, more clarity, better imaging.

 

[Mr Newyear]

  I have 2 HPA-1s. Bought a mint/used 2012 v.2 model for a gift desktop system I'm setting up for my brother, and when I heard how good it sounded (shockingly musical in my system), I promptly purchased another used one, an extremely mint 2013 v.2 model for myself.
 
I changed the volume knobs on both--the originals are impossible to see and don't feel very good to actually handle/adjust--and ordered the OPA627AP opamp (on browndog adapter) which I'll put in my 2013 HPA-1. It already sounds very nice...just hoping to fine-tune that niceness. 
 
Someone mentioned possibly driving the Fostex TH-X00s with the M Stage HPA-1 a few msgs back in this thread. I have done that w/my TH-X00, and the HPA-1 drives it about as well as any other HP amp on hand (the TH-X00 aren't a difficult load in my experience).
 
Something I should emphasize about the HPA-1 that no one else seems to remark on: it works exceedingly well as a preamp. True, there are only 2 inputs (2 RCA input pairs), which is fewer than the 4-6 inputs found on most full-function preamps. But on the desktop, that's really more than enough. I use the RCA inputs from my DAC, and send the output of the HPA-1 to my powered speakers (Swan M200 MkIII) + sub. The volume control of the HPA-1 works silently & well...no pops or surprises (important w/powered speakers!).
 
In the coming weeks I'll replace my current DAC (Peachtree Audio DAC ITx) with an Audio GD NOS 19, and I'll run it through the HPA-1. That's a huge DAC upgrade, and it tells you how well I regard the HPA-1 as a preamp...

What size/which volume knobs did you get? And how do you remove the stock volume knob?

 

[Pharmaboy]

First off, you need a 1.5mm hex wrench (the 90 degree kind) to remove the stock volume knob. That's not a common size--smaller than usual. I had to go to Harbor Freight and buy a big set, of which the 1.5mm is the smallest wrench.
 
Then I spent a crazy # of hours online looking for a volume knob that would fit the width (30mm) and rather long depth of this volume pot's shaft. I ended up buying 2 pairs from GD Parts on ebay (I have 2 x HPA-1's)--but oddly, only 1 pair actually fit.
 
Here's the listing for the pair that fits (and actually good & in proportion to the HPA-1):
http://www.ebay.com/itm/Full-Aluminum-Pointer-Knobs-for-Amplifier-CD-DAC-Radio-Turntable-30x22mm-Black-2-/321976848465
 
If you want a single volume knob like this, you'll just have to slog through the listings from GD Parts store on ebay.
 
Oddly, the replacement knob requires a 2mm hex wrench, not the 1.5mm wrench used to take off the stock knob (go figure).
 
FYI, it takes a full 2 weeks for the order to arrive via ePacket from China.
 
It's still a bit difficult hard to see what volume the replacement knob is set to in very low lighting--but in any semi-normal lighting you can see this knob just fine, unlike the stock pot, which is just about impossible to see in any lighting. It also feels a lot better "in the hand" when you're using it...

 

[Mr Newyear]

  First off, you need a 1.5mm hex wrench (the 90 degree kind) to remove the stock volume knob. That's not a common size--smaller than usual. I had to go to Harbor Freight and buy a big set, of which the 1.5mm is the smallest wrench.
 
Then I spent a crazy # of hours online looking for a volume knob that would fit the width (30mm) and rather long depth of this volume pot's shaft. I ended up buying 2 pairs from GD Parts on ebay (I have 2 x HPA-1's)--but oddly, only 1 pair actually fit.
 
Here's the listing for the pair that fits (and actually good & in proportion to the HPA-1):
http://www.ebay.com/itm/Full-Aluminum-Pointer-Knobs-for-Amplifier-CD-DAC-Radio-Turntable-30x22mm-Black-2-/321976848465
 
If you want a single volume knob like this, you'll just have to slog through the listings from GD Parts store on ebay.
 
Oddly, the replacement knob requires a 2mm hex wrench, not the 1.5mm wrench used to take off the stock knob (go figure).
 
FYI, it takes a full 2 weeks for the order to arrive via ePacket from China.
 
It's still a bit difficult hard to see what volume the replacement knob is set to in very low lighting--but in any semi-normal lighting you can see this knob just fine, unlike the stock pot, which is just about impossible to see in any lighting. It also feels a lot better "in the hand" when you're using it...

Wow sounds like a lot of work 

 Thanks for the info! 

 

[Pharmaboy]

yeah, it is a lot of work. I kinda got carried away: the stock volume knob annoyed me, plus I'd seen pictures of HPA-1's with aftermarket knobs, so I knew it could be done.
 
also replaced the stock opamp w/the OPA627AP purchased from Tam Audio. it's only 1-2 days since that mod, but the change is audible & rather nice--well worth the time & cost IMO.

 

[lakiozoon]

Is it possible to use Matrix amplifier with unbalanced line output as a pre-amp for studio monitors with balanced input (yamaha HS8 monitors).
As far as I am aware, it should work but I am looking to find out are there any significant drawbacks in doing so?
 
P.S.
Bear in mind, I plan to use the monitor speakers for home use (PC audio listening).
 
Any advice is mostly appreciated,
Regards!

 

[Pharmaboy]

The connections you describe are certainly no problem from the Matrix HPA-1 amp side: the RCA line-out uses a standard RCA interconnect plug that accepts RCA male plugs (R for right channel, L for left channel)--like any other single ended audio device.
 
As for the Yamaha, I just downloaded the manual and checked it (available at: http://download.yamaha.com/api/asset/file/?language=en&site=usa.yamaha.com&asset_id=67446).
 
Apparently you can connect single-ended, unbalanced interconnects to these speakers. Here are excerpts from the manual:
 
Pg-5, under "Connectable Cables"
"RCA pin
Source devices that only have RCA pin type output connectors can be connected via RCA pin plug to phone plug conversion cables (cables with an RCA pin plug on one end and a phone plug on the other). Connections using RCA pin plug to phone plug conversion cables are unbalanced."
 
(and)
 
"Balanced connections: These effectively cancel noise picked up from external sources. Balanced connections allow for longer cable runs that would probably otherwise result in more noise being picked up."
 
You apparently own the Yamahas and so would be familiar with their I/O connectors. I looked at those sections quoted above (which suggest 1/4" TRS-type unbalanced connections to me); then looked on pg-6, where the diagram confirms the unbalanced input connection is for 1/4" TRS connector ("These connectors receive the input signal to the speaker. Two input connectors are provided: one balanced XLR connector, and one balanced (TRS) phone jack.").
 
So all you'll need to make this work are 2 RCA female-to-TRS-male adapter; each one goes on the R & L end of the interconnect coming from the HPA-1.
 
I used a slightly different version of the adapters for years (the types needed to connect a 1/4" TRS cable to RCA input connectors) with great success & zero sound degredation. I researched these connectors thoroughly, and the best reviewed ones I could fine were made by "Hosa."
 
The type of adapters you need are "Hosa GPR-101":
 
-- Amazon has a pair @$2.55 each (plus you can read the reviews):
https://www.amazon.com/Hosa-GPR-101-inch-Adaptors-pieces/dp/B000068O3S/ref=sr_1_2?ie=UTF8&qid=1473091484&sr=8-2&keywords=Hosa+Cable+1%2F4+inch+male+TS+the+rca+female
 
-- Sweetwater has the pair for $2.95. I bought my Hosa connectors at Sweetwater bacause the shipping was more reasonable than Amazon's, plus there's none of that uncertainty of Amazon sellers "who's who":
http://www.sweetwater.com/store/detail/GPR101
 
(of course, you could buy this type of adapter made by other mfrs--up to you)
 
BTW, everything I've heard about the Yamahas is that they're very clear, accurate monitors. So I'm guessing the big warm sound of the m stage HPA-1 will be a great match for them. Please give me your impressions once you get the system hooked up and have a chance to evaluate its sound...
 
Regards,
 
Peter

 

[Pharmaboy]

Forgot to respond to the pre-amp part of your question: yes, the line-out of the m stage HPA-1 is definitely controlled by the volume control, so it definitely makes a good preamp to control powered speakers. In fact, that is how I'm currently using mine:
 
-- the speakers are Swan M200 MKIIIs. they have their own volume knob, but i bypass that by turning it up to the max so that the HPA-1 is controlling the level
 
-- the source is an Audio GD NOS-19 DAC run into the HPA-1 as a line-in source
 
With the sole caveat being that the stock volume knob of the HPA-1 (as explained above) is a pain to see & use, this amp otherwise is an extremely functional & rational pre-amp solution for powered speakers. In 4+ months of using mine as a preamp, I've never has a single odd noise, burst of static, or other unexpected event.
 
Bear in mind that whatever gain setting you select for the amp will be fully expressed in the line-out, and therefore will affect the volume of your powered speakers. So I suppose that if you needed to routinely select the highest gain setting to drive finicky headphones, but found doing that meant you're maxing out speaker volume at 9-10 o'clock on the HPA-1's volume knob...oh, well.
 
BTW, when you plug headphones into the HPA-1, it mutes the line-out to your speakers. Some people like that; others don't. But it works exactly as designed, and again, I've never had a moment of noisy/unexpected behavior from the unit when plugging/unplugging 'phones.

 

[lakiozoon]

 
Woah, thanks for your support, this answered all my questions/doubts. Most helpful post I've ever gotten, /salute!

 
I own the Matrix HPA-1 and I've been using it with my Sennheiser HD650 and M-Audio AV40 speakers. With HD650 the sound is on the warm side, but i do like it.
 
I considered buying Genelec-s (8030/G3 series), but then I would most likely need a woofer and that would be well over my budget. So now I'm set on getting the Yamaha-s since 8" driver doesn't really need a woofer, at least from what I've heard.
I will report on them when I get them, but it will take some time (need to get the new table etc...). Probably in a month or two.
 
Quote:

With the sole caveat being that the stock volume knob of the HPA-1 (as explained above) is a pain to see & use, this amp otherwise is an extremely functional & rational pre-amp solution for powered speakers. In 4+ months of using mine as a preamp, I've never has a single odd noise, burst of static, or other unexpected event.
 
BTW, when you plug headphones into the HPA-1, it mutes the line-out to your speakers. Some people like that; others don't. But it works exactly as designed, and again, I've never had a moment of noisy/unexpected behavior from the unit when plugging/unplugging 'phones.

1. I also considered replacing the volume knob, and will do it eventually mostly cause it's a pain to see the little red dot in the dark environment. 
2. About the line-out muting, it never failed on me, but personally I would like to have a switch just so I don't need to plug/unplug headphones every time I switch to my speakers. That modification is probably doable but I don't have the knowledge to do so.

 
I've been using the HPA-1 for over a year now and I'm really satisfied with it. Noise is almost non existent and it serves me as a pre-amp too. I compared it to a few much more expensive amplifiers and I couldn't hear the difference, it held it's ground.
 
Again, thanks for all your help.
Regards!

 

[Pharmaboy]

You're welcome! HPA-1 owners have to stick together...
 
That little amp is shockingly good. If you spend big bucks you can get better, but it has to be at least 2-3X the cost of the HPA-1 to get much better.
 
Anyway, I forgot to tell you 1 possibly important factoid about the HPA-1 used as a pre-amp. When I first put it in my system, I had it plugged into a different outlet thethe speakers + sub + DAC, which I turn on/off via the switched, 6-plug power strip they're all plugged into. Once those components were on, I would turn on HPA-1, but it made an unwelcome turn-on "thump" (more objectionable because of the sub, no doubt).
 
But when I plugged the HPA-1 into the same power-strip at the other components, so that they all turned on/off at the same time, no more thump.
 
I probably could have made the problem go away just as well by turning on the HPA-1 before the other units (and keeping it plugged in separately)--but I found the power-strip solution easier/more convenient.
 
(something to be aware of when using it as a pre-amp)
 
Good luck w/the Yamaha speakers. They look excellent...
 
I never looked at them for myself (too big for my desktop)--or the Genelec (too much $$). I did jones a lot for the Adam 7X, also a lot of $$ + borderlline too big, but I'm really happy w/the Swans (very musical). And in 1-2 months I'll upgrade the sub to an SVS SB-1000, which should be a nice bump.

 

[rikk009]

Does HPA-1 and HPA-3 have same amp section/sound? I am thinking of jumping on a used HPA-1 for amp.

 

[Pharmaboy]

I own 2 HPA-1s (both are 2012/2013 rev-2 vintage). Along the way I read many reviews of all HPA iterations. Can't remember all the details at the moment, but I'm almost certain the design changed significantly from HPA-1 to HPA-2, and even more from 2 to 3, losing that warm, euphonic, bass-rich quality I & others find so appealing about the HPA-1. I recall one or more reviews of the HPA-3 describing it as "tonally accurate," a term never used to describe the HPA-1 (I wouldn't own it if that was the case!).
 
The HPA-1 totally suits my taste in sound reproduction--listening to it right now. I use it as a desktop pre-amp/HP amp. I have a better HP amp (Lake People G109A) but the HPA-1 is really good in its own right. It's definitely not a throwaway as a headphone amp. I cranked it up a few nights ago w/my Fidelio X2s and that baby really rocked.
 
Some links are listed below. BTW, if you go looking for HPA-1s, something to keep in mind is this model was revised sometime in 2012, with improvements in power and specs for the HP amp section. Better to look for models with 2012 or 2013 in the SN (1st four #s of SN are the model year).
 

Here's a 2010 review of the HPA-1:
http://www.headfonia.com/matrix-m-stage/
 
Specs on the HPA-1:
https://headphoniaks.com/gb/dac-amplificadores/53-matrix-mstage-headphones-amplifier.html
 
 
An October, 2015 review of the balanced version of the HPA-3:
http://headphone.guru/the-impressive-m-stage-hpa-3b-balanced-headphone-amplifier/
 
More specs on the HPA-3B:
http://www.noisymotel.com/product.asp?ProductID=940

 

[rikk009]

Thanks Pharmaboy. Yes I looked at those reviews some even said there was no difference between HPA-1 and HPA-2 amp sections hence my confusion. Thanks once again for clarifying that. I will ask the seller for the version. This one comes with a DAC which is not any noteworthy if I go by the reviews.