AudioCircle
Audio/Video Gear and Systems => All Solid State => Topic started by: mresseguie on 7 Dec 2019, 01:12 am
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For anyone interested....Tom Christiansen Audio's upcoming SS HPA-1 has hit a snag with the amp case manufacturer, so delivery has been pushed back to <approximately> the third week in January. Here's a reprint of Tom's announcement:
"As you may have read on Audio Science Review, my chassis vendor for the HPA-1 suffered a setback in their production of the aluminum extrusions needed for the HPA-1 chassis. As result, they had to start over on the production. Unfortunately, this means the chassis will not ship until the middle of January, which means I can't ship until about the third week of January at the earliest.
This delay is incredibly frustrating, as I had pulled out all stops to get the HPA-1 ready in time for Christmas. Sadly, this production issue is completely beyond my control. I can only thank my vendor for being honest and upfront about it.
The good news is that the circuit boards needed for the first 50 HPA-1s will be ready by Monday. All I need now is the chassis. I have a few prototype chassis reserved for demo units, so I should be able to get an HPA-1 to Amir at Audio Science Review for review and measurements. At least then you'll know what you can look forward to.
Again, I profusely apologize for the delay. Thank you again for your patience and support. I really appreciate it. Expect good things to happen early next year.
Thanks,
Tom"
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Yeah...I saw that...its frustrating for sure!
But its not that far off!!
:>)
Alex
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For anyone interested....Tom Christiansen Audio's upcoming SS HPA-1 has hit a snag with the amp case manufacturer, so delivery has been pushed back to <approximately> the third week in January. Here's a reprint of Tom's announcement:
"As you may have read on Audio Science Review, my chassis vendor for the HPA-1 suffered a setback in their production of the aluminum extrusions needed for the HPA-1 chassis. As result, they had to start over on the production. Unfortunately, this means the chassis will not ship until the middle of January, which means I can't ship until about the third week of January at the earliest.
This delay is incredibly frustrating, as I had pulled out all stops to get the HPA-1 ready in time for Christmas. Sadly, this production issue is completely beyond my control. I can only thank my vendor for being honest and upfront about it.
The good news is that the circuit boards needed for the first 50 HPA-1s will be ready by Monday. All I need now is the chassis. I have a few prototype chassis reserved for demo units, so I should be able to get an HPA-1 to Amir at Audio Science Review for review and measurements. At least then you'll know what you can look forward to.
Again, I profusely apologize for the delay. Thank you again for your patience and support. I really appreciate it. Expect good things to happen early next year.
Thanks,
Tom"
Michael,
will the HPA-1 units be available for Demo when you get it ! Just picked up 2 sets of Wywire Diamond IC cables from Alex at Wywire ! , very impressed by the Diamond Interconnects , they just vanish in the system they will compliment my new Daedalus/Wywire speaker cables :popcorn:
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Michael,
will the HPA-1 units be available for Demo when you get it ! Just picked up 2 sets of Wywire Diamond IC cables from Alex at Wywire ! , very impressed by the Diamond Interconnects , they just vanish in the system they will compliment my new Daedalus/Wywire speaker cables :popcorn:
Ashgar,
Yup 。Nothing has changed regarding my plans for my HPA-1. Well, the only change is that the start date has been pushed back by one month. The end date will be around the middle of (or end of) March.
Nice find on the ICs. Have you found audio nirvana? :thumb:
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This might be a long shot, but I just registered and don't appear to have authorization to make posts myself yet.
I see though that in your picture you have what appears to be a tube amp. Are you knowledgeable about these, I have a few questions about a particular Cary model and am hoping to find someone that might be able to give me a little more information and the possible value of one. If you or anyone you know can help me will you please let me know. Thanks so much and sorry to ask a question unrelated to your original post.
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This might be a long shot, but I just registered and don't appear to have authorization to make posts myself yet.
I see though that in your picture you have what appears to be a tube amp. Are you knowledgeable about these, I have a few questions about a particular Cary model and am hoping to find someone that might be able to give me a little more information and the possible value of one. If you or anyone you know can help me will you please let me know. Thanks so much and sorry to ask a question unrelated to your original post.
Ask your question in the Tube-o-phile Circle. (https://www.audiocircle.com/index.php?board=144.0)
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I'd also be worried about naming it HPA-1. Isn't the Pass Labs named HPA-1?
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I'd also be worried about naming it HPA-1. Isn't the Pass Labs named HPA-1?
Oh, You're correct about the Pass HPA-1. I'll ask Tom about it.
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This might be a long shot, but I just registered and don't appear to have authorization to make posts myself yet.
I see though that in your picture you have what appears to be a tube amp. Are you knowledgeable about these, I have a few questions about a particular Cary model and am hoping to find someone that might be able to give me a little more information and the possible value of one. If you or anyone you know can help me will you please let me know. Thanks so much and sorry to ask a question unrelated to your original post.
Mrapol,
Questions are alway encouraged. However, in this situation, the Admin is correct in that your question would best be addressed in the Tube-o-phile circle. The folks who tend to hang out there are very knowledgeable. While I do own some tube gear, my experience is very limited to three or four brands. I know precious little about Cary products, so I'm not qualified to answer your question.
Michael
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Ashgar,
Yup 。Nothing has changed regarding my plans for my HPA-1. Well, the only change is that the start date has been pushed back by one month. The end date will be around the middle of (or end of) March.
Nice find on the ICs. Have you found audio nirvana? :thumb:
Michael
Nirvana is a never ending quest :P some time I do with something new and than again I am at Square one ! :duh:but pretty satisfied with the high Quality of music from my system or systems that I have I am always tweaking to get the 9th out of the music !
Asghar
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Finding it might not be fun !!!
Imagine not getting any new toys !!!
:>)
Alex
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It did very well:
https://www.audiosciencereview.com/forum/index.php?threads/tom-christansen-audio-hpa-1-headphone-amp-review.10416/
Best,
Anand.
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It looks really good from a measurement perspective for sure....now we have a bunch of less than $1000 amps that are close and should provide us all a great audio experience..
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Anand,
Thank you for the link.
I'm looking forward to my HPA-1 once I'm back from the fun and food of Taiwan - already gained a couple pounds. Someone will have to play with it until I'm back.
Michael
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I had to alert the reviewer to the repeated misspellings of Tom’s last name.
It’s Christiansen not Christansen.
#respect
I’m looking forward to my Neurochrome HP2 diy kit build and will probably send it over to ASR with both the original switcher supply and my custom linear supply. The linear supply is just for giggles, we’ll see if it makes any difference at all!
Best,
Anand.
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Will be interesting to compare to the THX stuff and Schitts new Magni Hersey...
Alex
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Yesterday I had a chance to try the HPA-1 at the Florida Audio Expo. While I'm not a headphone guy, the sounds was great with no downfalls that I heard or the measurements suggest. For $899, it's a no brainer if cans are your thing. The unit is very tidy externally, and there was a clear cover on one HPA-1 at the station and the board is just spotless. Well done TCA!
I look forward to the future offerings as he had a prototype of a smallish headphone amp there.
https://www.tomchr.com/products/hpa-1 (https://www.tomchr.com/products/hpa-1)
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The amp has exceptional specs for sure.
$899 for some might be up there and there is competition with good specs at lower cost...
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Another product that has balanced on one side (input/output) and single ended on the other. What's up with that?
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Tom will have to speak to that.
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Understood, but why not offer a balanced output too? Maybe the inside/front panel is too small?
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JLM thats a good question, I dont have an answer but I did send Tom a PM.
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So I'm gonna 'spill my own beans' so to speak. :o
A few months ago when I decided I just had to try Tom's new HPA-1, I knew that it would ship while I was over-wintering in Taiwan. Well, rather than asking Tom to hold it for a couple months, I came up with a wild scheme to host a small tour with my new, never heard HPA-1 as the star attraction. I contacted 8 or 9 AC or AN members to see who was interested in taking part in a mini-tour. Once I had succeeded in conning...er...persuading 5 or 6 to take part, I informed Tom of my plan. He was delighted to help out. 8)
In the next few weeks, you can expect to read a number of fellow audiophools' impressions of this headphone amp in their respective systems. My HPA-1 is currently burning in at mcgsxr's home. Perhaps, he'll post his impressions soon? :thumb:
Michael
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I received the unit late last week and let Tom and mresseguie know it had arrived safely.
My first mistake! Now I’ll never be able to steal this lovely unit and disappear into the Net.
I felt really special getting to participate in this tour and receive the unit first.
Pics below don’t do the packaging and presentation justice. This feels really well cared for in terms of how it was packed (great styrofoam cut outs, double boxed etc) with care. The volume pot alone makes me want to steal this. It’s so smooth in operation and a cinch to nail the right volume.
I plugged it into a Bolder power cable and into my modified Grant Fidelity TubeDAC-11 via Bolder Nitro IC’s. then a 1/4 adapter and my Noble iems. The Nobles are likely not the ideal match but don’t tell the TPA amp that.
Right out of the box it sounds really nice. Richness and PRAT to spare. The soundstage surprised me. My exposure to phones and amps in the past had not delivered much of that. Makes me wish I still had my Senn’s or Grado full size cans to see how it drives them, but at the moment I’m down to just iems for phones.
I’ll pass it along next week (please remind me who is next) and look forward to what others think. I threw in a set of isolation feet for mresseguie to thank him for the generous offer to play around with his new toy!
Pics of the unboxing below.
(https://www.audiocircle.com/image.php?id=204510)
(https://www.audiocircle.com/image.php?id=204511)
(https://www.audiocircle.com/image.php?id=204512)
(https://www.audiocircle.com/image.php?id=204513)
(https://www.audiocircle.com/image.php?id=204514)
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Awesome!
Please let us know what you think!
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Looks like a quality product. Should be an enjoyable experience to review.
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I think we all know measurements arent everything in this "hobby" but the design specs for Tom's amp are nothing short of spectacular.
That said the THX AAA amps are spectacular in measurements as well...
That said Schiit's new Magni 3 Heresey has spectacular measurments as well....
Having so many amps here, there are differences, but realistically the diffrenences are subtle at best when you get down these very
low diminishing tolerances...
Its a really great time in headphone and audio in general for many stellar choices, that are affordable as well!
Alex
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The HPA-1 is now in stock and shipping. The first batch of orders shipped about 10 days ago and the amps have started to arrive in the various destinations. One of these days I should send out a newsletter saying, "hey... buy my stuff..." I've been busy with the Florida Audio Expo and with assembling and shipping the amps.
Another product that has balanced on one side (input/output) and single ended on the other. What's up with that?
The reason is pretty straight-forward, actually: There is no real meaningful technical advantage of the balanced or 4-pin output. Yes, you do get rid of the few mΩ of shared ground impedance in the 1/4" plug, and, yes, that does improve the channel separation slightly. But that's it. The channel separation in the HPA-1 with the 1/4" output is about 100 dB. With a 4-pin output (balanced or not), you could possibly improve that to 110-115 dB. That sounds dramatic, but both are way below audible, so the difference is honestly only of academic interest.
The other reason is that I cannot fit another connector on the front panel of the HPA-1. So I would have to bring to market an amp that had only the 4-pin output. That's a non-starter. The 1/4" output is a must have whereas the 4-pin output is a nice to have.
Some may argue that a balanced output could provide better performance (lower distortion). That may be true in some high-distortion designs, such as many tube amps. However, in low-distortion designs, such as mine, I generally find that trying to cancel out distortion by going with a balanced circuit actually results in worse performance (higher THD and 6 dB higher noise).
One area where the balanced output does shine is the output power. Assuming the output stage is not current limited, a balanced output stage could deliver four times the output power of a single-ended stage from the same power supply rails. However, this higher output power would only be available on the 4-pin connector and not on the 1/4" connector. I don't think the customer should just have to accept lower performance on the 1/4" connector. Many don't have headphones with 4-pin connectors.
That said, the 4-pin output certain has some marketing advantages. Many will perceive an amp with a large-and-in-charge 4-pin output on the front panel as a more serious amp. And certainly, a 4-pin output would be a must have on a more expensive (say $1500-2000) amp; even if only for marketing reasons.
Tom
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I’ve had my fun, and the unit has shipped off to the next lucky participant.
Really enjoyed my brief time with the amp and look forward to what others find and think with their own gear combinations.
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Great!
Who is next on the list?
Alex
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The amp is on its way to my house. Looking forward to spending some time with it. I may take some time out from speaker listening to listen through the little amp. Might even use the balanced inputs. :P
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Looking forward to your observations.
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Awesome!
I am on the list!
Looking forward to comparisons with the amps I have in house and a variety of headphones!
Alex
:D
Didn't know about this. How do you get on the list? Would love to try HPA-1 on my Abyss 1266 Phi TC!
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This amp belngs to : mresseguie and its a list that he compiled for specific reasons.
Alex
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I asked Tom whether removing the cover would void the warranty. Sure enough. Removing the cover or damaging/defacing the serial number will void my warranty.
Please be nice to my HPA-1. Leave the cover on. :thumb:
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I asked Tom whether removing the cover would void the warranty. Sure enough. Removing the cover or damaging/defacing the serial number will void my warranty.
Please be nice to my HPA-1. Leave the cover on. :thumb:
Absolutely. There's a nice picture of the inside on the website.
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Roger on the case cover!!
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Actually, Alex, I'm pretty certain you're next after Timind has his turn at it. Keith's turn is after yours, no?
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This was the only room I went back to for a second time to ensure my ears weren’t deceiving me, it was just that insanely good.
Scroll down:
https://hometheaterhifi.com/features/show-reports-film-festivals-concerts/florida-audio-expo-2020-coverage/
Best,
Anand.
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mresseguie! Yes your correct!!!
poseidonsvoice, thanks for sharing!
Cant wait to test!
Wonder how the audio quality would compare to the DIY only HP2?
Alex
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Wonder how the audio quality would compare to the DIY only HP2?
Alex
Alex,
I've listened to both but not in the same system/context.
All I can say is that there is a family resemblance to all of Tom's headphone designs. I listened to the Tom Christiansen Audio HPA-1 for quite a while at the Florida Audio Expo. The TCA HPA-1 forges ahead on tougher loads (i.e. 32 ohms and lower) and at higher power levels than the Neurochrome HP2. Otherwise, the Neurochrome HP2 I heard was sublime. I am not surprised though. Tom Christiansen has a baseline minimum standard design metric he must meet or else the product won't make it to market. It's in the Tom Christiansen psyche.
I have yet to finish building my Neurochrome HP2, but I am taking pictures systematically to show how to populate the board, assemble the enclosure, etc...
I plan on posting it on this subforum for those who want to read it. I also plan on comparing it to the Orchard Audio Pecan Pi DAC/headphone amp, as well as a few high end spreads if I can get my buddies to collaborate since they have them.
Best,
Anand.
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Anand.
Please start a thread for the HP2 DIY build!
It would be interesting to see how its going and I just might come on board and do a build as well in the future...
I have a lot of stuff coming in in the next few months for comparison etc so my time is getting squeezed abit for DOY projects....but I do like them!
Thanks for the updates!
Alex
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Those interested in what the HPA-1 looks like on the inside, see below:
(https://www.audiocircle.com/image.php?id=204930)
Home Theater Hifi awarded the TCA HPA-1 Best of Show for the Florida Audio Expo. You can read more here: https://hometheaterhifi.com/features/show-reports-film-festivals-concerts/florida-audio-expo-2020-coverage/
I have plenty HPA-1 in stock and available for immediate shipment.
I do agree that the HPA-1 name is not unique. If you google "HPA-1 headphone amplifier" you'll find Nelson Pass's headphone amp. If you google "HPA-1 headphone amplifier -Pass", you'll find mine. There are several other HPA-1 headphone amps. I'm not overly concerned about the naming conflicts.
I did consider a more unique naming scheme, but decided against it as I didn't think they'd offer any better connection with the amp than a generic name. Also, after a while you run out of Nordic gods, local mountains and rivers, and whatnot anyway. That reminds me of when I worked for National Semiconductor where one of the product groups would name their projects after local rivers. This was going well until they reached the Nooksack river. Apparently that was deemed an inappropriate name and projects were given generic names from that point on. :)
Tom
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Stellar build, Tom, and the sonic accolades for this are growing. Frankly, you could name this one Nooksack and it would still be a hit. :lol:
Keep on doing that voodoo that you do so well, -dGB
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Update: I received the amp yesterday and neither the Canadian or US postal services caused any damage.
After letting the amp come up to room temperature I plugged it in for a short listen to ensure all is well. Sounds nice. I'm going to leave it on as it produces no heat and will listen more over the next few days. I hope to try out the balanced inputs once my dac (out on loan to another A/C member) returns.
After a few days with the amp, I plan on doing a side by side compare against my Nuforce HDP amp. I've been using the HDP for probably 4 years now as I stopped trying to better it.
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Great!!
Good it got to you unharmed!
Will be very interesting on your comparisons to the Nuforce HDP amp.
Is the Nuforce amp just an amp or is it a dac/amp?
If thats the case can you only use the amp by itself or not?
Alex
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The HDP is a DAC/preamp/Headphone amp. In my case though, I've really only used it as a headphone amp. I went looking for a review to give you a detailed description and found this. After skimming the article, I definitely agree with the assessment. And after reading the final paragraph, I guess I've been using the best part of the amp.
https://6moons.com/audioreviews/nuforce14/hdp.html (https://6moons.com/audioreviews/nuforce14/hdp.html)
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Great and thanks for the information...
I kept seeing its a DAC/AMP combo and didnt want the dac to get in the way of any comparions....looks like its a Class A amp.
Thanks again!
Alex
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THe HPA-1 arrived here today and I am listening to it right now...getting setup for tomorrow to do some critical listening and comparisons...
The amp apprived here in good condition!
I already have some first impessions and will share them with you soon!!
Alex
NOTE: Full disclosure this is NOT my amp. Its an amp that a member purchased and generously asked a few other members if they would like to try it out. It will head out here next week to another member. Many thanks to "that" member!!!
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First Impression sonically, is this is a wonderful amp....all around close to being a straight wire with gain...works well with all my headphones, more than enough power etc..
Lots more later...
Alex
(https://www.audiocircle.com/image.php?id=205373)
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Keith,
Its definitley not bright to me, its indeed very neutral in a brutal way...good stuff in good stuff out , Uncolored....put some trebly poor recorded stuff and your ears will bleed...its so very transparent and clean....
Some folks that are used to whats generally (in terms of amps) out there today as a "standard" might jump at calling this amp "bright" just because they havent used an amp of this quality.
Having the THX AAA amp for a few months tells me when an amp is designed with extremly low distortion etc...this is what neutral sounds like or "not" sounds like.
This morning I was listening to a variety of material most all very good quality stuff then a Kim Pensyl tune popped up and the treble in this "once" like tune made me cringe....on how "hot the treble" was in the recording.
With lesser amps its more tolerable.
I would call this a TOTL amp or a reference amp for sure.
Alex
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The advent of THX AAA amps have been a huge disruptor in the SS headphone amp market. The cheapest one, SMSL SP200 THX AAA-888 only costs $289.99, and one can literally buy three of them for HPA-1's price. Some reviews have even preferred the AAA-888 sound quality a bit over more expensive AAA-789.
(https://live.staticflickr.com/65535/49567445833_d958801da6_c.jpg) (https://flic.kr/p/2iw77K4)0221202055 (https://flic.kr/p/2iw77K4) by drjlo2 (https://www.flickr.com/photos/60017347@N03/), on Flickr
If I were a SS headphone amp designer, I would face quite a challenge making an amp that sounds demonstrably "better/different" yet not come in at multiples of AAA amp prices, as can be gleaned from this Comparison review of AAA-888, AAA-789, and Benchmark HPA-4 ($3000).
https://www.youtube.com/watch?v=6Zuynm3o3vs&t=6s
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OK, thanks for the feedback. I do think that different amps that are tagged as neutral can have different sonic signatures, especially in the treble region. The Pure Bipolar amp is one of the very best headphone amps I've come across. It has a lot of reserve power, the circuitry is all balanced, and employs soft clipping when the limits are hit.
Since you have a variety of amps and headphones at your disposal, your views on the amp is very insightful.
To me, the headphone itself has more to do with hot treble sound than the amp.
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With amps of this quality the material in is as important as the transducer used in listening...the amp just gets out of the way....
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JonL.
Thanks for the video review link...I just watched this.
I am not saying the review is inaccurate, its his opinion etc....but the one thing thats missing and from many reviews that are very subjective..is actual
blind testing and having people not know what they are listening to and have them pick our the best gear etc..
But the fact still stands there is a wide price range on some good stuff out there for sure...
Again, some will not want a low cost amp made in China amp vs a billet aluminum cased amp....but something tells me more that the lower cost probalbly sells
more in the long run...
We should take this conversation to its own thread so folks can focus on the HPA-1.
https://www.audiocircle.com/index.php?topic=168509.new#new
Alex
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Tom,
I'll be using a Oppo Sonica DAC. Will that DAC be sufficient to evaluate?
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Oppo specs the Sonica (https://www.oppodigital.com/sonica-dac/) to "<-115 dB THD+N", which likely means that either a) they can't measure lower than that or b) the worst performance expected from the DAC is -115 dB but most perform better.
Either way, -115 dB THD+N is well below audible.
They also spec SNR to > 120 dB, so the noise floor of the DAC should be nice and low.
So, yes, I would say that the Oppo Sonica DAC would be a good candidate to test drive the HPA-1. Ideally, I would like to see a DAC with THD better than -130 dB and a noise floor below/around 1 uV (A-weighted), but that's a rather tall order. The Topping D90 should be able to get there.
Tom
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Thanks, Tom. I can also use the pre-amp out from a Devialet Expert 200 as well.
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That is a great write up Alex.
I had the amp prior to Alex and although I wanted to do a write up, I couldn't come up with anything useful to say. After reading Alex's review I know why. He summed up my impression perfectly with these words: "The HPA-1 has no real sound....other amps often have a sound signature, some like this and some do not,"
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Here is a site that is very interesting that will help you determine how much distortion you can actually detect with your ears! And then can apply this in a meaningful way to a piece of gears distortion measurements and see if this will indeed matter or not in your listening experience:
http://www.klippel.de/listeningtest/
Here is a link to a discussion of the HPA-1 that speaks to this test and how it might
apply to whether or not these measurments have a correlation to what you hear or not.
https://forum.headphones.com/t/tom-christian-audio-tca-hpa-1-headphone-amplifier-official-thread/4982/40
You can read the entire discussion or scroll down to March 1 and read post 41. Very interesting read...
Alex
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Here is a site that is very interesting that will help you determine how much distortion you can actually detect with your ears! And then can apply this in a meaningful way to a piece of gears distortion measurements and see if this will indeed matter or not in your listening experience:
http://www.klippel.de/listeningtest/
Here is a link to a discussion of the HPA-1 that speaks to this test and how it might
apply to whether or not these measurments have a correlation to what you hear or not.
https://forum.headphones.com/t/tom-christian-audio-tca-hpa-1-headphone-amplifier-official-thread/4982/40
You can read the entire discussion or scroll down to March 1 and read post 41. Very interesting read...
There's also this: http://harmanhowtolisten.blogspot.com
Tom
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Thanks for that Tom, I posted this sometime ago as well...good information:
https://forum.headphones.com/t/listening-skills/4595
Alex
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I had about 100 participants in my market survey. I posted survey links about a year ago on ASR, DIY Audio, my Facebook page, and via my Neurochrome Newsletter. I ran the survey for a few weeks.
I see two directions from the HPA-1:
- Up: Prettier chassis, XLR and 1/4" output, XLR and RCA input. Maybe a preamp output. Maybe higher output power. Possibly some other surprises that I'll keep as surprises for now. Price target: Somewhere in the $1-2k range.
- Down: Cost reduced version with a lower quality volume pot (the ALPS RK097 is a pretty decent pot that is one tenth the cost of the RK271 "Blue Velvet" used in the HPA-1), lower output power, RCA only input, 1/4" only output, one gain setting. Smaller version of the "upper class military look" (thanks for that term) chassis. Price target: $499.
Tom
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This will arrive on Thursday. I don't have a large collection of headphones, but I've a few of different quality levels I'll try out as fo follows
- Sony MDR 7506
- Sony MDR V700 (early Japan made)
- Sony MDR Z7 (Japan made)
- Audeze LCD 3
If I can get a single ended cable, will also try a Abyss Diana. Will spend most of the time with the Z7 and LCD-3. Just want to see how this amp improves the 7506 and V700.
I'm interested to see how well this drives the planr cans (especially the Diana). Should be fun.
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This will arrive on Thursday.
Fantastic!
I'm interested to see how well this drives the planr cans (especially the Diana). Should be fun.
Indeed. I'm looking forward to hearing about it. The only planars I've tried so far have been the Andover Audio PM-50 (https://www.andoveraudio.com/products/pm-50-planar-magnetic-headphones). They worked quite well with the HPA-1. I'll also take the opportunity to listen a bit tomorrow when I go pick up a loaner HPA-1 from Absolute Audio (https://www.absoluteaudio.ca) in town. They had the amp on display this weekend and have an extensive collection of Audeze headphones.
Tom
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I (think) the LCD-3 will be OK. I'm less sure about the Diana.
My migration to planar is the reason I obtained a Mjolnir Pure Bipolar. I was able to get a cable that will allow for audition of the Diana.
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I (think) the LCD-3 will be OK. I'm less sure about the Diana.
LCD-3: 110 Ω, 101 dB/mW -> 650 mW -> 129 dB SPL. That's instant permanent hearing damage.
Diana: 42 Ω, 91 dB/mW -> 1.0 W -> 124 dB SPL. So your ears may last a split second longer with these before permanent damage occurs.
120 dB SPL is the threshold for permanent damage within seconds. So I think you'll be fine with either. :)
I estimated the output power from the output voltage at the onset of clipping for the various impedances from the graph below.
Tom
(https://www.audiocircle.com/image.php?id=205452)
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Looks like the amp should have no trouble with the planar headphones then. :thumb:
There are two different issues. One issue is possible hearing damage from playing headphones too loud, which I am very careful about not to get into that situation. That can happen even with a phone driving headphones.
The other issue is one where while the amp is driving the headphones. the overall presentation can vary even with the same Spl level. Transients, tonal characteristics, etc. can be different between amps. For example, I've noticed that the balanced Pure Bipolar amp has better overall sound with the LCD-3 than the Dynalo amp. I assume that is because the Pure Bipolar is balanced, and has roughly 5 times the available output power over the single ended Dynalo. They both sound somewhat similar, but the difference in presentation is noticeable with the planar cans, less so with dynamic cans.
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One question I have is as follows:
What are your thoughts regarding the gain switch? When would a customer use one setting vs. the other?
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I will always recommend using the lowest gain setting possible. Basically, only increase the gain if you can't get satisfactory SPL with the volume control maxed out.
The gain switch is just to accommodate low-output sources, such as phones, tablets, etc.
Tom
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The HPA-1 headphone amp arrived yesterday. . The build quality is quite nice, and the controls have a nice feel to them. Given the amp’s small stature, this would be a good candidate for a desktop system for use at work or at home. I want to thank Michael for this opportunity to review this amp. I’m sure he will be most happy with it once he gets it back. 😊
Some background is in order: The input to the amp was via a Sony UBP X-1100ES, with the Digital Sound Enhancement Engine enabled. This doubles the sample frequency to 88.2, 96, or 176.4 KHz to an Oppo Sonica DAC. The Sonica DAC employs the ESS 9038 Pro DAC, and sounds very good. The connection to the HPA-1 was via the single ended connection.
So far, have done the listening with the Sony MDR Z7, and the Audeze LCD-3 headphones. Most of my observations were with the Z7 headphones, as that combination sounded very good overall.
The music with Z7 sounded quite nice. The Z7 is an interesting headphone from Sony, hand made in Japan. The headphone demands that good electronics drive them, or it won’t sound very good. The HPA-1 is an excellent match for the Z7. Music was re-created with good depth, clarity, and space. The bass is deep and powerful (a bit warm from the can), but not overpowering. The amp does a good job of controlling the driver here. The midrange sounds well balanced. On good recordings, instruments such as horns sounded like horns, which a lot of headphones can’t seem to get right. Vocals were clear, especially female vocals. The treble response is excellent overall, with a slight tendency to sound a bit bright. There is plenty of power to drive the Z7 cans to very satisfying results.
The reason I didn’t do as much listening with the Audeze LCD-3 cans is that this combination was not as good as I had hoped. Planar cans can be a tough item to drive. While the HPA-1 can drive the LCD-3 cans, the sound from this combination came across as a bit compressed. This was very noticeable with instruments such as piano and strings. I tried using the gain switch, but all that did was make it louder, it didn’t resolve the issue. I also noticed this issue to a slightly lesser extent with my Dynalo amp driving the LCD-3. Wound up obtaining a Pure Bipolar balanced amp to resolve the issue with driving planar cans. The HPA-1 and Dynalo amps can drive the LCD-3’s fairly well, but not to the can’s full potential. Stax electrostatic headphones suffer from this same issue, and need a higher-powered amp than what Stax makes to get them to sound their best. I view this as more of a headphone design issue.
Will provide additional observations prior to sending the amp to the next member.
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Fantastic. Thank you for your feedback and detailed writeup. "Horns sound like horns"... Yep. That's one of the things I listen for as well. I used to play the trumpet, so I have a decent idea of what one sounds like. Also snares on snare drums, cymbals, etc. Those types of sounds are often hard to reproduce accurately, so those types of sounds are what I listen for (along with other things, of course).
Yeah. I would not expect the gain switch to change the sonic character of the amp. That's by design, actually.
If you were to point at an amp that really makes the LCD-3 shine, which one would it be?
Tom
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Glad you enjoyed the write-up. Still need to listen with the 7506 and V700 to see what improvements are wrought. The amp works very well with the MDR Z7, which is not an easy headphone to drive.
One amp I know works very well with the LCD-3 is the Mjolnir Audio Pure Bipolar:
https://mjolnir-audio.com/product-selection/ (https://mjolnir-audio.com/product-selection/)
I have the black version. I got it second hand for a very good price. Here is some additional information on the amp:
https://www.innerfidelity.com/content/katzs-corner-episode-18-icelandic-wonder (https://www.innerfidelity.com/content/katzs-corner-episode-18-icelandic-wonder)
Bob Katz loved this amp with the LCD-4, which is harder to drive than the LCD-3.
I personally have not heard this amp, but it should work well with planar cans: ( A wallet hit to be sure :-) )
https://www.headamp.com/products/gs-x-mk2 (https://www.headamp.com/products/gs-x-mk2)
My experience with headphones is mostly Stax, which is how I came across the Kevin Gilmore/Spritzer connection. My past experience with Stax is why I migrated to planar cans for the dynamic world.
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Got a email for Michael , I am next on the list !
Happy on getting an opportunity to listen to the HPA-1 -Thanks Michael U are a GR8 Audio Buddy !
OK Just read the whole thread for the 1st time I am GR8 fan of Amir at ASR believe in measurement but they don't tell the whole story .
I am certainly looking forward to listening and Enjoying the HPA -1 please don't expect any critical listening reviews on the HPA although I am very capable of creating great reviews if need be.
Any way here is what I have- it's a partial list !
Head phones among others
1. Audeze LCD -X ( easy to drive ) even though it is Planner
2. Audeze iEM LCD 4I
3. Audeze ISine 20 IEM
forget the Boses & Beate etc etc etc
HP. Amps:
1. QuickSilver audio SET Tube Amp: my most favorite non fatiguing listening amplifier, I can never give that up. ! others may come and go :popcorn:
2. Audeze Deckard
3. Chord Mojo /DAC /HPAmp
DAC's
1. Schiit Gungnir
2. Chord Mojo
3. Directstream PS Audio DirectStream DAC ( I could try listing to this unit with the HPA -1 , Do own a OPPO 205 which has a headphone out I believe comparable to Sonica DAC ( but won't have time for that !)
. Misc.
JCAT USB reference Cable
Silver plated Audeze cable that came with LCD 4i
Solid Silver HP cable from Larvicables from Poland
Wywire Red HP cable made for me by Alex of WYwire GR8 chap !
ISI Purifier 3 ( into Schiilt Gungnir inputted by JCAT reference USB cable )
all outlets are PS audio , Clean electricity, no hum anywhere in the circuit semi dedicated wring both to my DEsktop home office system and Main system
thanks :thumb:
Asghar
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Ashgar,
Aw, shucks. You're very welcome. :wave:
Enjoy!
Michael
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This thread is now in All Solid State. If you have questions specifically for Tom, please ask him in his Industry thread -> https://www.audiocircle.com/index.php?topic=168574.0
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Admin,
Thank you. :thumb:
I anticipate receiving my amp in approximately two weekss and I'm looking forward to it!
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Hi,
just my personnel impressions of the HPA-1, Of course these are subjective and personnel , I have used two DAC's with the system , I find the better combination and pairing with the Schiit Gungnir & the LCD-X . My impressions are from listening classical to POP music including piano recitals & violin. The amplifier is very neutral and " DAC" & source dependent .With the Shiit Gungnir DAC and streaming( Tidal & Quboz) it has a very good dynamic range, the layering & separation of instruments is very distinct & clear , females voices sound as they should . however one gripe I have with the unit is that the volume knob is small for a high end headphone amp . :popcorn:
Asghar
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Thanks for your impressions, Ashgar.
I'm looking forward to listening to this soon. :thumb:
Michael
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Well, I finally retrieved my HPA-1 from my cold garage where it had been sitting in its shipping box for a few days. I was too busy to hook it up till now, but I also wanted to make damned certain any viruses died before I risked drooling on the box or amp. :drool: Ashgar told me he made an extra effort to disinfect it - just in case. Thank you, Ashgar!
I've got my 2014 Mac Mini feeding my dB Audio Labs Tranquility SE DAC which is feeding my HPA-1 via a pair of Triode Wire Labs RCA ICs. My HD650 cans are plugged in and I have MUSIC! The amp is still quite cold, so I will give it a bit of time to warm up before I get too picky about what I'm hearing. :banana piano: :guitar: :bounce: I don't even know if I have the settings correct for my cans. :lol:
I'd like to thank all the guys who participated in this tour, and to Tom Christiansen for agreeing to ship it off to someone other than the guy who purchased it. It is in remarkably good shape considering it skipped across North America to 5(?) locations before landing on my front porch. Thank you. My hat's off (revealing my bald pate). :bowdown:
A special thank you goes to Alex (adydula). If it weren't for his enthusiasm and freely offering help, advice, and friendship, I quite likely would not have hosted this tour.
I'll be back before too long with my impressions. Stay tuned.
Stay well.
Michael
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I appreciated the opportunity to hear this and play around with it.
A great gesture as part of the AC community.
Looking forward to the insights from the owner!
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Mark,
Thank you for being the first to burn it in! Should I call you 'Guinea pig #1?' :green:
I'm listening with the same gear as I mentioned in my previous post. Both the DAC and HPA-1 have been on continuously for ~24 hours, so they're nicely warmed up. The volume setting is at ~9:30. I'm listening to Yo Yo Ma plays Ennio Morricone. It's one of my favorite CDs. I really enjoy listening to cello music, and I like Yo Yo Ma. Gabriel's Oboe just started...nice..cello and piano duet...The piano is so clear and distinct. How much of this is the DAC and how much is the amp?
[Perhaps, this weekend, I'll take my amp downstairs and connect my SW1X DAC III to it for a short comparison. That DAC can run circles around my Tranquility DAC.]
Now playing Mark Knopfler's Irish Love. Acoustic steel string guitar...nice...mellow...just what I need after the last few weeks! Next up: Marina by Skip Ewing & Billy Joe Walker Jr....Now: Beni Beni by Niyaz. Niyaz is a Turkish group. I can't understand a word of it, but I love this song. Now I'm listening to Where Do The Children Play? by Cat Stevens. Now: Fields of Gold by Eva Cassidy....heavenly...I love this song. The "s" sounds at the end of words are clear without sibilance. Inferior systems or speakers impart a harsh "SSSS" sound that pushes me away. This combination of gear pulls me in.
Wow. My wife hasn't come up once to distract me or to tell me to do something... :thumb: [If you know her phone number, don't call to ask her to bother me!]
Deborah's Theme by Chris Botti....clear; no sibilance. Sometimes, trumpet and/or sax can mess with my ears. This is smooth. Now to find some sax music. Oops. I stumbled upon Astral Weeks by Van Morrison while I look for sax music. This is so cool. Guitar on the right, flute on the left, Morrison and rhythm guitar in the center.
I've already noticed that bad/flat/uninspiring recordings don't sound very good. That's not a negative. It's the same situation I experience in my main system. The better the recording, the better it sounds. I think I'll try a couple songs I love to listen to on my car radio, but can't bear listening to on my main system.
I'm really enjoying this.
More later...