Integrated Amplifiers and Preamplifier with Good, Great or Excellent Headphones Output - Contribute to a LIST of amps!
Nov 29, 2014 at 10:01 AM Post #63 of 75

4N6

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The PrimaLuna Dialogue Premium HP looks like an interesting new addition to the list. New review in Stereophile, but the headphone section was relatively glossed over. Would love to hear it and compare to the Cary and Leben products.
 
Oct 9, 2015 at 1:16 PM Post #64 of 75

ZoNtO

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The PrimaLuna Dialogue Premium HP looks like an interesting new addition to the list. New review in Stereophile, but the headphone section was relatively glossed over. Would love to hear it and compare to the Cary and Leben products.

 
Rather than start a new thread, I thought I'd build off of this one.
 
PrimaLuna DiaLogue Premium HP integrated amplifier
I recently inquired about the headphone stage in this unit and have included PrimaLuna's responses to my questions in quote tags below:
 
-----
 
Hi there, I'm interested in the DiaLogue Premium HP Integrated Amplifier to use in a combination video 2.0 system using a pair of Magnepan 1.6QR speakers where I'll also use a pair of headphones, either Sennheiser HD650 or Sennheiser HD800.
 
I'm very curious about the product's headphone amp and was hoping for more technical information.
 
I noticed on your product page the following description: "Finally, we added an all-tube headphone amp. In fact, it's one of the best headphone amps you can buy. Remember whether a speaker driver is mounted in a box or in a headphone, it's still a speaker. And the amplifier requirements are the same. So it makes sense that if you have an incredible amp with the finest output transformers, put it to use to run the headphones by simply dividing the output power. That's exactly what the larger tube headphone amps do. Compare the HP to the most expensive and esoteric stand-alone headphone amplifiers in the world and you will see what we mean."
 
I'm wondering if you could provide me with more technical details about the headphone amplifier:
 
1. Is it run through the same circuit as the speakers, including the transformers, with just a resistor or something to reduce the output power? The reason I ask is because this is in line with the above description, but the description also says it is an "all-tube headphone amp" which would imply an Output Transformerless design. Is there anything else in the headphone circuit path that's not in the speaker path?
 
Yes, the headphone amplifier runs direclty off the same circuit as the speakers.  "All tube" does not mean no output transformer... If we used an OTL design, 4 EL34s would produce significantly less power.

 
2. What is the output impedance through the headphone output?
 
The output impedance varies depending on the load being presented by the headphones.  It's about 4.88 Ohms when presented with a 32 Ohm load, goes up to about 6.4 Ohms with 300 Ohm headphones, and 9.54 Ohms @ a 600 Ohm load.

 
3. With the stock tubes you include, what is the output power at 32, 300, and 600 ohms? I'm most interested in the 300-ohm figure for my Sennheisers, but the others are pretty standard in headphone measurement world.
 
The HP's headphone amp puts out a lot of juice.  The power output at 32 Ohms is approximately 11.4 watts.  Into 300 Ohms it's about 1.6 watts, and at 600 Ohms it's about 800mW.  It's been able to power any pair of headphones we've thrown at it including several Audeze models, the Abyss headphones, AKG, Sennheisers, and Grados. [my emphasis added]  

 
4. When headphones are inserted, does the unit automatically mute the speakers?
 
The main speakers do not automatically mute when you insert the headphones.  There is a switch on the side of the amp that allows you to switch between loudspeaker and headphone listening.

 
Lastly, unrelated to the headphone questions above, do you think the amp can power my Magnepan 1.6QR effectively? I know they are current-hungry, 4ohm, with a flat impedance curve due to the planar technology. 
 
Quote:
The Premium HP integrated will easily drive Maggie 1.6s.  We even have customers using the standard DiaLogue Premium integrated with 1.6s and having great results.  The DiaLogue's power and output transformers are massively over-built, so the amp is capable of producing enough clean, stable current to drive pretty much any speaker on the market.
 

 
Oct 9, 2015 at 1:20 PM Post #65 of 75

ZoNtO

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Rogue Audio:
 
Sphinx and Cronus Magnum II integrated amplifiers
Chip used is the TI LM386N-4. Puts out roughly 1W into 32 ohm load and distortion is very low (near 0%) at normal listening levels.
 
Pharoah integrated amplifier
Driven directly off the preamp tubes (12AU7). Also responded that there are certain tweaks they can make to optimize the circuit for Sennheisers. EDIT: this tweak is simply to change the gain structure of the headphone circuit so that the user does not need to turn the volume knob as high when using Sennheiser's high impedance headphones.
 
Oct 9, 2015 at 1:25 PM Post #66 of 75

ZoNtO

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Crosspost from the Simaudio Moon 430HA thread:
 
I debated about posting this here, but figured I might as well in case anybody else is doing the same research I am on the 430HA and other Simaudio units for use in a combined headphone and video 2.0 setup with speakers in a living room. As the preamp functionality is equally, if not more, important to me, I inquired about the preamp and headphone capabilities of the 230HAD, 430HA, 350P preamp, and 340i integrated. Email chain below (with some grammar edits and a minor redaction I thought appropriate):
 
Email #1:
Hi there, 

I am very interested in a few products from your Moon Neo line for use in a combination video 2.0 system that will also double-up for headphone use. 

I take it that the 430HA is your highest performing headphone amplifier in the Moon Neo line, but I was hoping that someone with the technical knowledge of the line could compare the preamp and headphone amplifier circuits between the 430HA, the 350P preamplifier, and the 340i integrated amplifier. Additionally, I'm hoping you can provide technical specifications for the headphone circuits for the 350P and 340i so that I may compare them to the more detailed headphone specs provided for the 430HA on your website. 

Is the 350P a better speaker preamp than the 430HA because there is less circuitry focused on the balanced headphone design? 

As of now, my source will be an Oppo BDP-105D and headphones will be Sennheiser HD650 and/or Sennheiser HD800. 

Thanks! 
 
Response #1:
 
Dear Mr. [
biggrin.gif
],
 
Thank you for your email and your interest in MOON products.
 
Indeed, the 430HA is the highest performing headphone amplifier, which it excels at. The 350P is the better preamplifier though.
 
The 230HAD, however, is almost on par with the 350P headphone amplifier’s performance, it also uses a transconductance circuit, similar to the one found in the 230HAD.
 
Our integrated amplifiers from the Nēo series  (220i, 250i & 340i) use the same amplifier as the speakers output, which is scaled down using a resistance, and so, sounds better with very high impedance headphones.
 
I hope this answers your question; if you need further information, do not hesitate to contact us again!
 
Best regards.
 
The Simaudio Team
 
Email #2 with Response #2 overlaid:
 
Hi there,
 
Thanks for the quick response. I have a few follow up questions:
 
1. Could you please provide the technical specifications for the headphone out for both the 350P and the 340i? Wondering about output impedance; power output at 50, 300, and 600 ohms; and any other figures (distortion, frequency response, crosstalk, etc.) that you have available. Those specs are provided on the website for the 230HAD and the 430HA because they are headphone-focused, but not for the 350P and 340i headphone outputs.
 
340i and 350P headphone out specs:
 
340i Headphone Out Specs:
Output impedance: 330ohms
DHT: 0.03%
Power:
2W @ 32ohms
3W @ 60ohms
5W @ 180ohms
6W @ 330ohms
5W @ 600ohms
 
350P Headphone amp section specs:
Output impedance: 1.25ohm
DHT: 0.005%
Power:
1W@ 50ohms
200mW@ 300ohms
100mW@ 600ohms
 
The 340i appears to be the powerhouse here, but there is a huge output impedance difference (the lower the better), and this is the main difference between an headphone amp and an integrated amplifier with an headphone output. With Sennheisers like you mention, although it would work well with a 340i, any of our dedicated headphone amp will deliver much better sonics.

 
[430HA specs added for convenience:
Output impedance: 1.25ohm
DHT: 0.005%
Power:
8W @ 50ohms
1.33W @ 300ohms
667mW @ 600ohms]
 
[230HAD specs added for convenience:
Output impedance: 1.25ohm
DHT: 0.005%
Power:
1W @ 50ohms
200W @ 300ohms
100mW @ 600ohms]
 
2. Could you please elaborate on the difference between the transconductance circuits as you move from the 230HAD to the 350P to the 430HA? 
 
350P and 230HAD are very similar headphone-wise. 430HA is overwhelmingly superior with the similar topology, but doubled for full balanced differential, with higher power semiconductors and also power supply rails powered via M-LoVo regulators. Also adds the (defeatable) crossfeed circuit.

 
3. Relatedly, is the transconductance circuit in the 430HA just the circuit in the 350P doubled up in a true balanced configuration? I'm probably most interested in this comparison because these two products seem to be the closest to what I'm looking for.
 
See above.

 
4. If a user sends the 350P a balanced analog signal through one of its rear balanced inputs and then listens through the headphone jack, does the audio signal remain balanced like it does in the 430HA until it reaches the headphone jack (even though the jack is single-ended)? Or is it summed somehow before then.
No it is summed up in the 350P; the headphone amp section is single in this model. Note that it is still incredibly quiet and musical. 

 
[Note: I have since followed-up to confirm if a user inputs a balanced analog signal into the 350P and then outputs via its balanced outputs to a power amplifier, whether the signal remains balanced.]
 
5. Is the option to add a DAC board to the 350P for the same updated DAC board that is available for the 430HA (at $800 for both)? I'm considering this as an add-on, but wondering if there's really a performance benefit compared to the DAC section of my Oppo BDP-105D that is also based on an ESS Sabre chipset.
 
It is the same card in 350P and 430HAD. [The] internal card is certainly better suited with the linestage inside; we optimized it. Have a listen and let your ears be the judge. [Note: my edits here]

 
6. Lastly, what are the differences in the preamplifier/line-stage circuits as you go from the 230HAD to the 430HA to the 350P?
 
230HAD is basic single-ended linestage. Works wery well and sound fantastic for the price. 430HA is much better, but everything inside was optimized for headphone amplification. In the design, the preamp section is a useful addition to the product, not the main focus. The 350P is by far the better preamp, with a kind-of equivalent of 230HAD headphone amplifier headphone out section. Between 350P and 430HA, it depends on which type of listening you want to favor the most; loudspeakers or headphones? But rest assured in both cases the musical performance is excellent. For non-exotic headphones such as Sennheisers you have mentioned, the 350P can delivers astonishing performance.

 
Since both the HD650 and the HD800 are 300-ohm headphones, it may work with the 340i, but I want to compare the various options in more detail if possible.
 
I really like the idea of the 430HA, but the lack of balanced stereo output makes me wonder if the 350P would be a better fit in my system. 
 
Thanks for your help!
 
 
Oct 9, 2015 at 1:29 PM Post #67 of 75

ZoNtO

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Peachtree Audio Nova (Nova125, Nova125SE, presumably Nova220SE) integrated amplifier
Uses the TI IC=TPA6120A2. Output impedance is 4.7 ohms.
1170 mW, 32 ohms (0.1% THD)
182 mW, 300ohms (0.1% THD)
 
Nova integrated line being replaced by the Sona separates, but will use the same TI chip in the headphone stage on the Sona DAC/pre.
 
Dec 28, 2015 at 3:57 PM Post #68 of 75

Me x3

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Hey Guys!
 
(Not sure if this was mentioned before or not)
Here's a review I've found for the Cambridge Azure 851A
 
" Headphone listeners will be pleased with the onboard headphone amp.  With a wide range of phones from the Grado 60i, all the way up to the LCD-2 (a range of about $100 – $1,000), the internal amp is on par with anything you’ll find externally for a couple hundred bucks.  Not a bad thing to include on the chassis. Those who haven’t partaken the pleasures of the head-fi world will find the 851A a great place to start your journey."
 
http://www.tonepublications.com/comparo/the-latest-flagship-components-from-cambridge-audio/
 
Jan 5, 2016 at 3:43 PM Post #69 of 75

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I've contacted Cambridge Audio and shared a few emails asking for information about the headphone amplifier built into the Azur 851A. The support was excellent. Thumbs up for Cambridge Audio.
 
Here's the info about the built in headphone amplifier:
 
- Topology: Class AB
- Components for the headphone amp include complimentary bipolar transistors (Part numbers BD139 and BD140)
- The output impedance is 10 Ohms
- According to Cambridge's engineer the math works out to be 600-800mW RMS into 32 Ohm load
 
Sep 19, 2016 at 9:39 AM Post #70 of 75

jdmeyers77

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I've been through a fair number of dedicated head amps (Earmax Pro, Single Power, Mapletree, etc.).  The best by far is my Cary 300SEI with NOS tubes.  As well, it's the finest amp for my big Spendor loudspeakers as well.  YMMV.
 
Apr 19, 2018 at 1:03 PM Post #71 of 75

ZoNtO

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Wanted to bump this up and see if anybody else has info out there. Particularly interested in integrated amps with enough grunt to power a pair of Maggies, that also have a decent to great headphone out.
 
Apr 19, 2018 at 2:28 PM Post #72 of 75

jnorris

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Wanted to bump this up and see if anybody else has info out there. Particularly interested in integrated amps with enough grunt to power a pair of Maggies, that also have a decent to great headphone out.

With very, very,very few exceptions, integrated amps and receivers don't have headphone "amps" per se, they have headphone jacks that are tapped from the speaker outputs through a 120-330 ohm resistor. I have found this to have decent to poor results on my headphones depending on their impedance. You would be better off finding your perfect amp for the Maggies and use a dedicated headphone amp like the Schiit Magni 3 driven from the integrated amps' tape out jacks.
 
Apr 20, 2018 at 9:12 AM Post #73 of 75

jnorris

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another “high end”,suggestion: Mcintosh D100 or D150 Digital preamp.

An older, however superb DAC, in my opinion. Mine sounds superb paired with my SimAudio transport and HD800 cans.

Expensive, and still needs an amp. This is another category of "headphone amp", those built into preamps. In many cases these amps are again just a jack tied to the preamp output, usually through some resistors, or a low-cost IC amp thrown in as an afterthought. As mentioned elsewhere here on Head-Fi, the headphone output impedance is 47 ohms on the D150. Hardly reference quality.
 

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