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Speaker amps for headphones - Page 155

post #2311 of 2899
Quote:
Originally Posted by zilch0md View Post
 

 

Interesting!  Most of the op-amps I've rolled in my iBasso PB2 Pelican have datasheets that show what you're talking about.  For example, the OPA1611 and 1612 allow a minimum supply voltage (Vs) of something like 4.5V (if I recall correctly) and a maximum supply voltage of 18V (I'm certain of this figure), but they show lowest THD+N at a supply voltage of 15V (and I'm certain of this, but too lazy to look up the datasheet at the moment).

 

So, yeah, lots of op-amps show an improvement in noise measurements until some peak is reached - always close to the maximum allowable supply voltage, it seems. That's had me scratching my head for a while, now. Your hypothesis makes sense to me, but I'll remain open-minded, especially since I've tried real hard to actually hear the difference, between 8.4V and 15V with the OPA1612 into HD800, for example, to no avail.  So, the whole subject is moot, with my ears and my gear, at least.  But...  I run at 15V because the output voltage increases better than linearly with an increase in supply voltage - and that I can hear, as improved dynamics and bass control, with inefficient headphones.

 

Mike

 

Mike,

Ok you've gone and done it! :wink_face:

 

I looked up the spec sheet on an LM4562.

I chose this one because I have a downloaded copy of the datasheet, but don't have a copy of the OPA1611 Op Amp. 

In practice, not much difference in distortion between +/-17 and +/- 2.5 Volt power supply rails so long as you stay below clipping.

Sure, distortion is lower with the higher voltage power supply, but the levels are so low, well, it'a academic.

Is 0.0002% THD low enough?

Or is 0.00002 % THD enough?

Numbers for IM are fairly similar, power supply voltage does not make enough of the difference in the real world.

post #2312 of 2899

Got recommend to post in here by Gary about speaker amp comparisons. I recently picked up a Marantz PM6004 to compare to my existing Emotiva Mini-x-a-100 with respect to LCD-3. Initial impressions - the PM6004 killed the Emotiva. I'm finding my CD5004/PM6004 combo more fun to listen than even the BHA-1/BDA-2 combo. More serious impressions to come later. Just thought of posting two lines in the unlikely event that someone was also considering a Marantz to drive headphones off the tap.

 

 

post #2313 of 2899
Quote:
Originally Posted by Chris J View Post

 

I would argue that when using power amps with headphones, the big elephant in the room will almost always be signal to noise ratio: excessive hiss and/or hum.

Speaker power amps are never designed to be used with drivers that output 96 dB when driven from 1 mW.

And 26 dB or even 32 dB of gain is a bit much for a headphone amp.

Hence the need for resistors.

 

As for voltage and current ranges, usually irrelevant in a well designed amp, as the THD will be low enough to be academic, unless you are approaching clipping.

Remember, you are often listening to a power amp deliver a Watt or less to your loudspeakers.

The idea that a transformer coupled vacuum tube power amp must see an 8 Ohm load if you are running off the 8 Ohm taps is grossly exaggerated.

 

In a perfect world, it would be nice to A/B one of the megapower headphone amps (like the Bryston and it's bretheren) against one of these resistor/power amp combos.

 

Or hack the amp to lower the gain, but that's beyond the capabilities of most.

 

The folks with megawatt amps are probably running low efficiency speakers and probably crank way more than 1W, but meh I see your point.

 

And sure the THD may be academic, but this is practically arguing rhetoric with rhetoric where half the things we talk about are placebo and the other half are self gratification where we quibble over things like cables and blocks of wood under our solid state devices. Or perhaps that THD really is noticeable, particularly when added into that inherent in the transducer *shrug* or not.

 

Quote:

Originally Posted by potterma View Post
 

I have a difficult time believing charts that show a decreasing THD figure with increasing output power.  One is trying to measure extremely small signals with outrageous precision to make these measurements.  I'd wager its more about exceeding the capabilities of the measurement equipment (hence an artifact of the measurement) and not a real increase in performance.  You're "getting into the sweet spot" of the measurement equipment, not the amplifier.

 

I've seen several charts that show a decreasing THD with output before increasing near the limits (hence that so called sweet spot). Bah don't ask me to find the sources though, I don't keep track of my arguments well enough to quote anything :rolleyes: Tubes are moreso wonky than solid state. Increase one factor, you get increased distortion in one component but decreasing in another, and there's various spots in the middle depending on the bazillion other thingies that you can fiddle with. Oh and then let's change tubes and play the game all over again, or something like that. I tried rolling opamps once, because apparently I hate myself, and then I did it again because I developed a masochistic streak.

 

 

 

post #2314 of 2899

Well I'll be contributing a lot to this thread relatively soon. This week I'll have the HE-6 and a Bantam Gold speaker amp coming in and I'll be experimenting with the Project Ember as a pre-amp. If I get a balanced HD650 cable I'll also hook them up to the Bantam.

post #2315 of 2899
Quote:
Originally Posted by Zoom25 View Post
 

Got recommend to post in here by Gary about speaker amp comparisons. I recently picked up a Marantz PM6004 to compare to my existing Emotiva Mini-x-a-100 with respect to LCD-3. Initial impressions - the PM6004 killed the Emotiva. I'm finding my CD5004/PM6004 combo more fun to listen than even the BHA-1/BDA-2 combo. More serious impressions to come later. Just thought of posting two lines in the unlikely event that someone was also considering a Marantz to drive headphones off the tap.

 

 


Thats quite a nifty device, even a phonostage pre-amp! I look forward to your impressions, especially if it's a step up from the mini-x. If it takes some of the edginess off the treble, that would be tipping the scales quite a bit.

post #2316 of 2899
Quote:
Originally Posted by Zoom25 View Post

Got recommend to post in here by Gary about speaker amp comparisons. I recently picked up a Marantz PM6004 to compare to my existing Emotiva Mini-x-a-100 with respect to LCD-3. Initial impressions - the PM6004 killed the Emotiva. I'm finding my CD5004/PM6004 combo more fun to listen than even the BHA-1/BDA-2 combo. More serious impressions to come later. Just thought of posting two lines in the unlikely event that someone was also considering a Marantz to drive headphones off the tap.

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Interesting.
I'm curious, why do you prefer the Marantz over the Bryston set-up.
post #2317 of 2899
Quote:
Originally Posted by Zoom25 View Post

Got recommend to post in here by Gary about speaker amp comparisons. I recently picked up a Marantz PM6004 to compare to my existing Emotiva Mini-x-a-100 with respect to LCD-3. Initial impressions - the PM6004 killed the Emotiva. I'm finding my CD5004/PM6004 combo more fun to listen than even the BHA-1/BDA-2 combo. More serious impressions to come later. Just thought of posting two lines in the unlikely event that someone was also considering a Marantz to drive headphones off the tap.




Big thanks for posting this. I have lately been considering exactly PM6004 and PM6005 on speaker out for my LCD-2 and HE-500. Also maybe Denon PMA520AE and PM720AE. All of which can be bought at ok price levels here in EU. Just need that speaker out cable to try them out. I do not want to butcher my original cables.
post #2318 of 2899
Quote:
Originally Posted by HiFiRobot View Post

Just need that speaker out cable to try them out. I do not want to butcher my original cables.

 

It's pretty easy to make balanced cables for the HE-400 and HE-500. Here's my DIY: http://robrobinette.com/BalancedCable.htm#Make_a_HiFiMan_HE-500_Balanced_Cable_

post #2319 of 2899
As for denon. They have thx certified
Recievers like the two it have
Ave 5805ci and the ave 3805.
Great units and you can buy them used as these models are not made
Anymore. I tried both with headphones from the speaker terminal
And they worked great

Al
post #2320 of 2899
Quote:
Originally Posted by vaed View Post
 


Thats quite a nifty device, even a phonostage pre-amp! I look forward to your impressions, especially if it's a step up from the mini-x. If it takes some of the edginess off the treble, that would be tipping the scales quite a bit.

 

While I still have to get used to this and figure out, I'm confident this takes the harshness off in comparison to the Emotiva Mini. There is slight roll off in the very upper treble regions, but still good resolution and attack.

post #2321 of 2899
I think for anyone buying an amp you have two choices.
By a proven one or buy a yet unproven.
And then find someone with a proven one and compare the sound.

Al
post #2322 of 2899
Quote:
Originally Posted by Chris J View Post


Interesting.
I'm curious, why do you prefer the Marantz over the Bryston set-up.

 

With the BHA-1, the bass was super deep, had good impact, the mids were on point and transparent. Treble was clean, without harshness (although a bit fatiguing with the LCD-3 in balanced mode) but surprisingly not with the D2000 (single ended), which is supposed to be brighter. Both were being driven properly as far as I could tell. I mostly tried the BHA-1 and BDA-2 combo. I had to keep changing the volume, sometimes turning it up and sometimes down, just to get the perfect treble and bass ratio. I think I could've gotten used to if I had more time with it. However, in my four hour audition, it never really moved me, especially considering the price of the setup. Later on I tried the BHA-1 with Arcam D33. This took care of the treble for sure and preferred more, although had less energy and maybe dynamic. I can't tell which one I would've picked though.

 

With the Marantz combo so far, for a week or two, I'm going to figure it out more and report back, before getting all critical on it. Although I will say that music on the Marantz combo actually sounds music for a change. For me, with speakers I'm less nitpicky about the sound, but with headphones it has to be just right for me to really enjoy it. The BHA-1 while had everything going for it just couldn't really engage me in a fun sense. Like I kept listening to how well it did the music but just couldn't get it to sound fun after that.

 

I really want to try the BHA-1 again though.

post #2323 of 2899
Quote:
Originally Posted by Armaegis View Post

 

Or hack the amp to lower the gain, but that's beyond the capabilities of most.

 

The folks with megawatt amps are probably running low efficiency speakers and probably crank way more than 1W, but meh I see your point.

 

And sure the THD may be academic, but this is practically arguing rhetoric with rhetoric where half the things we talk about are placebo and the other half are self gratification where we quibble over things like cables and blocks of wood under our solid state devices. Or perhaps that THD really is noticeable, particularly when added into that inherent in the transducer *shrug* or not.

 

Quote:

 

I've seen several charts that show a decreasing THD with output before increasing near the limits (hence that so called sweet spot). Bah don't ask me to find the sources though, I don't keep track of my arguments well enough to quote anything " src="http://files.head-fi.org/images/smilies/rolleyes.gif"> Tubes are moreso wonky than solid state. Increase one factor, you get increased distortion in one component but decreasing in another, and there's various spots in the middle depending on the bazillion other thingies that you can fiddle with. Oh and then let's change tubes and play the game all over again, or something like that. I tried rolling opamps once, because apparently I hate myself, and then I did it again because I developed a masochistic streak.

 

 

 

 



Perhaps I should point out that I am one of those guys with the Mega Watt power amps and the inefficient loudspeakers.
Average power of a LOUD listening level is 1-4 Watts.

I wouldn't call the point where distortion is a minumum the sweet spot.
That would mean you are running the amplfier full out, maximum output voltage.
And since we often operate headphones with a Volt or less, often much less, then I guess we are not in the sweet spot.

Pre-amps?
Typically outputting 100 mV into a Power Amp.

The whole tubes are more wonky than Solid State comment gives me a headache.
It is one of the those statements which is not really true, but not really a lie.
If you are comparing Op Amp rolling to tube rolling then you are comparing Apples to Oranges.
When you roll Op Amps you are replacing one complete amplifier block with another.
A much better comparison would be to replace transistors in discrete circuits and compare that with tube rollling.
So we are back to "it depends".
How complex is the discrete transistor circuit?
How complex is the vacuum tube circuit?

However I do agree, it is rather masochistic to roll Op Amps and try to hear a difference. Or realize you don't really hear a difference.
post #2324 of 2899
Quote:
Originally Posted by HiFiRobot View Post


Big thanks for posting this. I have lately been considering exactly PM6004 and PM6005 on speaker out for my LCD-2 and HE-500. Also maybe Denon PMA520AE and PM720AE. All of which can be bought at ok price levels here in EU. Just need that speaker out cable to try them out. I do not want to butcher my original cables.

 

I might still consider the PM6005 later on if I like the PM6004 enough and if the digital inputs are half decent. Another option is PM8004 but with resistors for sure. I had the LCD-2 and HE-500 with Emotiva. I loved those two pairings on the Emotiva. The HE-500 wasn't 3D enough for me on that and the treble at times got bright. Although the LCD-2 was amazing.

 

At the moment, I sold them both for the LCD-3, so can't comment. However, I think both would sound really well on the Marantz. The Marantz should merge perfectly with the HE-500 in the treble region.

 

The mids are quite involving on the PM6004. It's a dynamic and powerful sound. It's less aggressive and less in your face than the Emotiva, but the vocals and presentation of the music is still quite lively.

 

Even the headphone output jack was a success. While directly off the taps, the LCD-3 sounded better with more deeper bass, it was still good off the jack

 

A huge success was trying the KRK KNS 8400 off the headphone jack. It was driving it perfectly. Usually these are considered bass light, but on this combo, it worked perfectly, also no weird treble. I'm going to try a D2000 next week when I get back to the PM6004, but I think it should be able to drive it fine and take off the edge. If it can drive the D2000 well, I'm sure that in the future I'll be able to drive a TH-900 right off the headphone jack.

post #2325 of 2899
Quote:
Originally Posted by Zoom25 View Post

 

With the BHA-1, the bass was super deep, had good impact, the mids were on point and transparent. Treble was clean, without harshness (although a bit fatiguing with the LCD-3 in balanced mode) but surprisingly not with the D2000 (single ended), which is supposed to be brighter. Both were being driven properly as far as I could tell. I mostly tried the BHA-1 and BDA-2 combo. I had to keep changing the volume, sometimes turning it up and sometimes down, just to get the perfect treble and bass ratio. I think I could've gotten used to if I had more time with it. However, in my four hour audition, it never really moved me, especially considering the price of the setup. Later on I tried the BHA-1 with Arcam D33. This took care of the treble for sure and preferred more, although had less energy and maybe dynamic. I can't tell which one I would've picked though.

 

With the Marantz combo so far, for a week or two, I'm going to figure it out more and report back, before getting all critical on it. Although I will say that music on the Marantz combo actually sounds music for a change. For me, with speakers I'm less nitpicky about the sound, but with headphones it has to be just right for me to really enjoy it. The BHA-1 while had everything going for it just couldn't really engage me in a fun sense. Like I kept listening to how well it did the music but just couldn't get it to sound fun after that.

 

I really want to try the BHA-1 again though.

 



Yeah, the Bryston stuff tends towards the analytical and neutral.
Personally, I like analytical and neutral.
OTOH, I used to be all about the tubes. I guess I changed.
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