[dennis h]

 Is the headphone out on AVA products enough to drive the following headphones ?
 Sennheiser HD 800
 Audeze LCD-2
 Audeze LCD-3
 thanks in advance,
 dennis h
 

[dennis h]

specs for headphones :

HD 800's
Description: Circumaural, open-backed dynamic headphones with detachable 3m cord (straight Y type) Connector type: 1/4". Frequency response: 6Hz–51kHz, –10dB; 14Hz–44.1kHz, –3dB. Sensitivity: 102dB/1V RMS. Impedance: 300 ohms at 1kHz. THD: <0.002% at 1kHz/1V. THD+noise: 0.02 % (1kHz/1V).

Audeze LCD2's
Specs
Frequency Response   10-50k Hz
Sensitivity   101 dB
Impedance   70 Ohms

Audeze LCD3
Specs
Frequency Response   10-50k Hz
Sensitivity   102 dB
Impedance   110 Ohms

[dB Cooper]

Can't speak to the Audezes but my AVA peamp drove a different 300Ω Sennheiser model (similar load) like a champ.

[dennis h]

Can't speak to the Audezes but my AVA peamp drove a different 300Ω Sennheiser model (similar load) like a champ.

thanks DB
dennis h

[dennis h]

  Thank you for helping me to get my post count up to the level that I could use the search function to get the info that I needed.
The answer I got was yes from experienced users.

Next Question :

   Providing both the sources and the headphones used were not the limiting factor, does the headphone performance improve
the higher up the food chain so to speak you go with AVA Pre-amps because the line stages are better ?

[retnuh]

I’m curious about this too, is the headphone amp better as you move up the product line? Max power? My T10RB works just fine, drives every pair I have very easily, just generally curious on any info about that part of the preamps.

[avahifi]

Our headphone drivers in all our preamplifiers are simply very high quality unity gain current amplifies used to translate the output impedance of the associated line stage down to abut 30 ohms and with excellent current drive to match the needs of modern headphones.

Since the basic specifications of the current amplifiers used (LME49600) are .0003% THD and 1000V/Sec slew rates, they are essentially transparent. You are thus actually just listening to the preamp output stage.

So any differences you may hear using headphones with an AVA preamplifier is just whatever the actually differences in our various preamp line section designs are.  All are excellent cost effective designs.

Frank

[dB Cooper]

I would like to stir the pot/initiate a conversation by including a link to an article by nwavguy, the electrical engineer and designer of the well-known O2 headphone amp. It is a discussion of the effects of having a higher output impedance than 1/8 that of the anticipated load. The 300Ω headphone load will not suffer these effects, being 10x that of the source impedance mentioned here, but anything below that will show increasing effects as the load impedance goes down. This includes the Audezes you mention which have a low impedance of around 32Ω IIRC. That is about equal to the source impedance being discussed. 32Ω being a relatively low impedance as headphones go, you then have a damping factor of ~1 into such a load and likely frequency response variations unless the impedance is purely resistive, which most headphones (like most speakers) are anything but. It is the equivalent of driving a typical 8Ω speaker from an 8Ω source, which is tube amp territory. NWavguy identifies a target headphone amp output impedance of 2Ω or less for this reason. A Benchmark paper shows similar test results. Both articles include real-world measurements and examples of the FR, electrical damping, and distortion effects that result for source:load relationships that veer below the traditional >8:1 guideline. They are the same effects that would affect a speaker amp setup.


Output impedances of 1Ω or less are commonplace for dedicated headphone amps these days although your 300Ω Sennheisers should work fine from the 30Ω source.
Clarification welcomed if I have misunderstood the presentations of Benchmark and nwavguy.


Benchmark article: https://cdn.shopify.com/s/files/1/0321/7609/files/Headphone_Amplifier_Performance_-_Part_2.pdf?1361


nwavguy article:  http://nwavguy.blogspot.com/2011/02/headphone-amp-impedance.html

[trebejo]

...The 300Ω headphone load will not suffer these effects, being 10x that of the source impedance mentioned here, but anything below that will show increasing effects as the load impedance goes down.

Did you hear anything unusual with your headphones?

Hmm... maybe there's a tweak there somewhere, I don't know, but I have a pair of Shures that have 65Ω impedance and they sound pretty good to me plugged into the current Vision preamp.

[dennis h]

thanks Frank

That's what I needed,

dennis h

[floresjc]

I have a T10 RB on my desk at work and it's a fantastic headphone amp. Probably overkill seeing as one can get a Schiit stack that sounds good for $200 but since I work a in a secure area I need gear that's not USB enabled.

With both Senn HD600 or Beyer Dt 1770 Pro they sound amazing at all volume. I just kick the power as I'm logging into my computer and after I'm all set up and the tubes are warm it is just a pleasure to listen all day.

[dB Cooper]

Did you hear anything unusual with your headphones?

Hmm... maybe there's a tweak there somewhere, I don't know, but I have a pair of Shures that have 65Ω impedance and they sound pretty good to me plugged into the current Vision preamp.

I had only 300Ω Sennheisers at the time I owned the AVA pre. These met the widely accepted '1/8 rule', so no problem. But the average impedance of headphones has trended lower over the years, perhaps spurred by the ascent of mobile audio. Many headphones are neither high nor flat in their impedance characteristics. I suggest you read the article and the paper. Have you?


I have nothing but respect for AVA. I have owned a number of pieces of their equipment and have met Frank. I was just asking about info I have seen backed up with objective test data. I have asked these questions before. Seems like there is little interest in such a discussion here so I will move on.