[kukkurovaca]

I'm not sure what +/-27vdc rails translates to in watts @ 300 ohms and I sure would like to know!

I think voltage swing ≠ power output. I would actually love to have a breakdown of how to interpret voltage swing specs for non-technical folks like me...

 

[Namtar]

I'm wondering the price point compared to the A100 (and the other similarly priced amps - say from Schiit) . That's going to be the interesting part.

 

[targetrein]

A little background: I'm coming from an O2 amp + Mad Dog, a combination I've used for several years. I sent the Dog's in for Dan's 'Prime' upgrade back in February. They're scheduled to arrive on Thursday, finally.

I have my new Emotiva A-100 sitting at the office waiting for the Alpha Primes and couldn't help myself. Today, I plugged in my buddy's M50x's in and geezus.... I know it's complete overkill (I'm using full power - resistor bypass) - crazy how much a little power can open up a set of cans.

That being said, there is constant hiss, even at low / no volume. At moderate music volume, hiss is fairly negligible. I'm guessing it's due to the M50's efficiency and the Primes will be better suited for the amp - the hiss won't be as noticeable. Right?

Anyway, power. Lots of power. Hot damn.

 

[lambdastorm]

A little background: I'm coming from an O2 amp + Mad Dog, a combination I've used for several years. I sent the Dog's in for Dan's 'Prime' upgrade back in February. They're scheduled to arrive on Thursday, finally.

I have my new Emotiva A-100 sitting at the office waiting for the Alpha Primes and couldn't help myself. Today, I plugged in my buddy's M50x's in and geezus.... I know it's complete overkill (I'm using full power - resistor bypass) - crazy how much a little power can open up a set of cans.

That being said, there is constant hiss, even at low / no volume. At moderate music volume, hiss is fairly negligible. I'm guessing it's due to the M50's efficiency and the Primes will be better suited for the amp - the hiss won't be as noticeable. Right?

Anyway, power. Lots of power. Hot damn.

These are pretty much unusable with any headphones cept planars and high impedance cans. You can't twist the volume knob too much without blowing the drivers.

 

[targetrein]

Yeah, volume is set at a quarter. Any more and these M50s will explode. Can't wait for the Primes - they're gonna sing

 

[m usicguy]

Try turning down your source output some and then add in some volume with the a-100

Your going to love the a-100 with mr speakers prime. Im running my alpha primes and this amps makes them sing. I normally have my dac at -15 db and jumpers installed on the a-100. volume is also at 1 o clock no hiss.

this amp really shines when you need good sound with low compressed digital files. Like prince and early 80's cd's. This is my fav amp to listen to Onigo Boingo Alive double cd!!!



m usicguy

 

[targetrein]

Your going to love the a-100 with mr speakers prime. Im running my alpha primes and this amps makes them sing. I normally have my dac at -15 db and jumpers installed on the a-100. volume is also at 1 o clock no hiss.

That's reassuring - you're pretty much using the same setup as I will be and you've got no hiss. Excellent.

I'll be running FLAC from an iBasso DX90.

For once, I'm going to be excited to go to work on a Friday morning

 

[KeithEmo]

THERE IS A SIMPLE SOLUTION.....

If you find that your headphones are so sensitive that you can barely move the Volume control on the A-100 off the bottom stop....
Or, if you find that, because you end up with the Volume knob so near the bottom stop, there is a slight but annoying channel imbalance....
Or, if you find that there is too much background hiss, AND THE HISS IS COMING FROM THE SOURCE (you'll know because the hiss will drop when you turn off or disconnect the source).

The solution is to "lower the gain structure of the A-100" by putting a pair of passive attenuators between your source and the inputs on the A-100.
For example, if you put a pair of 12 dB passive attenuators on the input, then you will end up turning the Volume knob on the A-100 12 dB higher to achieve the same output level as before.
This will "put the knob on the A-100 in a higher and more linear portion of its control range".

Note that, while this will not lower the noise floor of the A-100 itself, if the output of your source component has a noise floor, and that's what you're hearing, this may reduce it significantly.
(The result will depend on exactly where in the circuitry of your source component the noise is coming from.)

If you want to try this, I would recommend these (and they are quite economical).....
https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244

These are pretty much unusable with any headphones cept planars and high impedance cans. You can't twist the volume knob too much without blowing the drivers.

 

[iamjaymo]

These are pretty much unusable with any headphones cept planars and high impedance cans. You can't twist the volume knob too much without blowing the drivers.

You’re right! If I plug my 25 ohm Fostex dynamics, I hear a slight buzz/hiss. When I connect my harder to drive planars, I hear the music and that’s all. Variable source eliminates all this as the previous poster indicated. All good.

 

[lambdastorm]

THERE IS A SIMPLE SOLUTION.....

If you find that your headphones are so sensitive that you can barely move the Volume control on the A-100 off the bottom stop....
Or, if you find that, because you end up with the Volume knob so near the bottom stop, there is a slight but annoying channel imbalance....
Or, if you find that there is too much background hiss, AND THE HISS IS COMING FROM THE SOURCE (you'll know because the hiss will drop when you turn off or disconnect the source).

The solution is to "lower the gain structure of the A-100" by putting a pair of passive attenuators between your source and the inputs on the A-100.
For example, if you put a pair of 12 dB passive attenuators on the input, then you will end up turning the Volume knob on the A-100 12 dB higher to achieve the same output level as before.
This will "put the knob on the A-100 in a higher and more linear portion of its control range".

Note that, while this will not lower the noise floor of the A-100 itself, if the output of your source component has a noise floor, and that's what you're hearing, this may reduce it significantly.
(The result will depend on exactly where in the circuitry of your source component the noise is coming from.)

If you want to try this, I would recommend these (and they are quite economical).....
https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244

Thanks a lot for the reply Keith, your awesome.

From what I know most of the time the amp itself is the issue, not the dac. These are designed to mate with planars and high-impedance cans, so its only reasonable that they have too much gain/volume for high-sens/low-impedance cans.
Right now I'm driving my Abyss with these and I have to say that, even for headphones as inefficient as Abyss (on par with HE6) there's still too little usable volume. I'm able to turn the volume knob past channel imbalance point but that's pretty much where it starts to get too loud. Here's what I did:

I made a pair of speaker taps to XLR adapter with cheap Belden speaker cables, one end terminated with banana plugs (+/-) and the other 3-pin female XLR (GND/+/-) . This combination works very well and so far there's no channel imbalance, not even at the lowest volume. BUT I do think my Abyss sounds better single-ended. I don't exactly know why as balanced is supposed to be more resolving and airy, but to my ears single-ended is just more euphonic and easy on the ears. I do know tho that some users prefer single-ended to balanced so I guess I'm not the only one........

I want to buy the attenuator you recommended, it really seems like I can get more usable volume out of these. Few questions tho:

1. Does it muddy the sound in any way? Would I hear less details or get less dynamic range?

2. Does it work by dropping the voltage from the source?

Thanks.

 

[lambdastorm]

You’re right! If I plug my 25 ohm Fostex dynamics, I hear a slight buzz/hiss. When I connect my harder to drive planars, I hear the music and that’s all. Variable source eliminates all this as the previous poster indicated. All good.

Or there's a better solution:

make yourself a speaker tap to 2*3-pin XLR connectors and free up the front 1/4 port. That way you can leave the jumpers unengaged for hiss-sensitive headphones and drive your planar to another level . Win-win.

 

[IBJamon]

My solution was to put an adapter in-line with my headphones that need the attentuation. I detailed it in a post on page 15:

https://www.head-fi.org/threads/emotiva-a-100.825970/page-15#post-14057326

The 'grainyness' from the adapters I made went away, and I use them almost all of the time with my Monoprice M1060s, and I bypass the adapter for my Fostex's.

 

[KeithEmo]

Yes, attenuators work by directly dropping the signal voltage (and dropping the noise by an equal amount).

In engineering terms, an attenuator should have no effect whatsoever on dynamic range, detail, or anything else.
What they're doing is lowering the overall gain structure (so, since everything is lowered by the same amount, dynamic range and detail are not affected).
It is possible, however, that a certain piece of equipment itself might sound different when operated in a different portion of its gain range.
It's pretty easy to make an attenuator that produces no "side effects" and I've never heard any difference (other than the intended level shift) when using these particular ones.

Thanks a lot for the reply Keith, your awesome.

From what I know most of the time the amp itself is the issue, not the dac. These are designed to mate with planars and high-impedance cans, so its only reasonable that they have too much gain/volume for high-sens/low-impedance cans.
Right now I'm driving my Abyss with these and I have to say that, even for headphones as inefficient as Abyss (on par with HE6) there's still too little usable volume. I'm able to turn the volume knob past channel imbalance point but that's pretty much where it starts to get too loud. Here's what I did:

I made a pair of speaker taps to XLR adapter with cheap Belden speaker cables, one end terminated with banana plugs (+/-) and the other 3-pin female XLR (GND/+/-) . This combination works very well and so far there's no channel imbalance, not even at the lowest volume. BUT I do think my Abyss sounds better single-ended. I don't exactly know why as balanced is supposed to be more resolving and airy, but to my ears single-ended is just more euphonic and easy on the ears. I do know tho that some users prefer single-ended to balanced so I guess I'm not the only one........

I want to buy the attenuator you recommended, it really seems like I can get more usable volume out of these. Few questions tho:

1. Does it muddy the sound in any way? Would I hear less details or get less dynamic range?

2. Does it work by dropping the voltage from the source?

Thanks.

 

[MyPants]

Is there any reason other than price that fixed attenuators would be preferable to a passive pre-amp (ex. JDS Labs OL Switcher @ $45)? Assuming that your pre has a quality volume pot, you shouldn't be introducing channel imbalance. In my system I put the A100 downstream from my Asgard's pre-out, so I can infinitely vary the input signal to match whatever headphones I plug into the A100. This way you don't have to settle for a particular level of attenuation.

 

[KeithEmo]

Is there any reason other than price that fixed attenuators would be preferable to a passive pre-amp (ex. JDS Labs OL Switcher @ $45)? Assuming that your pre has a quality volume pot, you shouldn't be introducing channel imbalance. In my system I put the A100 downstream from my Asgard's pre-out, so I can infinitely vary the input signal to match whatever headphones I plug into the A100. This way you don't have to settle for a particular level of attenuation.