[garbulky]

Been listening today with my Fostex headphones, 25 ohm impedance and easy to drive, so I am using it with the resistors in play and the sound is big, powerful and smooth. I can literally feel the power of the amp - I can't imagine what putting in the jumpers would be like. Don't know that I really need to as my all my cans are relatively easy to drive...’cept for the HD-6XX.

You'll never know.... Think of it like this. You obviously like it. So explore the options it offers. You wont damage anything as long as you turn the volume down first. . Its just a few screws to take off the case. then you just push the jumpers in (with the power cable disconnected). You can listen with the case off to see if you like the result or not. And pull the jumpers out if you dont like it.
Instructions on pg15
https://emotiva.com/wp-content/uploads/2017/05/BASX_A-100_User_Manual_v10.pdf
Ive always been curious about Fostex. Ive heard good things.

 

[m usicguy]

@peepr

How do you have your amp configured? Jumpers installed. Or standard set up with 220 resistors. I own he560 also.

M usicguy

 

[peepr]

@peepr

How do you have your amp configured? Jumpers installed. Or standard set up with 220 resistors. I own he560 also.

M usicguy

I have the original A-100 without the headphone jack so I run speaker tap adapters and run my 560 right from the taps. I have a picture somewhere I can post later.

 

[lambdastorm]

Had this amp a year ago, at that time I paired it up with LCD2 and didn't feel like its the best combo out there. Sure it has loads of power and sounds fairly laid back, but there's simply not enough improvement that I can justify keeping it over my NFB11. Now that I'm planning to get an ABYSS, is it worth re-purchasing? Just asking cuz most Abyss users out there isn't budget conscious while I'm super poor........

 

[m usicguy]

Well?

I got my A100 yesterday. Listened to it for about a day and half. I put the bypass jumpers. Even with my Thx00. It seems more clear and dynamic. Its a very laid back sound. MY q701 really come to life. More to follow. Just have to figure out how not to blow headphones up. I have controllable sources. So I think I might tape the volume knob on the A100 not to go above a certain limit.

M usicguy

 

[kernel8888]

Yea I was really nervous to put my k712 directly on, but I kept it quiet for night listening, and it was very impressive and lively for low level listening. My he500's sound great, but aren't as impressive at quiet levels to be honest, they like to rock out loud

 

[m usicguy]

Its me again, M usicguy,

HOLY Schiit Is this a dynamic MONSTER!!!

 

[iamjaymo]

Well?

I got my A100 yesterday. Listened to it for about a day and half. I put the bypass jumpers. Even with my Thx00. It seems more clear and dynamic. Its a very laid back sound. MY q701 really come to life. More to follow. Just have to figure out how not to blow headphones up. I have controllable sources. So I think I might tape the volume knob on the A100 not to go above a certain limit.

M usicguy

Hi, with the X00...do you have much play with the volume knob with the jumpers in??? Only 25 ohms for the X00s so you could blow them easily if not careful. Sorta scared to put the jumpers in

 

[garbulky]

Hi, with the X00...do you have much play with the volume knob with the jumpers in??? Only 25 ohms for the X00s so you could blow them easily if not careful. Sorta scared to put the jumpers in

Look at the specs. Its designed to take 1.8 watts and is 94 db sensitive. Id be careful but its designed to absorb a lot of power.
https://www.massdrop.com/buy/fostex-x-massdrop-th-x00

The specs of the a100 are not linear with the resistors in. They dont decrease from low to high impedance. They are very low in output at 30 ohms at only 0.2 watts. (Your fostex are 25 ohms). The resistors add high impedance to something like 150 ohms output causing this weird behavior.
https://emotiva.com/product/a-100/

 

[kernel8888]

So I heard that the volume knob will determine how many WATTS are being sent to the headphones, so for simplicity sake if you've got 50wpc, and only have the volume up 10%, you're only sending 5 watts to the headphones?

is that correct?

 

[garbulky]

So I heard that the volume knob will determine how many WATTS are being sent to the headphones, so for simplicity sake if you've got 50wpc, and only have the volume up 10%, you're only sending 5 watts to the headphones?

is that correct?

No. Not linear

 

[iamjaymo]

Look at the specs. Its designed to take 1.8 watts and is 94 db sensitive. Id be careful but its designed to absorb a lot of power.
https://www.massdrop.com/buy/fostex-x-massdrop-th-x00

The specs of the a100 are not linear with the resistors in. They dont decrease from low to high impedance. They are very low in output at 30 ohms at only 0.2 watts. (Your fostex are 25 ohms). The resistors add high impedance to something like 150 ohms output causing this weird behavior.
https://emotiva.com/product/a-100/

Makes sense...I'll grow a pair and just put the jumpers in. I'll do it tomorrow... busy with other crap today. Will advise how it goes.

 

[m usicguy]

The first thing I did was make a volume indicator on the knob. So I know where it is. Really emo? I think being able to see where the volume is important. But no big deal

I use a variable source. On my DAP, i use the headphone out and my dac has a controllable volume out. I turn both down. Then i turn the amp up to 12 o clock and start turning up the source. **Verify first your source is turned DOWN FIRST***

Then i find the happy spot between the two. I actually get a lot of usable adjustment on the amp. Right now im using it on my computer set up. But when i put it on the tv, I will tape the volume knob down so my wife doesn't touch it and use the volume on the dac/tv to feed the amp. Im going to leave my jumpers in. I think this really opens the amp up.

Ive been using my fostex thx00 on this amp with no problem. I error on the safety side and keep my source turned down. I can almost max out the knob on the amp. Sounds really good.

For 229.00 dollars this is a steal!!!

M usicguy

 

[s2kPanda]

Yall think it'd be safe to run Aeon Flows through these with the jumpers in? Seems like the headphones would blow up from looking at the insane amount of power to it.

 

[m usicguy]

Well when Fed Ex learns how to drive in the snow Ill know. I ordered a pair and waiting for a week now due to snow. Ill be running the open aeon on this amp. Its going to be my wifes tv setup.

If you have a controllable source you should be fine. *************Do Not use a fixed output source!!!!!!!********* If you do, do not put the jumpers on and use the resistors instead and have a traditional headphone amp. With the resistors its just like a normal amp. and do what you want. It wont be as powerful and safer. I think the resistor kinda flatten and compress the sound alittle. Just my 2 cents.

Proceed with extreme caution!!!!!!!!!!!!!!

M usicguy