[PascalT]

I've been experimenting with the various gain settings on my LD MKIII along with HD595s. The high impendance setting (better for 300+ohm phones according to the manual) sounds so much better than the low impendance one (better suited for the phones I have). Not only is the bass much stronger but the sound in general is much tighter, a lot less "airy", and it has a lot more punch.

On the "correct" low impendance setting the sound is extremely harsh and the soundstage is extremely wide, with very little bass and punch.

I am wondering what are the technical reasons why the high impendance setting fits my phones with very low impendance better? Is it just the manual that is wrong in its settings' recommendations? Are the HD595s too sensitive for the low impendance/sensitive setting? Why is there such a big difference with the bass and soundstage?

I'm very curious about all this.

thanks for any info!

 

[Bozz_Keren]

well i'm using Gain 5x in my LD MKIV, it sounds better and widened the soundstage with RS2 and PK1,
what is the setup of your gain? sw1 on and sw2 off?

 

[PascalT]

i'm using 10x (off/off)

the others lacked bass and the treble made my ears bleed

 

[classic_rock_69]

Phones like grado's work better on the low impedence setting which is both switches on or switch 2 on and switch 1 off. The high impedence setting works better with senns and with my k701's it works much better as well. The reason for that is most likely due to the impedence level of the phones, grado's have low impedance compared to phones like the akg or the senns.

 

[Bozz_Keren]

well my setting is sw1 on/sw2 off, i like the sound better, that setting made my RS2 kinda laid back though

 

[PascalT]

Quote:

Originally Posted by classic_rock_69 /img/forum/go_quote.gif Phones like grado's work better on the low impedence setting which is both switches on or switch 2 on and switch 1 off. The high impedence setting works better with senns and with my k701's it works much better as well. The reason for that is most likely due to the impedence level of the phones, grado's have low impedance compared to phones like the akg or the senns.

That's the thing, the 595s are low impendance, which is why i wonder it is like this.

 

[classic_rock_69]

Quote:

Originally Posted by PascalT /img/forum/go_quote.gif That's the thing, the 595s are low impendance, which is why i wonder it is like this.

They are? I'm sorry I figured they'd be similar to 6xx's. What impedence level are they?

Ya I got no answer to that, i'd be interested to see why as well.

 

[PascalT]

yes, there's a 50ohm version which is what I have.

There's another that is 120.

 

[classic_rock_69]

Quote:

Originally Posted by PascalT /img/forum/go_quote.gif yes, there's a 50ohm version which is what I have. There's another that is 120.

Ya that's still quite a bit higher than Grado's which are 32 and akg's are 60.

 

[Negatron]

I might be able to toss in a little food for thought. The 'Gain' switches in the LD's are negative feedback switches, the lower impedance settings increase the loop or negative feedback, both switches off (gain 10) lower the feedback to an insignificant level.

When loop feedback is increased distortion and output impedance is lowered, HOWEVER in the process odd order harmonics are added to the mix. The output stage of the MK's is an White cathode follower, a circuit very low in distortion to begin with and the primary distortion is only second harmonic the third harmonic is down in the noise. When feedback is added the second harmonic is decreased but the 3rd is added as well as phase distortion.

The 'specs are important group' will celebrate the lower impedance setting, it measures better. Personally it bothers my ears, I much prefer no loop feedback in a linear design. The MK's drive lower impedance 'phones just fine with the feedback off but output voltage drops off which is not important since the lower Z 'phones do not need as much voltage to begin with.

It is all a mater of personal taste, but there are a few who can not tolerate odd order harmonic distortion, even in very small amounts. All this is personal opinion only and not meant to imply a right or wrong. Besides, it's only $0.02 worth.

 

[mallethead]

This is a very delayed response but just saw the thread.
Just what I was looking for my self. Bought a LD MK3 a few months ago and was comparing sound to new Beresford DAC I just bought. When i turn volume up on DAC I get more bass impact with everything else. With the LD I just get more treble. I was suspecting gain settings and was about to experiment. What setting did you eventually end up with?

 

[PascalT]

I am using both settings at OFF with the 595s. At ON it was just way too harsh for me.

 

[Dept_of_Alchemy]

It changes the tone in the same way that the 'hardness' control does on the Single Power amps. Basically, the tone goes from 'soft' to 'hard' as the amount of feedback increases.

Your preference with the amount of feedback should also correlate with the types of tubes you're rolling in your amp. For instance, if you're using the richer sounding Mullard M8100 it is usually better to go with more feedback whereas if you're using a tube like the Voshod 6J1P-EV then less feedback would compliment the tone of the tube better.

- DoA

 

[Henmyr]

I had no idea that this was the case. Will be very interesting to try increasing the gain.

 

[shadowmoses]

When i switched the gain of the Mk III from +4 to +10 after i got a pair of HD650s, i found the amp to exhibit a lot more hiss and splutter, which of course is unacceptable. i reduced the gain to +5 and things were better. Any idea why this is so?