[OctavianH]

Might be the adapters but I have no idea what I can do to them...

 

[kamzak88]

Is it worth to exchange stock oamp LD on OPA2107AP http://allegro.pl/show_item.php?item=6673849042

At this moment I have 6ZH1P-EV, sometime M8161 or 6CQ6

Which Mullard ebay deals are worth paying attention to?

 

[dobigstuff]

Before both were towards ON (which I think is high gain according to the manual)
Even the volume knob now is lower for the same output level. Anyway, many thanks for help.

Octavian:
The Gain in the Manual for the MK II is the Same as the MK III.
Switch 1 & 2 OFF = Gain 10
Switch 1 ON, 2 OFF = Gain 5
Switch 1 OFF, 2 ON = Gain 4
Switch 1 & 2 ON = Gain 3
Possible Buzzing due to high Gain?
Yes the C3G's need to break in as do your 6SN7's

 

[gulakpii]

Might be the adapters but I have no idea what I can do to them...

Do you have a multi-tester?
If so, I suggest to try Gibosi's suggesting!

 

[J Mirra]

The buzz if it is the same as mine in low gain is not a ground like hum it is a full on loud as hell buzz in one channel.

It only does it in low gain though any other combo of switches it is fine.

 

[OctavianH]

Octavian:
The Gain in the Manual for the MK II is the Same as the MK III.
Switch 1 & 2 OFF = Gain 10
Switch 1 ON, 2 OFF = Gain 5
Switch 1 OFF, 2 ON = Gain 4
Switch 1 & 2 ON = Gain 3
Possible Buzzing due to high Gain?
Yes the C3G's need to break in as do your 6SN7's

Yes, now both my 1 & 2 switches are pointing towards OFF so I have Gain 10 (for low impedance).
In the past, when the buzzing was occuring I had them towards ON which means Gain 3.

The buzz if it is the same as mine in low gain is not a ground like hum it is a full on loud as hell buzz in one channel.

It only does it in low gain though any other combo of switches it is fine.

Yes, it is that kind of buzz, like you describe, and it is gone with Gain = 10.

OK, so my preliminary conclusions are:
- related to Gain and adapters
1) the output tubes (6SN7) work fine only on Gain = 10
2) the sound changed somehow changing the Gain from 3 -> 10
- related to overall sound
1) Siemens C3G + Jan Philips 6SN7WGTA => clean but somehow harsh and metallic, perfect ballance of tonality
2) Siemens C3G + 6N6P-IR => clean but a little bit too cold (need more bass here)

I will try today some 6H8C in the output, too see if the harshness goes out.
What I described at 1) might be related also to lack of burn-in but I think that Gain settings are also affecting the sound somehow.

Some guys talking about gain settings influence:
https://www.head-fi.org/f/threads/little-dot-mk-iii-gain-settings-affect-sq.410545/

And yes, I think they are right, so I might give up the 6SN7 only to put back Gain = 3.

My overall best setup remains Voskhod 6J1P-EV + 6N6P-IR but I still dig into these C3G because they have great potential co redefine my taste.

PS. I realize that MK2 has a problem because you need to open it every time for adjustment of the gain settings. The screws already are damaged and I will need soon to replace them. I would need to have a mixture of MK2 and MK3: an amp without any rings and with direct accessible gain switches.

 

[J Mirra]

I have left my screw's out for easy access 1& 2 off is high gain.

I always have to bump the EQ in the 30Hz bass on my T1.1, M1060 and MDRMA900's with any tube config, I like a warm sound signature.

Edit : What I noticed with the C3g's and 6N6P-IR combo over the Mullard 8100 and 6N6P-IR is that I could turn the volume louder with complete coherence, no harshness I have never had that before it would always get to harsh.

The separation and sound stage is just brilliant as well, give them time

 

[OctavianH]

I will definitely give them time, but I think that if 6SN7 will not change, I will stick back to 6N6P-IR because I saw no real improvement.
C3G will remain there for some time to see what is happening.

 

[J Mirra]

I am running C3g with the 6N6P-IR and it is definitely an upgrade in quality, sounds great with the T1.1 and the Monoprice M1060 I am really happy with my purchase.

Once the C3g have had some time to open up then you will hear what I do I am sure. At first I was the same thinking I am not sure there is a difference but relaxing and turning it up a little more than I used to yielded the results I hoped for.

 

[OctavianH]

Ok, back to Gain = 3 and 6N6P-IR in the output. The sound is more "natural" than with the 6SN7 which was somehow muffled. I will let the C3G for a few days to see if they improve because at the moment they are behind the Voskhods.
The sound is a little bit harsh and I still have the problems with the "cymbals" which I had with M8161. We will see, this was my last investment on MK2 because I do not really see what I can do more. If C3G remain like this I will which back to Voskhods and leave them there forever. Best sound for my taste.

 

[J Mirra]

If you do not get on with the C3g let me know if you do not mind and I would buy them from you.

 

[TrollDragon]

I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...

A tube doesn't make a sound, it only has a transfer curve that must be considered before designing a circuit and running signals through it. Most "tube rollers" haven't got the foggiest idea how a tube really works, or what the transfer characteristics mean.

A bad sounding tube is simply one used in a circuit that wasn't designed for it. It really is that simple.

So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.

 

[OctavianH]

I played with 6SN7 and gain settings again, and the conclusion is that on MK2 on Gain = 5 and Gain = 10 we have no buzz with 6SN7 on output. With Gain = 3 we have a significant buzz, and with Gain = 4 a reduced one, but still hearing. If no one complained about this on MK3 it seems that its PCB does not behave identically, which makes me wonder on other differences between MK2 and MK3. I will leave the Gain = 5 and see how the sound changes during some listening hours.

 

[waflet]

I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...



So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.

Hideeho
LOL!
That reminds me of the difference between a scientist & an engineer...

 

[i luvmusic 2]

I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...



So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.

This is so true i have used 6SN7 with all my amps but none are designed for it,The 6SN7 works/sound good with all my amps so i thought these tube is really good until i build these amp(see pictures)that is designed to run 6SN7 and WOW! these tube really shine it sound much much better than before.