[jr41]

@saber8689
I'm with you on the improvement they bring to the HD 650 - a very spacious and clean sound.
 
The MK IV can be used with the EF92, CV131, WE403A/B, GE5654, M8100, CV4010, EF95 and 6JI families of tubes, which gives a lot of options RE tube rolling (although I haven't rolled any tubes in my KM IV yet). The MK III is compatible with exactly the same families of tubes as the MK IV, so you should be able to glean plenty of relevant information from MK III tube rolling thread.
 
I don't know if a MK IV tube rolling thread exists, perhaps you should start one . I'm sure everyone with a MK IV would like to hear your impressions.

 

[.Sup]

Quote:

Hi all,
 
I finally received my MKIV. Looks much much better than its pics on little dot website.
 
Though , on preliminary inspection, I found there is an issue with volume control. It gets stuck at around 50. If lot of pressure is applied, it goes past 50 and then its smooth till 100.
I have not yet switched the unit. Do I need to open it once, to see that there are no shipping related damages, before I switch it on ?
 
Have sent an email to David too for the volume control.
 
Thanks,
Hifisound
 
 

you could increase gain with internal jumpers so you don't have to go past 50 volume

 

[jr41]

If you're driving any headphones around or over 300 ohms I believe you should be using full gain anyway.

 

[.Sup]

Quote:

If you're driving any headphones around or over 300 ohms I believe you should be using full gain anyway.

Yes but if he had it maxed he wouldn't go over 30. I have the gain maxed and never go over 15. So I believe he doesn't have it maxed.

 

[Hifisound]

 
I did switch on the amp and the initial impression quite nice. Everything sounds very very clear. Only problem is the drums (Sheffield disc) lack the attack or power as compared to my 372 headphone out. But I started with gain 4. Will be changing it to 10.
Maybe the burn in will solve it or it could be the very nature of the tube sound.
 
Though as .Sup said , I will not have to go above 30 at gain 10.
 
But its still a problem with volume control for which I will await David's reply.... Hope I don't have to send it back for just this problem...
 
Thanks,
Hifisound

 

[rosgr63]

Hifisound, congratulations, hope you'll sort out your volume control problem soon.
Lots of gain may not be the best solution.
After you sort out the VC you might want to try some other tubes like the Mullard M8100.
Tubes take time to burn in so give them time.

 

[.Sup]

David personally set the gain at "10" for my (ex) HD600 but like Rosgr said it might not be best for the SR60s

 

[Hifisound]

@rosgr63
 
Thanks!. Yes tube rolling is the next project Though I will spend sufficient time (min 6 months)  with the stock tubes before changing.
I would be looking at mullards (m8100/8161) and then maybe the power tubes.
 
@.Sup
I will finally keep the setting most suitable for HD600. since I be using Sr60s only rarely.
 

 

[jr41]

Quote:

Quote:

If you're driving any headphones around or over 300 ohms I believe you should be using full gain anyway.

Yes but if he had it maxed he wouldn't go over 30. I have the gain maxed and never go over 15. So I believe he doesn't have it maxed.

 
Totally agree, mine was just a general observation

 

[Hifisound]

David suggested removing the volume knob and adjusting it.
I removed the volume knob, the front plate and refitted all back and now its fine.
 
It was basically a problem with metal knob grinding with the external circular surface. Now its fine...
 
Back to burn in and listening now

 

[Hifisound]

Btw is it safe to use mk iv as pre for audioengine A2s ?
 
Will there be any DC related issues ?

 

[Hifisound]

I confirmed with AudioEngine and they confirmed that it will be safe...

 

[jr41]

Glad it turned out to be a simple issue easily sorted, Hifisound.

 

[jr41]

A couple of pics of my MK IV SE and DAC_I:
 

 ​

​

 

​

 
I will get around to posting some impressions of this pairing with my HD 650, just holding off until everything is burned in.

 

[kwang411]

I'm just wondering if the driver tubes that came with the SE version are made by Mullard?
On my tube it just says:
CV4010
KQDD/K
83-22
 
Also, would the same tubes sound different if they are made by two different brands? For example the Tung-sol 6AK5 vs GE 6AK5?
 
Thanks in advance!