[G~mann]

PanamaRed,
 
You list the additional tubes you ordered.  Have you received any of them yet?  How do they sound?
 
If you don't mind me asking, did you get your CV4010 from Ebay?
 
Thanks,

 

[PanamaRed]

Quote:

PanamaRed,
 
You list the additional tubes you ordered.  Have you received any of them yet?  How do they sound?
 
If you don't mind me asking, did you get your CV4010 from Ebay?
 
Thanks,

 
I pulled the trigger on all of the tubes tonight (through ebay). I have a local tube connection but I haven't inquired about local pricing at all.
 
The CV4010 I bought are these: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290546585784&ssPageName=STRK:MEWNX:IT
 
From my limited ability to decipher tube codes it seems like these pairs are from the Mitcham factory in the UK.
 
A major plus about the MK III is how inexpensive 6AK5 tubes are.
 

 

[Impulsive]

PanamaRed good source, my CV4010 are from there too. Grear price and even better sound

 

[G~mann]

Well Guys,
 
I have followed suit and purchased the Mullard M1000 from Vintage Audio as well.
 
So now I have these tubes and the 6J1P-EV /EF95 one it's way.
 
There both coming from across the waters, so I am sure it will be a while.
 
Thanks again for the info.

 

[mordy]

Hi Panama Red,
 
[size=x-large]R1L3[/size]
R means the Mitcham factory, as you state.
 
1 means the year, with an educated guess 1971 (or 1981?)
 
L  means November
 
3 means 3rd week
 
If I got it wrong, let me know.

 

[AlexRoma]

 
 
Quote:

G~Mann, sorry for delay. You've asked me if russian tubes would be good match for HD595. Actually I think these are the perfect match for all HD5** series (as I am quite familiar with these headphones). I am glad you've bought Mullards too, because M8100's are the smoothest, yet punchy tubes of the group. But Russian tubes are on the dynamic/brigher side, the right cure for HD595's boringness. 
 
Now I have a serious dilema to solve.
 
I have a constant filling that my DT880 (600ohm) would benefit from extra power (at least 500 mW). 
Passport says, MKIII delivers 350mW on 300/600ohm load. Looks like this is the minimal requirement for these headphones, as I have to push my MKIII to the limits from which the hiss noise starts bothering me (80% on gain 10).
 
Here is the question :
 
Dear owners of 6H30** power tubs...
 
Give me please the exact answer if upgrading stock power tube to 6H30** series would (also) bring more horse-power? 
I need more power the stock 6H6p tubes deliver, and I have to decide, am I upgrading power tubes or am I upgrading the entire amp (Darkvoice 336).

 
Problem solved. Stock Power Tubes (6H6p) had exhausted their life period. New tubes solved the problem. No mo under-power complains on 600ohm bayers. 
 

 

[G~mann]

AlexRoma,
 
Although I have the 6H30s they came with my MKIII when I bought it here a few weeks ago from a fellow Head-Fier.  It did not come with the stock power tubes.
 
I do recall hearing that the 6H30**  put out more volume than the stock tubes. I suppose the HD 595s are pretty efficient phones - I don't think I ever gone over 35 or 40 on the volume knob.
 
 
 

 

[john57]

There is a new Little Dot tube rolling guide now available in case you have not noticed yet.
 
http://www.head-fi.org/forum/thread/563884/little-dot-tube-amps-vacuum-tube-rolling-guide 

 

[FrankWong]

Quote:

There is a new Little Dot tube rolling guide now available in case you have not noticed yet.
 
http://www.head-fi.org/forum/thread/563884/little-dot-tube-amps-vacuum-tube-rolling-guide 

 
[size=medium]

That is the most awesome comprehensive guide I've seen. 

 Looks like a lot of work went into it.
​

[/size]

 

[john57]

As far as the 6H30  tubes goes. I am using the less powerful MKll and even so the LD MKll can drive my Fostex T50RP which is a power hungy phones just fine. The 6H30 tube gives just a touch more power with the Fostex but not with others headphones in my collection and I am not using it at the moment. I am happy with the current Russian power tube I am using. I think that the Schiit Lyr   hybrid amp may be a better choice for your needs.

 

[mordy]

Hi all,
 
This tube rolling guide is amazing! I agree with almost everything there. Would be nice to add the Telefunken and Raytheon small mica EF95 tubes to the list.
Looking forward to the power tube reviews which are not included yet.
The only thing left after this is to point out which combinations of power tubes and driver tubes work best.
(From a different post: I found it noteworthy that the 6N6P power tubes tame the overpowering treble of some tubes and make them very listenable.)
 
I am also questioning how important tube matching is, having heard that there are very large differences with a range of tolerance of up to 10% in the production lines. Another thing I do not understand is the statement in section 4.1 that power tubes failed after 100 hours due to mismatching. According to David of Little Dot the amplifiers are designed with totally separate circuits for right and left to the point that you can run different tubes on each channel without causing any problems. Since I also had one my OEM power tubes fail after five months, perhaps one has to conclude that the power tubes are more prone to failure than the driver tubes.
 
To be very picky and only buy the tubes from regular retail outlets takes the fun out of the bargain hunting. (Isn't that why you bought a $200 amp in the first place?) I am sure that you get very good stuff paying full price, but I maintain that with patience you can get the same tube for a fraction of the cost.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

[mordy]

AlexRoma,
 
Regarding the volume of your headphones, did you try to change the settings on the gain switches for headphones (located underneath the amp)?

 

[AlexRoma]

No. I find no reason for this, as DT880 600ohm are clear low sensitive, high impedance headphone. I've used max gain (10) from the very beginning

 

[TMRaven]

Quote:

Now I have a serious dilema to solve.
 
I have a constant filling that my DT880 (600ohm) would benefit from extra power (at least 500 mW). 
Passport says, MKIII delivers 350mW on 300/600ohm load. Looks like this is the minimal requirement for these headphones, as I have to push my MKIII to the limits from which the hiss noise starts bothering me (80% on gain 10).
 
Here is the question :
 
Dear owners of 6H30** power tubs...
 
Give me please the exact answer if upgrading stock power tube to 6H30** series would (also) bring more horse-power? 
I need more power the stock 6H6p tubes deliver, and I have to decide, am I upgrading power tubes or am I upgrading the entire amp (Darkvoice 336).
 

Are you sure you have the MK3 on a gain of 10?  If so, either I have a fake pair of DT990 600Ω or the DT880 600Ω is just that much more insensitive.  Even with an MK2 and the DT990 600Ω I never find myself raising the volume knob over 20%, that's how much overhead I have for volume and power.  This is even with the slightly less powerful 6H6N power tubes that I replaced the stock power tubes with (of which I never had to increase the volume knob over 15%)  At the factory default game the MK2 came with (3) I had to raise the volume knob to around to 70% or so.
 

 

[john57]

[size=medium]I am now trying the EF91 CV4014 GEC tube. It is a General Electric tube made in the UK and has GEC painted in large letters on the tube. This tube is built like no other EF91 that I have seen, with a square wire anode ring on top and large rectangular structures underneath the anode ring. The tube is rather heavy and has a heavily gettered coating on the tube. This tube is nothing like the Mullard CV4010 EF95 tube in terms of sound, and turned out to be one of the biggest surprises in my tube rolling. [/size]
[size=medium]The CV4014 GEC tube is a very detailed tube that appeared to have a bit of a grain that migrated out after a bit of tube burn-in.  It is a bit brighter in the midrange than the Mullard CV4010.  The soundstage is the biggest that I have heard to date. In choral music such as the Bach B-minor Mass and Mahler 8th Symphony, it is easier to pick out the sections of singers in the choirs while listening to the music. I get much better separation and placement of instruments in well recorded music. The GEC tube just has to be one of the finest examples around of the EF91 family of tubes. This driver tube also has great dynamic range and seems to be able to drive my Russian 6N6P power tubes a bit harder.[/size]
[size=medium]There are some tradeoffs. First, poorly recorded music sounds worst like my STAX headphones. Second, this tube is not the best for closely miched recordings since the sound stage can fluctuate wildly depending on the kind of microphone being used by the performers. This tube really shines with my latest recording of the Carl Rütti Requiem, which was recorded in a huge space, yielding a spacious acoustic and large dynamic range. This tube resolving power is outstanding and my current favorite of the EF91 family of tubes. [/size]
[size=medium]Next I will try the[/size] United Electron EF92 tube and I will be finished with my driver tube rolling for my Little Dot.