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How much heat will this thing put off? What sort of space will it need? Will it be safe sitting next to a turntable, or how much room should be between it and the turntable? Would it be ok having its own bin inside one of those standard Ikea Kallax shelves? Would the heat be too much for the Kallax walls next to it or the records in the next bin over? Thanks
At lower volumes with a high-impedance headphone this amplifier shines. Once I replaced the stock tubes with a Winged C 6H13C and RCA Black Plate 6SN7 this amp really sung and demonstrates its superiority in tonality over my Little Dot MkII (which has upgraded tubes as well). However, finding the correct tube combinations on this amp is a challenge as it can hum, especially as you go past 12 O'clock on the dial. Overall I find the Little Dot MkII a more versatile amp that is much less finicky, though it is lacking the beautiful midrange of the DV. For the best bass impact and treble micro-detail a solid-state amp in the same price range may be preferred, but it probably won't have such a liquid midrange.
Finally hooked this up after receiving it in early January from the last drop. Easy setup - unpacked, plugged in the tubes, plugged in the power cord, turned it on, waited 5 minutes, plugged in my HD6xx, plugged it into my Dragon Fly Black with Tidal Hi-Fi Master quality and... great! Stock tubes, sound fine to me. To my ears, everything is clear and details are definitely all there. Vocals seem a little more smooth and the HD6xx's sound much better than on my Shiit Asgard. I still have to play it a lot more and try it with my Schiit Modi 2 Uber, but for now I am happy and I have no complaints (strangely the tubes were a bit dusty, but no problems).

Notes:
1. Well recorded music is much more quiet in volume than "modern" more compressed tunes. The Cowboy Junkies "Trinity Sessions" has to be turned a bit past 12 O'clock - it is missing a tiny bit of headroom with stock tubes so far
2. Many newer (compressed) songs have good volume at 7-10 O'clock for most songs on streaming (320kbs and Flac)
3. Turning up newer music past 12 O'clock does not get louder - just more distorted.
4. I would call this sound fairly neutral with some taming of upper treble - it smooths out some harsher recordings.
Hi everyone,
awaiting for my new tube amp, having read a few info on tube rolling, I have found that the 6sn7gt models have a 250v plate limit whereas the gta and gtb are rated higher. Can you use the GTA and GTB with the darkvoice?
(anybody knows a user manual accessible online?)
starboard
Yes, you can use GT, GTA, and GTB
So I just setup an amp with what I thought was a passthrough on the darkvoice. It would seem that it is not a passthrough instead it takes the input signal and runs it through the amp, then back out to the other amp. Anyone else experience this? Or is it just mine. I can't believe that they would only do this to mine.
I have the US 110v version of this amp. How can I use it in the UK? Do I need a step-down voltage transformer? If so, which one will work?
moman108
https://www.amazon.co.uk/Stepdown-240-120v-Transformer-100VA/dp/B000NIYF0K
Does the Darkvoice make Dt1990 Pro sound different from a solid state amp?
Mr_audioguy59
Yes.
After the first gentle 20 min using, the 6N5PJ tube turns black... What is going on?
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It's normal and was most likely there before you even turned it on, you might not've noticed. No rudeness implied in any way, tube amps are complicated beasts. Here's an example of another unused 6N5PJ from Ebay showing the same colouring:

https://www.ebay.com/itm/6N5PJ-Double-Triode-Valve-NOS-Tube-fr-DarkVoice-Headphone-Amplifier-Preamplifier-/121959462818

My stock 6N5PJ also shows the same black coloration on the bottom. It doesn't effect its use. From my cursory understanding of tube audio it's likely the Getter for this particular tube:

" Flashed getter – The getter material is held inactive in a reservoir during assembly, then heated and evaporated after initial evacuation, usually by induction heating. The vaporized getter, usually a volatile metal, instantly reacts with any residual gas, then condenses on the cool walls of the tube in a thin coating, the getter spot or getter mirror, which continues to absorb gas. This is the most common type, used in low power vacuum tubes." (Wikipedia)
Zhengyan
it turned dark to reflect its name
Darnit, wish the DV dropped before the Little Dot MK2 I bought the other week.

Anyone know if there would be a big difference between the DV and MK2 with the upgraded tubes? I use HD6XX and mainly game/listen to Rock/Mashups.
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Hey thanks for sharing info's, I really appreciate it, you're so kind!

Whoa! thanks for the update i'll check it out, maybe i will get it, but i also need a 5998..
Are these good 5998?
https://www.ebay.com/itm/5998-Black-Plate-Tung-Sol-Used-USA-Valve-Tubes-VT2/112733741113?hash=item1a3f746039:g:xaoAAOSwBV5aTpeY
and
https://www.ebay.com/itm/5998-Black-Plate-Tung-Sol-Used-USA-Valve-Tubes-VT5/112733785063?hash=item1a3f750be7:g:804AAOSwMYRaTp~q
which one should i get?
Hi guys. Last week I’ve ordered my first headphone here, a Sennheiser HD 6XX. Becouse it’s my first good pair I want to try Some different options but am lacking the knowledge to make an educated guess. I’ve ordered a O2 AMP and a Darkvoice to explore what I prefer. For the Darkvoice I want to order some additional tubes witch combine well with the HD6XX. Suggestions are very welcome!
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ah, you found the area where I'm completely clueless (HOW this all works). If a pile of parts found inside an amp were put in front of me, I wouldn't know a transformer from a banana (well maybe I'd get the banana right). I do however trust some of the guys at headfi (there are a bunch of them, like "skylab" who post regularly about tubes of all types and really know their shit)....there are quite a few great threads, but these will help for DV:

6as7g thread: https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/
DV thread with tube rolling discussion of powertubes: https://www.head-fi.org/threads/darkvoice-336-336i-tuberolling-tubes.193214/page-6

I'm cutting an pasting tube info for 6as7g variants from the beginning of that 6as7g thread (I think this will ease your mind):
tried to put together some 6AS7G equivalents with notes (from my personal experience). of course, the usual brand/re-label disclaimers apply. So no need which one is better. The goal here is just to list the main equivalents that may work in your amp's circuit. Did I miss any equivalents?
6080 - low gain @ 2- great vocals, wide soundstaging
7236 - medium gain - great bass, fast and dynamic. Almost SS sounding
5998A - medium gain in straight bottle. Plate construction like 6AS7.
5998 - medium gain at 5, full-bodied sound, same current load as 6AS7
421A - same as 5998 but with matched plates/sections
6AS7G - low gain, the standard tube for most, plentiful
6AS7GA - low gain, like the standard 6AS7G in striaght bottle
6520 - premium 6SA7G, sometimes with 5998 plates
6H13 - russian 6AS7G equivalent. nothing magical with these
ECC230 - european 6AS7G equivalent. haven't seen one in person
6528 - equiv to 5998 but very high gain at 9, twice the current load. Make sure you amp can handle it
6336 - like 6528 but low gain at 2, still twice current load. Make sure you amp can handle it
Danbstein
Hey, Dan-

Yeah, Head-Fi is a great source... I've been a member there for about 6 years now (ID: TigreNegrito) and that's one place I do a lot of my research and get info (granted you have to sift through a lot of chatter). I've read the tube-rolling threads, but those are mostly geared to the output tubes, so thanks for posting the link to the power tubes. I knew there was one, I just didn't bookmark it at the time and forgot what site I read that info on, but the stuff you cut and pasted must be from where I read about the gain changes with different tubes.

I found a few more you can look over, but they are geared towards internal mods. I'm not yet at the stage where I'll start taking stuff out and soldering newer stuff in, but it's interesting to read:

http://www.just-hifi.com/Custom-Edition-Darkvoice-THA336FM-arrived-56K-warning_10059904.html
This is a breakdown of all the mods Fitz did beyond the original cathode bypass caps, but unfortunately the photos are all gone, since he posted this 12 years ago!
http://rockgrotto.proboards.com/thread/2734/darkvoice-336-kiss-mods
This one actually has some pics so you can see the progress.

http://forum.polkaudio.com/discussion/145315/yaqin-cd3-darkvoice-336se-mods-coupling-caps
Just found this one and haven't read through it all yet, but I think it has some photos, just a few of which are the DV mods.

For now, the Syl 5998A is pairing nicely with the Raytheon VT-231 and really cut back on the bass, making for a much better experience listening to classical music with the 6xx (most of the other combos were too heavy in the bass region to listen longer than half an hour or so).

It feels like its running cooler, but thermometer readings at the top mica of the power tube are 300F, top mica of output tube 185F and the top of the case around the tubes about 100F. I'll swap back in some of my other tubes and take measurements tomorrow to see the difference, but as I said, it feels cooler overall than it did when I first tried the 5998A this past weekend.

Cheers!
Anyone have experience using tube amps for trance music?
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well get a decent dac over a new amp for tubes
Uzuzu
Thanks for the advice.