Quote: I'll be posting the power tube reviews shortly, just waiting for the gold Russian tubes to arrive. =)  

Quote: Thank you for your kind words. Looking at their data sheets, the stock 6N6P tube draws 750mA compare to the 6H30Pi which draws 850mA heater current, which is not much of a difference. Empirically I never noticed a volume difference between the two (I'm using matched Novosibirsk...

Check out these 6J1 driver tube rolling reviews: http://www.head-fi.org/forum/thread/563884/little-dot-tube-amps-vacuum-tube-rolling-guide#post_7625993  

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  5. CONCLUSION   5.1 Can’t Decide Which Tube to Buy?   To Little Dot’s credit, their Mk-series amps have an impressive number of tube rolling options and there are more than a few very informative threads dedicated to this topic.  I would recommend anybody interested in upgrading their...

  4. POWER TUBES   4.1 Overview   The power tubes reviewed in this guide only applies to the current production Mk series amps. Unlike their impressive flexibility with signal tubes, most current production Little Dot amps can only accept 6N6/6H6P power tubes with the exception of the...

  3. EF95 FAMILY   3.1 Overview   The EF95 family is the most versatile and widely available of the three families of tubes reviewed in this guide. I recommend beginning users to start tube rolling within this family because it has the most variety of manufacturers and models to choose...

  2. EF92 Family     2.1 Overview   The EF92 family tends towards a more neutral sound with an emphasis on great vocal presentation, but the sound quality can vary wildly between different manufacturers. This is the only family of driver tubes that can be used on the older (out of...

  1.EF91 FAMILY   1.1 Overview   Known for its linear and extended presentation in the top-end but sometimes suffering from ‘boombox’ bass, the EF91 family of signal tubes is a great choice for jazz aficionados looking for that crystal-clear treble and who prefer (or do not mind)...

Little Dot Tube Amps: Vacuum Tube Rolling Guide   A quick introduction: Who is this guide for? (plus some background)   When I purchased my first Little Dot amplifier in 2005 I was in a position many of you are in now.  I was new to high end headphones, and curious about the ‘tube’ sound...

Great episode. Kudos!

A quality alternative to the 6H30Pi -DR (which are incredibly expensive IMO) is the Electro Harmonix 6H30Pi Gold Pin. I've used them in my MkIII with good results, certainly much better sounding than the stock 6H6P.   - DoA

It was certainly the best amp Headroom made at the time. I was always struck by how enormous the enclosure for the amp is, it looks like a huge chunk of aluminum on your equipment rack.   - DoA

I used to have both the MS2i and the HD650, at the same time. Now I only have the HD650. So there. =)

You can do the 6H30Pi mod so you can use the much better power tubes on the MkIII.

Quote: Originally Posted by Donnyhifi Not sure where they came from to be honest. I bought the Amp on the forums and the tubes were thrown into the package. The previous owner also got them with the amp when he picked it up, not sure about how they were acquired and I have a feeling...

Quote: Originally Posted by Donnyhifi I found the Russian 6Zh1P-EV somewhat disappointing, muffled, like someone put a blanket over the music, the stock ones have greater extension but less full in the mids and the bass is looser. I'm thinking what should I try next, I would like...

I have both the Mullard M8161 and the CV131 civilian version, I'd say they sound pretty much the same they certainly have the same construction.

I vote LD amps as well.

I just want to echo what other people are saying about the LD amps, they are designed to be used with the HD650 so synergy is good, tube rolling is also a lot of fun down the road if you're into that.

I like the LD amps with my K701 as well, tube rolling options are great with LD amps too so you can optimize the sound to your preference.

I would recommend a full size amp of at least Little Dot MkIII quality to drive the HD650 headphone. In your setup I think the HD595 would better serve the purpose for now.

Quote: Originally Posted by RonMiller1 Any tips on where to find the Sylvania Gold 408A? I've been looking all over. Yen Audio on ebay used to carry matched pairs, that's where I got mine. They're the most reliable place to get Little Dot tubes and they're great guys I would send...

Yen Audio on ebay would be THE place to get matched 6H6P-I tubes for your LD. I would send them a message and see if they take payment other than paypal.

I have a latest generation HeadRoom Max with DAC and stepped pot for sale (link in sig). The best way to learn about the amp would be through the HeadRoom website and the amp costs $3500 when new. I did a serious amount of research and listening at meets before I made the decision to buy the amp...