Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 3

Hi G~M,

Look, for $2/tube you cannot complain about the prize. I am a little surprised that the tubes did not have markings - that is not the norm, even with used tubes, although some of the markings may be faint. Most of the tubes I bought on the cheap did not come with individual boxes. My guess is that many of these Russian tubes come egg crated 100/box, so you would not expect individual boxes.

In any case, AlexRoma pointed out that these tubes need a very long burn in, maybe 120 hours, to sound their best. Just be patient, and take your time. The tubes will sound much better after the long burn in, and I could understand how they could be a very good match for certain headphones.

Personally, I prefer the Mullards, but I really like a good bass presence, and here the RCAs really shine.

this is an excellent thread... keep the updates going... Endless tube shopping

Awesome.  Thanks so much for this!  I just bought the hifiman ef2 and a set of mullard m8100s today.  :)  I'm extremely excited to get into the world of tube rolling, even though I should probably have gotten a solid state first with my listening preferences...but i just love that tube look. 

Would a set of Amperex 6AK5 be the same tube as the one you reviewed?  I'm looking for that mythical bass-happy Amperex tube that I keep hearing mentioned, and I think I may have found one set.  In Russia. And they're about $65 shipped...i don't want to pay that for a single set of tubes unless they're the ones I"m looking for.

Thanks!

Hi Benzo,

Before you overpay for the Amperex tubes, get a pair of 60's-70's RCA black plate tubes. These are plentiful, cheap, and have great bass. Again, my tube rolling experience is with the Little Dot MKIII, and I am not familiar with the Hifiman equipment and how it reacts to different tubes.

Your work is awesome DoA, I cannot thank you enough for all the mini-reviews you're written. :)

Can't wait for the power tubes review though! :D

I am starting to wrap up my own power tube testing on my LD MkII. It took me some time since the EF91 GEC tube was so clear sounding with the power gold grid 6N6P tube. I had to readjust the setting on my Behringer SRC2496 DAC, which is the master DAC. It is now easy to hear the difference between 16, 20 and 24 bit internal processing option. I also can reliably tell the difference between line and internal clocking options. I also had to readjust the internal sampling rate on the SRC2496 for best clarity and it was not the same setting as before. The SRC2496 then feeds my slave DAC which is my brand new RDL HR DAC1 DAC by way of an AES connection between the two DACS. Both DACS uses XLR balanced outputs for which I use a conversion PylePro cable that switches the  XLR balanced outputs  to RCA outputs  to my two Little Dot amps. My slave RDL HR DAC1  DAC drives my Little Dot MKII.

The gold grid 6N6P power tube is punchier and more dynamic sounding than my standard Russian 6N6P tube.  Both have good tonal range. The standard OTK 5 Russian 6N6P tube is a more relaxed and just a bit softer sounding tube than the gold grid Russian 6N6P. Both tubes are good, but the gold grid 6N6P tubes are hard to find. Both power tubes have great synergy with the EF91 CV4014 driver tube.

On the other hand, the Sovtek 6H30 power tube is awful sounding. It was very thin sounding and had very little bass compared to the previous two tubes that I mentioned above.  The EF91 GEC tube, which is just a bit brighter from neutral, just makes matters worse with the Sovtek 6H30. The synergy was not there.

I did not try the Electro-Harmonix 6H30Pi Gold tube but depending on what DoA finds on his power tube reviews I may revise my decision.

I ran into another surprise. My Denon AH-D2000 headphones, which I was thinking of selling because  of the burry bass, huge recessed midrange, and peaky treble, were transformed by the GEC EF91 and the gold 6N6P power tube combination. The midrange came back and the bass sound much better. The sound stage on the Denon is now huge, even better than the Sennheiser HD 598. However, the Denon headphone at 32 ohms is showing a bit of a strain on my LD MKII amp and I am in process of doing  an experiment to see if I can make the Denon headphones to work even better. 

Wow, thanks for the insight John!

Those output tubes are quite pricey on the bay, especially if you want them matched (which is rather important for output tubes).

Where are you getting yours?

Hey John

I was wondering what DAC are you using? Because Im currently using the LD I+ with M8083 and can't figure which dac will be best paired with the combo.

Hi John57,

Can you comment on how the sound is in your set up with the OEM 6N6Pi power tubes?

My experience has been that with tubes with a lot of high frequency energy the 6N6P tubes sound better than the 6N6Pi. With this type of driver tube the 6N6P power tubes seem to bring out the bass better and make the top end sweeter.

I am mostly getting them from Ebay because that is the cheapest I can get the Russian tubes from Bulgaria easily without being concerned about currency conversation using PayPal and Ebay buyer protection. Only $7.77 for a tested 6N6P NOS pair with the OTK 5 mark from lci_electronics. You can even get the Russian 6N6P tubes cheaper by buying in lots. The gold grids 6N6P version came from Ebay seller 4951511020. The ones I was using are the 1982 version. He also has the gold grid 6N6P 1978 version as well for a bit more. May take a month or more for delivery  

Quote:

Originally Posted by donluca 

Wow, thanks for the insight John!

 

Those output tubes are quite pricey on the bay, especially if you want them matched (which is rather important for output tubes).

 

Where are you getting yours?

Quote:

Originally Posted by eclipes 

Hey John

 

I was wondering what DAC are you using? Because Im currently using the LD I+ with M8083 and can't figure which dac will be best paired with the combo.

I have two DACs listed in my previous post Behringer SRC2496 and RDL HR DAC1

Are you using the Cowon J3 player? That is a good player that has good quality outputs as I understand it. Have you tried the optional Cowon AV cable and use the audio jacks directly into the Little Dot amp? That way you can use all the Cowon audio effects to the Little Dot. I would look at that idea first and see if it will work for you.  

Quote:

Originally Posted by mordy 

Hi John57,

 

Can you comment on how the sound is in your set up with the OEM 6N6Pi power tubes?

 

My experience has been that with tubes with a lot of high frequency energy the 6N6P tubes sound better than the 6N6Pi. With this type of driver tube the 6N6P power tubes seem to bring out the bass better and make the top end sweeter.

My original power tube was the Beijing 6N6 which I threw away once the new Russian 6N6P  came in.

Thanks for your comment.  

Quote:

Originally Posted by john57 

I am mostly getting them from Ebay because that is the cheapest I can get the Russian tubes from Bulgaria easily without being concerned about currency conversation using PayPal and Ebay buyer protection. Only $7.77 for a tested 6N6P NOS pair with the OTK 5 mark from lci_electronics. You can even get the Russian 6N6P tubes cheaper by buying in lots. The gold grids 6N6P version came from Ebay seller 4951511020. The ones I was using are the 1982 version. He also has the gold grid 6N6P 1978 version as well for a bit more. May take a month or more for delivery

Thanks for the info!

I've bought some tubes from 4951511020, but didn't see that he had the 6n6p as well because they weren't under the category "output tubes" :|

They are under the normal tubes category... too bad, I might have saved a bit of money with the combined shipping.

I saw a pair of tested 6n6p nos from orpheus_2005 (whose store is very similar, almost identical to lci_electronics) which are very close matched... I might try them.

Do you think that the gold grid makes any difference?

EDIT: by the way... take a look at orpheus' 6n6p... it seems that they have the gold grid as well:

Many Russian 6n6p  tubes use copper posts for the grid wires which may look like gold wires but are steel alloy. The Sovtek 6H30  tube that I was testing also uses steel alloy grid wires. See post #36