[ScottieB]

Quote:

Originally Posted by J.P.6 /img/forum/go_quote.gif Hi guys, I'm using some Ultrasone Pro 750 cans with my Little Dot Mk III, I've still got the stock power tubes in there (6H6П) and rolled out the stock drivers a while back with some Mullard EF95 (CV4010) tubes. I get a little bit of distortion with high amounts of bass and treble on certain tracks and was wondering what other tubes people suggest for trying to overcome this? The DIP switches are set for high sensitivity/low impedance headphones to match my Ultrasones. I've also tried some Mullard EF92 (CV4014) tubes, however these gave me a lot of distortion. Thanks in advance.

This is EXACTLY what happened to me. It sounds like your power tubes are on their way out - how old is your amp?

The ultrasones are low-impedance headphones, which are actually a higher load for this amp than low impedance cans. When this happened to me I'd been listening to Sennheisers (300 ohm) and heard no distortion, but when I used my Grado's (32ohm) I heard it in the same types of places you are noting. If I put my Senns back in, no distortion.

I replaced the power tubes and all is well. The old ones still work fine with my Senns, but not Grados. New power tubes can be bought pretty cheap so it isn't a big deal, but I also bought an impedance adapter to raise the impedance of my Grados (and Ultrasones) in my Little Dot.

Do you have any other headphones you can use to test this theory?

 

[J.P.6]

Ah good to see it's not just me then.

Well the amp is about a year old, which I bought second hand and as far I know these tubes are still the originals, so may be quite old/on the way out.

I don't have any other cans to use to test unfortunately, though using an impedance adapter may be a good idea, didn't think of that. Did it make much difference for you?

 

[ScottieB]

YEah my first set of tubes went after about a year so that matches up. It has been about a year since and the tubes have held up so far, with heavy Grado use with the adapter, so I'd say it is working. I didn't notice a sound difference and still love my 325is's with tubes. I had someone here make it for me - top quality and I think I paid maybe $40 or $45 shipped. PM me if you'd like the name of the guy - I'd have to dig it up.

 

[Narynan]

I apologize if this is in the wrong section, I debated if here or sound science was the right place....

Anyway. I couple days ago I ordered the Little Dot MKIII, and now in this thread I'm reading about all these great tubes and all the fun everyone is having. But I know NOTHING about tubes. Does anyone have any good base links for what I need to know about the tubes? I am near page 15 or so of the thread, so I am going to rear it from top to bottom. There is just alot missing in my knowledge.

Other than just googleing or ebaying the model numbers, how do I find good tubes? How do i know what I am looking at in a 40+ y/o tube is good?

As it stands right now other than plugging it in, I have no idea what going to go on with the tubes. What am I looking for on ebay for good tubes?

If this has been asked, I apologize. I am just seeking guidance.

Thanks everyone!

 

[Nachkebia]

Little Dot MKIII and MKIV have same rolling capability right?

 

[hipcat]

Narynan, a few months ago I was in the same boat as you. I brought a mkIII and did not know very much about tubes. The best advice I can give you is to read this thread (also the thread review of the little-dot mkIII tube headphone mp/pre-amp by Penchum). It will take a little while but alot of your queations will be answered and you will know alot more about your ld. The only way to see if a tube works for you is to try it. I read this thread and started to buy tubes that most recomended. For the most part I found that some sounded great others were o.k. But you have to try them with your anp/hp combination to see if they sound good to you. In aroond pages 90 to 100 there is a link with all the tubes numbers you can use in your ld for a ebay search. I pasted this in ebay and check daily to see if there are any new tubes for sale. Also in the diy forum in the first 2 pages are so There is a thread by Vixr (handy tube substitute guide ) with a good link in it. In this forum in the sticky threads at the top is a tube site thread were you can get differtent web sites to buy tubes and a sticky for The new and improved tube faq for newbies, this one will tell you the basic's about how a tube works.
I hope this helps you out.

 

[bik2101]

Quote:

Originally Posted by hipcat /img/forum/go_quote.gif Just brought a set of the russian " grove tubes" can't wait to roll them! Has anyone tried the sovtec 6h30pi power tubes, I can't beleive the improvement in SQ I got after I installed them!

isn't there an issue with the resistance not being correct or something like that? i thought that's what i read in penchum's review of the mkIII - that in order to use these 6h30pi power tubes, you have to modify the amp.

 

[hipcat]

From what I understand LD upgraded the mkIII's so they could use these tubes.I have beed running them for a little over a month now for hours at a time with no problems.

 

[theryaner]

waaayy too many pages in this topic so I'll just ask.

What's the difference between the m8100 and the m8161? I currently own the m8100 and it definitely smoothed things out for my grado 325is.

Also, I'm curious about the GE 5 star, how does that sound like in comparison to mullard tubes?

 

[hipcat]

the m8100 is a ef95 tube, the m8161 is a ef92 tube. I have both the m8100 and 5 star
they are both great sounding tubes but the m8100 is my current favorite it has a little more bass to it than the 5 stars.

 

[Narynan]

Will these tubes all work? I think they will but I'm about to order and dont want to get the wrong stuff.

4X NOS NIB CV138 / EF91 / 6AM6 MULLARD TUBES. - eBay (item 330380567291 end time Jan-24-10 02:44:55 PST)

Are these the cheap-o good bass Russian rock tubes im reading about?
6J1P-EV = 6AK7 = EF95 Tubes NOS Lot of 10 - eBay (item 110440675090 end time Jan-28-10 12:46:16 PST)

2x NOS MULLARD CV4010 VALVE EF95 M8100 6AK5 5654 Tubes - eBay (item 270506323434 end time Jan-24-10 13:20:14 PST)

CV4015 M8161 EF92 9D6 MULLARD QDD TUBE VALVE NOS PAIR - eBay (item 270280786849 end time Jan-21-10 03:42:27 PST)

 

[Trapper32]

Yes those will all work. Can''t tell whether those Russians have the three grooves or not. A year ago I tried the non groove ones and wasn't impressed but awhile ago I purchased some more with the grooves and was blown away by them....I think they were made in the Voshkod factory in the 70's
Good luck!!!



Quote:

Originally Posted by Narynan /img/forum/go_quote.gif Will these tubes all work? I think they will but I'm about to order and dont want to get the wrong stuff. 4X NOS NIB CV138 / EF91 / 6AM6 MULLARD TUBES. - eBay (item 330380567291 end time Jan-24-10 02:44:55 PST) Are these the cheap-o good bass Russian rock tubes im reading about? 6J1P-EV = 6AK7 = EF95 Tubes NOS Lot of 10 - eBay (item 110440675090 end time Jan-28-10 12:46:16 PST) 2x NOS MULLARD CV4010 VALVE EF95 M8100 6AK5 5654 Tubes - eBay (item 270506323434 end time Jan-24-10 13:20:14 PST) CV4015 M8161 EF92 9D6 MULLARD QDD TUBE VALVE NOS PAIR - eBay (item 270280786849 end time Jan-21-10 03:42:27 PST)

 

[Narynan]

Alright! Thanks. I decided to go with a link from an earlier post and make sure I get the matched pair for those Russian grooves.

I dont know what to do with my last $30. I got some 8161's and the Voskhods.

Any recommendations? I am thinking that either that batch of 10 NOS 95's.

Links would be great. I am up for suggestions. Mostly rock and on Grado 325is.

 

[hipcat]

WOW! I just got the russian "groove tubes" in this morning stuck them in my amp and 4 songs in they sound awesome! I just ordered another set as back ups ( at 8.99 a set you can't go wrong ). They sound as good as the 5 stars I have and if they get any better with some burn in time WOW!!! Right know I'm listening to Van Morrison's Gloria and they bass is nice and tight.

 

[David.M]

these m8161 are starting to shine slowly

I only got about 15-20 hours burn in on them, but i can notice the clarity in the mids evening out and the highs starting to get better. definitely more warmer and balanced then the stock tubes.

I think this needs another 20 hours or so to be complete. I have the newer mkiii version 2.0 so i can use the Sovtek 6H30PI power tubes. I'll definitely give these a try.