Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 57

Update to the Sylvania 6EW6 tubes

My fresh wind of LD tubes comes in doses, so I have some time to spend with the Sylvania 6EW6 tube, which I quite enjoyed. The tube is burned in now for approximately 24 hours. It got clearer in terms of reproduction and cleaner in terms of noise floor. The background is not as black as military grade tubes but since it got reduced with the burn in process, it is low enough to not bother me. The tube is slightly microphonic.

General signature

When compared to the CV4015, the 6EW6 is quite a bit louder and on a similar level to my CV4014 (EF91). Compared to both, the tube is warmer, sounds fatter. Just for clarification, CV4014 and CV4015 are surely more on the analytical side of the sound signature band. The 6EW6 is not overly warm though and quite transparent. Overall, the tube is well balanced in terms of frequencies. 

Treble

Extended but also tubey smoothness. I very much like the treble. No sign of grain. Generally, I also like the "crunchy" type of treble, which this is not -  you start hearing it, you think that you are not missing anything and just flow with it.

Mids

Now comes a tube classical phrase: The mids are lush. They are very enjoyable, also because of the addictive but not overly mellow warmth.

Bass

Good presence and articulation, goes deep as well.

Stage

The stage is smaller than for CV4014 and CV4015 tubes, on which - in comparison - instrument separation is better and more organized. With the 6EW6 everything moves a bit closer together but each instrument gets a more pronounced appearance. The sound is relatively forward, but not "in your face". The CV4015 imaging is better but then it also is the best I had so far.

Summary so far:  Warmer than CV4014 and 4015 - no analytical signature, still revealing, very musical, non-fatiguing and well balanced.

Exciting times.

After burning in all day, I am pleased to report that these 6J38P-EVs did not explode! lol. In fact these are very nice tubes. It has been quite some time since I have listened to the classic Voskhod 6J1P-EVs, so I dug them out to do a quick A/B. It seems that 190mA gives little if any more volume than the Voshkods. The volume sounds about them same to me. And the sound signature is also very similar, strong punchy bass and warm vocals, again very nice. 

I almost want to say that if you have the Voskhods and you are happy with them, it might not be worth getting these tubes. Having said that, with all the tubes I have been listening to recently, I think I am getting a little burned out.... In the end, for $1.50 a tube (10 tubes for $15.00 plus shipping) I have no regrets. These are very high quality tubes.

I notice they have the same polished silvery metal pins as the Voskhods... Can someone tell me what these pins are made of?

Tomorrow I have some Mil-spec 6BC5/6CE5s coming:  Sylvania (1974) and GE (1962)

this really is a great thread. I have been trawling these pages for a while now and have now got more tubes then I think I will ever need, the line up is like this:

6J1P-EV EF95 6F32 Voskhod 

Matched Pair Tung-Sol NOS/NIB 6AJ5/6ak5/6J1/EF95

matched 6J1P-EV (EF95 6AK7) Gold-Platinum grid

GE 5 Stars 5654 6AK5W

Novosibirsk 6H6P-I

M8100 CV4010 MULLARD 6AK5 EF95 E MATCH PAIR

Sylvania JHS 6AK5 Matched Pair

Voshkod 6ZH1P-EV

and I am collecting these from the post office today:

MATCHED PAIR of 6J1P GOLD GRID NOVOSIBIRSK EF95 6F32 6AK5...

2x MATCHED TUBES < GOLD GRID > 6J1P 60's NOS PAIR NOVOSIB...

TESTED & MATCHED PAIR of 6N6P NOVOSIBIRSK GOLD GRID TUBES...

at the moment my favourite tubes are the 6J1P-EV gold/platinum grids and the novosibirsk 6H6P-I gold grid and pins. this combination is full of detail and warmth, as I use my set up for writing electronic music, I have found the mixes done with these tubes transfers most accurately to my dynaudio bm5a studio monitors (I write with headphones out of respect for the neighbours!) 

I found the tung sol's to have a weired back ground noise, when  I touch the amp or anywhere near it, it picks up the sound and produces it to the headphones, i think this is microphonics. I found the mullards gave me a false representation of the mix, sounding great in the headphones but leaving me lacking in the bass and the highs quite dull when checking on the monitors. the 6ZH1P-EV's are also very accurate when comparing the mix, a real joy to listen to. the GE 5stars are very similar to the mullards but i have not given them very long in the amp, maybe 10 hours, the sound just has not opened up for me. the sylvania's are nice, quite a delicate sound for my ears but again I find I cannot trust the mix. my verdict, my favourite sets have been in the amp for a while now and I trust the sound I am getting, so I wonder if it is time to lock up the wallet and live with what I have for a while. These new families are quite exciting and I am having trouble resisting another purchase but the issue with the excessive heat concerns me. thanks everyone for your contingued inspiration and keep on.. z

Nice, well I recently when on an INSANO tube swwping spree with my hybrid 12ua7 tubes

although I've been wanting a LD tube for a while now and well I'll need something to replace the  5963 12ua7 Mullard I have in there now, basically a thick tube, they will b paired with a 250 [maybe 600ohm] Dt 880, so as of right now my 250 ohm likes the mullard... ALLOT, I have 2 pairs of RCA Clear Tops and they sound AMAZING... but not with the byer, the already mellow and delicate beyer sounds a little empty on the clear tops [unlike my Mad Dogs and dt 990s] so again the byer already has wonderful airy trebele and super epic tight bass, all it needs it lush sexi mids any tips on a tube that would compliment :D 

In addition since I'm used to Hybrid Tubes, should I jump right to LD4 or maybe try the LD3 first

Quote:

Originally Posted by Mshenay 

In addition since I'm used to Hybrid Tubes, should I jump right to LD4 or maybe try the LD3 first

Considering you have the Beyers (especially if you are going 600 ohm eventually), and given that the price between the MKIII and MKIV is only ~ USD 100, I'd just save a little longer and go MKIV.  You know you'll end up there eventually anyway 

IMO it pairs really well with the Beyers (also with my Senns).  The IVSE would be worth it as well.  I have the IV but eventually wound up with the upgraded 6H30PI gold pin anyway ....... 

Here is my daily update. I put in the 6J3P-E for burn-in and tested them again after about 10h (which imho is enough to have a feel for the "tone" and capabilities of a tube, even if the bass might still improve and highs might tame a bit, and other minute improvements; I just can't justify burning in every mystery tube for 50 hours...).

I would say the 6J3P-E is a bit cozy and warm, it sounds kind of like a higher gain warm 6AK5. Treble is pleasant and not too spiky, but not rolled off either. Mids are a bit grainy, lush, warm, and could use a bit more microdetail and separation. Bass is you typical average good tube-y bass, with a slight lack in punch, but OK for most music. Overall, a solid all-rounder C+ grade tube (at this point I think I need some objective grading system, as random words and comments just don't enable real comparisons), good overall but never excellent, and a bit too mellow for my tastes. This being said, I could imagine these tubes being very nice for listening to singer songwriter type music where you don't want too much microdetail, but warmth and mellowness with more grain, kind of like a more powerful M8100 with less instrument separation and detail. And they might improve after 100+h of burn-in the Voskhods, but that shouldn't add detail or change the tube's performance.

After the -unburnt-in- GE 6AG5 that were way below these 6J3P-E, I'd say I might just try one last special quality/military 6AG5 and be done with testing this tube family for the time being -or until someone else makes an awesome breakthrough.

Speaking of "grading" tubes, I would tend to grade on an relative scale not an absolute one, meaning that an A++ tube that suddenly pops up would mechanically make all the other tubes go down one grade and become my de facto new A+ reference. So right now, for me, the GEC CV4014 would be my A+ tubes, and my Mullard CV4015 would be an very solid A as well (probably A+ in some setups). Voskhod 6J1P-EV would have been a solid B+ tube and the Mullard CV4010/M8100 an A- (B+ for electronic music). The best Mullard M8083/CV4014 would hover between an A- and a B depending on the version tried, there's just way too much variety in that family.

After 9-10h of burn-in, the Military GE (non-JAN) 6EW6 tubes seem to have matured to the point where giving an opinion would be reasonable. These are some very good tubes, considering they're not a special quality or military tube (which doesn't exist in that family). Bass slams down on you in a powerful way and gives music a body and impact that is very enjoyable, it extends enough that wouldn't think anything is missing, not especially fast but not slow either, just visceral and well grounded. Background is not quite as black and empty as my best tubes; instruments, while very well rendered, don't stand out as clearly as they could, but they are all there, just sort of in each others face (like somewhat superimposed, but not in a bad way and still each audible). Soundstage is your average 300mW+ heater current large stage, not a mile-large like some EF91s but enough to not sound too squeezed, and is noticeably extended vertically, and very good in depth -big 3D bubble- in your head kind of stage but never in your face; the sense of space is definitely there, but again not quite as much or well as the best tubes, but very very close. Mids are ever-so-slightly warm but not as much as a GEC CV4014, I'd say in between these and the CV4015 or the more recent analytical 8136. The transients scream of realism and almost reach the best of the best, decay is just a tad slower than my fastest -analytical- tubes, but that's not necessarily a bad thing. Highs are well extended and sound like "it's all there" without ever being grating, airy without sounding silly or surreal. Overall, this an excellent tube, which I'm starting to think may still evolve a bit with an extra 10h of burn-in; a very solid A tube imo, that might get an extra point at 50 hours.

I'll try to *finally* formulate an objective opinion on the 6CB6A/6676, 8136, 6GX6/6GY6 at some point, and the 6GM6 when I get a chance to actually plug them.

Quote:

Originally Posted by zedmeco 

this really is a great thread. I have been trawling these pages for a while now and have now got more tubes then I think I will ever need, the line up is like this:

6J1P-EV EF95 6F32 Voskhod 

Matched Pair Tung-Sol NOS/NIB 6AJ5/6ak5/6J1/EF95

matched 6J1P-EV (EF95 6AK7) Gold-Platinum grid

GE 5 Stars 5654 6AK5W

Novosibirsk 6H6P-I

M8100 CV4010 MULLARD 6AK5 EF95 E MATCH PAIR

Sylvania JHS 6AK5 Matched Pair

Voshkod 6ZH1P-EV

and I am collecting these from the post office today:

MATCHED PAIR of 6J1P GOLD GRID NOVOSIBIRSK EF95 6F32 6AK5...

2x MATCHED TUBES < GOLD GRID > 6J1P 60's NOS PAIR NOVOSIB...

TESTED & MATCHED PAIR of 6N6P NOVOSIBIRSK GOLD GRID TUBES...

 

at the moment my favourite tubes are the 6J1P-EV gold/platinum grids and the novosibirsk 6H6P-I gold grid and pins. this combination is full of detail and warmth, as I use my set up for writing electronic music, I have found the mixes done with these tubes transfers most accurately to my dynaudio bm5a studio monitors (I write with headphones out of respect for the neighbours!) 

I found the tung sol's to have a weired back ground noise, when  I touch the amp or anywhere near it, it picks up the sound and produces it to the headphones, i think this is microphonics. I found the mullards gave me a false representation of the mix, sounding great in the headphones but leaving me lacking in the bass and the highs quite dull when checking on the monitors. the 6ZH1P-EV's are also very accurate when comparing the mix, a real joy to listen to. the GE 5stars are very similar to the mullards but i have not given them very long in the amp, maybe 10 hours, the sound just has not opened up for me. the sylvania's are nice, quite a delicate sound for my ears but again I find I cannot trust the mix. my verdict, my favourite sets have been in the amp for a while now and I trust the sound I am getting, so I wonder if it is time to lock up the wallet and live with what I have for a while. These new families are quite exciting and I am having trouble resisting another purchase but the issue with the excessive heat concerns me. thanks everyone for your contingued inspiration and keep on.. z

So far my inventory is:

Western Electric 403b

LM Ericsson 403b

Mullard M8100

Mullard M8161 x2 (EF92)

Telefunken 6AK5W

Raytheon 6AK5

Russian Military 6X1Π-EB

Voshkod 6ZH1P-EV

Tung-Sol 6AK5W x2

Tung-Sol 6AJ5

GE 5-star 5654W

On the way:

GEC CV4014

RAYTHEON 6GY6/6GX6

Power Tubes:

6N6P-IR

Electro Harmonix 6H30Pi

I'm really liking my Tung-Sol's with the 6n6p-ir tubes! can't wait for my GEC CV4014 tubes that have gotten so much praise on here.

Quote:

Originally Posted by Brooko 

 

Considering you have the Beyers (especially if you are going 600 ohm eventually), and given that the price between the MKIII and MKIV is only ~ USD 100, I'd just save a little longer and go MKIV.  You know you'll end up there eventually anyway 

 

IMO it pairs really well with the Beyers (also with my Senns).  The IVSE would be worth it as well.  I have the IV but eventually wound up with the upgraded 6H30PI gold pin anyway ....... 

Hanks, that's what I've been told and yea might as well save up the Extra $50 or so it takes

It's finally Saturday, so I've had time to reach some conclusions on my most recent tubes.

First the GE 6GM6: These are comparable in gain with the 6AK5, so very low for a 400 mA filament current. They are extremely noisy, with actual ssshhfffSSSjjjFff sounds coming in randomly and loud enough to be heard during the music. They have fast decay, great instrument separation, PRaT and excellent transient response, with a nice realistic studio-size 3D soundtstage. Great treble with excellent instrument definition and positioning, things come at you from logical places in the mix and sound great. Mids are neutral, which I don't often get with tubes, no too tube-y not analytical either, and not natural but neutral. Bass might be a bit lacking in power though and doesn't have the weight and punch it could, but it is fine and doesn't distract from anything. Excellent A grade tube (borderline A+) that will forever be marred by intense random noise issues that didn't go away after 13h of burn-in, and that I will unlikely be using because of those occasional loud airy instrument-like noises and the more constant random less loud Psschftt noises all over the channels.

You can so tell these are consumer grade tubes it is not even funny. I suddenly realize how accustomed I've grown to hearing delicious mil spec/spec quality tubes and why it is a bit purposeless to get regular tubes (is this the kind of crap noise people had to listen to with consumer grade tubes back in the day?). Alas, no military or special quality version of the 6GM6 exists, just like for the 6EW6 where I was lucky enough to find them in a military box with the military green GE ink on the tubes, but still labeled essentially plain Jane "6EW6" not JAN or any special quality number. No more consumer grade tubes for me...

GE 6GX6/6GY6: A bit grainy, not as in noisy but a slight coarseness of sound that reminds me of dithering (adding random noise to sound or images to give the illusion of more detail, usually to make crappy old recordings sound better). Slightly in your face sound, opposite of watching a band play way in front of you. Quite detailed, sense of power in the mids, airy slightly grainy highs (explained earlier). Pretty punchy bass, not the best but very good and powerful, could extend a bit lower. Average decay, not slow nor too fast either. These tubes scale well with the quality of recordings. On good ones, they have an enveloping sound that's all 3D-like around your head/face (as it is still a bit forward), on poor ones, they sound kind of like an engineer's attempt at restoring music from old tapes. Overall, again, an excellent tube that came out of nowhere, I'd say A- grade, just because it sounds a little funny and extreme on some songs, a little "analog" sounding actually, that would be the right word. That ever-so-slight invisible graininess, warm and rounded bass sound that makes music sound like it's being played from reel to reel tapes, which I'm sure a lot of you would like! So try 'em if you like that sort of thing.

I was going to review my 8136 a bit more thoroughly today but one of them just crapped out on me... That's the second one too, they make Pfft Pftt Pffffttt sounds that don't go away. Oh well, I still have 12 left, now I just need to find another strong one in the pile.

I have been burning in some 6BC5/6EC5s:

The GE (date code: 62-39) in the middle and the Sylvania (date code: 7452) look identical even though manufactured 12 years apart by different companies. These came in military boxes, but no JAN or W designations. The internal structure of the GE on the left (date code 0-13 - 1960? 1970?) is very different than the others but unfortunately they were packaged in a new plain white box so no additional information.

Unfortunately, I woke up this morning with a flu-like virus and am just not up to listening critically to these now... Later....

Quote:

Originally Posted by Audiofanboy 

First the GE 6GM6: These are comparable in gain with the 6AK5, so very low for a 400 mA filament current. They are extremely noisy, with actual ssshhfffSSSjjjFff sounds coming in randomly and loud enough to be heard during the music. They have fast decay, great instrument separation, PRaT and excellent transient response, with a nice realistic studio-size 3D soundtstage. Great treble with excellent instrument definition and positioning, things come at you from logical places in the mix and sound great. Mids are neutral, which I don't often get with tubes, no too tube-y not analytical either, and not natural but neutral. Bass might be a bit lacking in power though and doesn't have the weight and punch it could, but it is fine and doesn't distract from anything. Excellent A grade tube (borderline A+) that will forever be marred by intense random noise issues that didn't go away after 13h of burn-in, and that I will unlikely be using because of those occasional loud airy instrument-like noises and the more constant random less loud Psschftt noises all over the channels.

 

I have two pairs of 6GM6s, RCA and Sylvania, and they are very quiet, so I would guess you just got unlucky... :(

Otherwise, my impressions are similar to yours. In fact, I like these more than my Raytheon 6EW6s.

Dear G,

In the past I have received tubes with a date code silk screened on the glass tube that was several years before the date code printed on the box. My guess is that suppliers simply took old stock and put them in new boxes for the purpose of selling them to the military. Truth is, I have tubes that are 68 years old and they perform fine, so I don't think it matters so much with a few years here or there.
 

68 years old? Late WWII? That is old! This is good to know if I ever come across a quality tube from that era. Thanks!

Is the LIttle Dot MKIV good for Orthos? My Mad Dogs need some mo juice! 

Oh, I just realized that I had not posted 6GM6 pictures:

The Sylvanias appear to have the same internal construction, but the printing is different, and one has darker smoked glass. The RCAs appear to be identical and were manufactured within a few months of each other, EA = Oct 72 and ED = Jan 73.  An added benefit is they light up nicely in a dark room. :)