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Little Dot I+ Tube Rolling - Page 95

post #1411 of 1977

Changed my mind again, must be my mothers genes in me, I don't know lol. I'm 100%, without a doubt, concrete, getting an Asgard, have a deal in place to get buy it off another head-fi member in about 10 days.

 

Put this up a couple days ago in the OPamp thread, no responses, so I'm trying here now,

 

I have 3 OPA 2107 I received from TI, I have decided against getting the LDI+ and will be getting an Asgard. So no need to keep them. Brand new, unused, still in anti-static bag, just opened it to verify contents.

Got them for free, will sell them for free. Just pay me for postage and you can have all 3 - I won't split them up because I'd have to get different cases for each. Will ship them a couple days after Jan 7th, so we can do it then, just wanting to put this out there early so it's all set up and ready to go when the day comes. First response gets them, just PM me!

post #1412 of 1977

This thread has been pretty quiet recently....

 

 

 

Has anyone tried this tube?
 
"PHILIPS MINIWATT TS62 / 6028 / 408A  The TS stands for "Telefonica Serie"..... Made for telephone networks in Europe.... These are durable, low noise, long life tubes and have silver plate with gold internal wiring and pins....."
 
 
This is European Philips Miniwatt, a Dutch company. Around 1980, Philips bought the Electronic Components and Consumer Electronics divisions of Sylvania from GTE, which included the Sylvania tube plant, and continued to make Sylvana tubes under the new Philips ECG brand name. However, these Philips ECG tubes are completely different from the earlier European Philips Miniwatt tubes manufactured in Holland.
 
The build quality of these Philips Miniwatt TS62s looks amazing, and of course, durability, low noise and long life are very desirable features as well. But I have no idea how they sound.....  So decided to give them a try and have a pair on their way to me...
post #1413 of 1977
Popping into tell tell folks that this is a great deal:

http://www.ebay.com/itm/6J1P-6AK7-EF95-6F32-Pentode-Tubes-Lot-of-8-NOS-/150943037957

I got some in and they sound, to me, just like the more pricey Voskhod EF95s. They very well may be Voskhods, they have the same symbols, including the little missile graphic, and the inverted "UFO" getter. 8 for $8 shipped, go get `em.
post #1414 of 1977

I haven't read all 95 pages of this, but I've spent a few hours searching and scanning through it. Wow, so many possibilities.

 

How important is it to buy tubes as a matched pair? Anyone bought loose singles and had problems? What's the worst that could happen if they aren't matched? Also, what does matching actually refer to? Impedance? voltage change?

 

Thanks

post #1415 of 1977

For a given input BOTH tubes should have -if not exactly the same as near as possible the same output'

                   In tubes this makes a large difference in THD

                    Yes it would "work" with any two tubes of the same type/variety.

                      Dont use tubes of different manufacturers.

                        For what it costs it is WELL worth buying -MATCHED tubes.

post #1416 of 1977

Yeah, so far, I've been able to find matched pairs, but there's a few tubes I've wanted to try that I can only find singles or pairs that don't say "matched". Just wondering how much I should worry about that.

 

thanks!

post #1417 of 1977

That depends if you have any friends or know anybody with a tube tester.

 It doesn't matter if the tester isn't too accurate as long as you get a gain reading near the same on the two tubes you would use. 

   I am sure they must be some people round your area who repair old electronic equipment you could phone around.

 That's one of the problems with tubes unless with a guarantee or a reputable seller you need to test them.

 And its why tube testers are so dear to buy. Unless you can build one plenty of circuits this side of the Atlantic on UK web-sites.

post #1418 of 1977

In my opinion, matched tubes on the 1+ are not so important. The tubes in this amp are used as cathode followers. That is, they provide absolutely no gain, and in fact, the signal out of this tube stage is at a slightly lower level than the input, maybe something like 97%. In fact, you could bypass these tubes with a straight wire and this amp would still work fine. Their main function is to give a "tube flavor" to the signal.

 

That said, for sure, you would want both tubes to provide the same "tube flavor". Of course, you would not want to mix different brands, but as long as the tubes are of the same brand, manufactured around the same time and the interior construction, that is the plates and getter, are the same, I would say go for it. :)

 

And if you want a real tube rolling adventure, I would suggest you visit the Little Dot Tube Rolling Guide forum:

 

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/735

 

About half way down this page (50), begins a thread about using very non-traditional tubes in your LD. For example:

 

6CB6A/6CB6/6676/6CJ6/7732

6DK6/8136
6BC5/6CE5
6EW6
6GM6
6GX6/6GY6
6AG5/EF96/6186/CV848/6J3P
6J38P-EV
 
And if you are really feeling adventurous... as you will need to strap pins 2 and 7 together for these to work....
 
8425A/6AU6A/6136
6485/6AH6
6HS6
 
In my opinion, many of these tubes are superior to any 6AK5/408A I have, and a number of them are superior to my GEC EF91 and Mullard EF92 as well.
 
Happy tube rolling. :)

Edited by gibosi - 3/30/13 at 12:05pm
post #1419 of 1977

Thanks for the info! I've poked around in that thread and eventually got overwhelmed. Right now I'm playing with opamps. I'm liking the LM4562. I have a OPA2107 in now and cant really tell a difference between it and the LM4562. I prefer both of these over the stock and LT1364. I don't know if it was a coincidence or a "feature" of the opamp, but I seemed to pickup more interference noise (pretty sure it wifi) with the LT1364 in.

 

For tubes, I've tried the Mullard 8100 and am currently on the Voshkod 6ZH1P-EV. I'm pretty happy with the Voshkods. Unless there's something else out there that is just marvelous, I may stick with this config for a while. I'm really not hearing radical differences with the tubes - differences with opamps are noticeable, but also very subtle. I think I'm learning that I'm not that discerning or particular about what the amp does to the sound. I can find small improvements here and there, but I'm glad I only spent for a Little Dot and not something far more expensive to conduct this little experiment.

post #1420 of 1977

After trying the various op amps discussed earlier in this thread, I settled on the opa2107. As to 6AK5s, the Mullards and Voskhods are at the top of most recommended lists, so you have saved a bit of money by just buying two of the best to begin. However, I would also encourage you to try the 408As, EF91s and EF92s. My favorite 408A is the Sylvania Gold Brand with gold pins. It can be expensive, but if you are patient you can often find a good buy. Many people also like the Western Electric 408A and these can be found quite cheaply. The best EF91 to my ears is the GEC CV4014 and the best EF92 is the Mullard CV4015. Unfortunately, these are also not cheap. But again, if you are patient, good buys often appear. Of all the standard tubes for Little Dots, my favorite is the Mullard CV4015 and if you were to decide to buy only one more tube for your Little Dot, this is the one I would recommend.

post #1421 of 1977

Nice. You just boiled down 95 pages into a paragraph. I've scanned though maybe half of this thread and was trying to find the tubes most people had settled on after trying numerous ones. Your post confirmed a lot of what I was thinking. The 408A Sylvania Golds are one of the tubes I kept finding singles and pairs not advertised as "matched". I'll keep my eye out. The Mullard CV4015 is also on the short list. Maybe I'll try just one more...

 

Apparently, I have one more opamp to try. A LME49720NA showed up yesterday. I forgot I had ordered that one. I read somewhere its supposed to be an improved version of the LM4562. I guessing I wont be able to hear a difference, but it was $5 so, why not?

post #1422 of 1977

Keep in mind that some Sylvania Gold Brand 408As have gold pins and some do not. So make sure you are buying gold pins. And again, matched pairs are nice if you can find them, but matching is not necessary, especially NOS tubes. In fact, the tubes shipped from the factory with the LD 1+ are not a matched pair. Moreover, David ZheZhe of Little Dot has gone on record to say that matching is not necessary. I have 4 pairs of Sylvania gold pins, 3 pairs were NOS and 1 pair was used. No matched pairs and they all fine.

post #1423 of 1977

Got my Little Dot I+ today. Put in a LM4562 and Mullard M8100s. Initially disappointed by the rather loud transformer hum. However I dismantled the whole thing and finally worked out that if I isolated the transformer casing from the main chassis that it became much quieter. So I stuck some foam padding where the transformer casing screws attach to the chassis (didn't have any rubber washers on hand) and reduced the hum considerably. I also isolated the transformer a bit too for good measure. Not really what I wanted to have to do, but I couldn't be bothered with trying to send it back to China for replacement.. Anyway, switched to OPA2107 now. Seems a little less bright but not as clean. I have a load of AD8599 SOICs from a few years ago that I'm waiting for DIP converter boards to arrive so that I can try them. From what I remember they are much better than both the 4562 or 2107.

 

edit: realised today that the transformer vibration was being amplified by the top of my DAC which it was resting on. It's almost silent when I lift it off the DAC... will work out some way of damping this thing and put my engineering degree to some use. Also, switched back to the 4562 for now, don't really like the 2107 much (I know this is a tube rolling thread but yeh..).


Edited by lawrywild - 4/4/13 at 5:18pm
post #1424 of 1977

I just got my little dot 1+ on Tuesday (7Th) and I am currently burning it in as per Davids suggestions (8 hrs - 30 mins to 1 hr rest). I have ordered a LM4562 op amp as an upgrade as I read good reviews. I will be getting a pair of replacement pair of AKG Q701  (last amp took out the left channel). I was wondering what would be a good first tube upgrade, I like a clean open sound stage with controlled bass. I listen to most everything. smily_headphones1.gif I have read this whole thread and as it is very informative, I am till a bit overwhelmed.

 

Thanks everyone


Edited by Rossy007 - 5/11/13 at 6:15am
post #1425 of 1977

Just got my AKG Q701's, plugged them in and had to turn the volume to 8 (not very loud). I opened the little dot up and removed the two jumpers (j3 + j4) plugged it back up and.......no difference, still have to turn it up to 8? am I doing something wrong?
 

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