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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 78

post #1156 of 8751

Theres one thing i would like to know is how much you guys paid for the latest tubes .here are the prices i was quoted from my guy are those prices in line with what you guys paid the 6AT6, 6AH6WA, 6AU6A, those are $5.00 each and they are General Electric and the 8425A are $10.00 each. no shipping involved. Thanks.

post #1157 of 8751

Hey,

 

Firstly, Gibosi, you are a great part of the team and thanks for your contributions, appreciated.

With respect to Hi-Fi vocabulary, check this glossary:

 

http://www.head-fi.org/t/220770/describing-sound-a-glossary

Thanks for the link Acapella11 shurely is going to help me describe tubes to.
post #1158 of 8751
Quote:
Originally Posted by MIKELAP View Post

Theres one thing i would like to know is how much you guys paid for the latest tubes .here are the prices i was quoted from my guy are those prices in line with what you guys paid the 6AT6, 6AH6WA, 6AU6A, those are $5.00 each and they are General Electric and the 8425A are $10.00 each. no shipping involved. Thanks.

 

All the last batches of tubes I bought cost me anywhere between -converted to US $- 4 and $14 when you include shipping. The most expensive I bought recently were the Sylvania 8532W, which I have yet to get (which is quite frustrating considering those are the most expensive driver tubes I've bought in the last month or two)...

 

The 6AH6/6485 family has pretty stable and fairly cheap prices; not that much to select from anyway, though they are quite amazing.

 

The 6AU6/8425A family is kind of all over the place in terms of pricing, but still cheaper than all those horrifyingly overrated 6AK5 tubes, save for the $30-40 Telefunken EF94 and 20$ used Mullards...

 

The 6AT6 family has quite a bit of variety, so prices are all over the place as well but not that expensive, and the premium -which I would still get over the plain-Jane ones- are closer to $10 a tube than not. It seems that some of these are clearly identified as half of a 12AT7 and are starting to corresponding prices, only a few though. Again, you could get really cheap basic RCAs or such for $2-3.

 

And finally, the brand new 6BE6 family has tremendous variety, and I haven't quite figured out the price pattern for these -or the similar 6BY6 family btw- but prices seem to be between $5-15 closer to 10 for premiums.

 

Hope that helps, I have a couple more families that I'm currently investigating, so things might get even more confusing lol!

post #1159 of 8751

Hi Mikeleap,

 

Part of the fun is to try to get good deals on the tubes. This involves looking through the many different offers on Ebay, communicating with sellers (asking what they have and combining shipping), and being patient. To date I have not payed more than $8 for any one tube, and many times much less. However, sometimes it involves buying four or more tubes. (It could be that I am caving in one day and spending the $200 on a set of DR power tubes - nah, I'll rather buy another back up Little Dot MkIII amp instead - just kidding!)

 

All prices include shipping:

For the 6AH6WA tubes (Tung Sol and Sylvania - altogether 7 tubes) I paid $2.11 each.

For the 6AU6A/4825A Tektronix matched tubes I paid $12.84 for each set of GE and Westinghouse; for a second set Westinghouse without Tektronix labels I paid $10.

 

This seller:  http://stores.ebay.com/TUBEHUNTER  still has GE 6AU6/4825 for $9.84 for a pair, and the Westinghouse Tektronix 6AU6A/4825A for $12.84/pair. (Shipping is free for the US - don't know about Canada). He also has an assortment of 6AU6 tubes for around $1 and change if bought in a lot.)

post #1160 of 8751
Quote:
Originally Posted by Audiofanboy View Post

The 6AT6 family has quite a bit of variety, so prices are all over the place as well but not that expensive, and the premium -which I would still get over the plain-Jane ones- are closer to $10 a tube than not. It seems that some of these are clearly identified as half of a 12AT7 and are starting to corresponding prices, only a few though. Again, you could get really cheap basic RCAs or such for $2-3.

 

 

And the 6AV6 is purportedly half of a 12AX7....

 

Interestingly, I cannot find any "premium" versions?  I usually check here

 

http://www.radiomuseum.org/tubes/tube_6at6.html

 

to find other variants, and no premium or "other class quality" versions are listed for any of the 6AT6 family tubes. So my assumption is that the premium versions are in fact the military versions....

 

On a whim, I searched google for "best 12AX7 tube" and was somewhat surprised to find that RCAs are often listed quite high. So perhaps $2 RCAs from the 6AT6 family might be well worth trying. My Sylvanias sound great but I just might try some cheap RCAs next. :)

post #1161 of 8751
Strapping Pins in the Socket: Best Practices
 
1. Use stranded wire. Do not use solid core wire.
 
2. Use a socket tester during periods in which many tubes are being compared and evaluated.
 
As Audiofanboy was using 26 gauge stranded wire, I figured that 30 gauge solid core, which is significantly smaller, would actually be better. However, in hind sight, I now understand that solid wire plus the pin stretches the springs in the pin hole considerably more than stranded wire, even though 26 gauge stranded wire is fatter. As a result, the springs in pins 2 and 7 of my Little Dot have been stretched to the point where there is no longer enough tension to grip the tube pins tightly.
 
If these were the old phenolic sockets, it would be a simple matter to re-tension the springs using something like a very small jewelers' screwdriver or a dental tool. However the ceramic sockets in our LDs do not permit the insertion of such a tool behind the spring.
 
For now, I have to insert a piece of wire into pins 2 and 7 to use any tube. Below is a picture of a 6AT6 with these wires. Moreover, I usually have to roll the tube around a bit to finally make a good connection. Obviously, in its current state, I can no longer swap tubes easily and conveniently.
 

 

Again, I recommend the use of only stranded wire to strap pins in our Little Dots.  And perhaps, for our Tung-Sol 6485 and other top tier tubes which require strapping, maybe we could send them to Inphu510n as he has evidently perfected the art of soldering wires onto tube pins? :)
 
If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
 

 

 

 

As you can see, it is very simple to use standard hookup wire inserted next to the copper test points in order to do your strapping on the socket tester, completely eliminating the risk of stretched springs in the socket.
 
I purchased these from Leeds Radio for only $7 each. :)
 
Further, for my situation,I have looked into having the sockets replaced, but it would cost more than just buying a new LD 1+, as a new one costs only $110. For now, I intend to purchase some longer machine screws that will be inserted all the way through the middle hole of the ceramic socket to enable me to bolt the socket testers to the ceramic sockets with a nut and washer underneath. I am hopeful this will work well.

Edited by gibosi - 5/2/13 at 12:09pm
post #1162 of 8751
Quote:
Originally Posted by Johnnysound View Post

 

This is my very first post in this forum,  just to concur with Audiofanboy when he says that you can trust people's opinions here, which have been very useful to me.  I am not new to high def audio,  (in fact, I have a long experience)  but have to confess that headphones were not exactly my priority (kind of heresy said here).  I do have an excellent pair of  vintage Stax electrostatics and some mid range Sennheisers, but I simply was not into it, until I saw  some highly positive comments in this forum about the LD MKIII, so I decided to give it a try.  Paired in stock form with my relatively modest but splendid-sounding  Audio Technica ATH-M50 LE (Anniversary Edition), the result was really astounding.

 

 Since this is a tube rolling thread,  I do not want to go off-topic, so let me say that I followed the excellent guide from Dept of Alchemy  and replaced the stock GE 5654  tubes with a pair of Voshkod 6J1P-EV gold/platinum grid,  NOS military tube ("OTK" rhombus seal) made in the 1980´s in the Voshkod plant,  Kaluga city, sent to me from an Ebay seller directly from Moscow at a cost of around $ 18 the pair (including postage).  Authentic military stuff, these Russian tubes are clearly extremely  well made, solid and sturdy, a little bigger than the stock ones.  I wonder what its military use was in the Cold War, I suspect they were made by the thousands so there is still a big stock of NOS tubes you can get at around $ 3 each.  Very interesting historical piece, it was obviously not made for commercial purposes but for reliability and ruggedness, so its original cost must have been much higher, no problem for the mighty URSS military budget.  

 

Before I give my humble sonic impressions as a newcomer in this forum of  headphone experts,  I must say that I am fully aware that a closed back headphone is not the ideal tool to evaluate  the LD MKIII.  It really needs a good open back HP to be appreciated.  I am thinking seriously in the HD 650 or Beyer 800 series. (My wife will kill me if she ever find out the price of these) I do favor a dynamic but natural sound, with precise, not overextended bass and very good soundstage.  Any suggestions ?    

 

On the other hand,  a good studio monitoring HP like the ATH-M50 LE is like a microscope.  Maybe not much soundstage or spatial clues, but It will reveal a lot of detail in the music and has superior bass rendition.   My feeling was that the stock GE 5654 tubes are not that bad,  as stated in the "rolling guide",  in the sense that these tubes are rough and have bad midrange or highs. Perhaps not so delicate and yes, an "upfront" presentation,  but overall a nice, balanced, dynamic sound with more than adequate bass, and they improve a lot  after about 50 hs, of use.  The Voshkods, however, are a different story.  With no burn in at all these tubes inmediately revealed themselves as high definition ones.  Suddenly,  there was more music and more information:  powerful and tight bass, extended highs,  great midrange and a superior spatial rendition of the performance, very  dynamic and revealing.  However, after my initial positive impressions, and after listening to a lot of different music ( jazz, rock, classical, latin, etc.)  with some VERY demanding HD recordings in both 24/96 and 24/192,  going to the limit, the Voshkods showed a kind of "over the edge" quality with some HD music at perhaps the 2k to 4k range resulting in  some  mild "hardness" in the midrange. The highs were surely very extended, but not as sweet as I would like.  I have no doubt that a good burn in will solve some of this problems.  It is kind of funny that I am talking about one or two tubes here when the people in this forum have experience with hundreds of them. Well, this is the good thing, as Audiofanboy said, I will trust your advice...                           

Hi fellow newcomer to this forum.

 

Re. your interest in the Senn HD650, may I say that I have been overwhelmed by the sound (or should I say "sonic experience") of these when fed by the amazing MKiv SE - and so, I should imagine, the MKIII. It seems to me they fulfil pretty much all the criteria you mentioned, assuming a good source...I must admit I have probably helped things along by replacing the stock cable with one I made up using 8-stranded pure silver cable, but the stock is still pretty good!

 

I do however feel I must guide you - if you are not already there  -  to follow the threads from Audiofanboy, Gibosi et al with regard to the latest discoveries they have made concerning driver tubes. So long as you are happy implementing the wire modification they mention, taking careful note re the "cleanliness" of insertion and use of thin STRANDED wire, I would urge you to forego the VERY lengthy burn-in time needed for the Voskhods (mine had 100+ hours!) and go for the Tung Sol 6485s. Have just received mine, and straight out of the box were far superior to the Voskhods and the Tesla 6F32s others have mentioned. After just 10 hours' burn-in the sound coming through the Senns is nothing short of unbelievable...I am in sonic heaven!

 

I suggest you read all the threads you can find on this topic and I am sure you will find the confidence, as I did, to discover what the LD can really do - not to mention the Sennheisers.

 

Good luck.

post #1163 of 8751
Quote:
Originally Posted by gibosi View Post

 
2. Use a socket tester during periods in which many tubes are being compared and evaluated.
 
....
If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
 
.....
 
I purchased these from Leeds Radio for only $7 each. :)
 

 

It's weeks that I'm continuously looking for something like this on eBay, but it seems that only 9-pins socket savers exist. frown.gif

Are you aware of ANY eBay seller selling these adapters/savers and shipping to Europe?

post #1164 of 8751
Quote:
Originally Posted by gibosi View Post

 
2. Use a socket tester during periods in which many tubes are being compared and evaluated.
 
....
If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
 
.....
 
I purchased these from Leeds Radio for only $7 each. :)
 

 

What a cool item gibosi. I will put that on my shortlist. Cheers.

post #1165 of 8751
Quote:
Originally Posted by vic2vic View Post

It's weeks that I'm continuously looking for something like this on eBay, but it seems that only 9-pins socket savers exist. frown.gif

Are you aware of ANY eBay seller selling these adapters/savers and shipping to Europe?

 

I too looked for these on eBay, but couldn't find anything....

 

I bought mine from Leeds Radio located in Brooklyn, NY:

 

http://leedsradio.com/

 

And they will ship internationally.

post #1166 of 8751

On some of the LD products you make to make sure that you have enough room to insert the socket saver because of the rings.

post #1167 of 8751

http://www.ebay.co.uk/itm/2-x-ROHREN-TUNG-SOL-6485-NEU-OVP-6AH6-/261150136993?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7384774600389803262%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D261150136993%26

 

I just got these delivered! they look quite substantial but I haven't plugged them in yet and reading your comments about the damage done to the pin sockets i am now afraid to stick the wire...but I am itching to hear these babies to see if they really are as good as you all say they are! i was thinking, could i use a slightly thicker gauge of fuse wire to wrap around the pin a few times, then pass it along and then a few wraps around the other pin, perhaps a little blob of solder to keep the whole thing sweet? how much current is actually going to pass through this wire? any thought? 

post #1168 of 8751
Quote:
Originally Posted by zedmeco View Post

http://www.ebay.co.uk/itm/2-x-ROHREN-TUNG-SOL-6485-NEU-OVP-6AH6-/261150136993?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7384774600389803262%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D261150136993%26

 

I just got these delivered! they look quite substantial but I haven't plugged them in yet and reading your comments about the damage done to the pin sockets i am now afraid to stick the wire...but I am itching to hear these babies to see if they really are as good as you all say they are! i was thinking, could i use a slightly thicker gauge of fuse wire to wrap around the pin a few times, then pass it along and then a few wraps around the other pin, perhaps a little blob of solder to keep the whole thing sweet? how much current is actually going to pass through this wire? any thought? 

 

As long as you use stranded wire, everything will be fine. I was shoving tubes in and out of my LD like a mad man and using solid core wire. It takes time and a lot of rolling to do any real damage. So by all means, use 26 gauge, or smaller stranded wire, and enjoy them.

 

Oh, there is very little current passing through this wire, measured in milliamps at most. A very tiny wire is more than sufficient.

 

I have two comments regarding your suggested alternative. First, it is very difficult to solder wire to tube pins. You want the surface of the tube pin right up against the glass base to be very clean and shiny. You will likely have to use sandpaper or a sharp knife to get down to shiny metal. Otherwise, the solder will not adhere properly. And second, if you use a "slightly thicker wire", the thickness of the wire will prevent the tube from sitting properly in the socket and the pins will not make good contact.

 

That said, if you are willing to put in the necessary time and effort, soldering a wire is the best solution, IMHO. And if you are willing, I would recommend 30 gauge solid core wire.

 

 

I did not try to solder this connection, but as you can see, 30 gauge wire is tiny enough not to cause any problems when the tube is inserted into the socket.

 

But again, they have just arrived! Don't deny yourself!  Use a little piece of small stranded wire and enjoy. :)

 

And then, if you end up loving these TS 6485, it will be worth the extra time and effort to figure out how to get a good soldered wire connection.

post #1169 of 8751

Gibosi's approach is excellent.

Use the socket wire mod until you find a tube you really like and then solder the pins together.

I used 26GA stranded copper wire, probably way thicker than was needed. I haven't posted pics of it but I will eventually. I just have a lot going on right now.

I have some even thinner gauge stranded wire that I'm going to try using on my 6AV6 tubes.

 

Once I get pics posted and if it looks like acceptable work I can definitely offer to do the soldering for people. For a small fee of course ;)

Looking at the LD boards it really wouldn't be that hard to pull them off and replace them. It's just a matter of finding the exact (or higher quality) tube sockets that will fit.

 

Honestly though, I'd like to sketch something up and have an adapter made for our purposes. I've been trying to think about the mechanics of making an adapter that would allow for several configurations but I haven't spent enough time thinking about it to come to a useful conclusion. The 2-7 pin mod is obviously easy to achieve though I'm unsure what manufacturing costs would be like. This is really small batch, niche stuff here. Having never had anything put into manufacturing, it would be a good exercise because there are other ideas I'd like to have produced for use in the world.


Edited by inphu510n - 5/2/13 at 11:26pm
post #1170 of 8751
Quote:
Originally Posted by gibosi View Post

 

http://leedsradio.com/

 

And they will ship internationally.

$50-$60 for delivery cost :-(

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