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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 241

post #3601 of 6943
Quote:
Originally Posted by Artsi View Post
 

700

And here is ready to use product.

 

 

I want to give a HUGE shout-out to Artsi for showing us how to make an adapter box to allow us to easily use these double triodes in our LDs. If anyone wants to use these tubes (And everyone SHOULD want to use these tubes! They are THAT GOOD!), all that is necessary is to purchase a few parts and supplies, solder a few wires, and voila -- you have a "magic box"!

post #3602 of 6943
Quote:
Originally Posted by gibosi View Post
 

 

I want to give a HUGE shout-out to Artsi for showing us how to make an adapter box to allow us to easily use these double triodes in our LDs. If anyone wants to use these tubes (And everyone SHOULD want to use these tubes! They are THAT GOOD!), all that is necessary is to purchase a few parts and supplies, solder a few wires, and voila -- you have a "magic box"!

most interesting though I wonder if its possible to add in more sockets whereas the switch allows us to switch between EF95 tubes and the double triodes. So there would be three sockets middle will have the double triode and the left and right side will be our regular EF95's(eg. 6dt6a, EH90, 6AH6WA)

post #3603 of 6943
Quote:
Originally Posted by siles1991 View Post
 

most interesting though I wonder if its possible to add in more sockets whereas the switch allows us to switch between EF95 tubes and the double triodes. So there would be three sockets middle will have the double triode and the left and right side will be our regular EF95's(eg. 6dt6a, EH90, 6AH6WA)

 

Of course, this is possible, but I think it would be more complicated and difficult than it is worth. As this box simply plugs into your sockets, if you want to listen to a 6DT6A, all you have to do is unplug the box, set it aside, and then use your LD as normal.

post #3604 of 6943
Quote:
Originally Posted by gibosi View Post
 

 

Of course, this is possible, but I think it would be more complicated and difficult than it is worth. As this box simply plugs into your sockets, if you want to listen to a 6DT6A, all you have to do is unplug the box, set it aside, and then use your LD as normal.

ah icic i thought it was permanently rigged on the lil dot xD

post #3605 of 6943

Hi Artsi,

 

If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?

 

Is this the same switch?

 

http://www.ebay.com/itm/140923600452?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

And is this the box?

 

http://www.ebay.com/itm/281036052511?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Thanks,

post #3606 of 6943
Quote:
Originally Posted by mordy View Post
 

Hi Artsi,

 

If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?

 

Is this the same switch?

 

http://www.ebay.com/itm/140923600452?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

And is this the box?

 

http://www.ebay.com/itm/281036052511?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Thanks,

I think any 3pdt switch with on-off-on would work though agreed whats the use? a dpdt should work just fine for this application.

post #3607 of 6943
Quote:
Originally Posted by mordy View Post
 

Hi Artsi,

 

If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?

 

Is this the same switch?

 

http://www.ebay.com/itm/140923600452?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

And is this the box?

 

http://www.ebay.com/itm/281036052511?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Thanks,

Hey mordy you have the right part number as long has you buy1591 msbk that one sustains heat the 1591S not made for that purpose it seems. You can also get it and the switch at DIGIKEY box sizes 3.339L x 2.205W x 1.023H INCHES


Edited by MIKELAP - 10/20/13 at 12:25pm
post #3608 of 6943
Quote:
Originally Posted by mordy View Post
 

Hi Artsi,

 

If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?

 

Is this the same switch?

 

http://www.ebay.com/itm/140923600452?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

And is this the box?

 

http://www.ebay.com/itm/281036052511?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Thanks,

Purpose of the switch is that you can use 12.6v and 6.3v heated tubes. There are few 12v tubes that do not have possibility to use with 6.3v. And i noticed few 6.3v tubes that have possibility to be used with 3.15voltage, and this tubetype could break if switch is in wrong position. Switch looks right one, but the box is much bigger, what i used. My box is 1591MSBK. Switch could be ON-ON type too.


Edited by Artsi - 10/20/13 at 12:21pm
post #3609 of 6943
Quote:
Originally Posted by Audiofanboy View Post
 

Alright! I managed to find a single, super strong (as in 20% over NOS) Amperex "Orange Globe" 6DJ8 from the late 60s (so not a "Bugle Boys" 6DJ8 from the early or mid-60s, and not an "Orange Globe" with an A-frame getter from 70 onwards), so the best Amp'ex short of some crazy rare tubes, recommended by all who have tried them. I just communicated with a seller who was selling some very nice pairs for "OK" prices, asked him if he had singles, and obviously he had plenty and was willing to sell them for less than half of the price of a pair (cheaper than buying pairs, which is a bit ironic).

 

Keeping up on my strategy of just going for it and getting the best -instead of spending the same money on more tubes I'll never use- I got the best I could, basically. But even then, I don't find the prices that shocking really, compared to the 3 digit legends I see over on the Lyr thread (I ended up paying $42 for the tube, shipping to France included, and that's $10 right there; seller would have shipped for $37 to the US, which really isn't horrible for super strong premium tubes). Again, I think the "pair effect" really ramps up the prices, and sellers are just dying to sell single tubes they don't have a match for!

 

I have a pair of Bugle Boys, 1960, and A-frame Orange Globes, 1970, and to my ears the Bugle Boys sound better. Based on the reviews of others and my experience, Amperex with halo getters from the early sixties through the late sixties do seem to be better than the later A-frame versions. 

 

And speaking of going for the best, I found a pair of white label Amperex 6922 / E88CC, relabeled as Beckman, with gold pins, made in the US, for $83.00, including shipping. I have seen these for upwards of $200 a pair, especially if they carry the Amperex label. However, as we have seen many times, the label on a tube is not all that important. Gold pins and the Philips tube codes tell us everything we need to know: In this instance "7L9 *4J"    7L= 6922 / E88CC, 9 = change code, * = Amperex, New York, 4 = 1964, J = October.

 

$T2eC16Z,!)UE9s3wDdZ+BSGn5g6iiw~~60_57.JPG 

post #3610 of 6943
Quote:
Originally Posted by gibosi View Post
 

 

I have a pair of Bugle Boys, 1960, and A-frame Orange Globes, 1970, and to my ears the Bugle Boys sound better. Based on the reviews of others and my experience, Amperex with halo getters from the early sixties through the late sixties do seem to be better than the later A-frame versions. 

 

And speaking of going for the best, I found a pair of white label Amperex 6922 / E88CC, relabeled as Beckman, with gold pins, made in the US, for $83.00, including shipping. I have seen these for upwards of $200 a pair, especially if they carry the Amperex label. However, as we have seen many times, the label on a tube is not all that important. Gold pins and the Philips tube codes tell us everything we need to know: In this instance "7L9 *4J"    7L= 6922 / E88CC, 9 = change code, * = Amperex, New York, 4 = 1964, J = October.

 

This is definitely getting to be a more and more expensive hobby... Less tubes but 5-10 times more expensive than the previous types! It's not that bad though: I ended up getting free international shipping on my Amperex tube, so I paid $37/28€, which is the price of a few beers in town where I live...

 

Seller is http://www.ebay.com/usr/mercedesman6572 . Very good seller imo (and I've seen people on the Lyr thread say the same), just communicate and he should be able to get you virtually any single 6DJ8 you want -for a price of course, this isn't Grandpa's attic lol.

 

People say that the early to mid 60s Holland-made Amperex tubes -Bugle Boys- are some of the most musical you can find, but, while very nice, aren't the last word in terms of microdetail and both upper and lower frequency extension (despite a slight upper bass "hump", or so I've read). That's probably what makes them so musical and euphonic though.

 

Late 60s -Orange Globes- with a halo getter are supposed to have better extension, and much better "precision" or focus, at the expense of some degree of musicality (still quite musical though).

 

70s A-frame getter Amperex are a bit more forward (vocals are anyway), with more emphasis on highs, and maybe more "perceived" detail as the tubes above, with a bit less focus. Some people prefer the A-frame Orange Globes to the halo getter late 60s ones, but most people either prefer the late 60s version or the more musical Bugle Boys. Speaking from my own limited experience with Philips group ECC88 tubes (my EI Yugo ECC88 with an A-frame getter, very very close to Holland production), I do find that the later A-frame tubes are too forward and a little spiky for my tastes. I've read that EI version is even more forward than the original Philips/Amperex, but the treble emphasis is exactly like what I read about those 70s A-frame Amp'ex tubes.

 

Nice catch on the US Amp'ex tube, gobosi. I'm going to wait until I get my late 60s Orange Globes before I decide whether or not it's worth forking out more money for ECC88 tubes in my amp (either as opposed to 12AX7 tubes, or as opposed to just being happy with what I have!). Right now, I still can't believe how good my anonymous looking EI ECC83 with smooth Telefunken plates sound. I'm finally taking pleasure from listening to music again, instead of the old burn-in -> swap tubes -> burn-in -> swap tubes -> burn-in cycle of hell where nothing ends up sounding good after a while...

post #3611 of 6943
Quote:
Originally Posted by MIKELAP View Post
 

 

Here are intructions on how to modify 6BQ7A or ECC/6DJ8 DOUBLE TRIODE tubes and the sockets they use.Its not pretty but it works. Pins 1-2-3-9 need to be bent or cut off on 6BQ7A tubes or if you are using ECC/6DJ8 and Littledot has to be on EF95 setting. you need to insert in a sequence tube pin 4-5-6-7-8 into pin holes 3-4-5-6-7 of the adapter and insert adapter in Littledot in regular position (remembering that there is 2 pins that were cut off on the adapter)                                                                                                                                                                                                                                                            Regarding socket mod ;using  wire solder pin 6 to pin 1 and pin 7 to pin 2 on adapter .Also you will need to cut  pins 6 and 7  those are the pins on the adapter that go in the Littledot. One last thing you can link pin 6 to 1 and 7 to 2 inside the adapter also for a cleaner look using 30 gauge wrapping wire .Wire used in picture is 22 gauge which is to big .                                                                                                                                                                                                                                                                                                                                                                                                                            Of course soldering the wires inside his not easy for a novice also you have to reinsert the pin assembly into socket holes which is loads of fun.ALSO ALWAYS REMEMBER THOSE WIRES HAVE ELECTRICITY PASSING THRU THEM SO BEWARE DO NOT TOUCH THE CONNECTIONS WHILE USING AMP.By the way a special thanks to Audiofanboy,gibosi, and Troll Dragon for there advice, instructions,and patience .Thanks guys.

                                                                                                                                                                                                                                                                                                                                                                              

 

 

                                                                                                                                              

 

 

                                                                                                                                              

 

New improved found some 30 gauge wire so now small enough to solder inside socket adapter. Nice clean job. Also if you can get a small vise and a pin straightner you insert your pins in it and put it in the vise makes a good holder when you solder and your hands are free.


Edited by MIKELAP - 10/21/13 at 9:54am
post #3612 of 6943
post #3613 of 6943
Quote:
Originally Posted by Audiofanboy View Post
 

Nice catch on the US Amp'ex tube, gobosi. I'm going to wait until I get my late 60s Orange Globes before I decide whether or not it's worth forking out more money for ECC88 tubes in my amp (either as opposed to 12AX7 tubes, or as opposed to just being happy with what I have!). Right now, I still can't believe how good my anonymous looking EI ECC83 with smooth Telefunken plates sound. I'm finally taking pleasure from listening to music again, instead of the old burn-in -> swap tubes -> burn-in -> swap tubes -> burn-in cycle of hell where nothing ends up sounding good after a while...

 

Similarly, I am also wondering if my long tube rolling marathon might finally be coming to an end.... Having listened now to a number of ECC88s -- Mullard, Amperex, Siemens, Reflector and Tesla -- I find that I prefer the Amperex sound. However, even though my Amperex Bugle Boys sound incredibly good, I thought I might try to find some late 1960s Orange Globes, similar to the ones you have just ordered. Plus, I am not sure how much success I will have re-straightening the pins on my Bugle Boys, so I thought I would like to have some nice Amperex to listen to once I get my 9-pin adapter put together.

 

In my search for the OGs, I stumbled across the Amperex-USA 6922 / E88CC. Reviews I have read suggest these are among the best. And it seems to me, that if I prefer the sound of Amperex ECC88s, I might also prefer the sound of a premium Amperex over a premium Siemens or others. Plus, the price was right... :)

 

Of course, even if I am close to the end of this marathon, there are still a few other tubes I would like to try. I have read some very good reviews of Voskhod 6N23P from the 1970s. And of course, I want to try at least a few 12AX7. :)

post #3614 of 6943

Hi all.

 

After artsi's wonderful work on the switch box, the natural-born pessimist in me is coming to the fore and pushing me to play 'devil's advocate'...

 

I may well be worrying unduly, but I am reminded of the wise statement in a related field of sound reproduction - namely : the best connector is NO connector.

Applying this principle to such a box, could we be degrading our signal transfers somewhat...especially if top grade wire isn't used, along with (possible) so-so soldering?

 

Perhaps I am barking up the wrong tree? (I know I am sometimes barking MAD!!).

 

Ah well, just a thought...

 

There certainly is some SERIOUS work going on in triode land at the moment - it's hard to keep up!

 

Keep up the good work lads - am still awaiting my sockets from China so I can see/hear what all the fuss is about...can't wait...

post #3615 of 6943

My 9-pin breadboard socket assembly arrived today.

 

And it looks pretty ugly, but it is working! lol. I found that leaving pin-9 floating still results in ground hum. But when I tied it to the cathode of the right 7-pin adapter (which is the same adapter which supplies the heaters), everything is fine. So I suspect that pin-9 just does not take kindly to being left completely disconnected. Tying it to the switch in Artsi's magic box or to the cathode in my setup makes it happy. :) 

 

Nothing is soldered. I used 28 gauge (.32mm) solid core wire and wrapped one end tightly around the test points on the 7-pin adapters, and then connected the other to the 9-pin breadboard compression terminal blocks. 

 

And of course, this is very temporary until I get around to building myself one of Artsi's magic boxes.... 

 

Testing with an RCA / Amperex (Holland) 6DJ8 from 1974. I think this was manufactured after the A-frame versions as it has a much simpler getter structure. The sound is a bit brighter than my Bugle Boys, but still very nice.... and it works! :)

 

Edit: changed catheter to cathode. lol 

 

 


Edited by gibosi - 10/21/13 at 2:59pm
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