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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 218

post #3256 of 7489

A couple small packages have arrived here recently:

 

These are Amperex Bugle Boy 6DJ8 / ECC88. They have matching Philips tube codes, Delta 0A, so Heerlen, Holland, January, 1960. I am trying very hard to be a bottom-feeder in the 6DJ8 / ECC88 world lol, but finding decent tubes for less than $8.00/tube is tough. These were $13.00/tube shipped, and I feel pretty lucky to have got them for that price. These are now my favorite tubes. :)

 

 

A pair of batch-matched (HK) GE 6DJ8 / ECC88. I found these for $8.50/shipped. However, it appears that one of them was damaged in transit. With the smoked glass it is difficult to see, but the entire getter assembly on the right tube is broken and rattles loose inside the tube...  Very disappointing... I am waiting to hear back from the vendor....

 

post #3257 of 7489
Quote:
Originally Posted by Oskari View Post
 

 

Are you sure about the tZ type code?

 

 

Hi Oskari.

 

I really am screwing up with the identification of these tubes aren't I?! Mind you I do have a good excuse this time - the tube code link on audiotubes.com lists tZ, which is on my tubes, as being PCC85. No wonder you have doubts...looked around, and they are NOTHING like 6HM5s. Thanks for the query...cannot understand what on earth those letters are doing on these tubes. Perhaps my eyesight has totally given up the ghost...and I'm only 63. Is there any hope for me?!! Ah well, live in hope, die in despair - as the saying goes!...

 

Cheers.

post #3258 of 7489
Quote:
Originally Posted by gibosi View Post
 

 

I have two kinds of adapters. The pictured adapter is a little cheaper and simpler, but otherwise, they are essentially the same. There is a long machine screw that extends from top of the adapter and secured with a small nut in the bottom, between the pins. So you simply take it apart.... 

 

 

This particular adapter is setup for 2-7 pentodes. I used 30 gauge wrapping wire, wrapped and soldered around pins 7 and 2. For these dual triodes, you would need to add another piece of wire to connect pins 6 and 1. Also, for dual triodes, I simply cut pins 6 and 7 short so they do not extend through the bottom of the adapter and into the socket.

 

Oh, and make sure there is some slack in the wire as it crosses over the hole for the machine screw. On one adapter, the wire was a bit too tight, and when I tried to insert the machine screw, I broke the wire.... (>_<)

 

 

Just wanted a precision regarding bottom picture with wire you said its configured for a 2-7 setting my question is the pins are inverted in picture right the wire at top is on pin 2 and at bottom is  pin 7 right

post #3259 of 7489
Quote:
Originally Posted by MIKELAP View Post
 

 

Just wanted a precision regarding bottom picture with wire you said its configured for a 2-7 setting my question is the pins are inverted in picture right the wire at top is on pin 2 and at bottom is  pin 7 right

 

Yes, you understand this picture correctly. :)

post #3260 of 7489
Quote:
Originally Posted by hypnos1 View Post
 

Thanks for the query...cannot understand what on earth those letters are doing on these tubes. Perhaps my eyesight has totally given up the ghost...and I'm only 63. Is there any hope for me?!! Ah well, live in hope, die in despair - as the saying goes!...

 

It doesn't have to be your eyesight. :normal_smile : The people at Ei might have created this confusion. :angry_face:

 

Quote:
Originally Posted by gibosi View Post
 

 

Mullard seems to have used a three-character type code AEB for 6HM5, if I'm seeing right.

 

[The code for EC900 (6HA5) is listed as C7.]

post #3261 of 7489
Quote:
Originally Posted by hypnos1 View Post
 

 

Hi gibosi - and oskari - and anyone else interested, as things seem to have gone very quiet on the 6HM5 front (no wonder, with the exciting experiments going on courtesy of AFB once again!...).

 

Anyway, my "premium quality tubes for export" arrived today and my word, they are of VERY classy construction. Yugoslavia on them, with codes that ARE Philips, but NOT Mullard...

Actually : tZ1 (= tube type PCC 85 ) and G5A (G being Loewe Opta, post-1954, and Mullard/Fleetwood prior. As 5 must be '65, we are looking at Loewe therefore - no wonder the tubes look classy...they are quite some outfit, no? And no doubt VERY picky...

 

So, popped them in; gasped at the blinding flash from their bottoms that ensued; resisted the temptation to switch everything off; calmed down as they settled to a beautiful glow, and (thankfully) was rewarded with a sound that bodes very well indeed right from the off. These would appear to have the potential to knock the lovely RCA 6DT6As off their lovely perch...time will tell...

 

 

Quote:
Originally Posted by Audiofanboy View Post
 

 

 

Factory code "G", you sure? Maybe factory code:

 

 

EI, Nish factory, (ex-)Yugoslavia. The similarity with a "G" isn't that obvious here, but on the pics of real tubes I've seen and on my EI ECC88, the factory code circle is longer and more "circle-like", making it look like a 90° turned G to the untrained eye -or uninformed soul lol.

 

Factory code "G" would make little sense, whereas the EI factory is about the only Yugoslavian tube maker I know about.

 

Depending on the tube type, EI could have used Philips machinery (ECC88 for instance), Telefunken machinery (ECC83 for example) and maybe even some other production gear for all I know. These tubes, with their shape (top "nib") and codes, could have been made on ex-Philips gear. Or maybe not. If we compare it to a Mullard Blackburn or Philips Heerlen-made tube, we might be able to tell.

 

Hi again AFB... Gibosi and Oskari - you may also be interested...

 

Curiouser and curiouser...as my symbol was similar but different to yours, I researched further and found one that matches perfectly...and wait for it...it is listed as MULLARD/Whyteleaf ("B").

What on earth is going on? Mind you, this was from the tube code link at audiotubes.com - the same list that has my tZ code as PCC85! So something VERY weird is going on here, to say the least. Ah well, I'm sure there's a good explanation SOMEWHERE!!

 

BFN

post #3262 of 7489

The Ei symbol can look quite similar to the Whyteleafe "B" plant symbol. See the rightmost photo here:

 

post #3263 of 7489
Quote:
Originally Posted by gibosi View Post
 

 

I think your understanding of what you are hearing makes intuitive sense. In a more 2D stage, everything is focused very tightly, right up against your face, so to speak. But in a more 3D sound stage, there is more space between the instruments, especially front to back, and therefore, some vocals and instruments do seem to be further away.

 

And yes, the setting is EF95. No other settings are possible or advisable.

 

And these EI tubes do look very similar to my Blackburn tubes, so it would seem very likely that they were manufactured in Yugoslavia using ex-Philips factory equipment. And perhaps they sound similar too.

 

 

 

Hi gibosi.

 

Yes, I suppose what you say re 2D v 3D brings to mind Holmes and "elementary, my dear Watson"! It's just that I had never noticed such a difference before - obviously these 6HM5s have a MASSIVE soundstage, compared to all the others I have tried before...So take note anyone looking for more "3D" sound.

 

Also elementary I suppose is that our tube rolling highlights the varying skill/tastes of the recording engineer - something I had never really fully appreciated before (but that can also bring immense frustration, when you hear what CAN be achieved by a Master in the field as opposed to a lesser one...especially when your favourite piece of music ended up in the hands of the latter!)'

 

Also highlighted is the immense advantage we rollers have over even vastly more expensive (better?) solid state gear - WE can compensate (to a degree) for a so-so engineering job, in a way no equaliser or similar can do...lovely...

 

 

Happily, with another 20+hrs on them, things are "coming together" quite nicely - ie still tremendous detail, but with more coherence. Bass is developing a bit more...(either that, or I am 'habituating' myself to higher volumes - not to mention early deafness!). Whatever, I think I am falling in love all over again. Oh the pain...

post #3264 of 7489
Quote:
Originally Posted by Oskari View Post
 

The Ei symbol can look quite similar to the Whyteleafe "B" plant symbol. See the rightmost photo here:

 

 

Hi Oskari.

 

Yes indeed, VERY similar...but mine are much more like the other. Perhaps they were using the wrong stamp?!!

Thanks for your interest.

 

Time for a scrub.

BFN

post #3265 of 7489
Quote:
Originally Posted by Oskari View Post
 

It doesn't have to be your eyesight. :normal_smile : The people at Ei might have created this confusion. :angry_face:

 

Mullard seems to have used a three-character type code AEB for 6HM5, if I'm seeing right.

 

[The code for EC900 (6HA5) is listed as C7.]

 

Yes, you are seeing right, it is AEB. On the other hand, the RCA/Siemens 6HM5 (the ones that sound like crap) has C7. Quite confusing indeed! lol :)

post #3266 of 7489

Perhaps C7 designates the shorter bottle type.

 

P.S. A couple of links for the interested:

 

http://frank.yueksel.org/other/Philips/PhilipsCodeListAB-v10.pdf

http://frank.yueksel.org/other/Philips/PhilipsCodeList.pdf

post #3267 of 7489

I finally received my Voshkods straight outta Mother Russia, they were shipped from Moscow. They're beautiful!


Edited by Sony Slave - 10/3/13 at 2:00pm
post #3268 of 7489
Quote:
Originally Posted by mordy View Post
 

Hi A11,

 

I have a pair of Sylvania 6BE6 that you inspired me to try. Which setting works best for you?

 

Hi Mordy,

 

Sorry for the late response but my spare doesn't match the vibrancy of this thread at the moment!

I mostly use 2/7-strap with my Raytheon 6BE6W, 1/7 is a bit less forward but has others qualities you may discover. =) This still is "my tube of choice" at the moment.

May RCA 6DT6A still haven't arrived. I'll come back later on this one.

post #3269 of 7489
Quote:
Originally Posted by TrollDragon View Post
 

There seems to be a bit of a single channel hum when connecting the Ultrasone HFI-780's @ 35Ω to the LD, so I made a 150Ω attenuator plug to connect up the 'Sones.

Two 150Ω resistors in series with the L+ & R+ signals raises the load on then amp and gets rid of the hum if any of you are experiencing it as well with low Z cans or IEM's

 

The shells were created with a piece of dowel that was drilled, cut off and then a little Dremel application.

The 4 wire braid that was already made up otherwise it should have had a cotton or paracord sleeve, but there wasn't any in the build box.

 

The Attenuator

 

Connected


I also changed the LED to amber when I had it apart, the Blue was just a little too intense.

 

They also make a commercial metal version from 15Ω to 300Ω sold on eBay for those that don't want to DIY.

:beerchug:

 

Great DIY stuff Trolldragon. If you open up an online store, we might get more in touch. ;)

post #3270 of 7489

Just throwing this out there, BUT the HD800 doesn't do so bad on the MK1+

 

I just finally bought these today (damn you brick and mortar boutique audio shops!) and while my Schiit stack and o2 power these well enough (I first heard these on a Taboo III) the baby Little Dot holds its own even in low gain! The detail level is similar to the o2 combo and Schiit Magni and Modi stack. SO just saying, I think this little guy will scale a bit if I fed it better. Anyone have a super nice/expensive/amazing DAC feeding the MK1+? What did you think?

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