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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 272

post #4066 of 10575
Quote:
Originally Posted by mkrzych View Post

Amazing guide!


Hi mk.

 

Hope you've been able to keep up with the lightning-fast progress of recent times! Who would have thought the humble LD could reach such heights?...Long may it continue. But surely we must be reaching the outer limits of what is achievable? Every time I think we have, another milestone comes along - what a great bunch of guys on this thread!!

post #4067 of 10575

For my next adventure in sub-miniature land ............

 

 

 

These are Raytheon CK5702 pentodes.

 

 

These work like all the regular pentodes we used to use. EF95 setting and I manually tied grid 3 to the cathode.

Initial impressions are that it sounds similar to the 6N16B twin triode I tried before. That is clear, forward mids that make vocals sound very good, sparkly highs, well defined soundstage, and all-round very smooth sounding.

post #4068 of 10575
Quote:
Originally Posted by gibosi View Post
 

In 2006, a guy with the handle Sir.Richard wrote that in his opinion, the Sylvania 6SL7WGT Gold (JAN-CHS-6SL7WGT) was the best of the breed. Of particular interest to me is this comment:

 

".......puts you front and centre - like the main instruments are just a couple of feet ahead of you -
forward of the speakers. Excellent depth and detail and solo instruments and classical music just

come alive. A real eye opener when you listen to these." 

 

http://www.head-fi.org/t/100774/top-5-6sn7-s#post_2011240

 

It seems quite likely that this Sylvania has a very different sound signature, perhaps a better match for my headphones, and so earlier today, I purchased one. :)

 

This is much better! :)

 

Sylvania Gold Brand - black plates, brown base, gold print (faded to white?) on tube, D-getter with top getter splash. There are no discernable date codes, but it appears safe to assume 1950s.

 

$(KGrHqNHJBMFJG!bYkoIBSUzecl,B!~~60_57.JPG

 

It was listed as NOS, so figure I need to burn it in before coming to any real conclusions. But my initial impressions are positive. From Sir.Richard's description above, I was a little concerned that this Sylvania might be too bright, but to my ears, the tonality seems about right, brighter than the Tung Sol, but definitely not too bright. I am not hearing anything I don't like, but it is too soon to say just how good it is.....

 

Edit: To clarify...

 

Sylvania 6SL7WGT Gold Brand was the consumer version and JAN-CHS-6SL7WGT was the military version - they appear to be same tube.....


Edited by gibosi - 11/22/13 at 6:45pm
post #4069 of 10575

Re: Sylvania GB-6SL7WGT / JAN-CHS-6SL7WGT plus some observations regarding octals and 9-pin miniatures....

 

I now have three octal double triodes, two Tung-Sol and one Sylvania, and in my mind, what really distinguishes these from the 9-pin double triodes is the bass. These octals have noticeably more bass presence. Kick drums are reproduced with considerable weight and punch. And the bass is also quite warm and wet, in the sense that reverberation creates the sensation of being in an enclosed performance space. This reminds me a bit of the difference between bass-reflex and acoustic-suspension loud speakers. Bass-reflex speakers typically produce more volume, but acoustic-suspension speakers often can provide more detail and sub-bass. In the end, neither of these designs bests the other in every category, and "best" is typically a matter of personal preference.

 

The Sylvanias feel to me like a good bass-reflex speaker system. The enhanced bass creates a sound that is enveloping and quite pleasant. Further, although I have not had a chance to compare it directly with the best of the 6DJ8, the Sylvanias are very quiet and have a nice 3-D sound stage, with good detail. Admittedly, I have not been able to spend a lot of time with this tube, but I am very impressed with it so far, and I would be interested to hear what others think.

post #4070 of 10575

Back to 6DJ8/ECC88 land...

 

Methinks I may have found a fierce competitor to the amazing Voskhod 6N23P - the Telefunken ECC88. At first I thought the bass not quite as hard-hitting, but later realised it was in fact giving a good bit more detail - more than I have ever encountered before, and I just love it. The high detail is also present throughout the other frequencies, and the soundstage is truly all-encompassing. As more tracks of Genesis/Duke are hitting my ears, it's getting harder and harder to concentrate on this post - that happens only VERY rarely, and hasn't for some time now...I think that must speak volumes - for me at least. I actually believe I may have (this time!) finally found my Nirvana. For everything to be sounding 'together' in such a way without the need for further analysis is almost making me cry - and I don't even care if that makes me sound naff!! All I can hope is that you all manage to find tubes that elicit the same response on such a deep (emotional) level...and that's from someone who is a natural-born analytical pessimist!

 

Enough already...time for tea, and a break from all this emotion - am not used to it!!

 

Happy rolling, everyone.

post #4071 of 10575

Re: 1950s Tung-Sol JAN-CTL-6SU7GTY and Sylvania GB-6SL7WGT / JAN-CHS-6SL7WGT

 

I have been listening to both of these octals this evening, and they are much more similar than I originally thought. I now realize that these octals need more gain than the 6DJ8 and 5751. That is, if you set your LD at 12 o'clock for 6DJ8s, you will need to set it at around 1 or 2 o'clock to achieve a similar volume with these octals. The other day, when comparing the Tung-Sol to the 6DJ8 and 5751, I was mislead by the fact that the Tung-Sol's bass is stronger, and I kept the volume at the same level. And of course, in hindsight, vocals through the Tung-Sol seemed too laid back. Now, comparing the Tung Sol and the Sylvania, yes, the Sylvania is brighter than the Tung-Sol, but not by that much. So to those of you who quickly jumped in and ordered the Tung-Sol, I think you will find it to be an excellent tube. And if you have already ordered the Sylvania, it too is excellent. :)

post #4072 of 10575

Hi Hypnos1,

 

Are these tubes them?

 

 

 

Cost: $399.00

post #4073 of 10575

Exploring various 12AX7 tubes. So far tried the following Sylvanias which all should be from the early 60's: 12AX7A, 12AU7A, 12AZ7A, 12AT7, 12BY7A. Did not like any of them, except for the 12AX7A which is excellent.

 

Next tried a Japanese 12AX7/ECC83 tube made by National/Matsushiiita. Tube looks well made with a 45 degree circular getter (tipping the hat to the Philips people? [Oskari, I looked it up, did not want to call it by the wrong name]) Sound is detailed but thin and light with weak bass - not for me:

 

 

 

How about a modern Russian tube? But first a little information on Ruby tubes. This company is a Chinese re-brander that caters to the electric guitar crowd, and apparently many guitar players like tube amps. Ruby is a re-brander with a twist: They carefully test their tubes before they put their labels on them, in this case on the box.

The tube I got is a Russian Sovtek 7025 /12AX7WA. Ruby calls it 12AX7AC7 HG+ which is a mouthful, so will just call it Quicksilver:

 

 

One unusual feature is that it looks like the mica plates are made of see through Lexan plastic or something similar. The sound is pretty good, but I get the impression that it needs a very high volume to come to it's forte (think electric guitar concert). Too few hours to come to a conclusion, but maybe promising.

 

Also waiting for my first octal tube. It almost arrived Friday, but was mistakenly sent to the next postal district for delivery, and then rerouted when the mail carrier could not find the address. Hope they don't send it back to Florida before it comes back here. Oh well.....

post #4074 of 10575
Quote:
Originally Posted by mordy View Post
 

Hi Hypnos1,

 

Are these tubes them?

 

 

 

Cost: $399.00

 

Hi mordy.

 

$399? Are you kidding?!! Mind you, it's nice to know my used ones at a fraction of the cost are in such hallowed company. NO tube is worth that kind of money in my book...

 

But yes, they're the ones - except not enough of the writing is left to discern the date...shame. So the moral to everyone is...wait until some decent used ones come along. All I can say is the wait should be well worth it.

 

As an update to my previous post, with further settling in (even though they are used, they really improved after several hours - perhaps the cleaned pins (not that they were badly corroded) needed the extra time) they have trounced the Voskhods. After the emotional response - which perhaps is the best judge? - my analytical side is kicking in (it needs to make sense of that emotion - leopard/spots?!)..

 

Anyway here goes :

 

Bass - As mentioned before, DETAILED. But add MORE extended than the Voskhods even. Tight? - Ouch! And never drowns other frequencies. Have never before felt it in my bones to this degree...

 

Mids - All there. Wonderfully detailed, clear/clean, without the tendency to be over-'lush' as can happen with so many of the Philips group variants. Even the lower mids/upper bass of acoustic guitar (via Clannad's PastPresent) had my bones tingling...

 

Treble - 'Scintillating' would be the first word that comes to mind (being emotional again!). OK, back to analytical : Extended; clear; massive detail/variety throughout the entire high frequency range, with a delicious decay to cymbals etc. Again, as with the bass, without imposition and no undue sibilance.

 

Soundstage - Wide and deep; instrument separation clearly defined yet nicely integrated; vocals positioned so as to sound 'intimate' without being TOO forward - all in all wonderfully 3D, with the (for me) vital sense of 'airiness' and space.

 

Transients - This is an area that until now I didn't really grasp or appreciate. I think I have suddenly been enlightened - if I'm right, they impart a magical ingredient to music enjoyment, viz : sudden, fleeting sounds that hit your senses and have you wondering "where on Earth did THEY come from?". I suppose it's an extension to overall detail, that otherwise would just get lost in the 'jungle' of sound. Whatever, tracks that I thought I knew well are in some cases sounding vastly different - depending, presumably, on the recording engineer's prowess...

 

And all these elements mesh together - in a beautifully silent/clear backdrop - to a degree that seems faultless, and in a way (with my setup anyway) that far exceeds anything I have ever encountered in these past months of trying countless tubes (but not as many as others, I have to admit).

 

Hopefully I have given a true and fair view of these particular tubes, and trust that anyone else lucky enough to find some at a reasonable cost will have a similar eureka experience - mine appears to be similar to AFB and Gibosi with their early '60s Amperexes...This (seemingly) long journey has been WELL worthwhile - thank goodness!!

 

Edit - As an added bonus, these tubes are now making my HD650s sound just as good as (the memory of) the MUCH more expensive 700s...


Edited by hypnos1 - 11/24/13 at 8:19am
post #4075 of 10575
Quote:
Originally Posted by mordy View Post
 

Exploring various 12AX7 tubes. So far tried the following Sylvanias which all should be from the early 60's: 12AX7A, 12AU7A, 12AZ7A, 12AT7, 12BY7A. Did not like any of them, except for the 12AX7A which is excellent.

 

Next tried a Japanese 12AX7/ECC83 tube made by National/Matsushiiita. Tube looks well made with a 45 degree circular getter (tipping the hat to the Philips people? [Oskari, I looked it up, did not want to call it by the wrong name]) Sound is detailed but thin and light with weak bass - not for me:

 

 

 

How about a modern Russian tube? But first a little information on Ruby tubes. This company is a Chinese re-brander that caters to the electric guitar crowd, and apparently many guitar players like tube amps. Ruby is a re-brander with a twist: They carefully test their tubes before they put their labels on them, in this case on the box.

The tube I got is a Russian Sovtek 7025 /12AX7WA. Ruby calls it 12AX7AC7 HG+ which is a mouthful, so will just call it Quicksilver:

 

 

One unusual feature is that it looks like the mica plates are made of see through Lexan plastic or something similar. The sound is pretty good, but I get the impression that it needs a very high volume to come to it's forte (think electric guitar concert). Too few hours to come to a conclusion, but maybe promising.

 

Also waiting for my first octal tube. It almost arrived Friday, but was mistakenly sent to the next postal district for delivery, and then rerouted when the mail carrier could not find the address. Hope they don't send it back to Florida before it comes back here. Oh well.....

One of the octals i just bought as that see thru mica as well . I am not lucky also been waiting for a month for sockets from China probably wont get them i asked for a refund at this point went to fast dough i could of gotten them at PARTS CONNEXION but forgot about them a well.should get the sockets this week and get this show on the road .Got almost all my tubes waiting for orange globes.

post #4076 of 10575

Thought of something that may be a little crazy:

 

http://www.radiodaze.com/images/thumbnail/IMGP3368.JPG

 

Here is the Vector 7 pin adapter. By using two of them we can connect a 9 pin socket with a 12AX7 or 6DJ8 tube and listen to double triodes. In doing so we are using some of the numbered tabs on the adapter.

 

What would happen if I stuck in a pair of say 6HM5 tubes in the adapters and used them together with a 12AX7 tube? Would the amp blow up?

post #4077 of 10575
Quote:
Originally Posted by mordy View Post
 

Thought of something that may be a little crazy:

 

http://www.radiodaze.com/images/thumbnail/IMGP3368.JPG

 

Here is the Vector 7 pin adapter. By using two of them we can connect a 9 pin socket with a 12AX7 or 6DJ8 tube and listen to double triodes. In doing so we are using some of the numbered tabs on the adapter.

 

What would happen if I stuck in a pair of say 6HM5 tubes in the adapters and used them together with a 12AX7 tube? Would the amp blow up?

 

ahaha... I cannot believe that this could be anything other than BAD! But if you want to try it, please do let us know what happens! :)

post #4078 of 10575

Yeah, I'd vote for answer B here: an explosion!

 

Hell, if you really want to try something new and different, here's an idea: let's try to use a 2C51 double triode adapted on two Vectors or the usual breadboard!

 

Anyone have a Western Electric 396A lying around, so we can try the best tube in that family right away lol?

post #4079 of 10575

I received a nice little package today....

 

 

The tube on the right is a DARIO / RT / La Radiotechnique E88CC manufactured in the Philips-owned Mazda factory in Suresnes, France. Tube code is F7B1, so manufactured in February, 1967. And it appears that it was silk-screened and packaged in February, 1968 (6802). 

 

And the vendor threw in a free Tesla E88CC with gold grids! What a nice surprise! :)

post #4080 of 10575
Quote:
Originally Posted by Audiofanboy View Post
 

Yeah, I'd vote for answer B here: an explosion!

 

Hell, if you really want to try something new and different, here's an idea: let's try to use a 2C51 double triode adapted on two Vectors or the usual breadboard!

 

Anyone have a Western Electric 396A lying around, so we can try the best tube in that family right away lol?

 

Ummm... How serious are you? 6.3 volts... .3 amps....  I could certainly do this very easily with my Vector-breadboard adapter.....  

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