Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › Analog Squared Paper Discussion Thread.
New Posts  All Forums:Forum Nav:

Analog Squared Paper Discussion Thread. - Page 10

post #136 of 3536
I thought this might be a useful site to share as it has great descriptions on the various sounds different tubes/valves have between brands. So far his descriptions have been spot on from my experience!
http://www.audiotubes.com

And to save time I include here a segment from his site on the varying differences in sound style between brands..


"OK, SO TELL ME HOW THEY SOUND!!

A tough question if there ever was one! The best advice is to get a few types and hear for yourself the good sounds you have been missing. All of these vintage tubes are excellent, much better than the Russian or Chinese yuck that is being made today. When replacing any stock Russian, Chinese, or East Europe tube with any of these vintage NOS types, you will notice immediately that the midrange glare is gone. Gone too is that honky, boxy quality, and the tiring upper midrange screech that current production tubes are famous for. Here are some VERY GENERAL observations about some of these vintage tubes:


TELEFUNKEN, SIEMENS, VALVO, LORENZ, and other German made NOS: These tubes are usually characterized by an impressive open "air" at the top end. The soundstage is large, even in mono applications these tubes have a great 3-D image. The midrange is ruler flat, and the bass is tight and accurate. These tubes have a fine sense of dynamics, and most are impressively quiet. These are not "warm" tubes, and to some ears their lack of midrange warmth may be heard as bright. I tend to think of them as accurate, and their clean, focused sonic image is astonishing. My personal favorites. The top types are as would be expected: the 7308/E188CC, the Cca, and the 6922/E88CC. The Cca is a very special 6922 made for the German government for telecommunications. They are excellent tubes, as good as any 7308. By the way, the 1970s versions of these brands are excellent as well, in spite of some trashing on "Some Guy's Tube Lore" and other web pages. Don't let anyone tell you what tubes you should like and what you should not like!


AMPEREX, PHILIPS, MAZDA and other Holland/France/Belgium made NOS: These tubes are a great balance of a clean, airy top end, nice midrange warmth, and accurate bass. They are very pleasant, clean, and musical to listen to in hi-fi applications. The white label Amperex PQ type or USN-CEP (same tube, the USN was made for the military) made in the USA are considered one of the best 7308 or 6922 types of all ever made. The D-getter and pinch waist rare types are also highly regarded, and are very quiet as well. The orange label types run a close second. Look for the white label USA and Heerlen Holland factory made for other brands. They are the same tube and usually less expensive than those with the Amperex or Philips label! Finally, Philips (the parent company of Amperex) owned a number of tube brands, and many were never seen outside of Europe. Most were actually made in the same Heerlen, Holland factory that turned out the Bugleboy 6DJ8 and PQ 6922 Amperex. Watch for tubes labeled E88CC with brands like Valvo, R/T, RTC, Miniwatt, Dario, Philips, and Adzam. These tubes are identical to the Amperex PQ and Philips SQ (Special Quality) types more often found in America, and are perfect if the Amperex is not available, since they sound and look the same. Also rare in America are these same brands made at the Philips-owned Mazda factory (La Radiotechnique) in Suresnes, France. These usually have a capital "F" in the second line of the date code. They are sweet like the Holland tubes, with a bit better detail and punch at the top end, and still have nice balanced warmth. We are one of the very few worldwide tube dealers to offer these rare NOS French Philips tubes.


MULLARD, GENALEX, BRIMAR, and other British made NOS: Like a warm British jacket of the finest tweed, these glorious tubes have an attractive sweet warmth in their midrange and lower regions. The top end is silky and pleasant, without being rolled-off. The best of these tubes retain a fine sense of "air" at the top, and the upper midrange is smooth and liquid. These tubes reproduce the human voice, especially female voices, with haunting realism. The 1970s Mullard made have an attractive sparkle at the top with the rich bass, and these tubes are usually priced less than the older types.


RCA, RAYTHEON, GE, SYLVANIA, and other USA made NOS: This group is very diverse. The older RCA, GE, and some other brands of 6922, 7308, and 6DJ8 were often made by Siemens, Mullard, or Amperex, and usually are a bargain. The USA made 1960s vintage 6922 and 7308 are nearly always made for the military, although there were some early industrial versions made by Westinghouse and other brands. They are fairly good and usually priced very low. Their sonics are reasonably well balanced. The 6DJ8 tubes made in the USA, and the 6922 or 7308 USA tubes made AFTER 1975 are generally best used in test equipment that calls for them, as they are not particularly attractive audio tubes. The earlier 1960s versions are somewhat better, including the greyglass GE. Their prices are usually very low, putting them on par with the Russian or Chinese types. You may want to try them if on a strict budget, for they will surely outlast several sets of current production tubes, and probably still sound better than the Russian-Chinese trash. Overall, the USA made tubes are a nice surprise with their low prices as compared to the European types."
post #137 of 3536
Another day, another post from me, please tell me if this bores you, I will stop, I promise!

So, awaiting me today, beautifully packaged from an Italian seller on eBay were my pair of Lorenz 1T4 tubes. Having learned my lesson they are as I type getting some hours on them before I comment on the sound so instead of that I thought I would describe my process in preparing NOS tubes for use in my amp.

Over the years of sitting in their boxes the pins of the tubes get oxidized so it is good practice to remove the oxidization from the pins so as to give a good contact and thus reduce any possible noise from dirty contacts. Likewise it helps with the tube bases remaining clean in the amp I feel.

I have taken a few pictures to show you the tools of the trade so to speak and before and after of the pins. I use 99% alcohol that you can obtain from pharmacies you could use deoxit as well but it is very expensive and having used a little bit of a friends I personally cannot hear any difference between it and just plain alcohol! Also needed is one of those $1 nail buffers, they are very very fine, mine has a green side which is slightly more abrasive and a white side which is finer. I tend to just stick to the green side.

I cut small pieces off it so that I can get behind and in between the pins and then using gentle broad strokes use the larger piece to clean the outside of the pins.

BE VERY GENTLE! It takes little or no pressure to remove the oxidization, one tube from start to end takes only a few minutes. I finish off with a small microfibre cloth such as you get with spectacles wrapped around a tooth pick dipped in the alcohol to remove any deposits left on the pins such as grease or oxidization debris.

The tubes are then ready for action! This may seem a complete faff but I just think it is good housekeeping and helps the tubes perform at their best, after all, the pins would have been shiny and clean in the first place!
Here are some pictures of the tubes and packaging. Apparently the Stuttgart made Lorenz tubes sound the best and these ones are Stuttgart made! I love the little guarantee that they are wrapped in!

Final picture is of the nail buffer I use and the tubes before and after, I think you can see easily the difference! Hope that helps anyone like me new to this tube malarkey biggrin.gif





And the difference between cleaned and as they come.

post #138 of 3536

ianmedium,

 

That's quite a transformation from oxidized to clean pins and very easy to spot the difference. I must admit to not bothering with pin cleaning but your photo has inspired me to do so henceforth. Please keep up the good work posting!

 

Cheers,

 

Andy. 

 

Quote:
Originally Posted by ianmedium View Post

Another day, another post from me, please tell me if this bores you, I will stop, I promise!

So, awaiting me today, beautifully packaged from an Italian seller on eBay were my pair of Lorenz 1T4 tubes. Having learned my lesson they are as I type getting some hours on them before I comment on the sound so instead of that I thought I would describe my process in preparing NOS tubes for use in my amp.

Over the years of sitting in their boxes the pins of the tubes get oxidized so it is good practice to remove the oxidization from the pins so as to give a good contact and thus reduce any possible noise from dirty contacts. Likewise it helps with the tube bases remaining clean in the amp I feel.

I have taken a few pictures to show you the tools of the trade so to speak and before and after of the pins. I use 99% alcohol that you can obtain from pharmacies you could use deoxit as well but it is very expensive and having used a little bit of a friends I personally cannot hear any difference between it and just plain alcohol! Also needed is one of those $1 nail buffers, they are very very fine, mine has a green side which is slightly more abrasive and a white side which is finer. I tend to just stick to the green side.

I cut small pieces off it so that I can get behind and in between the pins and then using gentle broad strokes use the larger piece to clean the outside of the pins.

BE VERY GENTLE! It takes little or no pressure to remove the oxidization, one tube from start to end takes only a few minutes. I finish off with a small microfibre cloth such as you get with spectacles wrapped around a tooth pick dipped in the alcohol to remove any deposits left on the pins such as grease or oxidization debris.

The tubes are then ready for action! This may seem a complete faff but I just think it is good housekeeping and helps the tubes perform at their best, after all, the pins would have been shiny and clean in the first place!
Here are some pictures of the tubes and packaging. Apparently the Stuttgart made Lorenz tubes sound the best and these ones are Stuttgart made! I love the little guarantee that they are wrapped in!

Final picture is of the nail buffer I use and the tubes before and after, I think you can see easily the difference! Hope that helps anyone like me new to this tube malarkey biggrin.gif





And the difference between cleaned and as they come.

post #139 of 3536
Thats great Andy! With dirty pins I used to experience an occasionally sound a bit like tissue paper being scrumpled up, clean pins got rid of that!

I am really looking forward to your sonic impressions as well.
post #140 of 3536
OK, I have been listening and burning in the Lorenz's since friday afternoon, they now have around 14 hours on them so I can now comment as to their sonic traits.

A reminder that the constant is the Mullard 3S4's in the power section.

So, what do the Lorenz's bring to the table? Firstly the desire to hunt out the remaining and very rare ones so I never run out of them! I am just thankful that this type of tube lasts a long long time!

They seem to have the best of all worlds, incredibly transparent and open revealing every detail you could ever wish for and yet smooth, liquid mids and trebles. These are the most lifelike tubes so far in representing the voice and musical instruments.
They also compliment the Mullards perfectly, adding to the bass depth but so cleanly and with no bloat or exaggeration. Just oodles of deep, clean bass to underpin the mids and treble.

There is an almost mystic feeling to music, how layers are unveiled to reveal the story, how each instrument is able to be heard in complex arrangements and yet feel at the same time cohesive and as a whole.

Absolutely black sonic background, zero noise can be heard even on my most sensitive IEM's

I am at the moment hunting out a pair of the 3S4's in these, they are though rare as hens teeth!

All I have coming at the moment now are some La Radiotechnique 3S4's to see how they perform in place of the Mullards.
post #141 of 3536
Hello, my name is Ian, and I have an addiction...blink.gif



And the tubes currently in place and giving me so much musical enjoyment...Mullard and Lorenz combination (and yes, I know, I have to line up one of the very expensive tube dampers!)


Just a note, there is no noise or ringing even without the dampers on the tubes but I have found they add a little more to the sonic experience in a positive way so I kept them on. I will at some point get some silicone O rings from my plumbing store, for appearance rather than anything else as these tubes don't generate any heat to speak of.
post #142 of 3536
Looking at my previous post I realized how tacky looking the green rubber bands are so I popped into my local plumbers today and for the princely sum of $2 obtained four Silicone O rings to replace them with!

Through some online research I found that placing them around the bottom mica sections inside the tubes gives the best performance so this is what I have done, by the way, though it looks like the left hand side ones are touching they are not, just camera angle!

So that looks better, have yet to listen to see if the shape and material make a difference in sound but as I said in my previous post thought not big it does feel like a positive slight difference in sound!

post #143 of 3536
Come of folks, lets see some other impressions of this lovely amp other than mine!

Today I received the La Radiotechnique 3S4 tubes and they are currently burning in. I will report back once they have ten hours on them!
On a side note I am really excited as I have bitten the bullet and managed to score one of the last HiFiman HM-801's for sale new, should be here by the end of the week so I am really looking forward to what that sounds like over the current source I have!
post #144 of 3536

Saw this on Analog^2 Paper's FB Page:

 

"300B ロフチン white made for direct connection amplifiers for sale. Price is ¥ 200000 around.

Pull the auction so up for auction on the tender ahead of contact to I will sell it. Is a rich amp to 150000 yen as raw material costs alone. Proceeds will be equipping A2P.
Please consider it. W, iPod Dock with it is 8 W+8. ( analog connections.
I sell the vacuum tube Integrated Amplifier 6SL 7 + 300 B.
This is made personally 2008, It's one in the world.
Price is about 200000 yen.
It is a high-quality amp that material cost 150000 yen. Please contact if you are interested! (Translated by Bing)"

 

 

*

post #145 of 3536
Just saw that myself, I have seen it on his website before as well, it looks a fascinating bit of kit but I think I would want a good dac like the solo attatched somewhere for the classic to plug into as it seems a shame to feed such a great looking amp direct from an iPod. I wonder if it has a line out round the back?
post #146 of 3536
Quote:
Originally Posted by ianmedium View Post

Come of folks, lets see some other impressions of this lovely amp other than mine!

Today I received the La Radiotechnique 3S4 tubes and they are currently burning in. I will report back once they have ten hours on them!
On a side note I am really excited as I have bitten the bullet and managed to score one of the last HiFiman HM-801's for sale new, should be here by the end of the week so I am really looking forward to what that sounds like over the current source I have!

 

You're probably the only person who's got this on head-fi :p. Anyhow, I dropped a mail to Shikada-san and hopefully I'll get a sample TU-05b and TUR-06 to test. I'm a little worried about the preset gain setting as I've pm-ed you about the issue I encountered a few weeks back.

post #147 of 3536
Excellent Anak. I am really looking forward to your thoughts on them both. I would ask him to send you units with gain suitable for the headphones you use see what he has. On the subject of gain I had one of those nice little audio moments yesterday! Oh yes, there are at least two others here with the amp.

I had been using my LCD's and had set the amp to mid gain (16~120ohm) but then yesterday plugged in my preferred earphones, the piano forte's which are 16ohm impedance. I normally have them on the low setting (8~32ohm) but yesterday I forgot to switch the gain setting so was listening to them on the mid setting.

I did not realize this but was listening and thinking, eh, something has changed, the music feels more effortless and the detail and bass seem to have gained slightly. At first I just thought it was the effect of burn in but then I saw the gain switch!

So I did some experimenting by changing the gain setting back and forth (Very Very important, make sure you unplug your headphones before switching the gain!)

Its difficult to A/B as you have to wait for the tubes to warm up a little but having said that it was a noticeable thing and so now I have my amp set at mid.

Likewise, not all tubes are the same. I had ordered a little while ago so extra sets of Mullards both DL92 and DF91. The DF91's arrived this week and are far better than the original set of DF91's I got a few weeks ago, clearer, deeper base and more melodic. Up till this happened I had been really enjoying the Lorenz/ Mullard combination but with these new ones in I have reverted back to an all Mullard set of tubes and very much enjoying it!
Edited by ianmedium - 2/28/13 at 3:30pm
post #148 of 3536
I thought it time to post a more comprehensive review of the amp now that it has got a good number of hours on it and I have settled on two tube combinations. Also, hopefully this week a new and unfamiliar source is due to land at ianmedium towers so it is going to take some time to get used to its sonic signature before I can do more reviews!.

I hope you enjoy and I am really looking forward to other owners reviews so as to balance my thoughts out!


Review of the Analog Squared Paper TU-05 transportable Tube amp..


I thought is was time to do a more comprehensive review of this amp as I have now 7 weeks and around 250 hours use of the amp under my belt.

This review will be based upon using non standard tubes. There is nothing wrong with the sound of the stock tubes it comes with. If I had not heard another tube I would have been happy with the sound of the Tung Sol/ Sylvania combination that Shikata San provides with the amp. However they are I have found somewhat microphonic and even with many hours use that never really subsided.

One of the many great things about this amp is the tubes it uses! They were designed for old radio sets both domestic and military and so were made in very large numbers and thus are relatively cheap to buy so you can afford to tube roll to your hearts content (I know I did!) To give you an idea and set of four Mullards tested NOS came to less than $40 including shipping.

More on tube rolling in a little while but first initial impressions of the amp.

Shikata San builds these one at a time and to your individual requirements if necessary but to call this amp a product of a DIY builder earning a few bucks on the side would do a great injustice to both Shikata San and his amps.

I prefer to think of the maker and company as a bespoke audio company crafting beautifully made amps for people who's main motivation is to extract the most from a musical performance.

This is definitely a niche product and will not appeal to many. It is not a bass lovers amp. If you like thumping bass look elsewhere. It is most certainly hand made and all that comes with a hand made product so if your looking for paper thin joints in the case work look elsewhere. Having said that the case is beautifully hand crafted, solid and looks wonderful to my eyes. One thing more about the case. It is something that requires some sort of stabilization so as to prevent it toppling over. I cobbled together with wood a frame to hold it in and to isolate it. (Isolation has become less important with different tubes but if you use the stock ones you will need something like cork or sorbothane under the amp to help with microphonics).

Inside though is where it is at! Everything is beautifully laid out and hard wired. Top quality components are used with note especially to the stepped attenuator which is the best volume pot I have used. Even with sensitive IEM's there is no channel imbalance at low volumes.

Oh yes, this amp does something that I have not seen in any other class A all tube amp and that is drive low impedance headphones, right down to 8 Ohms!

You have to treat this amp somewhat like you would a low powered SET amp in that the headphones you use need to be carefully matched to the amp. This is not a huge issue unless your headphones are rated over 200 Ohms as this amp does not drive headphones with greater than that.

I really encourage you when ordering to tell Shikata San what headphones you use. I did and he ended up giving me an amp with two gain settings, Low (8~32 Ohm) and mid (16~120 Ohm) You can also have the option to replace one of those settings with a High setting (64~200 Ohm).

One of the great reviewers here on Headfi, AnakChan tried a demo amp recently at a HiFi show in Japan but experienced a mis-match with headphones and amp that produced distorted bass. I am looking forward to hearing his thoughts on the amp when he gets a proper review sample and is matched with appropriate headphones


I promise that I will come to what this amp sounds like soon but first I want to talk tubes!

I truly feel that to do this amp full justice one needs to hunt out some higher quality NOS vintage tubes. Over the past few weeks I have gone on a binge of tube buying so as to not only get the desired sound for me but also hopefully to help anyone else lucky enough to purchase this amp get the very best out of it.

Now, if the stock tubes were not microphonic I would find them very enjoyable (BTW it has not only been my amp that had microphonic tubes, another member here experienced the same with his) however there are gains to be had in experimenting.

I dont want to say one tube is better than the other but rather say that differing brands bring slight sonic differences to the table. Want a warmer signature? Then go for Mullards, Want more air and treble? Go for German tubes such as Telefunken or the ultra rare Lorenz Stuttgart made tubes ( I managed to score two of these rare beauties for the Voltage gain/ 1U4 stage and am really glad I did!)

Want something a little sweeter combining the best of those two brands then La Radiotechnique from France might be the answer.

Good all-round worka-day tubes that sound great can be found in RCA's or GE's from the US.

I have found two combinations for me that rise above the rest. An all Mullard set up or, my favourite after much switching, Mullards in the power section (3S4) and the Lorenz's in the voltage gain section (1U4).

The Mullards underpin the music with a firm foundation and a deeper tighter bass while the Lorenz's bring speed, detail and air to the mids and treble. This combination is very far removed from what one thinks of traditional tube euphonic sound which brings me to what it sounds like!

Well, in a word, nothing!
I feel this amp is almost transparent, sure it brings traits to music but none that are not already on the recording in the first place. I feel it conveys music authentically. A guitar sounds like a guitar, a piano sounds like a piano, drums.. Well, you get what I mean! Even electronics such as in Kraftwerk's music sounds like electronics.

I find this amp to retrieve details that are deep within the sonic like no other amp I have heard this side of home amps such as Nagra or Naim to name two I have fairly good experience with. But all that detail retrieval is not at the expense of musicality, this is after all, a tube amp!

The ability of this amp to convey the acoustic a recording is made in, the texture of instruments or vocals is very compelling and draws one into the performance so that track after track, album after album are enjoyed until one reaches the point where the battery runs out (around 7 hours)

All of this is accompanied by an inky black, deep background. With headphones in and no music playing it feels like the world has disappeared so deep and black the sonic background is.

Treble is free from any grain, one can listen to a high note increase and never does it break down (unless you push the volume to far!) mids, well, its a tube amp, 'nuff said!

Bass, ah, bass! Now, if your into car door rattling bass then walk away right now, if your into deep deep bottomless bass then sir/madam, here is the door. However, if you like tight, defined, textured bass, bass that has you moving and grooving then this amp will provide you with limitless amounts of the stuff. Bob Marley and the Wailers sounds wonderful with this amp You can hear the distorted bass lines driving the music along and the fun is in hearing so clearly the distortion of the bass not just some wooly blob thumping away!

Acoustic bass has so much texture, notes rise and decay naturally, one can hear the bass's body move as it is played.

Strings are another strong area with this amp. One can tell gut from artificial so easily. The resonances in the body of a violin are conveyed so clearly one can hear them decay within the instrument and the waxy feeling of bow hair against string is tangible.

When it comes to percussion, the sound of a drum stick on cymbal's sounds like wood hitting metal, one can feel the texture of both. Likewise brush work on the natural skin of a drum feels grainy as it brushes against the grain of the skin.

I leave though the best for last and that is vocals.

I love early music the sound of voices in a small church or room unaccompanied are something I have experienced in real life many times and this amp conveys that perfectly I feel. Texture, and I make no apologies for multiple uses of that word in this review, is the thing with a voice.

For the emotion to be conveyed authentically so that one can fully engage with the artist one needs to feel the texture of the vocal, how the voice comes out through the mouth, how the air moving then hits the listeners ears and so engages and emotional response is vital to realistic vocal reproduction I feel.

So often now software is used in mixing to take that texture out and thus we end up with X factor vocals. Thankfully early music is immune to that I have found so that one can feel the resonance of the vocal as it hits the air and your ears hear it, this amp conveys that so well!

I want to talk a little about volume. I have noticed that there are sweet spots for each album with this amp. Take the volume too far and the sonic picture starts to fall apart, take it even further and the sound becomes harsh and glassy. Find the right volume level for each album though and it is magic! Thankfully the optional (read, you have to have this one upgrade if no other!) stepped attenuator is so accurate and does what any good volume pot should do, get out of the way of the signal that achieving the right level is effortless

And so I come to the end of this review. I do want to say again, this amp is not for everyone, in spite of my glowing review there will be many who will not like this amp as it is a gentle amp, not in your face, not a piece of HiFi, it simply gets out of the way so that the music and emotion can flow. It will not command or power, it will not take a vice like grip of music, if that is how you like music conveyed ( and note, I am not saying right or wrong, we all find our musical nirvana in different ways after all) then this amp is not for you.If you like to use a wide range of different impedance headphones or ones that are power hungry this amp is not for you.


However, if you like music conveyed in a natural way, not emphasized but rather the performance allowed to build and be created before your very ears and you are prepared to go to a little effort in matching headphones and making sure your source and music is of the highest quality (think high bit rate if your using downloaded or ripped from CD music) then this amp may be for you.

If your prepared to think of this amp as transportable rather than portable and battery life and size and weight are not issues then this amp I feel might be right up your street!

Combine that with the utterly delightful experience in dealing with the affable Shikata San and the thought that your amp is designed for your needs and the sheer quality of build and sound and I feel this amp at just over $1000 is somewhat of a bargain!
Edited by ianmedium - 3/3/13 at 9:30pm
post #149 of 3536
An awesome & most enjoyable read Ian. I feel I can understand your experience with the amp from your descriptive impressions. This is irrespective of me having a quick demo of one.

Despite my less than positive experience, I'm pretty sure it was a once-off anomaly & have high hopes for this amp & its little newer brother, the TUR-06. Looking forward to the day I can try this out myself for an extended period.
post #150 of 3536
Thanks so much.
I am really looking forward to your impressions of the amp as well. If you can get hold of a set of Piano Forte's even if they are not fully your cup of tea I would love to hear what you think of the combination. The amp drives my LCD 2's well as well though there is a little of the magic lost in comparison the the PF's

I think it must be in part due to the Horn characteristics of the PF's that match the tubes so well
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Portable Headphone Amps
Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › Analog Squared Paper Discussion Thread.