DIY Audio Blog

DAC and EM4 Progress

2012-02-01T12:30:00.001+11:00

Currently listening to Norah Jones'Come Away with Me on the iPhone and all I can say us that the sound is warm, effortless and intimate.What more can I say about it? The other night I was walking home and listening to Muse's Resistance and let's just say that the hairs in the back of my neck was tingling. Amazing.

My search now turns back to a suitable DAC. The long term goal us to have a computer based system with a DAC and headphone amplifier. Nothing special. The quest to search for the right DAC had led me to a few thoughts. Firstly computer technology changes faster then audio. In the sense that DAC technology moves relatively slowly. Bit USB or firewire changes much faster. And on that vein I have decided to separate the computer souse to the audio side so to speak. That is to get a USB or firewire to SPDIF or other interface without a DAC separate. This results in two points, one more box and the ability to greatly choose the best suited DAC available. One possibility is that I can then use the twisted pear audio buffalo, which is sitting waiting to be put together. Another alternative its to get a DAC that has digital output as well which allows me to choose which to use.

In the initial search for a computer to digital audio interface, leads to a few very standard offerings. M2Tech, SoTM, Lindemann, Halide, Wyred4sound, Audiophileo, Musical Fidelity, Berkeley Audio, and others. However the choice of this CDI is somewhat dependent on the choice of the DAC itself due to the interface type it can accept. For example the halide and Evo had only a single output, coax it RCA. Whereas the V-DAC has more. But at this point the most relevant question is whether or not I ever want to use DSD format. But that is almost another topic unto itself. So for the moment I will continue to enjoy the music whilst the search continues.

Software Players and some further thoughts

2012-01-28T02:49:00.000+11:00

I finally had a chance to try out some Mac software to improve the playback experience. In my quick test and review, I had the chance to use Pure Music, Audirvana and Decibel. The setup was my EM4 connected to the Calyx Coffee which was USB connected to MBP. All files were 16/44.1 Apple Lossless, ripped from CD via MAX, and a two tracks from HD Tracks in 24/96 FLAC files.

Very quick impressions of each so far, using the same 6 or so tracks. Decibel has a very laid back, flat sound. To my ears, using this combination was a tad boring, I also had some initial problems getting sound out of it, and after changing a few options, got it to work. Pure Music was a lot better in this regards. But overall, I found this setup to work really well with Audirvana. It was powerful, dynamic and engaging. I kept wanting to switch back to this player after listening to the others. This must be a good sign. This was a very quick review of all three software; and I really wanted to like Pure Music. But it didn't seem like a huge step up from iTunes itself; and I found the interface not to my liking. Although it is very powerful; the set of features that I would use will be limited.

Amarra is something to test next, as I just downloaded the 15 day Mini demo. Not sure when I will get another chance to have some dedicated listening, but I hope it will be in the next week, before all the other demo licenses wear off.

I also had the chance to do a direct comparison between 16/44.1 and 24/96 using one track, REM's Losing My Religion. The first basic impression was that the 96 had more detail and definition to the sounds and instruments. More dynamics and separation, which must be a good thing, cause I found the 44.1 very flat after listening to the higher res version. At lower levels, the differences were as pronounced, but as you cranked up the volume, the differences became more audible. I ask myself whether this would affect the overall enjoyment? Probably not. But then when you are not just listening for enjoyment and relaxation; and more about review, examination and appreciation; I think the differences would be worthwhile. I also found that the sound stage was a little larger with the 96 version. The 44.1 was well inside my head between the ears, and the 96 was more wider, and more around the ears, rather than between.

Anyway, more to come late, and I hope to put some photos of the current setup...

After 100 hours...

2012-01-23T01:59:00.001+11:00

It has been around 100 hours now, with several overnight burning in sessions on the EM4. The result? I can use the words; effortless sound, authority, control and articulate to describe the sound of these IEM. Listening to my very well worn mix of 10 or so songs that I have used in the last year or so to compare all my headphone listening, has demonstrated a sound more akin to the HD650, then any other IEM I have used (which is only two pairs). In terms of the imaging, it definitely is not 'in ear', but much more, around the ear. As such, very natural, and not like someone injecting sound into your ears.

To use the well worn phrase, "I have heard stuff that I have never heard before", would be true in this case. not just new sounds, but the same sounds sounding different, or more truthful to the recording. At this stage, there isn't a lot that I can find fault with them. I don't find these to be warm or dry. But it just feels like the right mix - the right sound.

What I can say is that during the burn in, over the last two weeks, the sound did change up and down by a fair bit, and it seems in increments of between 15 to 20 hours at a time. But right now, with over 100 hours, they have not sounded better! I am sure that it will continue to change until they settle down, at which point, I cannot say, but as long as they keep improving!

The biggest question for me was, were they worth the money? And a lot of money it was... The single most expensive audio item I have bought to date! Even my second hand Lowther DX3 were cheaper! Well, given my current circumstance, they are the closest that I will get to audio nirvana. When I am on the bus, or walking, I do feel like I am in my own private studio, listening to amazing music. This is so relaxing, and helps me deal with the hustle and bustle of everyday life. In this way, they are absolutely worth it. Without having to dwell on this too much, I spent the cash, got a result that I am happy with, and is on par, if not better than my previous reference headphones, can't complain!

What a difference!

2012-01-17T12:25:00.001+11:00

What a difference 12 hours of burning in makes. The bass issue I had last night is now gone. Again it is now firmed back up, but still not super tight but much better than last night. Overall the sonic presentation is much better.

Quick thought on EM4

2012-01-16T22:07:00.001+11:00

They now have had around 20 or so hours on them, and want to share a few thoughts. Firstly, I am hearing things on the music that I have not heard before, even withy he HD650, and this is on some very familiar tracks. This is good. Second, the sound is not like the other IEM, which sound like they are inside your ears. These actually like like they surround your ear. Much like the presentation of over the ears. This is a very good pint, as I was looking for an IEM that did not focus the sons into your ear. Thirdly, the guitars sound amazing! The way it strums and the intonation, amazing, best guitar sound from headphones. And also, the way it renders piano and keyboard, you can really tell if the mic was close or far, acoustic only, or with effects. Again, much better than all previous. All of this on my iPhone 4, can't wait to get it onto a proper amp and source!

Now onto the negatives thus far. The bass lost some impact and presence, but I hope that it firms up again after more burn in. And secondly, the isolation is not as good as the HF5, but the fit is so much more comfortable. Well that is all for now, more thoughts later.

EM4 Arrived

2012-01-11T12:44:00.001+11:00

After nearly a 5 week wait, including Christmas, my custom Earsonics EM4 have arrived! Currently listening to them and they have about 8 hours on them so far. Some initial comments. The supplied cable is very light and flexible, and not microphonic at all. But given their more delicate feel, a spare cable is probably a must.

The build quality overall is good. It does look and feel a custom product and I like that kind of design. Gives it some personality. The acrylic is a little cold to put on initially, but after 10 minutes, it feels fine. The fit of the customs are at superior to any of the other two IEM I have used. That is Shute SE210 and Etymotic HF5. Very comfortable and good noise isolation. This is especially good for the public transport system of Hong Kong. All of this was and is through Apple loss lesson my iPhone 4, with no external amp.

Onto the initial impressions o the sound. At first it was a little unbalanced and lacked warmth. But after about 6 hours they have opened up somewhat and definitely sound better the the well burned in HF5 and SE210. The bass is far superior. Well controlled and tight. The trebles are also much better than the HF5, which was itself better than the SE210. midrange is slightly warm so far, but well balanced in the mix, but slightly more forward than the HF5.

Overall, the sonic presentation is similar to my hD650. Which I haven't been able to for three months. As they were left at home. Since I am going to be home in a few months, and by then the EM4 should be well burnt in, should make a good comparison. Is it worth the money? Yes, for me it is on three levels: better fit and comfort; much better then the HF5, and approaching my memory of the HD650. More thoughts to come, as I am now on DAC hunting mode.

Q&A on Violectric V200 and V800

2011-12-05T05:23:00.002+11:00

Another Q&A on the Violectric V200 and the V800 DAC for use on IEMs.

1. For the USB input on the V800, is limited to 24/96kHz. It appears to be an add-on daughter card. In the future will you be releasing a 24/192kHz USB reciever card, and thus, can that be installed as an upgrade to the V800?
[VE] You are right, the USB input is sdituated on a daughter board and may be upgraded.
We intend to refurbish this PCB when a working 24/192 solution is deliverable. Currently it is not.
This new card will also be offered as an upgrade for existing systems.

2. Is the volume control in the V800 using the attenuation within the DAC chip? Or does it attenuate the signal after it has been processed? Where would be the best place to use the volume control? If the V800 is indeed a digital volume, then I'd assum that it'd be best to apply it there at the V800 and leave the V200 fully open?[VE] It seems that you do not share the common often reported issues on digital volume control.
For my opinion digital volume control is better than most analog solutions.
Best would be to position the volume from V200 fully open as here no channel missmatch/crosstalk issues have to be feared.
You can adjust the max. volume by operation the Pre-Gain adjstments from V200 or the max-gain adjustment from V800.

3. Using the EM4, which are 124 dB headphones, I am very concerned about noise, is this combo dead quiet?
[VE] It is !! We have several customers using In-Ears who proved that.

4. Ultimately, is it better, since my source will be a computer, to get the V200 with the 24/96 option instead? Are the DAC different? Will you be releasing a 24/192 USB module forthe V200 later?
[VE] Although the USB transceivers inside the HPAs and the DAC are equal, the overall circuitry differs much.
The USB PCB inside the HPAs offer a DAC called PCM 1793, inside V800 there is a resampling unit to completely remove jitter and a better DAC called PCM 1792.
Together with the daughter board for the DAC we will make a 24/192 board for the HPAs

Q&A for Justaudio AHA-120

2011-12-05T05:15:00.000+11:00

Here are some questions and answers from Justin of Justaudio regarding their AHA-120 and its use with high sensitivity IEM.

1. How is the background noise issue? I am very concerned and sensitive to background noise, and was wondering what are the dB levels or noise?

[JA] Measurements are better than specification - in practice with 6dB maximum gain preset and using sensitive IEM (25ohm, 114dB/mW) noise (hiss) is only just slightly (barely) audible at 80-100% volume control position; So dominant noise will be source/mp3 player.

2. I saw that you do offer a lower gain version for IEM, are there any cost differences?

[JA] Gain jumpers are fitted as standard now, so there is no difference in cost any more if using standard presets (6dB or 12dB).

3. With the pot on the AHA-120, what is the channel tracking like?

[JA] Very good - with new process it is possible to track within 0.5dB by grading the pots.

4. I read somewhere that you were going to release an IEM specific amp, is there a time frame for that, and will it be a Class A design?

[JA] No plans at present.

iBasso D-zero

2011-12-01T17:26:00.002+11:00

Out of impulse today, I laid down some cash for an iBasso D-zero. I really wanted to test out how an amp and USB would perform on the iPhone and iPad, an this seemed to be one of the cheapest solutions. At the same time I got a Fiio line out I connect.

The unit itself seems to be a standard decent construction, nothin terrible or excellent. Good fit and finish. Straight up I plugged her into the iPhone with the line out and started playing music. The phones were the Ety HF5, 105 dB balanced armatures. The gain was set to low. No noise or hiss. That was a great start.

Then I proceeded to play some very familiar tracks through them. The volume control was probably set around 50% or so. First thoughts were better midrange vocals and better extension an control on the bass. That was all I had time for. Now I await the unit to be fully charged and some burning in. But I look forward to more use and integration with the iPad USB. The O2 should also arrive next week, so something to compare.

New Earsonics Headphone Amp

2011-11-30T01:37:00.000+11:00

I just learned (from Earsonics) that there will be a new headphone amp being released by Earsonics, in 'a few days', designed for their IEM. With my EM4 coming, I will eagerly awaiting this product!

Headphone Amp Ordered

2011-11-24T16:40:00.001+11:00

After some quick research, I settled on a pre-built version of the O2 amp, purchased from JDS Labs, an open source headphone amp project. The main reason that I went for this headphone amp initially was:

Cheap.
Low noise.
High measured performance.
No time to DIY or try our more expensive options.

According to the shipping information, the amp should arrive in about a week, before my Earsonics EM4 arrive. But, I will still have an opportunity to test this with my HF5 and see how they stack up. I am keen to further explore again the Vioelectric V200, and it would be great that once the EM4 arrive, that I take the O2 amp and the phones to demo and compare it against the V200.

Custom IEM and Updates

2011-11-22T14:05:00.003+11:00

Well, it has been some time since the last post, but it has been very busy and hectic lately. We have finally moved our family and settled in Hong Kong. Quite a big adventure for us, but just settling in. All my plans for the C3g headphone amp went to bits after my last post. The Yamamoto teflon sockets just arrived last week (obviously I was gone) and the luggage left no room for anything audio. The only exception was my Calyx Coffee and the Etymotic HF5.

Well, with that change of plans, and me settling in Hong Kong, I realised that full sized headphones wasn't going to work. I spend about 2 hours on the MTR system to and from work, and to date, have been using the Ety. Small, easy to fit in the pocket, and gives a decent sound with the iPhone 4. What I can say, is that the music isn't very engaging, warm and lacks a top end sparkle. But given the current situation, I'll have to make do. Or so I thought!

From setting up a full sized headphone rig with tube amp, I have now moved my focus to highest quality IEM with small solid state amps. My search for the right IEM started with the Etymotic ER4S/P. Many describe their sound as 'bland', but accurate and surgical. Probably not what I was looking for. If anything, I am trying as best to find something that has a similar sonic signature to my well used (and loved) HD650. That warm and engaging sound. Moving on from standard (or universal fit) IEM, as I did not really like the fit and feel of any of the universals that I had, I decided on a custom fit. Having read around, it seems that custom fit gives two very important advantages; better isolation and higher comfort.

Doing a quick search on Google, I found a place in Hong Kong that does custom ear mold; Phonak. After finding this, and getting my impressions for HK$800, I also found a few others that are more focused towards the audiophile custom IEM. Phonak is more a general audiologist. Having got my custom ear mold and my list down to high end custom IEM, I started to look for shops and brands. A real benefit of Hong Kong is its abundance of audio hi-fi stores. From a quick search, I found the following; Jaben, Mingo, Kingsound and Audiophysics. Audiophysics does not sell headphones, but headphone amps.

I went to Mingo after work and had a quick sessions with the iQube V1 and the Westone ES3. A few quick notes. The iQube has background noise with the ES3. Irrespective of sound, that is off the list. The ES3 has a nice balanced sound, the mids were balanced, not too forward or recessed. The bass is quite good, firm, not flabby, but not too fat. It doesn't have a huge amount of treble sparkle, but much better than the HF5.

After this visit, I did some research and narrowed my choice down to Earsonic EM4/EM3Pro and Westone ES5. This was primarily based on various Internet reviews and commentary. Doing further research, confirms that these two brands would probably be better suited to my taste then the JH or Ultimate Ears.

So long story short, I went to Jaben a few days ago, had a quick session with the Earsonics SM3, and placed an order for the EM4. Have been told up to 4 weeks for delivery of the EM4, but was suggested that this would be a lot shorter in duration. I didn't order anything special, smoke grey for the housing with black cables. Well, I am not anticipating their arrival.

The next step, a good headphone amp.

C3g Headphone Amp Progress

2011-10-25T19:44:00.000+11:00

Here are some photos of the progress build of the C3g Headphone amp. As you can see, the TubeCAD Regulator PSU unit is assembled, and the various major components laid out. The key components: Acoustic Dimension 41 step attenuator, Lundahl LL1689 Amorphous core output transformer, TubeCAD PS-1 heater and HV regulator, two Hammond mains transformers, and massive IEC Inlet with filter, fuse and switch. All of this in a 16x8x3 Hammond aluminium case.

There are some time restrictions as I will be leaving shortly, and need to complete this within a few days, otherwise it will have to go in the post. Note that I am missing still the Yamamoto Loctal teflon sockets. Still, a lot of chassis work to be done, as well as testing, etc.

Some equipment Audition

2011-09-30T17:58:00.002+10:00

Had the opportunity to go to a local Hifi shop and demo some equipment this afternoon. The gentleman assisting me was very helpful and friendly. The equipment that I had the chance to audition was:

HD800 with Duson HA160D, Violectric V200 and Sugden Masterclass HA4.
Sugden Masterclass HA4 with the T1, Ultrasone Edition 10 and Audeze LCD-2.

The session last just under an hour and the majority of time was spent with the Sugden as the amp. The source was an old Luxman tube CD player and the CD was Coldplay's Viva La Vida.
The easy ones first. I found both the Burson and the Violectric to be not as good as my HD650 and Elekit. The difference was in engagement and 'musicality'. The Burson had wider soundstage than the Violectric, one being beyond my ears and the latter being between my ears. The V200 sounded actually a little boring, nice sound, a little less bass than the Burson. The Burson had a very heavy stepped attenuator, which was great, except that it may clicking noises through the headphones every time I changed volume. This was quite annoying. So after around 5 minutes with each of the Burson and Violectric, I moved onto the Sugden.
Never have heard of the Sugden, but was told this was a hand-made amp in the UK. This amp is class A, and having a look through the brochure, it appears to be discrete Class A with a very laid out PCB. Anyway, the amp was cold initially and was initially connected to the HD800. This was a very nice combination. The voices and vocals were very well focused, the bass tight and the overall sonic balance and presentation was very good. I started to warm to this amp. Compare with the other two, this amp felt like it had more control over the headphones.
Over the course of the next half and hour or so, I swapped to different headphones. The first being the T1. Less bass than the HD800, different sonic presentation, a little on the neutral (maybe sterile) side. Similar to the differences I found between the HD650 and the DT880. I then tried the Edition 10. Wow, they certainly are a different sound to the rest! Light weight, well built and quite comfortable on the ear. The Edition 10 had almost overwhelming bass for me on the Sugden. It dominated the sonic presentation. The vocals had a distinct clarity/sparkle to it, that I was not used to, and perhaps I could call it 'edgy', whilst the T1 and HD800 was 'smooth'. I don't think its' a bad paid of headphones, but definitely not my cup of tea. Finally, I tried on the LCD2. Again, what a difference. Massive and heavy; quite the contrast to the Edition 10. I found that it wasn't a great match. The sound was a little flat and one dimensional. It also seemed far away, even though the soundstage was in my head. Nice balance, but probably a little weak in the bass regions.
Finally, I put the HD800 back on, and I was immediately smitten with the combo. Perhaps it was the fact that I am so used to the HD650, that the sound was so much more easy on my ears. Good balance between the lower and upper ranges. Also, the vocals didn't seem as focused or coming from a smaller source than either the T1 or the Edition 10 (which sound like a small point source). Perhaps sonically the Edition 10 and LCD-2 are very good, but for my own ears, through the Sudgen, I'd rate the HD800 the best, with the T1 second, followed by Edition 10 and LCD-2.
Coming home, I immediately turned on my current setup and listened to the same music. Though it was through a completely difference source (Mac and Calyx Coffee) into the Elekit. I'd have to say that I still prefer this setup! Even with the hum, which in contrast to the other amps, which were all dead silent. Even though this was an exercise in testing headphone amps, it appears that it may have turned out to be more of a headphone selection, and it might be worthwhile to bring my own setup to the same place and try out the HD800 and the other headphones to see how it all goes.

Hi Resolution Audio

2011-09-30T09:34:00.000+10:00

Just a few more notes about my research into higher resolution audio than the standard 'Red Book' CD of 44.1 kHz at 16 bit. Reading a little about SACD/DSD, implies that the maximum possible with that format is around 20 bits, 96 kHz. But given my desire to run everything from the computer, means it is not really part of my audio landscape. Looking at a few HD audio websites, primarily HD Tracks, appears that 96 kHz at 24 bit is readily available. There was limited offerings at 24 bit 192 kHz. However, the range of music available is still limited, and only a few of the artists that I like to listen to are available. It would be interesting to see if the 192/24 becomes more readily available with a larger selection of artists, otherwise, it would seem moot at this point in time, to invest in hardware and tracks in this much higher resolution.

Again, my choice in the Calyx Coffee, which is limited to 96/24 would be a good choice for the short and perhaps medium term. The next step is to make available some of this high resolution tracks, and compare that against the standard Red Book versions.

The other question of over sampling is coming up. I am pretty sure that the Calyx oversamples 44.1/16 into its native resolution, due to the Block diagram with a component "Oversampling Filter". This would suggest that whatever sampling frequency is fed into the DAC, is samples it into its native frequency. Which I would presum is 96 kHZ. Again, going back to various historical threads, people seem to say a lot of positive things about Non oversampled DAC. Perhaps this is an area to do some more reading on.

Another reason why I chose the Calyx is because it used an ESS chip. As I have a full Twisted Pear Audio kit for the Buffalo II (using the ESS9018) along with the Legato and relevant PSU, I'd like to sample the audio signature of the ESS chips before I embark on the build. Given my limited time and space, I'd like to know whether this is something that I can live with, or live without. Hopefully, I can get a decent session tonight, and provide some more thoughts.

Updates and Digital Audio

2011-09-29T14:07:00.001+10:00

It has been an awful long time since my last post; but things have been pretty hectic of late. Primarily is our decision to relocate our family to another country, which will be taking place within a few months. This event, along side other life things, has meant very little, if any, time to blog. At the moment, I barely get any good audio sessions in...

In light of the relocation, this has spurred me to look into portable solutions. Having a good assortment of headphones already is a good start, but this has forced me to look into the weakest part of the chain. At present, all my music is run through iTunes (AAC Lossless) and played to the headphone amps via the standard audio out on my Mac Pro or Macbook Pro. Note an ideal solution. This then started to get me looking into improving the digital connection between the computer and the amp.

Welcome to the world of USB Audio... Initially, there were a catch up in the USB Audio technology. The way I understand it is, there is USB Audio 1 and USB Audio 2. USBA-1 only allows for 48kHz/16 bit. But the newer standard of USBA-2, can support high sampling and bit depth. The highest I have seen so far is 384kHz/32 bit. However USB1.1 can support stereo 96kHz/24 bit in terms of its band width, and USB2 can obviously go higher. On top of this limitation are the limitations in drivers in the various OS. Add further to this is whether or not the USB device is asynchronous or not. More technical terms and more technical information to digest.

The long and short of it, I decided that the best place to start would be a USB device that had RCA outputs that can handle up to 96kHz/24 bit. And in this market, there was plenty of choice. Being able to handle the higher resolution allows me to explore HD audio tracks, which would not be possible had I stuck with something simplier with only 44/48kHz at 16 bit. Through the various web pages, etc, I was able to gleem that there was an awful lot of South Korean and Scandanvian companies making USB audio devices. Alongside that, the standard Chinese offerings and others from US and Germany. Some of the companies that I came across includes: Calyx, Bel Canto, M2Tech, Lead Audio, Lindemann, HRT, April Music, Anedio, Bladeius, CEntrance, SoTM, Halide Design and a few otherse. Where possible, I tried to avoid the Chinese companies. When I get the change, I hope to write some notes about the various units that I looked at over the last few weeks.

Again, without boring everyone, I settled on a Calyx Coffee. An asynchronous 96kHz/24 bit USD DAC using a lower version of the ESS DAC Chips the ESS9023. I chose this because it was relatively good price (middle of the pack), had the ESS DAC chip, looked good and has external control buttons. This was brought from Wicked Digital and the unit arrived yesterday, and has started the burning in process. The main difference I can see from this chip and the top of the line ESS9018 is that it only has 1 DAC circuit for each channel (whereas the 9018 has 8 circuits that can be customised in various configurations) and it also has voltage output (as opposed to current output).

Well, hopefully, I can provide more insight into this DAC, which is currently hooked up to the Elekit and HD650.

Updates

2011-07-27T09:39:00.000+10:00

It has been a long time, but between work, unpacking and family, it has been hard to find the time to blog. I recently purchased a pair of Etymotic hf5 from Headphonic here in WA. Very pleasant experience and good price. It arrive to me in Melbourne on Wednesday morning, after ordering on Sunday evening. I am now listening to them at work, and the sealing is very impressive. I can't hear any of the basic office noises around me, including my own typing, etc. Not much to say about the sound yet, got to give them a least 20 hours of burn in. But at the moment, it sounds pretty balanced in its presentation, but a little lacking on the highs. Again, not enough time to write more or to try out new things. But hopefully in the coming months, I can get back onto some consistent blogging.

Updates and WE396a Tubes Arrived!

2011-07-05T00:37:00.000+10:00

After a few weeks of moving and settling in, I am not somewhat settled. Listening to the TU882R with the WE396a tubes right now. It is a good feeling to be mostly unpacked and most things setup. It is quite relaxing indeed. Anyway, in the last few weeks two notable events took place. Firstly, my order of 3 pairs of 396A tubes have arrived from Audio Tubes. I purchased from Brent;

WE marked WE396a tubes.
National marked WE made 396a tubes.
United marked and United made (in the UK) 5670 tubes.

They did attract a premium, being WE produced tubes and UK made tubes. I hope to get some photos up of these tubes, along with my three other types of 5670 tubes, once I find some space. It'd be good to do a sonic comparison of these tubes later on.

The second item of note was my ordering of the Jordan JX92s MLTL kit from Decibel Hifi. They also arrived quite promptly from Brian in Queensland. I must say that they were a lot smaller then I thought they'd be, but nonetheless, still sizeable. From initial impression, the fit is good, and being MDF, should be easy to finish. Along with this order, I also put in for a set of 4 Eichmann Silver Bullet plugs. This is to connect the various computer output and DAC to the standard amps with use the RCA. As some long time readers will know, I prefer to use the XLR style connectors. But, when dealing with kits, inevitably, they are all RCA connections.

Anyway, back on track, I hope to be able to put these together in a few weeks. With a proper sized TV/main room, I am excited to see the JX92s perform. I plan to dress these up a little with some hardwood cladding over the MDF. This will both function as aesthetic, as well as adding additional stiffening and allowing me to fix some speaker cloth to it, to protect against the young ones. Again, long time readers can see my Fostex MLTL towers... Finally, regarding the Fostex, I plan to revive them by turning them around and adding a Speakcon on the current front side, and turning the 2 sets of binding posts into a hole for the vent.

Lots to happen in the next few weeks, and now with a decent space to do some wood working, and space to place and use the speakers, I hope to be catching up with all the various speaker builds that have lay in abeyance in the last year or so.

TU882 and the DT880

2011-06-19T00:23:00.000+10:00

Again, I found an excuse in my packing to swap the headphones, from the Sennheiser HD650 to the Beyerdynamic DT880 (600 ohm version). The first thing I noticed was that there was no noise at all. No hum. Virtually silent. Very promising indeed. Listening to my standard favourite/test set of music, there were a number of differences between the Senns and the Beyers.

The bass is more present (i.e., louder) and rich with the Senns. The Beyer, they feel more articulate, but less in your face. Far more restrained on the Beyers, where on the Senns they feel like it has been let loose a little. The presentation of the Beyers was less warm than the Senns, and a little more clinical. The voices on the Beyer is more refined, but lack the lushness, similar as well with guitar strumming, the Beyers are precise, but lack that slight indulgence that makes it full and warm. Overall, the balance favours the mids and probably overall a little more balanced than the 650's, though probably a little shy in the bass region. I would regard the Beyers DT-880 as more precise, controlled and pristine. Whereas, I would describe the HD-650 as warm, natural and lush. Obviously very vague terms, which are highly subjective, not only to me, but between different sessions, moods, etc.

The above observations were made between two sessions, over two consecutive evenings at around the same time. The setup was identical except for the headphones, and it was the Elekit TU-882R with the Western Electric 396a (with around 20 hours on them thus far). The volume control was different by around 2 to 4 'hours' relative to each other.

C3g Headphone Idea

2011-06-18T01:03:00.000+10:00

Here is something that I knocked up quickly as I was listening to the HD650 and Elekit headphone setup. This is in a similar vein to my D3a concept and shares many similar parts. I think this project would be very quick to knock up. This would make use of the TubeCAD Regulator PCB kit, making the build itself even more straight forward. The main reason for considering the C3g as well as the D3a tube are the various comments on the Internet regarding the consistency between various D3a samples. It appears that there may be a high sample variation between the tubes, and careful selection is required. The C3g, being a lower Gm tube, may have less sample variation. But time will tell, as I have to actually build the two amps first, to test the outcome. Again, this might work for other triodes as well.

More thoughts on the TU882R

2011-06-16T00:17:00.000+10:00

Just having a lovely session with the TU882R and the HD650 right now. They WE396a tubes are in, and has been warmed up for over half an hour. Just a casual, easy listening session now, with Missy Higgins, Crowded House and Coldplay. A very nice way to end the day...

I am now trying the HD650 with the Medium impedance switch. The hum is now gone, and the amp is dead silent. According to the manual, this impedance setting is for 20 to 100 ohm headphones. However, I am trying to discern if there are any sonic differences between the two settings, apart from the hum. First impression is that the sound isn't as dynamic or lively. It is a little more laid back and somewhat 'lazy'. The bass isn't as well controlled or present either.

Well, after the recent experience with the WE tubes, I decided to order three more pairs of the 5670/396a from Brent at Audio Tubes. As usual, all my previous experiences with Brent has been excellent, and this time around, it was no different. He offered a good deal when I purchased three pairs; Western Electric 396a, WE made 396A for National and a British pair labelled 'National'. I have always had good experiences with British made tubes, the 12AE6A Brimars being a prime example, and thought that they could be a good counterpoint comparison with the others. Well, I hope to receive them in the next few weeks or so, and start to enjoy their different sonics.

As I am writing this, I am definitely preferring the high impedance tap, even though there is the hum in the background. It just mates so much better with the HD650. Well, more testing to come.

I have recently noticed that some of my music has very strong super stereo effect, where music is coming out of one side only. I do find this a little distracting at times, and started to look into placing a crossfeed. I installed with in my Mini Max Millett but never used it, cause it didn't sound right. On review of the setup, I think I might have wired it incorrectly. The next step is to remove it from the amp itself, and create myself a little stand alone box to house the crossfeed. This might make it easier to compare the effect and see whether it is right for me. Anyway, more to come later.

WE Strikes!

2011-06-13T23:37:00.000+10:00

The thing was, as I was starting to pack up the stuff ready for the move, I was in the room with all my headphone gear, and decided that it was best to do all the packing with the headphones on. As such, I thought, why not try the Elekit for the next week. So, out with the Crack, and in with the TU882. And the first thing I noticed was that the hum was not as loud as before (or so I thought), but it was definitely lower than the Crack that I just unplugged. That is the good news. The bad news was, I was using a pair of Raytheon 2C51 and I just wasn't all that endearing, the sound that is. So, I thought, I might spend a few minutes to change out the Raytheon and put in a pair of WE396a that I had purchased. Firstly, it was very soft on the right ear, almost no sound. My heart sank....

Was it the amp, or the new tubes? No idea. But as the amp got warmed up, slowly, the volume on the right side picked up and now it settled in to match the left. A sigh of relief. But boy, only the first hour of music, and the sound is so much better! So much so, I am thinking I need to get me more of the Western Electric NOS. Another thing I noticed was that the hum levels was actually less than the Raytheon tubes (this is going by memory...). But, it is now very quiet. Not dead silent, but very quiet. Not as quiet as the Ear, but close. Regardless, the sound was so much improved, it makes me really want to keep listening to this setup.

Anyway, a moment of revelation, and onto the shopping!

Crack and Speedball Up and Running!

2011-06-11T09:02:00.001+10:00

Finally put the replacement parts into the C4S board this morning. See the photos below. The rebuild itself was very quick, only 5 components to solder and 3 wires to reconnect. After doing a few visual checks to make sure everything was in order, I fired her up. And yes, it worked! No problems this time. Equal volume on both sides, and all LED lighting up as they should. Now this amp has been fixed, I now have four fully working headphone amps; the Crack, TU882R, Ear+ and the MiniMax Millet. I'd have to say that the sound stage is a lot more compressed then what I remembered last time I was listening to this amp. I am using the stock tubes supplied by Bottlehead, which is a Philips ECG 6080WC and (I think) a Sylvania 12AU7.

An initial observation about the floor noise of the Crack. There is a hum, but given it is AC filaments, it could be from that source, but it could also be from the B+, who knows. I would have to say that it is not as loud or obvious as the hum on the Elekit, but this is just anecdotal observation, as the last time I listened to the Elekit was a few weeks ago. Again, the Ear+ doesn't have this problem, but that is DC filaments. Could it be from the B+? The Crack has CRCRC filtering. The Ear has CRC for the output tube, and an additional RC stage for the driver tube. The Elekit has cap input, followed by a FET, which I can only presume is acting as some kind of series regulator.

Well, moving house very soon, and all of this needs to be packed up and transported. However, the beauty of the headphone amp and system, is that they are so portable, and can be one of the last things packed, and the first items unpacked. I think in the coming months, I'd have a good opportunity to start some comparisons between the three amps.

Repair of the Crack/Speedball

2011-06-04T18:40:00.000+10:00

Finally got around to removing the board that was damaged due to my own fault. See the photos below. You can see a very small hole in the small blue resistor 237R. It measures over 4k now. One of the diodes also do not bias up at 1.4V. All parts removed and the through holes cleaned. I accidentally ordered the 2N2907 and 2N2222, rather than the "A" versions. Now, I have ordered the correct ones, and also a replacement 237R resistor. Should all arrive by next weekend, in time for re-installation.

Comparison of Noise

2011-05-31T09:05:00.000+10:00

After been not satisfied with the low hum levels, I decided to plug back my Maple Tree Audio Ear, and low and behold, even more noise! I didn't remember that at all. But, I remembered that my son accidentally touched the driver tube, so I decided to give it a gentle jiggle, and noise gone. Obviously a dodgy connector, dirty or something along those lines. But yes, there is no noise in that amp at all. Admittably the Elekit's hum was very soft, but in my current home, the ambient noise levels are very low almost all the time, so the noise is a bit more audible. However, the Ear was built over five years ago, with similar spec'd components, and it is, noise or hum free. I think there might be another problem in my wiring or placement of components in the Elekit.

Going through this exercise has spurred me onto completing the D3a amp and the Aikido headphone amp. But due to the imminent house move, they will all have to wait until I unpack at the new home. At least I have three (!) working headphone amps. I still haven't got around to fixing the Crack just yet.