Vinyl pressing overview

About 2 weeks ago on Sunday I got visit from my DIY audio friends , my wife was out of town, kids were up stair, so that Sunday was Dad's day :D. Goodies are PCM1704 tube & opamp output DAC, balanced AD1865 DAC with Joyce & Moza output stage, fine and toasty DIY F5 with a pair of gigantic choke on its supply. Also my friends TDA1541-S1 balanced. Branded fine interconnect and digital cable also proved to give improvements.Too bad I forgot to take pictures.

After hearing all DAC, we found that Alex's PCM1704 DAC sounds very well and the owner challenges his1704 against Vinyl. This is an opportunity to hear what friends think about various pressing since I have planned to write about this on my own. I have some vinyl and it's CD version, so comparing is easy.

The gears are F5 power amp, Aikido tube pre, PCM1704 DAC, modified Azur 540P phono pre, Thorens TD320MK2, Kiseki MC cartridge & Scanspeak Elan speaker.

Here are the latest of my Azur, now with 2SJ74 JFET 's before LME49720 :) replacing original BJT's, note that 74s dancing legs and 2x 11 blue Siemens film cap :). Plenty room for improvement still, constant current source on the SJ74's, Salas Shunt regulators, better transformer also dearly needed.

The CD-LP's :
CD Tonny Bennet, Duets II, 2012 Grammy winner duet with Amy Winehouse (rip), LP Amy Winehouse, Lioness, Hidden Treasure, same track, Body and Soul. More about this 180gm 45rpm new pressing with digital recording and mastering. See her video with Tony here

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Verdict : Friends says vinyl sounds finer, no hard glare & digital edges compared with PCM1704, formidable opponent to his DAC says the owner. I noticed that my MC stage need more gain when paired with F5 power amp.

Next is CD / LP The Other Side of Round Midnight, 1986, Dexter Gordon movie sound track, Blue Note, track "What is this thing called love" with Bobby mc Ferrin, same verdict, better sound than Amy's LP. No wonder this CD/LP is recorded analogue, but mastered digitally.

Now the full analogue LP's, I have no CD version on them : Azymuth, Rapid Transit, Milestone Record 1983. Latin-fusion with fast and furious percussion. My friends seems to be feeling not so warmed up with previous LP's. This time it's different, the true analogue sound quality is way beyond the sound DIY DAC ..wide, deep, layerings, speed with tons of details, no harshness what so ever, and those cymbals....

Unfortunately, as with CD even a full analogue vinyl does not always sounds good, that usually depends on the recording label, the engineers and pressing. But old analogue vinyl pressing sound quality is well documented, just Google "vinyl", or check out online hifi magazines where they have music review. There are also good sounding new pressing, check out Classical Record.

Now about the music.
Why Amy Winehouse? it's about feeling and emotion, not all song sounds good and the real treasure in this LP is the track Song for You, I got hell of hairs rising on my neck and hands when listening to this track the first time. The song was recorded in Amy's house, wide - very analogue sounded, and as is recorded with Amy's bri'-ish' chatters at the end of the track. There is a guitar played faintly on the background, not very well played but tuned to the music though. Could this her guitar played half drunk? I don't know. In all this is a historical record, worthy to listen and its all about music, Amy's emotion and ours. Thank you Amy !.

Another design problem

This is a long due write up on design thing, postponed several times because of my diy audio adventure :), nonetheless still a fun part to write about design thing in and around our home.

My wife bought a nice plastic utensil, its a spoon, knives & fork container, the one that usually you use on your dinner table. Good product those containers with various approaches. Its spares you from visiting kitchen drawer every time you want to eat something. So here are the pics, more than words.

 Nice and tidy...

 

 open it, and the whole thing spreads apart..

 

 then try to close the cover...really a  hassle..!, hate it, what a waste

Another problem is this cooking gas/ propane regulator. Indonesian Industry Certified, cheap, must be safe. The packaging and the instruction sheet is inside, quite consumer friendly with consumer contact number and all, as required by law. But what happened was that when I put it to the gas bottle nozzle, I can not lock it and heard a 'snap'..what the...

 

Open the ***** thing, found a broken hook, made of diecast metal. It is this hook that should lock into the nozzle.

Upon closer look, as usual, poor design as mentioned many times in my write up...stress concentration, due to sharp corner. As simple as that, just add a rounding , or fillet there, none of this will never happened..sigh..

 Thanks for reading..

Audiophile Last Frontier? Phono thingies, Azur 540P tweak

What I called last frontier here is in fact returning to old format : vinyl. While today and in upcoming years the CD life is on a count down to and end.

Ironic isn't it? media format that was 'killed' by CD has since experiencing revival once again and this time I think for forever. There are new pressings both 45rpm 180gr disks, 33rpm of relatively new artist. Also there are so called Remastered ones, of course from old but still selling artists.
 
Why? Not just nostalgic I think, there are qualities in vinyl that sets them apart, even new young generation who never heard vinyl before begins appreciating the vinyl, spurred by many 'indie' bands that issues that odd media. A Retro-Cool aspect might play a role here, but old die hard audiophile always know better things :). Read here my write up on the 'perfect sound forever vs vinyl'. I was pleasantly surprised that young people aged 20-30 years old are enthusiastically digging old records, looking for 'roots' of today's music. They looks for van Morrison, Jimi Hendrix..., Neil Young,..hell...they even look for Miles Davis's Bitches Brew !...some roots they look for :).

For me it's just a returning audio life cycle. I always loved the sound of old vinyl, no CD beats a good set up turntable-cartridge-phono pre and a good pressing, preferably all analogue ones.

Unfortunately, we're living in digital world, so most of the new pressings and remastering were done in digital domain. But how about the groove and the needles? Aren't they analogue? Yes, they're full analogue, but the groove cutting head is driven by an amplifier with industrial DAC, and thank God, with no less than 24 bits resolution. So you always can expect better sound of new pressing than the CD :).

So, what next? get those friendly priced turntables, get a cartridge, MC or moving coil type is better, MM or moving magnet if budget is tight, and last but not least, a Phono pre amplifier if your pre-amp do not have phono input. But a separate phono pre is better though :).

Some years back I've bought this Cambridge Azur 540P MM phono pre. Very basic and so-so sounding, but the DIY soul in me got that itch, I want to tweak it to the max possible, that includes adding a MC input!. here are the story.

before tweaking, all standard cheap components, there are 2 op-amps, the famous 5532 they're replaced by Burr-Brown OPA2134 and the final op-amp is the sweet LME49720

After some tweaks, my tweak reference is from VinylEngine, check out page 28 and on
and also after adding a separate MC input in this small box, using Salas Simplistic NJFET MC gain stage, many thanks boss! . This hard wired MC gain stage is using the now rare quad match Toshiba 2SK170BL jfet's, the output of this stage is directly goes to the MM input through a switch.

this one is still fed by 2x 9V battery, does not last more than 7 disks, so next step is adding separate power supply for MC stage, here testing a pair of output capacitor :

And I let this combination quite a while before my last tweak :)

Last tweaks were replacing BB-OPA2134 with LME49720, C out to stacked blue Siemens 0.33uF, 11 pieces per channel, no big film capacitor will go in this small box!..and after some discussion with my DIY audio guru, Mr DWA, the diode's are replaced with schottky type, the blue Elna RE3 is replaced by Phillips 10.000uF/16V, last but no least, the 2SA970 transistors on the MM input will be replaced by even rarer Toshiba 2SJ74 :)...hmmm..yummy,...thank you pak Dhe!..

and now spin that disk , sit back and relax :)

Thank you  for reading !

in the pipe line :
Vinyl, new pressing vs digital mastered-direct metal mastering vs pure analogue...

Battle of the old NOS legend? Part 2

After the new year woes over, now it's time to write again about our good old NOS DAC's. I have listened extensively to my NOS TDA1541 hardwired prototype, NOS AD1865 with 74HC04 and 74HC02 glue logic. Are there differences between them? Yes...quite so, even between the two AD1865, how so? It's just there and measurement proves that.

Last month in 2011 I just listened to 2 or 3 CD's, with 3 DAC in turns. For critical listening I listened to the following CD's :

Herbie Hancock , Possibilities. This is a cool jazz - kind of progressive jazz rock mix with famous singer on each track. There is a movie version as well. I listened tracks with Christina Aguilera here (yup..WOW...that Christina..), now you know why I like her..:). Also the Sister Moon with Sting here. Highly recommended if you bored with the usual mainstream jazz. Believe me, this is a very good CD both music content and sound quality, not to mention the swingin' , and some kick in the *ss quality..

The second CD is very old classical promo CD, by Teldec 1991, the title is Jonge Mensen op het Concert Podium. free translation : Young people in concert podium...and what a young people they were and are today !
I listened to tracks of the (then very young) celloist Matt Haimovitz on Max Bruch's Kol. Nidrei, op.47, and the barely (then) teenager violist Midori on Frederic Chopin, Nocturne, op. Posth. in cis.

See the Midori video here , too bad I can't find the exact video of Matt. Both player's were passionately deep in playing their instruments, that can be heard !, bristles of Matt's vest against the cello and his gasp for air were repeatedly heard. While the tiny Midori accompanied with piano and several noises and coughs from the audience really wonderful, and then that applause!.... You know these music can make you cry...so little fingers so beautiful music...


Here are the cheapo but very good sounding CD :

To me, the above tracks and Herbie's album and a few more are my "eargasm" ticket after a long hard day..

My system is as usual, Sony CDP950-digital out, Aikido tube pre-amp, Aleph J clone and the gentle giant ScanSpeaks Elan.

After some quick evaluation, the Vout AD1865 / 74HC02 is not very good, it's noisy and I'm not using any filter on the output (120uH and 0.01uF ?) so I changed analog out to SE JFET, sound better but the noise stays. AD1865 / 74HC04 sounds very good indeed, no noises but tiny bit lacking attack & speed compared with TDA1541 and AD1865 / HC02.

In term of speed, attack and timbre the verdict is TDA1541 followed by the noisy AD1865/HC02 and the calm AD1865/HC04.

On staging, details, separation : AD1865/HC04-gracefully wide, then TDA1541 and AD1865/HC02, maybe this is why most of DIY DAC pcb's with AD1865/HC02 always using SPDIF pulse trafo and output filtering.

On foot tapping and musical involvement, this is my get into the music quality and personally I rate this highly above details, staging and separation : TDA1541A, then AD1865/HC04 and last AD1865/HC02

By no means one or all the DAC were sounds bad, they are the legend!, only my power supply is right out mediocre :) told you that in Part 1, and these King DAC does not deserve it at all.

I did measure the contenders, here are they and with surprises ha ha..some predicted and some not :).

The Silence (of the lamb...he he..)  : both channel measured

Woow...uugglyyy..!...this one is TDA1541A hardwired..a very far cry compared with Salas previously measured here, I'm surprised, strangely it's quite ok sounding, specially with frantic and very fast details on Herbie/Sting Sister Moon...already went to some haziness I admit.

 This one is from AD1865/ 74HC02, best of the contender

This one is from AD1865/ 74HC04, notice bumps on 50 and 100Hz, that's the power supply...hmm, the only difference with HC02 is decoupling bypass, red wima mkp on HC04, and green Wima FKP on HC02, the lytics are Nichicon Muse KZ, 47uF. So get that green Wima's guys!..

Conclusion , this confirms my suspicion, AD1865 gives better performance with mediocre power supply, while TDA1541 ask a lot more to get in par.

The square 1kHz signal, I can't see any particulars, all DAC's are multibit's, very little pre and post ringing and fast!, maybe we can see the rise time difference ? from what I've listened AD1865/ HC04 is a tad slower than the rest, so the square flank should be less vertical.

 TDA1541A

 AD1865/74HC02

  AD1865/74HC04

My favorite, 500Hz 0dB, now the results were predictable, especially that noise of AD1865/74HC02

 yup..there it is again...uuuglly...:), TDA1541A with garbage...

And this one? AD1865/74HC02, not very pretty as well, you see (too) many spikes also small ones before and after main harmonics, that's where the noise come from, also note that the 50 and 100Hz bumps re appears! In my simulation the data stream, particularly on the left channel have a very short duration pulse before each left channel MSB, I'll update about this later. Maybe that explain the inherent noise.

The winner is.....AD1865/74HC04, in spite of my 'prediction' of single data line for both channel it doesn't reflected much here, and this with no SPDIF pulse trafo and output filtering

I'm now listening to Christina & Herbies A Song for You on TDA1541A..that vocal quality of TDA1541A is really hard to beat, but in my case here, AD1865-N-K with single logic gate 74HC04 is the clear winner!

Thanks for reading & have fun..

Battle of the old NOS legend? Part 1

I don't want to miss writing in December :), there are some design things in the pipeline, but first my current DAC adventures. I have managed myself  a piece of equally legendary AD1865-N-K DAC. It is one of 'a must have' DAC chip, I'm always a fan of multi-bit DAC, next in my list is the expensive PCM1704, may Allah The Great permits.

Me not buying ready made PCB for the AD1865 :), not challenging and not fun enough :),  so the usual PCB layout-ing took some time, and to my surprise, this time designing is a breeze compared to TDA1541 board!. The AD pins are very layout friendly. I use both NOS schematic with 74HC04 hex inverter and the other with 74HC02 NOR, why?. Well, blessing in disguise really.

First I made CS8414 - 74HC04 - AD1865 pcb. After powering up the damn thing just gives noise, all effort to resolve failed, check and rechecking everything, tried other connections etc...very frustrating.

So then come the other schematic, now instead of 74HC04 I use 74HC02. I always think less is better. Using the 04 you use only 1 logic, while with 02 you use all 4 logic's.

The 04 however has 1 data line for both left and right channel, i.m.o. not so elegant, both AD1865 inputs are continuously bombarded with digital data, while in the OFF state, I can be wrong of course :). One way to try is to slit apart data trace with a cutter, and listen to your DAC, it still managed to get through!.

The 02 in contrary have 2 separate data lines for each channel. Mind you though, both NOS digital glue with 04 and 02 introduce data phase shifts between channels and clock (SCK from CS8414), with 02 comes worst. I know this from DIYaudio and by simulating the digital input-output data stream. But the shifts are small, and people says this is similar with moving your head 8mm during listening :), or is it?

This can be fun to check, because TDA1541A NOS with CS8414 data stream is exactly in phase! Ok, here are the plan, I use mediocre power supply (ex. Pioneer LD player), measure all 3 DAC boards : the original hardwired TDA1541A DAC, AD1865 with 74HC04 and AD1865 with 74HC02, all analog stage are my favorite single ended -DC coupled 2SK170 jfet, All board will use the same CS8414 receiver..how about that?..

How about the HC02 board?, still no luck bringing it alive!, must be the DAC...even a Vout mod from Iout did not help..

Frankly, I have listened to all of them :), I got my AD1865 replacement (many thanks Doc!....) , the AD1865-HC02 is still using Voltage output. This is preliminary listening though, I'll let them for a couple of weeks playing...

Here are the pics, AD1865 PCB's are CNC'ed, I tried as far as possible using same brand and same values component.

From bottom left : the 'Red' shoebox power supply, TDA1541A DAC, AD1865 with 74HC04 and SEJfet out, AD1865 with 74HC02 and Vout, note the coupling capacitors.

Now, back to listening he he he...

TDA1541A Balanced DAC, part 2

I'm listening now to Andrea Bocelli's Amore album, right now Estate's is playing, using balanced TDA1541A-S1 DAC and it's direct heated triode output... the sound makes you really enjoying the Andrea's emotion... man... I have to write this instance..:). There were few moments like this when you're deep in to music you're listening, really caresses my ears and you forget about analyzing music, let alone measuring he he..I lost my measuring urge :). I'm just going to enjoy it before this DAC moving to it's new home.
Damned!!.....that voice of  Christina Aguilera...what a talent!..what a waste in her pop music!...and just past midnight here, the volume knob barely at 9 ...Somos Novios......., my ears were tickled nicely here :)


It's have been almost 2 weeks since I have boxed up brother Y's balanced DAC and fired it up. Before that I use his DAC - Jfet - LME49720 opamp board and the little DHT bugger in my DAC box with the famous Salas shunt regulator.

I should mention that a few weeks back we have had a very nice blind test session. I for sure have participated, bringing this balanced DAC. The result? well a mixed bag really. I've heard 2 to 4 very beautiful sounded DAC there. A matter of taste though, only 1 of my favorite made it to final. The winner is a humble AD1955 DAC..congratulation ! here is the pic of my box with brother Y's boards.

There are the 4 Salas regs, at center the TDA1541A-S1, the DC coupled single ended Jfets, next to it is the balance-single ended opamp converter (with bit of gain) that going to ..yup, a pair of direct heated triode :). a very nice sounded ones those little buggers !, I did not believe my ears when listened to them the first time. I've made both anode & cathode follower/CF, the above is CF. Heater cathodes were battery powered. Why DHT output? I'm quite bored actually doing another 9 pin tube things, maybe octal tubes will be nice but I'm daunted with so many choices and what if the sound is not right...

Now in new box, not as large as mine, standard thin steel box, but modified with 8mm thick aluminium face plate and 2mm rear plate

Anti clockwise from top left : 2 EI trannies for digital supplies, 1st 2x Salas board, DAC board, 2nd 2x Salas , SE Jfet's, opamp with LM317-337regs for supply up to +/- 17VDC, DHT DC heater (modified Tom Ronan's supply), DHT board with supply, analog transformer (both high voltage, 2x 10V for heater and 18V for opamps). At center are cap banks for opamps.

This project to me is the most difficult and challenging, but worth the effort. This is my many "first-time" experiences with balance topology, first with I2S splitter, first  balance- SE opamp, all including Salas board were custom designed and CNC'ed, and yes, first time DHT and I highly recommends you guys overcoming that famous DHT hum with DC heater!. very frustrating and yet rewarding ..completely gone? nope, but I remembered 'complaining' friend's DIY DHT amp..now I have experienced it coming with that "low' hum is admirable!.

Thanks for reading....thanks to brother Y for the challenge, may the emotion be with you!

now on : Solamente Una Vez (oh my...Stevie Wonder just great with Andrea..), Sony CDP950 digital out, TDA1541A-S1 balanced DAC-DHT tube out, Aikido pre amp, Aleph J clone tweak nr.xx, Scanspeak Elan

A new DIY audio adventure, TDA1541A Balanced DAC, Part 1

With no design thing comes to my mind lately, why not sharing my on going venture into another TDA1541A DAC topology with you?. After finishing and more or less settled with my hardwired single TDA1541A DAC, a good friend have listened to it during a listening session at a friend place, he's blessed with a old pair match of TDA1541A S1 or what we called single crown. Pair match? yup that's right, each TDA1541 chip I've listened sounds different to each other, some subtle within one production batch, others like night and day :).

My friend 'brother Y' was impressed with the sound of his S1 chips sitting  in my hardwired DAC and rightfully asked a balanced topology, I couldn't agree more. Balanced topology requires pair match of everything, from DAC chip down to Jfet and opamp output stage down to single resistor & capacitor in the signal line. After long study at DIYAudio.com (as always, thank you guys..) I've found  the way how to do balance DAC using I2S splitter, yup, there is one good man behind this, Pedja Rogic, kudo's to you sir!.

The digital data from CD transport is first entering the receiver CS8414, which gives I2S data out, this data then go into splitter which feed 2 TDA1541A, one chip received Left data, the other Right data. Now the splitter does something else, it split the audio data into + data and inverts the other half of data into -data. So one dac chip will output L+ and L- analog out, the other R+ and R-, clever isn't?

From there I will have 2 pairs of (now) my favorite discrete 2SK170BL's single ended current to voltage converter I/V as in my hardwired DAC. From the JFET's the the L+/L- and R+/R- signal are fed to balance - single ended converter op amp :(...but this is the easiest & speediest way. After op amp you can do tube out, just what I did, later on that... :)

Meanwhile, I did got busy making that double sided PCB which since the start of layout I've incorporated possibility for paralel and balance configuration. Not a world class digital PCB I admit, but it works wonderful. I got also many valuable advices from the NOS TDA1541 man himself : Thorsten Loesch, thank you T.., and this means the layout is evolving :).

Well, quite an introduction to this challenging DIY project, now (finally) some pictures, I've made my PCB's using my (DIY) mini CNC machine that I've made back in 2004, told you that I'm a hardcore DIY guy :)

CNC ing is very nice if you do only limited quantity, and when you experimenting (read: playing :)) but take bit of time of tracing & converting ECAD data to usable GCode for machining, but what we get is nice clean process without chemicals and of course nice copper area for power and digital ground plane...

The long awaited parts were finally complete, specially the hard to find old Philip chip for I2S splitter, the  famous Toshiba 2SK170-V for the 4 Salas regs, and the most important, a pair of dual matched 2SK170-BL, quad match were simply not available anymore. Got 1 quad match in my MC phono pre though he he..hope to share this as well soon.

Here is how the DAC and splitter board looks like

Top of pcb, the splitter with 3 red cerafines and the left channel DAC, bottom pcb are for the CS8414 and the right channel TDA1541A, notice detachable risers for ground return and power supplies.

And does these things worked? You bet!..perfectly by the way :)... here are early measurement using TDA1541 non A and John B's single ended Jfet, tested here the L+ and L- signals, the usual 500Hz/0dB

Green is the L+ signal, red the L-, they are exactly,  well..within the limitation of our beloved VisualAnalyzer of course :), have you got one installed yet?
You see, the whole balanced thing comes to to this, you add 2 exact but opposite phase signal, summing will get rid of all even harmonics (what????...said a nice tube guy over there...:;D..), what left are the odd harmonics...and in total lower distortion figure.....why oh why???...said another tube guy....:(...

That yellow curve is full of even harmonic and it IS being removed. This cleaned signal then enters the op amp to be made single ended again, want to add flavour? you can, I'll add tube out just to add a pinch of 2nd harmonic. My brother Y will have options of  DAC outputs to choose, SE JFET, Balanced JFET, SE opamp out, or .....SE Direct Heated Triode tube out

stay tuned & have fun