Minggu, 22 Agustus 2010

Rejuvenating Spica TC50

I'm currently listening to my Spica and also waiting for my fastening break time, why not continue the Spica story?. This legend is known for its 'disappearing' and staging quality. When you listen to it soon you'll  forgot that there are speakers in front of you. Just sounds floating around and in front of you. That's the way I liked it just like my more refined Magnepan SMGa.

My Spica : pre 1988 built !

One box sounds not so loud as the other. So I starts measuring both with my DIY Speaker Workshop Jig II, here is the result, yes the "B' channel just sounds softer.

Now it's confirmed I planned to move the internal crossover to outside the box for better tweaking and checking. I opened both boxes & smells 22 years old odors of this spica. All drivers were in unbelievable good condition, original French Audax including hand markings for each driver to match the crossover. Not to forget, thick genuine sheep wool blankets



So lets see the crossover, as said in the forums, electrolyte capacitors , those yellow things says ECI on the marking. Hell of electrolytes, after more than 20 years !. Inductors are cheap ones with ferrite cores both for high & low frequencies. Resistors are good metal oxyde though.

One elco is not in good condition, white thing comes out so must be leaking then. Here is my old story about electrolytes in loud speaker. Not bad, one out of 10 elco after 20 years!. I just replaced it temporarily with cheap MKP until I have the mood for tweaking.

Leaking capacitor
Now it's the turn of the enclosures - a closed box with no leaks. I have to make sure of no leaks all the time.
I reversed the bolt and nuts for crossover PCB to be mounted out the box on the rear side. Notice white glue and rubber washer..no leakage.




Hmm..does not look pretty yet. I'll put the board in a box when all is tweaked right..that's a promise for an old friend. How its measures now? well quite ok I think, both box sounds more balanced now.

Here is the crossover as per today :) waiting for better components, some are almost ready and still in 'burning' process. Nichicon Muses and BP, recycled Philipes- Epcos- Wima MKC , some green and silverish Russian paper in oil and maybe a pair of 30uF big oil can?..who knows.

As for now I felt little to be modified, its sounds already good enough for me, groans-moans and throat sounds of Diana Krall's voice is just awesome also her piano 'kick'.  Maybe I need to remove a little harshness and sibilance a bit for complex music. That's the next tweaks are for. Thanks for visiting.

Kamis, 19 Agustus 2010

There are second chances in my simple life : Spica TC50 speaker

Have you ever thought that you'd have to make choices in the past, well a luxury choices that is. And all a sudden there you are, after say more than 10 good years being confronted again with the second chance right in front of you, dejavu all over again :).

Mine happened long time ago when I was still a near graduation student in the Netherlands. I started looking for a pair of serious loudspeaker to take home and live with it..just like a wife isn't ? except it comes in pair :).

At that time I was considering an unusual speaker, Magnepan SMGa and another pair which I have listened at my well funded friend apartment, Spica TC50 driven by high-endish gears such as Goldmund turn table with Van den Hul Grasshopper cartridge, Aitos tube MC Pre-pre and Aitos tube power. Really an experience not to forget to hear the sound.

Finally I married to the Maggie SMGa, took her back to my country home after graduation. Why SMGa? they are more expensive than the Spica, more than 3 times. The reason was that Maggie in combination with my system at that time, second hands Counterpoint tube pre & hybrid power amp sounds quite good, maybe scoring a decent 6 points out of 10 points of my friends gears.

Fast forward to present time, I started doing DIY audio thing and with several 'hardcore' audio friends planned a visit to a place known as electronic ghetto in Jakarta, a Bronx kind of place with many unexpected audio jewels if you're lucky.


And how lucky was I indeed. In one of the shop I saw a familiar sight...a TC50 Spica..to be honest I'm bit disappointed to see both grills full of holes and one of them are totally broken into 3 pieces. Hmm..lets see the speaker driver then..looks unfamiliar though, especially the woofer, not the same as my friends. Need to gather more info on the net after asking the price, quite pricey for jewel from the past. Got home and started browsing.

Here is a link on the net.  Yup exactly, the Spica's have stood bravely the cruel tests of the time. With many fanatics. A proof that the TC50 is a legendary loudspeaker. Woofers and tweeters are no longer in production, the designer John Bau just don't want to continue his creation, etc. etc...

To cut the story short, the next day I went back and got myself one of my 'youth' mistakes home to correct, a pair of legendary TC50-Spica, here is the pic. the date was 12th April 2009, just maybe after 10 years, nope, more than 18 years later, can you believe it?

Talk about second chance? I will give this Spica a real second chance..it needed too.., one speaker sounds not as loud as the other, the grill have to be made anew..hmmm..sounds yummy for a tweaker like me..so the story will continue for sure..thanks for reading

Kamis, 08 Juli 2010

DIY resistor for DAC current to voltage conversion

June this year is my zero writing month. Don't want to skip July so here it is another DIY audio adventure.
My tweak darling, the Sony CDP950 is almost weekly being changed. I used it for learning both digital & analogue wise. At DIYAudio I came across a strange resistor made by John a.k.a EC Design. It is quite complex to be made- although fully doable in my workshop. Here is my 'dream' Ri/v - the resistor that convert current out of the DAC to voltage that goes to the tube grids. In my case its valued 33ohm.


A beauty isn't? (hopes John wouldn't mind I use his pic.). Why all the troubles? well this DIY resistor promises low capacitance - non inductance - and high wattage. All good for tiny current out DAC.

What I can not get are a coated resistance wires & patience for winding it.  Being a naughty DIYer like me,  I have once hammered several of those white bricks, just to see what's inside :). It turned out that for low R value the R is wire wound. Higher value some kind of carbon film. Hmm..this brings me to an idea..

So, armed only with double tapes and 2 pairs of white bricks 39R/5W here we go :


The tools are 1 hammer, 2 pliers, cello-tape, double tapes (thick & thin semi transparent), scissor or a cutter, a tweezer.teflon tape...thats it.


Take care not to break the wire from the end cap. Tape the wire to the cap & legs for strength



Thick double tape both end stripped & glued to the table and start making zig-zag pattern of the first wire lay up about half of total wire length (my case 28cm ~ 1ft). plan for the double tape length.


Cover the first lay up with thin double tape, next lay up


The first lay up is now 'insulated'. Start now with a second layer, now you know why I need a semi transparent tape :).




Measurement shows a lower R value than the original 39ohm. This happen once you unwind the wire from the ceramic center piece. Not to worry & its closer to my 30ohm target :).


Cut both ends, add another thin double tape, peel wax paper on both sides & start rolling


Two DIY Resistors :)


Rolling & teflon taping. measurement shows quite acceptable 'tolerance'. After rolling the tapes the R value goes higher a bit.







In action :)


The sound? well the 'cocoon' beats my Philips metal film for sure, and about a 'tie' with the pink Takman's, not yet decided though ;). Highs of this DIY Ri/v are quite breath taking...



But...hold your horses, recent discussions on DIYAudio with EC reveals that this DIY Ri/v is not completely non inductance yet. But it can be made non inductance, using a so called Ayrton-Perry_winding and for this I need to insulate the wires using a proper lacquer. Not so hard to do compared with 5m long EC's wire :).

So ..my adventure is to be continued...thanks John..

Selasa, 18 Mei 2010

Don' buy just a faucet - buy a heavy one!

Did you ever change any of your water faucets at home? How often and how many already?. Well I'm kind of lost my count here, and add another count last long weekend..sigh...



There..the bad faucet number XX..totally new, bought in a well known hypermarket (c4), a well known brand (k**m****r), hyperlight, hypershiny and last but not least, hyperItaly as shown. This thing cost about 1.5USD, comes complete with thick lovely blue hanging plastic tag and a teflon tape, nice bonus..o is it?.

The usual routine: closed the central water tap, removing the old bad faucet number XX-1, happily wrap the teflon tape (my favorite thing to do)  laa..di dam..di dam..put and turn the number XX to the wall socket, there goes the wrench..laa di dam...la..di..WHACK..what the...? Is this faucet that bad? It's just can not took even the light twist of my light wrench..whaaa...!!.

Did I need to comment on the design - material - fabrication? No..not a bit. Even the fluorescent colored plastic faucet is doing better than this hyperItaly. This is an outright robbery...where is the Ombudsman here? Hellooo?..knock knock!.

Do me a favor. Just buy a heavy real brass nickel chrome plated faucet. It will cost you 10 times more but will safe you 10 years of not using those red plumbing wrench...while I left here with very expensive teflon tape...thanks for reading..

Jumat, 09 April 2010

Good, and not so good design, Plastic Clip & Microphone Jack





I've thought that after posting mainly DIY audio stuff, its time again to look at design things. First, a 'sorry' microfone jack for my son's electric guitar and second a deceptively simple clip.

I've bought these poor jacks to replace low quality cable that comes with the guitar. Just rush to nearest small electronic shop around the corner & found very low quality jack, asked for another but to no avail :(, My son just want to play (read: make noises..) so I grabbed a pair knowing I can fix them temporarily.

So whats wrong with these sorry jacks? See pic below, the paired one. Built is very poor, thin and flimsy solder prongs, cable grip that's too short to fully clamp my light brown Canare mic cable.

But the biggest problem is that the ground shank (negative) does not stay fixed to the threaded body, in fact you can easily turn the shank relative to the body. Now that's a good design or what ?. I can imagine my son will make more noises - pops and cracks all the time due to poor ground contacts...

The temporary fix?, I've soldered the prong to the body - so that's solved. The Canare's sounds cleaner and more full bodied against noisy giveaway cable :)..

Since I know this is a temp-fix, I bought another pair, a much better build and sturdier thicker metals and you can not turns any of the shanks. The clamp just can grip the cable nicely with slight overlap. Just a week ago or so the sorry jacks gave up, so 10 minutes jobs with this new jacks and my son can make more noises...sigh..

What I don't understand is why on earth you make things so badly? You'll do badly on the market, you've spent at least the same amount of money and effort to produce them and what a waste of resources? Think about the shiny metal plating process that pollutes river?. Beats me..that's why we need industrial standards, in our case SNI-short for Standar Nasional Indonesia



Now to the good executed design..a simple plastic clip shown below. What are they used for? It's used originally for bread plastic wrapping, yes to tighten the 'bag'. I always hate the green tapes - while they are a breeze to apply for the store clerk but not to us the user.

Now somebody very smart have made both the store clerk and us happier. this clip is very easy to apply and to detach. All plastic design philosophies are used..in short, one piece, integrate all functions in one single part.

Lets see, there is a hinge, a toothed ribs for better grip, there is a lock that function very well, easy to lock, not easy to open unintentionally but easy to unlock ..now..this locking things sound familiar to me? an echo of my past..yes it is one of the design requirement for an aircraft door - even after crashing !...how about that!.. for a simple plastic clip?

None of  any car doors in the world even come close to this clip! Now don't get me started on public transport doors in Indonesia ha ha....(this one is unique..you can throw garbage and yourself in and out the door while driving....)

And the best part of this 'simple' clip is...see for yourself....:), my 4 thumbs up for the clip designer

Minggu, 14 Maret 2010

iPod Mini alive again!

Last year sometime in November we got lightning strike at home, just when my daughter sat in front of her (and our family) PC..She told me blue light appears accross the main board. The PC is dead, so does the cable modem, the printer and my daughters iPod Nano..sigh..but thank God she is OK.

The Nano got so hot she put it in the freezer!.I wasn't at home. Alas it was over then with it. So with no budget after buying new motherboard-second hand-Phenom X4-cable modem, her dead iPod mini is my target operation. Thought that only the battery needs replacement.

Spend a half afternoon to read how to open the thing-and finally have luck to change the battery after admiring the Wolfson DAC-Phillips chips-no wonder people like the sound of this 1st gen mini. Apple just wants only  the best for their products that time. But the display shows discouraging message..a frowning face appears then followed by an URL..bah..., must be the mini drive that gives up..so did I..throw a towel.

But with luck and persistence of a DIYer-I found this link..of the late Mark Hoekstra, who back then in 2007 have already done it!..replacing the venerable minidrive with 4GB compact flash memory card. A couple month later and it's just yesterday I found a 4GB Transcend CF card that known to be working well with iPod. I've spent a couple of hours and yes..it works, here are the pics. Veel dank Mark..you've leave us wonderful knowledge..

The mini drive-new batt-and  CF card
This thing makes the old iPod mini to a cult status..(Wolfson 8711 DAC) and yes there are people out there tweaking this little guy !

after restoring with iTunes....

With backlit ON & the busted Nano..Apple proprietary chip in there and a korean memory chip..:(

This morning I've made my daughter happy, also my son who got new iPod shuffle for his birthday to day..not to mention my wife who otherwise will spent more money!..So, please throw away then your iPod 1st gen...to me :).

Senin, 08 Maret 2010

Sony CDP950 hardware mod-wooden transport

After modding this Sony CDP950 heavily, these are the results.
Electronic wise, well never ending tweak that is :). Found during a recent blind test with a poor result ha ha..It turns out that the R value for current to voltage is very important, and you need really second-third even fifth opinion to judge the sound when you're constantly modding and didn't know anymore of 'correct' sound. So it was my take for another lesson.

Hardware wise I consider it finished..yihaaa!. Acrylic plates does wonder and also a quite difficult task in taking care of the old transport. It's all wood now :)..not the famous Phillips VAM or something like that , I dubbed it Sony WAM :), short for Wood Augmented Mechanism..just kidding :). here is the tranny cover

The 'new' Sony CDP950 'Lampized'..thanks again for your mail Mr. Fikus..
A broken beam of my workshop roof, or a part of it :) & a design drawing
Made some noises..
Fitting & mating plastic, wood & the CD player..

Adding a nice old teak top layer
underside of the 'WAM'..
Nice gold plated springs..(guess where the h**** I've got it..)
Fits well..
fastened & adding brackets..
Well..more pictures this time. As February was a really busy times. Also recently this CDP yet again showing another sickness. The CD just turns very fast counter clock wise. After cannibalizing my 'spare' Pioneer LD player for few chips, particularly the spindle motor driver chip. this old guy just runs well again. Now back to that never ending tweak again...thanks.