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Interest check on learning modifying

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Post by kowtim Thu Jun 18, 2009 2:07 pm

Hi Guys

Whilst catching up with some of the new threads here in the equipment discussions section, I came across the Reclocking The CD Player thread.

In this, our fellow member Pocoyo makes a rather pertinent point that things are easy to mod for those out there who have the skills. But what if you don't have these skills?

This got me thinking, are there any folks out there who would like to learn how to modify their audio equipment? Naturally their are plenty of risks involved... but there is conversely an incredible amount to be gained!

To be able to service, tweak, fiddle and rebuild ones audio gear is truly an amazing satisfying rewarding and confidence building experience.

So... are there perhaps a few people out there that are willing to pay to be "competently" coached to learn things like how your gear works, soldering, changing caps, resistors etc etc.

I have a few ideas on how I would go about this that would bring enormous value to those who participate.

And so.... any bold brave gung ho guinea pigs?! Very Happy

Regards

study
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Post by hangleng Thu Jun 18, 2009 3:42 pm

I will be the first to participate if the timing and location allows. But how do you want to go about it? We are from various places. TQ

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Post by pocoyo Thu Jun 18, 2009 4:10 pm

uh...firstly i felt honoured that someone took my comment quite seriously. secondly, i don't mind participating if the time, location and cost is convenient.

TQ

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Post by azri Fri Jun 19, 2009 6:51 am

im interested also, have one cd63 in genuine condition
btw, do u know how to assemble a tube preamp?
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Post by cmboy Fri Jun 19, 2009 10:30 am

azri wrote:
btw, do u know how to assemble a tube preamp?
Basically,
1. Learn the fundamentals of how tube amplifier works. Need to know wiring essentials and fundamentals.
2. Ascertain which circuit/schematic you want.
3. Plot a suitable chassis on paper, get someone to fabricate a thick gauge steel chassis with cut-out holes for tube sockets, volume control, transformer, mounting holes...the works.
4. Source and obtain the correct parts for the intended circuit.
5. Do point to point wiring or DIY a tag board. You can also design and utilize PCB (more design and fabrication of PCB)

OR buy a ready to DIY kit from somewhere.

Its harder to build a quality pre-amp than power amp for obvious reasons relating to circuit fundamentals.
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Post by kowtim Fri Jun 19, 2009 11:40 am

Hi Guys

Wow... considering the thread is less than 1 day old... I guess there is indeed some interest!

Assuming anything at all happens, location would be at my home which is in Sg Buloh, Kuala Lumpur. Day would either be Saturday or Sunday.

Now, it should be said that anyone wanting to learn the "art" of modifying equipment must have realistic expectations about the whole thing.

From what I can see so far reading between the lines, there seem to be certain "types" of interest here in this forum...

1. Those that want to learn how to modify generally ( Most usefull longterm in my opinion and what I myself had intended to coach )

2. Those that want to execute a specific mod ( Perhaps they have "audio product A" and various forums say install component/s "X" into it to gain "improvement Y"...other than this they have no interest in modifying )

3. Those that want to build a complete product from scratch. ( For the real men out there )

4. Those that want to build a complete product from a kit. ( For the smart guys who see how this gives you such a headstart! )


So.... we have identified some areas of interest.

Now.... items 2, 3 and 4 require rather intensive and specific "one on one" coaching.

As cmboy has wonderfully described, some projects require mechanical skills as well. This is another area where many folks need some help.... there are sadly quite a lot of "chekai" looking projects out there. But there are some rather decent looking enclosures out there these days at rather affordable prices... so not much excuse anymore for that "chekai" look! lol!


I myself am interested in helping out the zero base guys who know so very little, maybe nothing.... but I am happy to do one on one coaching with those who have a very specific need.

So... perhaps we can have a show of hands and refine things somewhat.... Just what is it you
guys and any others are interested in? And what skills do you have
already?

Regards

study
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Post by kowtim Fri Jun 19, 2009 2:28 pm

Hi Azri

Yes, I would know how to put together a tube pre-amp. These things are actually usually quite easy if you have the right transformer for it's power supply. But this is contingent on a good schematic or circuit diagram being provided.

Why do you ask? Have you come across a good kit that you want some help putting together?
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Post by tycham Fri Jun 19, 2009 5:04 pm

Why need mechanical skill? To open up casing? These I think is still manageable.

But, over here you would need to know Fourier Transform to listen to a certain integrated amp because it involve harmonics.
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Post by kowtim Fri Jun 19, 2009 7:41 pm

Hi Tycham

Based on my experience, what you say is true 70 % of the time. You do not need much mechanical skills. Indeed, opening most things would just require a simple philips or posidrive screwdriver. Ocassionaly, you might come across some allen key fasteners. That should assist geting the case open.

But as always, things are never that simple. Many cases are easily opened as you say. But... the problem is Tycham that removing and replacing actual components from a circuit board requires that you have access to the rear of the circuit board.

To remove the circuit board to gain access to the rear usually requires some desoldering. Assuming you have the skills, then this presents little problem.

But what if the fasteners that secure the board to the chassis are "stuck" or damaged? I have come across many allen key fasteners that have "rounded" hexagons and cannot be easily removed. This requires mechanical skills.

Some folks may want to build their own circuit and place it into a new (or sometime pre-used) enclosure. Some might want to add in an IEC socket. Again this requires some mechanical skills.

Some Luxmans require total dissasembly to gain access to all the circuit boards as some are located behind the front panel. What happens if you end up stripping some threads along the way? Again, we are faced with requiring some mechanical skills.

Hope that points out why we need those mechanical skills!

Apologies Tycham, but I think that relating Fourier Transforms as being necessary to listen to something in the context of this thread is potentially confusing. With great respect would appreciate if you could perhaps start a new discussion thread of your own on Fourier stuff and applying it to listening to equipment.... it just might end up confusing an already tough thing here!

Regards

study

P.S. Thank you very much for pointing out to me that 405 for sale. Unfortunately Im only after a 405 for a short while and they are located too far away from me. But I do appreciate your gesture...
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Post by tycham Fri Jun 19, 2009 10:37 pm

Hi kowtim

Thank you for your clarification.

The mention of Fourier Transform is meant as an analogy. Sorry if it cause confusion.

I have recently also encountered an allen key fasteners that have become "rounded" hexagons when I overtighten it.

From my experience, I used a "star" screw driver about the same size as the rounded hexagon, poked it in and tilt it at a slight angle and I was able to unscrew the damge fastener. I would say that the grip is still strong enough to be able to turn the fastener. Maybe this would be helpful should anyone encounter the same problem.

I thought you were going to buy a 405, so when there was one for sale I kept you posted.

Anyway, do keep posting on any further development on this thread.
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Post by kowtim Fri Jun 19, 2009 10:57 pm

Hi Tycham

No worries about the Fourier stuff. I just want to keep the topic focused. I see that you are very descriptive about sound. Perhaps you should start a new thread about this Fourier stuff and expand on it there.

Your welcome for the clarification. Just for your information Tycham, there is a product out there that I came across at a metal tech trade show here in KL a few years ago. It is a greyish paste... sort of like toothpaste, but thicker and "grittier".

You use this product when you have "worn" fasteners, similar to what you and I are describing. What you do is you place some of this stuff on your worn out allen key fastener, and then you unscrew it with an allen key as before. What this stuff does is it goes in between the gaps and keeps the fastener and allen key (Or philips screw and screw driver) "gripped" together.

Amazingly, even with some pretty worn fasteners, you can get the fastener out!

The problem of owners over tightening things as you describe is a big one. I have come across bent / cracked panels and damaged tweeters due to over tightening on the part of the owner.

Regards

study
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Post by tycham Sat Jun 20, 2009 12:12 am

Fourier series - forgot to bring it with me when I graduated. Anyway worn out fastener should be replaced.

Overtightening of fastener! Maybe a thread on the lesson on torque forces should be started.


Cheers
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Post by kowtim Sat Jun 20, 2009 12:46 am

tycham wrote:
Anyway worn out fastener should be replaced.
Cheers

Yes indeed. But to do this, one has to remove it first.

Very Happy

Regards

study
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Post by chua55 Sat Jun 20, 2009 12:53 am

concentrate on one topic follow by another topic. Start with the safety follow by the basic, case studies of failures follow by improvement, then on to the advance such as use of digital scope (that come with spectrum analyzer) for advance tuning and troubleshooting.

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Post by pocoyo Sat Jun 20, 2009 2:23 am

for me i don't mind learning anything new...as long as it is beneficial for me...i myself is an engineer..i know how to do electrical works..but sadly not electronic because i'm only a building services engineer...okay back to the topic...i got an audio alchemy dac in the box lying in my cupboard for quite sometimes...and i know that last time many peoples find this dac a good pet project to modify...ie change the power supply, opamp, regulators etc...so if i have the proper knowledge..i also would like to join the band wagon to try to modify this.

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Post by kowtim Sat Jun 20, 2009 8:32 am

Hi pocoyo

It's been many years since I heard of a dac in the box. That sounds like a great project indeed. Good one!

If you have some familiarity with electrical items as you mention, you already have a good head start pocoyo.

And so... we potentially have one individual with a specific project. Kewl ! sunny

I would like to let this thread run till the end of the month pocoyo. This would give others the time to consider joining in and possibly even looking for their own pet project. Then we can see if we can come to some formal arrangement that we can agree to.


Regards

study
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Post by teleman51 Sat Jun 20, 2009 9:46 am

Great, kowtim,

I more of a vintage gear guy & had a all tube preamp project on my mind for some time now.
That's because I have a Leak Stereo 20 power section w/out the matching preamp.
Have the schematics & all and was wondering when & how to get started.
Great to have you start the ball rolling Very Happy


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Post by kowtim Sat Jun 20, 2009 10:24 am

Hi teleman

Fancy meeting you here Very Happy

If you have the schematics, that's great. But this is in my opinion a very advanced project that will end up perhaps costing you more than acquiring an original unit!

May I suggest you try and look for an old varislope over at echoloft in the diy section. Get one and refurbish it. At the end of it all you will have the "correct" looking and matching product and something worthy to sit beside your Leak poweramp.

Or.... go online and buy a more modern tube based preamp kit and build that as a project.

Not wanting to dampen your spirits, and you are free to do as you wish teleman.... but building a varislope from scratch is simply a bad idea from multiple perspectives!

Do ponder on it...

Regards

study
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Post by teleman51 Sat Jun 20, 2009 11:51 am

Hi kowtim,

Just read your post & fully understand your reasoning. Shocked
Yeah, it's really an advanced project I agree.I was pondering on this for about a year now and tried getting one over ebay, but was outbid every time.

Old Varislopes or Point One stereo units are hard to come by in Malaysia.Only saw 1 Point One Stereo at a friend's place in Tanjung Malim.

Heard the sound of his all Leak system & loved the old type of sound since then.

Was considering a modern preamp too, but didn't really get started as I need encouragement. Razz

And yes, building from scratch requires real skill.I have a "bit" of tube knowledge, but I ain't no real tube tech, if you get my drift.Have a small collection of NOS vintage tubes, as I started out on vintage tube guitar amps about 10 years ago.
Have several with me right now, mostly Fenders.

I would love to meet up with you and Sungai Buloh isn't on the other side of Malaysia.And I'll buy the coffee.May even bring along my Leak amp for you to check out. Laughing PM me soonest so that I can come over.

Nothing better than spending some time with a hifi brother kaki.

regards,

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Post by cmboy Sat Jun 20, 2009 12:28 pm

Hello teleman51.
I don't know about your actual taste but allow me to say a few things about Leak (or even Quad for that matter). Sorry if a bit off topic.
I've played around with Leak for donkey years to know enough about them.
1. Leak power amps are perhaps best sonic quality with passive pre, aka a quality volume pot, either installed into the amplifier or external. Leak power amp sensitivity is quite sufficient for direct patching (through passive pre) to line source equipment such as CDP, tape deck, etc. With a passive pre, there's less colouration, sound degrade and just more transparent. Speaking in broad sense, a tube or solid state preamp will do just the opposite in various degrees but offer more drive, more aggression and some color.
2. Leak, Quad or vintage pre-amps are a no-no if you're looking for highest fidelity in most departments. Those are dated designs and rather noisy by current standards. Many Leak pre's use expensive EF86 tubes and perform best with quality NOS tubes. Its up to you for choice. Of course you can construct a similar tube preamp but it must be done to highest construction standards for best S/N ratio and near zero hum.
3. Many people who own Leaks must replace all the caps and resistors to the best quality possible to give it a new lease of life. Its silly if "buy and install NOS or the original parts for restoration except good tubes". Kiwame, Shinkoh or great quality resistors sound best in a Leak and you've a choice for quality Paper in oil (quite expensive) capacitors for a smooth, sultry and a little laid back sound. Ok..won't go into component debate as the amp is only one part of the system and the performance is also dependent on the rest of the chain.
4. If you have the ST20, buy and use JJEL84, perhaps the best current production and most affordable output tubes available on the internet.

Good luck.
3.
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Post by kowtim Sat Jun 20, 2009 1:35 pm

Hi cmboy

It is obvious that your extremely knowledgeable on tubes... I would easily say... your knowledge on them surpasses mine. And technically, everything you say is indeed true.

Having said that, it appears to me that you have fallen into the trap that so many people who modify stuff fall into. There is just too much emphasis on "designer" parts and absolute sound quality and wholesale replacement shotgun style of everything inside with designer brand stuff everywhere.
Please have a look at my comments in the Quad 606 thread to understand my philosophy on this better.

I have had the fortune of consulting technically some extremely rich clients and along the way becoming friends with them. Some of these guys can afford to buy any car they want in the world. Yet, some of them will spare no expense to buy and restore the most humble of cars.... Morris Minor, VW Beetle or an old Mercedes sports. It is these that they treasure most... not their Ferrari's and such ( yes... they have these too)

There is more to life then performance and speed when it comes to cars. Similarly, there is SO much more to audio then absolute sound quality.

One can do what they want and spend what they want on this Leak. Yet at the end of the day... there will still be dozens of amplifiers out there that will simply blow it out of the water. So why bother modifying it?

Instead, these things should be restored cosmetically and functionally. Spare NO expense doing that. Get a nice set of period speaker for them that have REAL wooden cabinets. Get the correct matching preamp. Some 60's furniture to go with it would be perfect.

There is nothing wrong with listening to well restored but UNmodified 50's and 60's audio equipment. Indeed there is often much joy in doing so. Forget sound quality and designer brand names of components. Just get them looking mint and working as they are supposed to. Then enjoy them for what they are.

Please don't take my comments above personally. They are in no way intended to have a go at you. I would rather these vintage things be enjoyed as they were originally meant to be...


Regards and peace

study


Last edited by kowtim on Sat Jun 20, 2009 4:09 pm; edited 1 time in total
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Post by kowtim Sat Jun 20, 2009 1:45 pm

Hi teleman

Im glad you can see where I was coming from. You know.. it's very easy to hype someone up. But at the end of the day, why do this if you know that the project may not succeed or be worthwhile. Hence my reluctance to do what you originally asked. I just can't see a worthwhile ending building from scratch a varislope.

May I suggest that you double your efforts in locating one. I am sure in the UK or the net that there must be a group of Leak enthusiasts in a forum somewhere. I suggest you join them... and then write to the forum saying that could any member locate a unit for you. Give them your budget. Explain that you are in Malaysia and you have the poweramp but none are available here. I am sure someone will help you.

If you cant or dont know or are reluctant to do this, then you can pay me to do it for you...hee hee. Acquisition of rarities is something I am good at Smile

Im really looking forward to that coffee mate!!! I have ordered the last bits I need for my speakers and they are on the way. Hopefully another month...

Regards

study
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Post by teleman51 Sat Jun 20, 2009 7:02 pm

Hi kowtim,
Thanks for the reply.
Actually, I was very much considering having a good passive preamp builtwith good parts.A very simple version with just about 3 inputs.Plenty of schematics on the net.Have several on my PC and intend to print them out.

Passives may be my best bet as

a) are simple to build.
b) almost no maintenence like expensive EF86 tubes affraid ,transformers etc.
c) can spend my money on good pots,switches.rca connectors & casing.
Good quality connecting wire aslo important in passives I heard.

So cmboy may have a point there on the fidelity issue with tube preamps.
Heard about these issues from several places.Dated designs they are and there are so much more new designsthese days.
So cmboy I can completely agree with what you have written.
I love vintage equipment, but not to the extent that I would sacrifice good quality sound, just to make sure that it's truly all vintage.I went that route before with my guitars and guitar amps and got burnt financially. Mad

Actually kowtim, if I find a leak preamp at a decent price I wouldn't mind, but if not I'll just go the passive route.

I'm sure Sungai Buloh has some really good coffee mate.!!.Looking forward to meeting up with you soon Very Happy

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Post by kowtim Sat Jun 20, 2009 7:50 pm

Hi teleman

Earlier it was you who chose and said that you wanted an all tube preamp as your project. Then you add that you have a collection of vintage tubes.

Now you are saying you want a passive as you dont want to deal with tubes and maintenance and such.You also now bring up the need that you want good sound quality.

It seems you are an easily swayed person Smile !! But as it's your project of choice, that's your privilege. Very Happy

I personally don't see much value in doing a passive pre as a project here to learn on. It's more about as you say... buying the correct quality parts and placing them correctly in a suitable enclosure.

From your latest perspective and your point of view, this would indeed be the best bet for you. Perhaps cmboy can suggest a good passive combo for you. The good news is there are indeed no shortage of options available.

Just thinking of it... there is this locally made passive pre but also with an active stage teleman. I think its made by Euphonic Research. That might be an excellent choice for you. I think there was one for sale here recently.

I thought you were "bringing" us some nice coffee, not buying it near my place. Thats cheating. lol! Laughing

Regards
study
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Post by cmboy Sat Jun 20, 2009 8:31 pm

teleman51 wrote:So cmboy may have a point there on the fidelity issue with tube preamps.
Heard about these issues from several places.Dated designs they are and there are so much more new designsthese days.
So cmboy I can completely agree with what you have written.
I love vintage equipment, but not to the extent that I would sacrifice good quality sound, just to make sure that it's truly all vintage.I went that route before with my guitars and guitar amps and got burnt financially. Mad

Trust me, don't bother with Leak pre-amps unless you'd like owning a showpiece.
FIrstly, the potentiometer and selector pots are OLD 40 years or more and 40 years ago tech. Its inherently noisy (as with noise rejection, not so much any crackle). They'
re made with phenolic boards and thats not exactly high standard material currently and compared even to a China made RM1.50 pot from Pasar Rd. Servicing with switch cleaner is only a temp fix and not an ultimate solution. Old mechanical parts are not made to last forever, especially in British vintage pre's.
Secondly, if you do find one, many capacitors and resistors need to be replaced (unless you find one thats been done up meticulously) as I'm cocksure those Allen Bradley resistors would have changed value up to 100%. Most of those coupling caps would have been leaky and also needs replacement. Again, they're 40years ago stuff and EU or Brit components weren't the best. The Japanese did it better by miles and lasted longer amazingly.
Ok..If you insist, a nice simple pre-amp can be based on single 5687 tube per side which is still cheap and easy to obtain. Its a one stage triode preamp without much coloration compared to the likes of Marantz 7 pre. Personally, I don't like Maranzt 7 kit pre for a number of reasons, and I've seen a few local projects that are actually flawed. Another nice circuit for the Leak is the Foreplay cathode follower type, utilizing 2 pcs of ECC82/12AU7.
Whatever it is, a quality DIY pre should achieve near zero hum and very low noise floor. Its all in the careful and thoughtful construction with star earth, short signal path with point to point wiring. Google around for more info on the circuit and construction info.
Lastly, I've said its tougher to build a pre-amp than power amp. The lower the signal level process, the tougher it is.

Kowtim: Don't worry buddy. I'm just imparting my past experience for general knowledge here. Never crossed my mind to be sifu, king or mr. know all here. I'm still on the learning curve and we never stop learning till the day we drop dead.
Kudos and my respect to you for sharing your knowledge to others here.
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Post by kowtim Sat Jun 20, 2009 9:23 pm

Hi cmboy

No worries....We're kewl! Everything you say is correct. You just need to keep on going down the path your on.... and one day I'm sure you will get to the place where you will understand what it is I am saying here and see what it is I see.

It would be an honor if when my speakers are done, you would be gracious enough to bring one of your tube amplification pieces to my place when teleman and Luxman and I have a "Luxman" evening at my place..

Regards

study
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Post by chua55 Sun Jun 21, 2009 12:03 am

The best pre amp is no preamp. Just imagine the output voltage from source is around 2.2V rms and when it reaches the preamp, it is attenuated down to milivolts level, and amplifier again. Well that's the way market goes.

For diyer, u have the choice to control the volume.

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Post by mugenfoo Sun Jun 21, 2009 1:14 am

There are some pretty good "homebrew" passive pre-amps out there. Not hard to make, but the devil is in the details. Its more a matter of craftsmanship and care in making those items.

As for reclocking CD players, there are many affordable devices that do just that, for a couple hundred bucks or so. I remember seeing some Audio Alchemy re-clockers at some Amcorp mall s/hand hi-fi shop.

It would be less risky than de-soldering and re-soldering the crystal Oscillator on the Cd motherboard. What more if its SMT. Unless u got bench tools to handle SMT stuff.

Maybe its more fun to DIY on analog electronics as the parts are more readily available... provided your hi-fi gear uses common industry components.
Jalan Pasar anyone.... ?
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Post by kowtim Sun Jun 21, 2009 10:55 am

A note to all those folks who CAN modify who are chiming in here...

It might not be obvious to some of you, but the purpose of this thread is to help and inspire those folks out there who have no idea how to modify, who feel left out, but are anxious to learn. It's for the beginners.

Coming in and talking about absolute sound quality, surface mount technology and so on might seem helpful but it serves no benefit "here". In fact you might end up scaring potential people off.

Obviously many of you are very advanced indeed... certainly more so than I.

I would suggest that you guys start a thread of your own on whatever topics are close to your heart and perhaps some of you will walk the talk and commit and conduct a "clinic" based on a certain topic for the benefit of those who are interested. I would certainly be interested in participating and paying.

teleman here himself had indicated he wanted to build a tube preamp. How it would have turned out had he done so is not the important part here imo.... one extra Malaysian taking the leap from consumer towards technically able and empowered user was the goal. But... thats lost now.

I want people to START modifying or restoring or servicing their own gear. To make that start I am, I believe, most suited for this more so than any of you.

Of course, if there are those of you out there who want to go about building reference grade gear.... you know who to approach..certainly not me.

I mean nothing personal by any of this guys and wish you will stick around... I hope you just step back and look at the bigger picture.

So...we have one great project here... the dac in the box. No one have any solid state pre or power amps they want to fiddle with? These are rewarding to do!

Hopefully we will have others.

Regards

study
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Post by teleman51 Tue Jun 23, 2009 12:14 am

Hi kowtim,
as usual you write really provocative, inspiring posts.I always look forward to it everytime I get on this thread. Shocked

You really get me thinking.But all's not lost now friend.I still want to hear you out on all you have to say on this thread.And you ain't finished yet. Very Happy
Most hifi guys I've met refused to share their knowledge on the modifying/service part.Maybe I hung out with the wrong crowd.

I really do know anyhing about referrence grade gear, so i'll just stick with simple stuff.

Want to fiddle with my old solid state Luxman kowtim? Or at least show me how, without killing myself in the process. affraid

Just name the type of coffee.

Cheers.Stay happy always
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Post by mugenfoo Tue Jun 23, 2009 12:33 am

BTW, was digging thru some old stuff, and i found this complete schematic diagram from the "Service manual" (not owners manual) for this old Denon CD player i bought like 15 years ago.

Great for DIY modders i guess.

Change a DAC chip or two, swap out the clock Xtal.... beef up the transformer... apply some RF shielding here and there... Smile
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Post by mthoi Tue Jun 23, 2009 11:54 am

Anyone have the schematics for a Meridian 506.18 CDP or knows where I can purchase one? Tx

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Post by mugenfoo Fri Jun 26, 2009 12:25 am

Wah.. that one u prolly got to "kawan kawan" some Meridian agent and see if they got such info from Meridian or not.

I'd think that high end brands would not readily release scematics to their products even to authorised agents as the prefer all repair work to be sent back to the factory.
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Post by chua55 Fri Jun 26, 2009 1:27 am

Welll. Trace the circuit diagram. I do that but I dont call it reverse engineering. It is a good exercise and it bcome second nature next time u see a cdp.

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Post by kowtim Tue Jun 30, 2009 5:58 pm

Hi Guys

Well.. it's the months end. Overall analysis would suggest that there are extremely few Malaysians here interested in learning how to modify, build kits, learning how to service their own gear etc etc.

I have learnt some things here. But at this stage, there is not much point in taking this matter any further.

Thank you to those who contributed to this thread.

Those who, perhaps in the future, may be requiring personalized coaching or consulting for any "personal" audio projects, (I will be charging fees for this), may contact me via the personal messaging system here.

Enjoy the music

Regards

study
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Post by teleman51 Tue Jun 30, 2009 11:04 pm

Well kowtim,

I'm sad to read your report on this thread. Crying or Very sad

Me personally, I was looking forward to meeting up with you if only
just to see what you were up to.
I was also looking forward to learning under you the finer points in servicing amps.Apparently I have no hope of doing this now or ever, as most of those
with the know how don't want to share.Looks like all that is lost now. Sad

Anyway, it's a sad day at the forum.

Thanks again kowtim

teleman51


Last edited by teleman51 on Tue Jun 30, 2009 11:17 pm; edited 1 time in total (Reason for editing : addition of comments)
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Post by pocoyo Wed Jul 01, 2009 2:42 pm

uh..i'm a bit amazed this thread got such a cold response... Crying or Very sad

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Post by mllum88 Wed Jul 29, 2009 6:11 pm

Pocoyo,

Dont give up, Iam new here but I started down the diy road first with improving the power supplies of my equipment which I learnt from a booklet published by Russ Andrews.

A lot of designers will confirm that 80% of the sound comes from a properly sorted out power supply.

Start first with low voltage and low current consuming equipment like cd players or dacs. These all have voltage rails that rarely exceed +/- 20volts and have a current consumption of less than 0.5 amps.

A simple mod to start with is to change first the rectifiers from the standard ones which is in almost all equipment to that of schottky ones and to bypass the power supply caps with high quality polypropylene capacitors of a lower value. These first steps alone will make a difference and give you confidence to go further and go down the slippery path of diy audio.


Tube amps all carry high voltages but very low current which can be deadly for beginners. Likewise solid state power amps whilst having maybe +/- 50 volt rails may have current consumption even at idle in the 10's of amps; hence my suggestion to start with cd players and dacs.


Try it out and once you do, you will be hooked on diy audio.

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Post by joeling Thu Jul 30, 2009 2:20 pm

Well, I spent sometime last night typing a response but just in time for the site to go offline.

Anyway, here's my 2 cents again. Start with a kit. A kit will enable the beginner to build something by following the recipe with step by step instruction. Less chance of a mistake & more chance of success. If there is someone to guide along the way even better. Often, after completing the said kit & music is flowing, there is still room for tweaks & modifications by adding / subtracting components.

After that, can consider something more adventurous like scratch build. In between, can consider to mod existing commercial offerings for better sound. U will be surprised by the quality (or non quality) of parts used in mid range & sometimes expensive offerings.

Eventually, you'll see the world through rose tinted glasses in that nothing is sacred & everything can be modded to improve further no mater what the price. There is nothing mysterious about making music from a few boxes stuffed with electronics....oops ranting again. Sorry.

However, before one undertake the above mentioned endeavour, it is worthwhile to at least know something about the nature of the beast. One must have some basic knowledge of electricity & the fundamental theories of it. For example, what is volt, amp, V=IR P=IV, line voltage of Malaysia is 240V AC, which bit is the live, neutral or earth etc. BTW, electricity kills. Respect it & all will be fine.

Kits that got me started : Bottlehead foreplay. Audionote Dac 1.1.

As a first scratch build, can try a SET amp as parts count is low. For linestage, can consider www.vacuumstate.com FVP. Quite complete schematics & sounds great too.

I also heartily recommend Octave Electronics for DIY supplies. Also Yeo from DIY paradise. In Singapore, I have good experience with Larry Hifi, Robert of Ahfart (spell ?), Frankie of WAL & that uncle sharing the neigbourhood as Frankie.

Regards,
Joe Ling
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