Hi everybody! I'm new guy here, but not new in portable audio.

Please take a look in my brif review of JX303 and some more stuff in portable cassette.

Unfortunately I'm Russian, so please use google translate which could help with it a little.

Here is the link: http://translate.google.ru/tra...m%2Fforum%2F11-153-1

Just ave a fun

Sorry for mistakes which google made in translation, if you have any questions just address it to me.

Hello Alex and welcome to the forum.

Nice first post. Be sure to credit "The walkman archive" for using his photos.

Here is my repair of the Japanese version of the JX303, the JX30.

index.php?board_oid=193392314111653483&content_oid=251519934117612111

And here it is finally restored.

index.php?board_oid=193392314111653483&content_oid=252082971018338708

I don't plan to only restore the JX303. I wanna totaly tweak it to reach the best possible SQ in this form-factor and this format. No more, but no less

Right now I'm just waiting for them to arrive, I think some tweaks will begin at the end of February. So why I use not my photos (Big thanks for them for all owner btw)

If you want to know more on my works on portable audio, just take a look into the site Http://alexmod.do.am (unfortunatelly in russian)

почему "к сожалению русский" ??? постоянно

Потому что подавляющее большинство здешних пользователей по руски небельмес.

Чтобы сразу ссылку открывали в трансляторе.

Nevermind.

I'm  really proud to be Russian )

BTW some time ago have to see on your lot of DD9 by Sony, but it's price is out of my imagination.

thanks for russian fortune

I'm proud too

Hello Alex, and welcome to the forum.

Welcome Aboard Alex!

Welcome here Alex,

Good to see that you are reliving those loving old walkmans.

I see you are using my photos in your article. I don't care too much when there is no economic activities around it, however, it's a good practice to always credit the authors of the images.

Remember that any image that you see in the Internet has it's author. And even if you can see the image for free, that doesn't mean that you can copy and use if wherever you want, and also for free.

Try to always ask for permission, specially if the photos has been taken by a photographer with so much care.-> that means that the photos are not simple point-n-shoot shots.

Keep the walkman alive,

Regards,

www.walkman-archive.com

Please excuse me for using your photos. It is done only because I haven't catch my own JX303 on hands. I estimate it will arrived next Monday.

BTW all photo used have your watermarks, i don't remove em and never say it is mine.

Thank you and another Walkman's enthusiast wich helps me make my childhood dream come true I appreciate you work.

I think this project (if it come to the end at all) can't ever became economical

There are no any cassette maniacs around here, in Siberia, Russia.

You're being a bit hard on your nation

You cant think so, this is only warning for English-speaking people to turn on the translator. Nothing more.

Agent, there is no need in sarcasm in this case, imo, it looks like he wanted to say "unfortunately english is not my native language", and I'm sure you did understand it.

+1 

It's a tough crowd down here in the Walkman tech section, eh Cris?  

you love to provoke, Isolator, don't you ?
why ?

Nice to meet you guys.
Beforementioned phrase was write down just because im don't want to seat down and translate all the text writing before in my native language. So it is just a kind of excuse for needs of using translating engines by all of you and possible mistakes made by them.
You think the thread isn't technical enought? So let me be a little more technical.

I wanna say that I want to restore the little beast named HS-JX303 and tweak them to have a best possible sound. According to schematic my plans is: cut-off the DOLBY chip, bypass DSL circuit, bypass with high quality ones or remove (if possible) all weak smd ceramic caps used in signal chain. Tweak the nominal of passive components to reach the best from tape head on high frequencies using it's real parameters being measured(inductance and resistance) and carefully reach exact needed EQ parameters (tune the amplifier chip used for playback and recording.
Then I think to try adopt some Li-Ion batteries for supplying the unit (and charge em from say ordinary USB port) The higher voltage with additional filtering and stabilizing reach to a more good sound, isn't it?
Then I plan to estimate the performance of modern headphone amplifier chip with charge-pump schematic, which omit the output blocking capacitors totally.  If all will sounds great  I 'l work on the appropriate little circuit board which suit in place of original weak HA chip. That is enough for first time I think isn't it?
All results at first I'l write down on the blog (the link was write down above). All englishmen ( ) must to use translation engine to read the news (sorry-soorry!)

Looks good.

Putting aside the banter and camaraderie on this forum, it is a nice change to read how technically competent some users are and can be when they try to improve on the original design.

To that end, I wish you good luck and I look forward to reading your future adventures with your new JX303 when you get it and any modifications that you make.

Oh, metad, I was only commiserating with agentorange! No offence meant, truly.

Knowing him as I do, I believe his post was intended as humorous.

The phrase I used: "a tough crowd" is said by comedians to describe an audience who aren't enjoying the jokes.

...& with that explanation I shall leave you in peace  

My bad, I was just playing with words in my daft little English way.  I guess the routine needs some work before I take it to the stage.

Metad, you see things that are not there!, remember?

blah

mmm..Thanks for the big interest to my thread

WOW! I catch it! Not bad lookin, transport is in workin condition, sound is absent.

Hope it is cap problem, not tape heads...

Stay tuned!  

Except the JX303 does not have an amorphous head. From the 30x series only the PX30/PX303 has the amorphous head. The range of models with amorphous heads increases with the 50x series, however only the early model 50x series have the bi-azimuth mechanism.

Unlikely to be narrow gap either because this is a recording model and the narrow gap would affect recording capability.

All that means is that the JX303 you have, had a limited number of hours use.

I have models where it is actually declared that there is an amorphous HX head installed on various PX303, PX505, PL505, JX505, JL50; all with varying degrees of wear on them. Does that mean AIWA made a mistake and fitted sendust heads on all those examples?

If somebody interested there is lithium accumulator for old cellular phone NOKIA 7280 which suits in case. Named BL-8N. If remove all the covering from BL-8N and delete some plastic pins for original accumulator clamping it take a place inside HS-JX303 and moreover there is a place for USB jack and 4.2>2v linear stabilizer.  I'd made it: put BL-8N inside and made a little circuit board for stabilization. It plays right now. Let's see how many hours it will run from 700mAh*4.2v=almost 3Wh.

BTW the BL-8N could be charged from any phone charger with mini USB plug, but have no indicator for charging. I just connect it to the charger in evening and disconnect now.

There would be plenty of people on here that would be keen to see how you managed to create a stable regulated 2.0V circuit to power your AIWA.

I use LM317 chip  in SOIC8 body, typical schematic. A couple of resistors used to tune the voltage ( 240 and 150 Ohm 1% SMD resistors leads to the 2.05v almost exactly) Nothing exotic.

BTW exactly 6.5 hours lasts, it is spinning and spinning..

The problem is that I cannot clearly see the sound quality potential of the unit because just haven't got any high quality recordings on the tapes. Found some old tapes with poor records. So at first I might to find the test tapes. Than If i think it is really promissing I can work on the playback amplifier with extra high quality, think to use some nakamichi schematic, say BX300

Are you able to post a photo of how you managed to squeeze everything inside the JX303?

What about using a LM7802 and a few capacitors (and a diode for reverse voltage protection) as an option?

What for? LM7802 is 20 times bigger in volume than my board at all.

It is aproximatelly 10x10x2mm. My board is just cutted-off  part from my big board of a portable DAC. So it looks ugly, but workin well. I dont make a photo. Possibly later..If I plan to deal some more tweaks with the HS-JX303 than I could made board for playback amplifier with dc-dc converters and with this ordinary stabilizer used only for supplying the transport as well.

7 hours and 46 minutes of playback on totally charged BL-8N till stop.

So HS-JX303 on playback supplied approximatelly 90 mAmperes.

Remember that i don't remove the Dolby chip but don't use it anymore.

Ok, whatever works for you.

If a generic LM7802 is too big, then there are always surface mount options available.

Such as the AP7335

http://www.diodes.com/file_arc...A%20AP7365_AP7335_v1

What portable DAC did you rob the parts from?

Im an author of the Alexmod project. Ultra high-end DAP, made em from 2010 aproximatelly 120pcs already was made.In russia of cause, but some work on Ukraine and Belarussian and 1 psc in Canada.

look here: http://www.head-fi.org/t/44538...cowon-i-audio-x5-dap

and here: http://www.head-fi.org/t/48466...ip-vs-ipod-vs-iphone

LM317LM is smd part :

Hi. Some times later I return to this little beast for critical listening (One russian fan of walkmans send me high quality recorded cc for testing).

I ommit the Dolby and DSL schematic, signal pass right from the play amp to the volume potentiometer, and than to the headphone amplifier chip. Sound is easy, clear, powerful and dynamic.

What is a really disappointment that is a tape/amp noise. I already forgot such a problem with modern digital DAPs. The bad thing, that the tape noise by itself is on par with the amplifier noise, not less than that. So even if I try do the best and made absolutely noiseless schematic even then it  will be clearly noticeable.

This issue don"t allow me to made an easy upgrade such as changing the headphone amplifier to the more modern and hi-fi chip. It will possibly improve the quality but don't do anything with the biggest problem ( I mean the noise).

So I'm in a big thoughts about future dealing with this AIWA.

If this JX303 will become the best walkman ever born I write you some information here..possibly. if somebody have any question, please feel free and ask me.

Good luck.

Hi Alex,

Sounds nice all that.

Can you post some photos of the process you're doing? I'm curious to see it

What you wanna see exactly?

Oh, nothing in particular (I'm not in such technical stuff), but just to see how it looks inside with all those mods.

So, from time to time my thoughts fly back to the unit.
I see a couple of options for improvement.
1. The first is relatively inexpensive and simple would be to install a new little board for headphones amplifier based on the chip LME4917. This chip is interesting in that it creates for his own work a negative supply rail, allowing herself a normal bipolar supply from unipolar power. Its use will allow more than 4-fold increase in power  and eliminate the electrolytic caps at the outputs for headphones. Increase the quality will be, but the limiting factor will likely noise of playback amplifier  of  this AIWA.

The level of quality will be comparable (and possibly  higher), with a certain apparatus SONY WM-D9 which used a similar (but more old and descent) circuitry.

2. The second version is, in fact, no alternative superior upgrade for JX-303. In this case, I will design a new bipolar converter that will get + /-12V (and 2.4V to power and transport) from single lithium battery, a standard audio section is totally removed from the player, and it will replaced with a new playback amp on the base of one of the most low-noise op amp available in a compact body SOIC LM1612 (or possibly the LME49820/LME4562, as an option). The normal power supply can  be used for ultra high quality headphones amplifier chip THS6012 that is used by me in the project aleXmod have mentioned above. In the event of such a global this upgrade will most likely have to give up with the recording function as well as compromise with a significant reduction in operating time (remember now it is 6+ hours from full charged batteriy). The result is, I think, may be a result in the form of the really best in the world walkman ever made . All the "legends such as SONY DC6 or DD9", mentioned at the beginning of this topic will be "nervously smoking in aside".
The second option is possible in principle, but I was tormented with inability to properly test the constructed device. The fact that I do not have available high quality tape recorders and good quality tapes as well. Available tapes  has a very high level of intrinsic noise. To my ears it exceeds or equals to original playback amp noise. I can not evaluate the resulting level of quality of the obtained device, and whether is it  necessary to engage with this issue? ...Im keep on thinking

Hello everybody. Some times comes out, i had bought 1 more compact cassete player for maniac needs and stil want to made the best sounding cassette walkman ever build!

Now it is a KENWOOD CP-C7, i think it is rare SONY WM-550 clone, about 1988-1989 years of production. This black walkman is in a pristine condition and possibly just best looking/laconic walkman ever made.

I shall try to do my best for making them to sing with a kind of euphonic voice

Keep stay tuned, folks!

P.S. just try to measure wow&fluter via wonderfull software (can be found here)

Without any maintence the CP-C7 shows not bad result just as a 0.23% RMS of W&F.

P.P.S Also I catch the wonderfull WM-D6C unit, which i think i can totally rebuild as a best ever made sounding recording walkman. i think i shall start new thread about legendary WM-D6c, possibly someone has an interest for this issue in the future.