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djcl.ear 24th June 2005 02:44 AM

Tascam CD-302 Modifications
 
Explanation:
The Tascam CD-302 is a dual DJ player that spite it’s solid construction and relative noiseless operation(98 DB s/n), has plenty areas for improvement.

This CD player was the firm first venture into the Dj world and so the engineers put a lot of effort and creativity and crammed it with plenty of functions and unseen DSP processing and unlike other DJ players, most of those functions are user configurable via a complex menu where many parameters can be set.
However the typical DJ usage conditions are far more stressing than the usual studio environment were Tascam’s gear usually resides. As a result of all that, the machine showed temperature related problems and sound deterioration.
///I often share the idea that amplifying audio is similar to projecting pictures; if the resolution at the source is low, increasing its size will show a “pixelated” image, thus any improvement at the DJ source would be very easily appreciated specially with the recent “revealing” new levels of quality of Pro Audio amplification gear, and better acoustically designed venues.
Conversely several firms are announcing ways to tap the 96/24 format into new Dj mixers and PC software, so Dj “real time” controllers wont take much longer. Personally I very much welcome all of it…

After several mods to CD-302 I have already benefited from the added player performance: Improved the Analogue output stage( got replaced Op amps and caps), replaced KSS-213C for KSS-213D/&F(still evaluating but a ++ already) , replaced power caps for bigger ones, ventilated the coffin and filtered the dust from entering thru the tray opening.

Now I am at a point where I would like to ease its heavy DSP processing. Mind this particular player not only reads and reproduces the audio data, it simultaneously calculates and provides Tempo info(like most DJ CD players), allowing for the variation of the music’s speed using the dreaded sample conversion.
Not stopping there, this particular player ALSO calculates the key or musical pitch info, allowing for independent and simultaneous variation of the music’s key, something very useful for “harmonic mixing” .
I believe this is the first DJ CD player to have been modded by DiYers so far I know, … in a field where plenty of people could benefit from bringing audiophile advancements, if not to get to those high levels at least to vastly better the existing ones

Of course the algorithms have a definite amount of intelligence and sound limitations already built in, nevertheless their operation could be improved to some degree…, as it has extensively been shown in this forum.
And I always guessed that since it is possible to run this CD player so much into its limits, it would be very easy to notice any change induced by reducing its operating T° and bettering its supply capacitance or any other effective mod.
Mind there are audible artefacts when the pitch/tempo change is activated, increasingly so according to the amount of change applied. Those sound defects seem to be the exact opposite of a typical DIYer reviewing new film caps” Everything was clearer, sharper, more resolved, with much better rhythm and timing, and excellent instrumental and reverberant decay”. Note that this deterioration of(mostly) high frequencies mostly occurs when the actual control is being displaced and partly settles when is left into its new level…

Additionally, I noticed several IC s are running quite hot, which is very easy to understand since a DJ CD player operates very similarly to a Computer processor: The tempo slider -either augmenting or reducing- the speed, what it does, is to increase the processor speed(very much like overclocking a CPU): The higher the distance from cero position, the higher the voltage the IC s receive. The same occurs with the Key control.

So I see several possible tasks.

The Plan:

A-Install good film caps to stabilize the IC s power supply
B-Adding bypass capacitors next to each IC to reduce the ground
loops area and inductance
C-Install a heatsink at each IC
D-Ground the heatsink


My first IC candidates were chosen because of the high temperature they show:

1- Sony CXD2585Q
2- ROHM
BA 5974FP
943193
3- Each player(CD-302 is a dual CD player) houses 3 (three) units of:
TMS 57070FFT
HF 89NKLNJ
4- Each player has 2(two) units of:
Oki
W51181650-601K
TAIWAN A554


I wrote this thread as the mothership for ideas, additions, corrections and comments. All welcome!..

The plan is to post separate threads for each IC work for easing the focus, it will already follow with IC s N°s 1 & 2, since those are the ones I’ve gathered schematics to.
And no I haven’t yet obtained the CD player schematics, but have some for IC s . I will later post some pictures made of the analogue outputs.
Thank you.

dial 19th October 2006 05:45 AM

djcl.ear ,
Are you still here? I really need some help with my cd 302.
Could you please post some links to all the information i have heard you speak of?
Thanks

djcl.ear 23rd October 2006 10:54 PM

Well, yes I'd like to help anyone interested in CD-302.

Definitelly I would start by repairing it before attempting any modification, and the simptoms you speak of at your other post about this CD-player are rare... Apart from regularly checking forums, I have had the chance to keep track of several units of this machine and none elsewhere produced what you say yours does...

Anyway you might try a visit to:
http://www.kellerstudio.de/repairfaq....htm#cdintokss

If you or other CD-302 owner would like to start on improving this unit, I'd firstly suggest to replace the laser to the better KSS-213D(with the metal holders) and dont forget to also replace its suspension rubber ring.

Then I would address the machine stability by improving its temperature handling and the other related modds mentioned in this thread's first post.
Keep us informed how it goes.

About the links... you are precisely posting at a very educational forum, try the search system on the various interest you may have. It is not an organized body of knowledge, but as you learn, you also get to understand more of what you read.

Hope it helps

help 19th January 2011 10:23 AM

tascam cd302
 
i am a cd302 avid fan ive had mine since first release still think there a fantastic piece of kit but if anybody can help me bring them back to life
i am not getting any sound from cd 2 i have had no problems with over heating but i am going to move them into a smaller flight case so any suggestions on keeping them cool and any mods i can do to keep them going would be very nice


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