Mod a Rega Planet

Scytales · 27th May 2003, 07:10 PM

Hi!

I'm currently modifying my Rega Planet thanks to the advise provided on this -also excellent- site:

http://www.homecinema-fr.com/forum/v...php?t=29699595

Be carefull, it's in french!

I'm not an electronician, but I succeed to cleanely apply the suggestions that were given to me.

I've replaced the 100 µF Samwha capacitors which decoupled the output chip (Sanyo LA9216 - no datasheet avalaible, but doutbless a similar chip to the LA9215) by Black Gate BG 100µF/50V and the 47 µF one which decoupled the +5V Burr Brown PCM1710UDAC analog power supply by a similar Black Gate 470 µF/50V.

I have also changed the Samwha SG 100 µF output capacitors by cabled pairs of MKP Monacor 10µF + 82 nF MKS. All the ceramic capacitors on the PCCDAC board has been changed towards MKS, except for the 16.9344 MHz oscillator, which is now decoupled by 22 pF silvered mica caps.

Last, two 470 ohms series resistors on the ouput lines where replaced by 121+12.1 ohms.

Now, the sound has improved: more feel, more firmness in the bass (but no more power), more precise focalisation, and, more than all, no harshness. Perhaps the soundscape is now a bit to close from the auditor and sligthly less wide.

So, the mod succeed, but I wish to go a little further. Perhaps by changing caps of the power supply and some coupling caps in the output.

I have also a question: why do Rega put two 470 ohms serie resistors in each output line? That give an output impedance of 930 ohms across the audio band (mesurement of Stereophile).

The purpose of this resistors is quite a mystery to me and, also I reduce their values, I'd rather prefer know what about them.

Any idea?

Thanks.

Werner · 4th July 2003, 06:55 AM

A high output impedance is typical for Japanese-style CD-players. I guess it is for making the components utterly foolproof. Which is something that ties in with Rega's philosophy as well.

Two resistors in series because it is a T filter that with those small ceramic Cs filters incoming as well as outgoing HF garbage.

Do you have the datasheet of the 9215?

(Funny, I only modified my own Planet two days ago, and no time for listening yet. I did start this job because I have a boatload of Rubycon ZAs I have to find a use for.)

tbla · 4th July 2003, 07:04 AM

hi,
you should change the masterclock - search elso kwak clock...
also change the rectifiers to schottkies - http://www.schuro.de/Daten/IR/11dq10.pdf
http://www.schuro.de/Daten/IR/31dq10.pdf

good luck
troels

Werner · 4th July 2003, 07:08 AM

And the new version ...

Scytales · 8th November 2003, 10:09 AM

Hello, Werner.

Yes, I have the datasheet of the LA9215 in PFD file, but this is not very detailed

Thanks for your explanation about T filter. Anyway, I come back to the 2x470 Ohms: it's better for the transients and the soundscape with my associated IC cables and preamp input impedance. I remove the costly BG from the +5V of the DAC and put again the previous cap : it did change anything.

Nice work you have done. What are the improvements and changes?

nowalls · 20th October 2006, 05:14 PM

Guys,

owning a Planet too, i wanted to start some modifying.

a. SPINDLE

i split the wobbly spindle [with a junior handsaw blade]
the top half i secured with double-sided tape on the lid.
the remaining spindle/magnet is put by hand -upside down-
on the cd.
it gives less noise and more detail, firmer bass

b. LED-FILTER

next step is putting some blue-leds in the CD bay.
12v type with intgrated resistors, couple to a pot-meter and
a 12v transformer
did some testing already with blue led and watch-battery,
sound was impressive, but battery gone to soon

c. PRINTED CIRCUIT

surfing i found 3 threads:
1. acoustica.org.uk
2. homecinema-fr.com
3. audioasylum/tweaker's asylum/digital/ carlos' threads
4. the one i'm in now

in general they consist of the same:
change the clock
change capacitors
resistors

what i'm missing is a listing and a scheme
where is indicated where what is changed.
the pic's of werner are a start:
I can recognize that at C7 cap was changed to Rubycon ZA 35v 100Uf but that's about it.

schottky's: doe you mean that instead of 11DQ10 also the othe 3xx tyhpe can be used?

in other words can you provide more details?

a.wayne · 1st January 2010, 01:19 AM

Well it's been 3 yrs and i would like to mod my planet 2 ....

Any updates to what is already here guys ?

27th May 2003, 07:10 PM	#1
Scytales diyAudio Member Join Date: May 2003	Mod a Rega Planet Hi! I'm currently modifying my Rega Planet thanks to the advise provided on this -also excellent- site: http://www.homecinema-fr.com/forum/v...php?t=29699595 Be carefull, it's in french! I'm not an electronician, but I succeed to cleanely apply the suggestions that were given to me. I've replaced the 100 µF Samwha capacitors which decoupled the output chip (Sanyo LA9216 - no datasheet avalaible, but doutbless a similar chip to the LA9215) by Black Gate BG 100µF/50V and the 47 µF one which decoupled the +5V Burr Brown PCM1710UDAC analog power supply by a similar Black Gate 470 µF/50V. I have also changed the Samwha SG 100 µF output capacitors by cabled pairs of MKP Monacor 10µF + 82 nF MKS. All the ceramic capacitors on the PCCDAC board has been changed towards MKS, except for the 16.9344 MHz oscillator, which is now decoupled by 22 pF silvered mica caps. Last, two 470 ohms series resistors on the ouput lines where replaced by 121+12.1 ohms. Now, the sound has improved: more feel, more firmness in the bass (but no more power), more precise focalisation, and, more than all, no harshness. Perhaps the soundscape is now a bit to close from the auditor and sligthly less wide. So, the mod succeed, but I wish to go a little further. Perhaps by changing caps of the power supply and some coupling caps in the output. I have also a question: why do Rega put two 470 ohms serie resistors in each output line? That give an output impedance of 930 ohms across the audio band (mesurement of Stereophile). The purpose of this resistors is quite a mystery to me and, also I reduce their values, I'd rather prefer know what about them. Any idea? Thanks.

4th July 2003, 07:04 AM	#3
tbla diyAudio Member Join Date: Jul 2002 Location: denmark	rega mods... hi, you should change the masterclock - search elso kwak clock... also change the rectifiers to schottkies - http://www.schuro.de/Daten/IR/11dq10.pdf http://www.schuro.de/Daten/IR/31dq10.pdf good luck troels

8th November 2003, 10:09 AM	#5
Scytales diyAudio Member Join Date: May 2003	Hello, Werner. Yes, I have the datasheet of the LA9215 in PFD file, but this is not very detailed Thanks for your explanation about T filter. Anyway, I come back to the 2x470 Ohms: it's better for the transients and the soundscape with my associated IC cables and preamp input impedance. I remove the costly BG from the +5V of the DAC and put again the previous cap : it did change anything. Nice work you have done. What are the improvements and changes? __________________ ________________ Ce n'est pas se donner que de donner ce qu'on voudrait être. (Patrick Drevet)

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20th October 2006, 05:14 PM	#6
nowalls diyAudio Member Join Date: Oct 2006	Guys, owning a Planet too, i wanted to start some modifying. a. SPINDLE i split the wobbly spindle [with a junior handsaw blade] the top half i secured with double-sided tape on the lid. the remaining spindle/magnet is put by hand -upside down- on the cd. it gives less noise and more detail, firmer bass b. LED-FILTER next step is putting some blue-leds in the CD bay. 12v type with intgrated resistors, couple to a pot-meter and a 12v transformer did some testing already with blue led and watch-battery, sound was impressive, but battery gone to soon c. PRINTED CIRCUIT surfing i found 3 threads: 1. acoustica.org.uk 2. homecinema-fr.com 3. audioasylum/tweaker's asylum/digital/ carlos' threads 4. the one i'm in now in general they consist of the same: change the clock change capacitors resistors what i'm missing is a listing and a scheme where is indicated where what is changed. the pic's of werner are a start: I can recognize that at C7 cap was changed to Rubycon ZA 35v 100Uf but that's about it. schottky's: doe you mean that instead of 11DQ10 also the othe 3xx tyhpe can be used? in other words can you provide more details?

1st January 2010, 01:19 AM	#7
a.wayne Sin Bin Join Date: May 2008 Location: Front Row Center	Well it's been 3 yrs and i would like to mod my planet 2 .... Any updates to what is already here guys ?