• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Acurus P10 phono stage mod/rebuild

As far as I'm aware the 47K already came with cmf-resistors or something in that league. Quite good resistors.
Buy the best 10uf output cap that'll fit and remember to sort out the outer foil of the capacitor to get least interference in circuit. ClarityCap ESA 10uf/250V will fit perfectly with a very smooth midrange and topend. Definitely way better then the original caps.
After this, if you still feel the need to spend big boxxx :) go for the Naked WAR Z-foil resistors.

Best regards
 
Last edited:
If you want to experiment with constant current sources (CCS) as replacement of the 36.5Kohms, then you'll need:
-2pcs KSA992F, PNP transistor
-2pcs KSC1845F, NPN transistors
-4pcs TLLG4400, LED Green, 1.96Vf/2mA
-2pcs RN60D, 20Kohm or 22Kohm (one of these will replace the two 10Kohm in the picture (one channel shown)
-4pcs RN55D or RN60D in the region around 2.74Kohm. This value will give 464uA in a Acurus P10 with ±18V rails. Checked your rails in the 47K. A good practice is to measure the voltage drop across the 36.5Kohm the calculate the uA needed in a CCS, and adjust the 2.74Kohm either up or down in resistance to get the target uA before removing the 36.5kohm and replace with a CCS
1000004131.jpg
You can use other transistors and other diodes. Red LED-diodes should be the least noisy. But you'll have to adjust each resistor value accordingly, and the values written here cannot be used by default if other parts is ordered for the CCS. Especially the forward voltage of a chosen diode will have a big impact on the current output.

Regards and happy DIY;)
 
Last edited:
I think I forgot to crosspost this for reference...my 47K modified by Mondialfan (KC)

Modialfan Aragon 47K upgrade magic

Okay, I am not a DIY'er but I know someone who is and I figured people may be interested in seeing what the esteemed Kevin Chambers has done to my unit. And apologies to @mondialfan ahead of time if I have lost something in translation. I'm sure he'll point out my mistake(s). :) This particular...
audiokarma.org
 
Thanks again for sharing this stuff; yes I would like to do some of the upgrades you have listed above --
I actually have custom Bottlehead 2A3/45 Paramour monoblocks that use CCS.
Mirror built, Cardas input and binding posts, silver wire, all out build, Brazillian Rosewood etc --I just packed them up yesterday for storage.

Clarity caps are one of my likes as well-- I have Claritys in my Crossover for my Khorns - I think they are 12Uf 630V -- they are HUGE.
I have a couple 6.8uf Clarity's -- too bad they weren't 10's ... but I digress--

My choices for the big yellows would vary from Dueland, Jupiter. Of course $ become an issue with those names.
*Maybe some variation of Russian film cap, maybe Clarity.... I like AudioNote, and Amtrans as well, (Amtrans in my Mc2505) don't know if they would make a proper value for that spot though.

All that said, I am currently focused on getting my RS1500 R2R machine up and running - lots of boards with nasty caps that like to physically leak electrolytic, (want them out b4 damage to the boards)... and then there's the test tapes... Never has Audio been an inexpensive endeavor..

*I just redid my Khorn networks and after a few different flavors of caps, I am finding these huge Russian KBG-MN's and Clarity/ bypassed with Dueland Copper foils on the high and mid-- to be sounding pretty doggone nice.

Awesome stuff @atvalet

So much valuable knowledge here, once again off to digest more ...

Here's to a productive day!

Celadon
 
KNielsen said:
KNielsen said:
If you want to experiment with constant current sources (CCS) as replacement of the 36.5Kohms, then you'll need:
-2pcs KSA992F, PNP transistor
-2pcs KSC1845F, NPN transistors
-4pcs TLLG4400, LED Green, 1.96Vf/2mA
-2pcs RN60D, 20Kohm or 22Kohm (one of these will replace the two 10Kohm in the picture (one channel shown)
-4pcs RN55D or RN60D in the region around 2.74Kohm. This value will give 464uA in a Acurus P10 with ±18V rails. Checked your rails in the 47K. A good practice is to measure the voltage drop across the 36.5Kohm the calculate the uA needed in a CCS, and adjust the 2.74Kohm either up or down in resistance to get the target uA before removing the 36.5kohm and replace with a CCS
View attachment 3182216
You can use other transistors and other diodes. Red LED-diodes should be the least noisy. But you'll have to adjust each resistor value accordingly, and the values written here cannot be used by default if other parts is ordered for the CCS. Especially the forward voltage of a chosen diode will have a big impact on the current output.

Regards and happy DIY;)
Click to expand...
Click to expand...
@KNielsen

Hi Kaare, where did you get the PCBs for the CCS?
 
Last edited:
per5at said:
Ah thanks for the info, was hoping there was a premade option out there.
Click to expand...
Im out of stock for the last year or so. Had 20 of each polarity made for the CCS, but they went quickly!
I can't find the original PCB-files I did, it would have been an easy share here
 
KNielsen said:
Im out of stock for the last year or so. Had 20 of each polarity made for the CCS, but they went quickly!
I can't find the original PCB-files I did, it would have been an easy share here
Click to expand...
I was wondering about the PCB files, sorry to hear they've gone missing! If they turn up let me know, I'd be interested. I'd be willing to get extras PCBs made and offer at cost here if there's interest. I've never designed a PCB or might have given it a go myself. I just started upgrading my P10 the other day, looking forward to hearing it when I'm done.
 
You must log in or register to reply here.
Back
Top Bottom