Pioneer receiver mod

Buzzy · 18th August 2007, 03:28 AM

Hi ! I have a pioneer vsx 1015 receiver. I can't listen to music more than 1hr. It causes listening fatigue. I think it sounds bright and harsh.
Is there something i can mod in this receiver to make it sound better or something to make it less bright ?

This is my setup :
Pioneer dv393 dvd player feeding the receiver with digital outs.
mission m32i fronts

I opened up my receiver and found 2 big nippon chemicon capacitors each with a capacitance of 15000uF at 71V. The rectifiers are D5SBA20. At the signal input, I found these chips which are AK4628V0 but wat these are.I also found quite alot of elna cerafine capacitors being used.

Buzzy · 18th August 2007, 09:54 AM

no one mod pioneer receiver before ?

Buzzy · 29th August 2007, 05:25 AM

I found these opamps in the main board.

I think they might be pdc4570. Should i change these opamps ? Wat should i replace them with ? I often hear people talk abt changing coupling caps. Where would i find these ?

phreeky82 · 29th August 2007, 06:04 AM

Are you going about this the right way? Is the pioneer actually making it sound bright? Because a bit of googling shows some people saying the Missions sound bright themselves. Have you tried the speakers on another amp and/or the amp with other speakers?

Nrik · 29th August 2007, 08:59 AM

I agree with Phreeky.
Maybe you dont need to Modify.

Try first to run analog from your DV-939. It has a really great sound quality because of their Analog Devices DAC and 5532 opamp. (VSX 1015 uses Asaki kasai DAC and the 4570 opamp.)

Then try to fiddle with the MCACC system in the receiver. As I recall it has five band EQ for each channel. Do the auto-adjust, and then tune the EQ after your taste (set the two top bands 2-3db down in each channel)

If you still gets listening fatigue, then you can modify.

The Op amps will be tricky to replace, since there are a lot, and they are all SMD types. If you feel like it - knock yourself out.
OPA2134, or should do the job.

But I would bypass all the electrolytics before replacing opamps. Some of them you can probably replace with a short cut (you have to check the schematic first) but all of them can be bypassed with a 100nF-1uF polyester or polypropylene cap.

Buzzy · 29th August 2007, 10:28 AM

Nrik, wat i have is pioneer dv393 player which is the lowest end of the pioneer dvd range. So i expect the receiver to have a better DAC. BTW i use digital coaxial. When i auditioned the missions at the store which used a cambridge cd player with pioneer 1016 it did not sound bright. I remember that what hi fi rated pioneer 1015 as being bright.

I have also made a mistake in identifying the normal elna caps as elna cerafines. These are the normal elna caps. The black caps in the above pic are not elna at all.

These are all found on the mainboard

Buzzy · 29th August 2007, 10:31 AM

The resistors and caps to the binding posts.

The folowing are from the same board found close to the digital coaxial input.

Nrik · 29th August 2007, 01:31 PM

sorry Buzzy
...read your players number wrong - yes keep it digital.
But still you should try out the autoadjust, and then tamper with the EQ. The guy in the shop probably did that.
Equalising can do much more than most people think.

if you still want to modify:
I would still start by parallelling the caps.
Signalbearing caps in the analog sections are the most important ones.
Do you have a schematic? If not you can locate all these near the NJM4570 opamps and in the poweramp section.
Bypass 1-10uF electro (black blue whatever) with 100nF polyester, and 100uF electro with 1uF polyester if you can get these small enough.

Or simply replace them all with expensive audiograde low-esr electrolytics of same value and voltage.

The small silver electrolytics should be allright.
Forget about caps in the digtial section

Nrik · 29th August 2007, 01:39 PM

...but I should warn you:
Tearing apart a Pioneer receiver is not easy, or actually the hard part is getting it backl together, because of all these small multiplugs that carries the PCBs.

So unless you are absolutely sure of what you are doing, and willing to spend the time do it: Then don't.

Tune in what you can, and think about maybe buying one of Pioneers bigger receivers ( VSX-AX or VSX-LX series)

edit: What I am saying, is that spending a lot of money on new caps and opamps, and spending a lot of time modding this mid-end receiver, might not be worth the trouble. It will probably still be better to upgrade to a bigger receiver.

Buzzy · 29th August 2007, 04:13 PM

I think modding the poweramp section is the hardest as it would need me to take apart alot of stuff. I would like to try to change the caps to something more audio grade, maybe like elna silmics. I dun have the schematics and may i know which caps to change or bypass ? Is it those caps before or after the 4570 opamps ? Before all these i would try the MCACC again first. But i would like to know wat to mod beforehand so that i could do it this weekend if MCACC does nothing.

18th August 2007, 03:28 AM	#1
Buzzy diyAudio Member Join Date: Apr 2007	Pioneer receiver mod Hi ! I have a pioneer vsx 1015 receiver. I can't listen to music more than 1hr. It causes listening fatigue. I think it sounds bright and harsh. Is there something i can mod in this receiver to make it sound better or something to make it less bright ? This is my setup : Pioneer dv393 dvd player feeding the receiver with digital outs. mission m32i fronts I opened up my receiver and found 2 big nippon chemicon capacitors each with a capacitance of 15000uF at 71V. The rectifiers are D5SBA20. At the signal input, I found these chips which are AK4628V0 but wat these are.I also found quite alot of elna cerafine capacitors being used.

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18th August 2007, 09:54 AM	#2
Buzzy diyAudio Member Join Date: Apr 2007	no one mod pioneer receiver before ?

29th August 2007, 05:25 AM	#3
Buzzy diyAudio Member Join Date: Apr 2007	I found these opamps in the main board. I think they might be pdc4570. Should i change these opamps ? Wat should i replace them with ? I often hear people talk abt changing coupling caps. Where would i find these ?

29th August 2007, 06:04 AM	#4
phreeky82 diyAudio Member Join Date: May 2003 Location: Townsville, Australia	Are you going about this the right way? Is the pioneer actually making it sound bright? Because a bit of googling shows some people saying the Missions sound bright themselves. Have you tried the speakers on another amp and/or the amp with other speakers?

29th August 2007, 08:59 AM	#5
Nrik diyAudio Member Join Date: Feb 2005 Location: Copenhagen	I agree with Phreeky. Maybe you dont need to Modify. Try first to run analog from your DV-939. It has a really great sound quality because of their Analog Devices DAC and 5532 opamp. (VSX 1015 uses Asaki kasai DAC and the 4570 opamp.) Then try to fiddle with the MCACC system in the receiver. As I recall it has five band EQ for each channel. Do the auto-adjust, and then tune the EQ after your taste (set the two top bands 2-3db down in each channel) If you still gets listening fatigue, then you can modify. The Op amps will be tricky to replace, since there are a lot, and they are all SMD types. If you feel like it - knock yourself out. OPA2134, or should do the job. But I would bypass all the electrolytics before replacing opamps. Some of them you can probably replace with a short cut (you have to check the schematic first) but all of them can be bypassed with a 100nF-1uF polyester or polypropylene cap.

29th August 2007, 10:28 AM	#6
Buzzy diyAudio Member Join Date: Apr 2007	Nrik, wat i have is pioneer dv393 player which is the lowest end of the pioneer dvd range. So i expect the receiver to have a better DAC. BTW i use digital coaxial. When i auditioned the missions at the store which used a cambridge cd player with pioneer 1016 it did not sound bright. I remember that what hi fi rated pioneer 1015 as being bright. I have also made a mistake in identifying the normal elna caps as elna cerafines. These are the normal elna caps. The black caps in the above pic are not elna at all. These are all found on the mainboard

29th August 2007, 10:31 AM	#7
Buzzy diyAudio Member Join Date: Apr 2007	The resistors and caps to the binding posts. The folowing are from the same board found close to the digital coaxial input.

29th August 2007, 01:31 PM	#8
Nrik diyAudio Member Join Date: Feb 2005 Location: Copenhagen	sorry Buzzy ...read your players number wrong - yes keep it digital. But still you should try out the autoadjust, and then tamper with the EQ. The guy in the shop probably did that. Equalising can do much more than most people think. if you still want to modify: I would still start by parallelling the caps. Signalbearing caps in the analog sections are the most important ones. Do you have a schematic? If not you can locate all these near the NJM4570 opamps and in the poweramp section. Bypass 1-10uF electro (black blue whatever) with 100nF polyester, and 100uF electro with 1uF polyester if you can get these small enough. Or simply replace them all with expensive audiograde low-esr electrolytics of same value and voltage. The small silver electrolytics should be allright. Forget about caps in the digtial section

29th August 2007, 01:39 PM	#9
Nrik diyAudio Member Join Date: Feb 2005 Location: Copenhagen	...but I should warn you: Tearing apart a Pioneer receiver is not easy, or actually the hard part is getting it backl together, because of all these small multiplugs that carries the PCBs. So unless you are absolutely sure of what you are doing, and willing to spend the time do it: Then don't. Tune in what you can, and think about maybe buying one of Pioneers bigger receivers ( VSX-AX or VSX-LX series) edit: What I am saying, is that spending a lot of money on new caps and opamps, and spending a lot of time modding this mid-end receiver, might not be worth the trouble. It will probably still be better to upgrade to a bigger receiver.

29th August 2007, 04:13 PM	#10
Buzzy diyAudio Member Join Date: Apr 2007	I think modding the poweramp section is the hardest as it would need me to take apart alot of stuff. I would like to try to change the caps to something more audio grade, maybe like elna silmics. I dun have the schematics and may i know which caps to change or bypass ? Is it those caps before or after the 4570 opamps ? Before all these i would try the MCACC again first. But i would like to know wat to mod beforehand so that i could do it this weekend if MCACC does nothing.