The Phonoclone and VSPS PCB Help Desk - Page 141

rjm · 24th August 2010, 07:04 AM

@topdog

Voltage is always "with respect to" a given reference point. If you have 12 V and -12 V at the opamp power pins with respect to ground then all is well. The regulators should have about +16 V and -16 V with respect to ground at the input pin and +12 and -12 V with respect to ground at the output pin. Ground, common, IN- and OUT- should all be connected and therefore at 0 V with respect to ground.

It is a common mistake to connect one of the regulators backwards or incorrectly.

@quan

I still use Black Gate N for C3, as my build dates back to the time they were still available. Your transformer etc are all fine, no need to worry about tweaking or changing anything, though you can experiment with C3 is you feel you have to.

topdog · 24th August 2010, 12:59 PM

Quote:

Originally Posted by rjm

@topdog
Voltage is always "with respect to" a given reference point. If you have 12 V and -12 V at the opamp power pins with respect to ground then all is well. The regulators should have about +16 V and -16 V with respect to ground at the input pin and +12 and -12 V with respect to ground at the output pin. Ground, common, IN- and OUT- should all be connected and therefore at 0 V with respect to ground.

It is a common mistake to connect one of the regulators backwards or incorrectly.

Appreciate your patience with me. Still learning here. I'm good with the basics, but have never done anything with a split supply so this is new territory for me.

And you hit it on the head with the regulator. Bonehead of the month here. Used the same pinout for the negative reg as for the positive one, which is obviously a big mistake. Although the literature says the reg is "practically indestructable", I think I managed to damage it. It's reading -15v with respect to ground at the output pin. Going to do a complete teardown and rebuild it from scratch as soon as Mouser gets the new one here (today hopefully).

quan · 24th August 2010, 10:25 PM

Hi Richard, thanks for the tip- regarding the max value of C3-does it affect the performance if higher value cap is used? -I see some Valab PIO 10uF/100V for 6USD each or 4.7uF for 3USD. Currently it runs on the Arcotronics 2uF MKP.
Thanks.
PS-can't find BG ANYWHERE-PC-NO STOCK., AURICAP?

Crabpeople · 25th August 2010, 01:23 AM

Quote:

Originally Posted by Crabpeople

Hi there,
I have just finished building my VSPS project
and am quiet happy with the sound quality except for
a background hum that is more noticable at higher volume
any help would be most appreciated.
Thanks

Success Soldered a new pair of heavily shielded RCA cables into my turntable now no noticable hum unless i crank the volume to earth shattering
(but then the music masks it anyway

topdog · 25th August 2010, 12:40 PM

Finished the rebuild last night. Works perfectly and sounds great! So much better than the built-in in my Kenwood. Just need to finish fabricating the chassis and it'll be done.

Question - I used the NE5532P per the parts list. It's my understanding that OPA2604 is a direct replacement for the NE5532. Is that correct? If so, will it make an appreciable difference? Reason I ask is I have one sitting here, but don't want to swap it out if it'll do any damage.

rjm · 26th August 2010, 02:38 AM

@quan

BG are discontinued, and the N 4.7uF/50 disappeared from stores years ago.
2uF is generally sufficient, increasing the value tends to make the bass a bit boomier, the treble softer. It's a matter of taste to some extent.

@topdog

You can switch in the OPA2602 and see if you like it, there is no risk of damage. Any 8 pin dual audio opamp can be substituted, and many more besides.

topdog · 31st August 2010, 02:57 PM

Thanks again for everything Richard. Swapped in the OPA. Can't tell much, if any difference, but will probably compare again once the break-in period is done.

Another question for you - I need to build another one of these, but am looking at the VSPS 300 instead. It's not readily apparent from reading your site -- do I need a separate power supply for each channel or can I just run two sets of leads from the xreg board? My first thought is this would be that it's okay, but your write-up hints at separate supplies.

rjm · 3rd September 2010, 01:09 PM

Each VSPS 300 channel has its own Xreg on board. You can power this from a single shared power supply, or, better yet, one power supply for each channel.

quan · 11th September 2010, 10:50 AM

HI RicHARD, JUST TEST RUN THE PHONOCLONE 3-HUM+++,
have tried dummy load input with 47R-hum level unchange.Have reground using input ground instead of COM making no difference
I have not try 330pF on IC1 input as yet.
I had VSPS300 working fantastic without any noise.
Please advise what should i try next?

DARIO1997 · 11th September 2010, 02:04 PM

Hi Rjm,
I purchased these boards (Phonoclone and VSPS Group Buys), already assembled, what are the two holes on pins 2 and 3 of IC1 (C0)?
I have the problem of radio signals and i want to solder the capacitor to pin 2 and 3 of IC1.
I soldered the capacitor underside of the boards or in two holes near IC1?
Regards

24th August 2010, 07:04 AM	#1401
rjm Richard Murdey diyAudio Member Join Date: May 2004 Location: Kyoto Blog Entries: 32	@topdog Voltage is always "with respect to" a given reference point. If you have 12 V and -12 V at the opamp power pins with respect to ground then all is well. The regulators should have about +16 V and -16 V with respect to ground at the input pin and +12 and -12 V with respect to ground at the output pin. Ground, common, IN- and OUT- should all be connected and therefore at 0 V with respect to ground. It is a common mistake to connect one of the regulators backwards or incorrectly. @quan I still use Black Gate N for C3, as my build dates back to the time they were still available. Your transformer etc are all fine, no need to worry about tweaking or changing anything, though you can experiment with C3 is you feel you have to. __________________ RJM Audio (phonoclone.com)

26th August 2010, 02:38 AM	#1406
rjm Richard Murdey diyAudio Member Join Date: May 2004 Location: Kyoto Blog Entries: 32	@quan BG are discontinued, and the N 4.7uF/50 disappeared from stores years ago. 2uF is generally sufficient, increasing the value tends to make the bass a bit boomier, the treble softer. It's a matter of taste to some extent. @topdog You can switch in the OPA2602 and see if you like it, there is no risk of damage. Any 8 pin dual audio opamp can be substituted, and many more besides. __________________ RJM Audio (phonoclone.com)

3rd September 2010, 01:09 PM	#1408
rjm Richard Murdey diyAudio Member Join Date: May 2004 Location: Kyoto Blog Entries: 32	Each VSPS 300 channel has its own Xreg on board. You can power this from a single shared power supply, or, better yet, one power supply for each channel. __________________ RJM Audio (phonoclone.com)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

24th August 2010, 10:25 PM	#1403
quan diyAudio Member Join Date: Feb 2007 Location: sydney	Hi Richard, thanks for the tip- regarding the max value of C3-does it affect the performance if higher value cap is used? -I see some Valab PIO 10uF/100V for 6USD each or 4.7uF for 3USD. Currently it runs on the Arcotronics 2uF MKP. Thanks. PS-can't find BG ANYWHERE-PC-NO STOCK., AURICAP?

25th August 2010, 12:40 PM	#1405
topdog diyAudio Member Join Date: Aug 2010 Location: Austin, TX	Finished the rebuild last night. Works perfectly and sounds great! So much better than the built-in in my Kenwood. Just need to finish fabricating the chassis and it'll be done. Question - I used the NE5532P per the parts list. It's my understanding that OPA2604 is a direct replacement for the NE5532. Is that correct? If so, will it make an appreciable difference? Reason I ask is I have one sitting here, but don't want to swap it out if it'll do any damage.

31st August 2010, 02:57 PM	#1407
topdog diyAudio Member Join Date: Aug 2010 Location: Austin, TX	Thanks again for everything Richard. Swapped in the OPA. Can't tell much, if any difference, but will probably compare again once the break-in period is done. Another question for you - I need to build another one of these, but am looking at the VSPS 300 instead. It's not readily apparent from reading your site -- do I need a separate power supply for each channel or can I just run two sets of leads from the xreg board? My first thought is this would be that it's okay, but your write-up hints at separate supplies.

11th September 2010, 10:50 AM	#1409
quan diyAudio Member Join Date: Feb 2007 Location: sydney	HI RicHARD, JUST TEST RUN THE PHONOCLONE 3-HUM+++, have tried dummy load input with 47R-hum level unchange.Have reground using input ground instead of COM making no difference I have not try 330pF on IC1 input as yet. I had VSPS300 working fantastic without any noise. Please advise what should i try next?

11th September 2010, 02:04 PM	#1410
DARIO1997 diyAudio Member Join Date: Dec 2007	Hi Rjm, I purchased these boards (Phonoclone and VSPS Group Buys), already assembled, what are the two holes on pins 2 and 3 of IC1 (C0)? I have the problem of radio signals and i want to solder the capacitor to pin 2 and 3 of IC1. I soldered the capacitor underside of the boards or in two holes near IC1? Regards

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)