Why didn't I think of that earlier? I do have a few external interfaces and the like. I'll check back with you when I've replaced the caps/IC (maybe the IC got fried earlier when I had a short).
Also, I ran the preamp with the transformer outside the case - this didn't seem to make a difference.
Hi, I have similar problem. Did you resolve it?No, radio interference has been ruled out because I have tested without any wireless devices (wifi/celluar/bluetooth) near by or off and issue persists.
S.
I keep an archive of all the old stuff, but try to keep what's online limited to the latest versions.
R19,20 are 68k or 75k or whatever you have in that ballpark.
Note I don't recommend the X-reg based circuits for new projects. The VSPS with the S-reg is the 400m (I can give you Gerbers if you want to get yourself a set of boards) or simply go with the Emerald.
R19,20 are 68k or 75k or whatever you have in that ballpark.
Note I don't recommend the X-reg based circuits for new projects. The VSPS with the S-reg is the 400m (I can give you Gerbers if you want to get yourself a set of boards) or simply go with the Emerald.
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VSPS + S-Reg sonics review
I have built several VSPS's and VSPS+S-reg on separate boards in the past. I have now completed a build with an eval single board VSPS+S-Reg and, after extensive listening and comparing, have come to the following conclusions.
1. The sound quality gain in replacing the original simple voltage regulator PS with the S-reg (on a separate board) is substantial. The highs are smoother, less grainy, and the sound stage is larger with a tad more bass.
2. On going to the single board version there is a further, albeit smaller, improvement in sound quality. I would say more focus and precision in the sound stage - which translates to a more relaxed and pleasant musical listening experience.
As an aside... on the photo you can see that I have replaced the 2x 1000uF smoothing capacitors with 2x 6000 uF built with 2 banks of paralled 6x 1000 uF on a seperate uitrigger board. This gives IMO yet a further improvement in sound quality -the lower frequencies being significantly fuller without loosing the speed, punch and rythmic qualities of the VSPS that I like so much.
In conclusion, the VSPS + S-reg combined on a single board, represents, IMO a worthwhile and elegant upgrade on the original design.
Dutch Keith
I have built several VSPS's and VSPS+S-reg on separate boards in the past. I have now completed a build with an eval single board VSPS+S-Reg and, after extensive listening and comparing, have come to the following conclusions.
1. The sound quality gain in replacing the original simple voltage regulator PS with the S-reg (on a separate board) is substantial. The highs are smoother, less grainy, and the sound stage is larger with a tad more bass.
2. On going to the single board version there is a further, albeit smaller, improvement in sound quality. I would say more focus and precision in the sound stage - which translates to a more relaxed and pleasant musical listening experience.
As an aside... on the photo you can see that I have replaced the 2x 1000uF smoothing capacitors with 2x 6000 uF built with 2 banks of paralled 6x 1000 uF on a seperate uitrigger board. This gives IMO yet a further improvement in sound quality -the lower frequencies being significantly fuller without loosing the speed, punch and rythmic qualities of the VSPS that I like so much.
In conclusion, the VSPS + S-reg combined on a single board, represents, IMO a worthwhile and elegant upgrade on the original design.
Dutch Keith
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Here we are.....
Thank you Richard !!! for your project and your assistance..
I m not finised yet (box of PSU) but sounds exellent !!!
The very very very small noise with volume at the end it comes from my Thorens TD280..
Untitled on Vimeo
i will try with this cable to eliminate this litle noise...
Thank you Richard !!! for your project and your assistance..
I m not finised yet (box of PSU) but sounds exellent !!!
The very very very small noise with volume at the end it comes from my Thorens TD280..
Untitled on Vimeo
i will try with this cable to eliminate this litle noise...
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Hi Jose! from your post i saw this cable i forget to mention this ,i will use the same cable like yours, mine cable is double shielded....
The third pic shows the end of the cables of the TT Thorens TD 280
the first mp4 2(1) record the litle noise from tweeter mid woofer
And the second 2(2) mp4 record NO noise at all from tweeter mid woofer without connect the TT on Phone stage
the volume it is at the end (Buffer 6V6 Salas) and my amps Mimesis clone 9.2 (220W-250W) per channel
The third pic shows the end of the cables of the TT Thorens TD 280
the first mp4 2(1) record the litle noise from tweeter mid woofer
And the second 2(2) mp4 record NO noise at all from tweeter mid woofer without connect the TT on Phone stage
the volume it is at the end (Buffer 6V6 Salas) and my amps Mimesis clone 9.2 (220W-250W) per channel
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Two steps removed, but yes. The S-reg is based on the Crystal M shunt which is a mod of your PS design.
Nice custom job. Such high Zo version done in low biased BJTs to stay cool sans sinking can even help towards taking out the edge of some anxious recordings especially when using op-amps. Did you also try with better noise & linearity types than BD139/BD140 in the S-Reg? Like the Fairchild's 2SA1381/KSA1381 pin compatible TO-126s based on Japanese SANYO low Rbb' and speedy original types from the high definition CRT monitors era.
I spent some time on optimization, but I didn't try transistors except for BD135/6 and BC327/337. I removed a couple of capacitors and verified that the emitter resistors on the shunt transistors were in fact needed ... that's about it.
You found oscillations on the scope if without those Re or you just subjectively preferred to have them there for enhancing smoothness like I mentioned? IMHO do try the KSA types also when having an opportunity, provided they will function properly in open loop analysis which I would rather expect, they could even add some extra sound quality or not. The BDs may well have some characteristic you find synergistic to the rest of the circuit though. While the Philips originals used to be faster with less Cob than in current production multi brand copies, their base spreading resistance and 1/F noise were always much as in those newer. Technically the KSAs are surely better process type parts at least.
Υes my friend Nick based on the service manual you gave me shows it to be a relatively good TT based on his years, of course the money I gave to acquire it, is in very good visual condition but also mechanical.
I looked it up for a service manual after the photo you posted where I saw a large electronics board inside its plinth. It has motor phases sine wave circuitry indeed shows the manual as I wondered if it may. Nowadays such circuitry is usually sold as external control unit for expensive models. It has a light plinth and platter on the other hand but again it was a budget TT in its day. Seems like a good find in very good condition. Well done.
Hi Gents,
Need help - just finished my VSPS build and it works but i have this wierd buzz in my speakers:
YouTube
It gets quiter when i touch the preamp enclosure with my hand.
Below couple of pics of the build ( in pictures the GND is not connected to the enclosure - now it is )
how to start trouble shooting?
Need help - just finished my VSPS build and it works but i have this wierd buzz in my speakers:
YouTube
It gets quiter when i touch the preamp enclosure with my hand.
Below couple of pics of the build ( in pictures the GND is not connected to the enclosure - now it is )
how to start trouble shooting?
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That's a typical symptom of an improperly connected ground. Either something is connected to earth that shouldn't be, or something isn't connected to earth that should be.
One thing to be careful with is those black anodized chassis. The individual panels are often not in electrical contact with each other, so your box is not, electrically speaking, a metal box. You have to file off the coating at the parts that touch each other to ensure electrical contact.
The main VSPS looks to be connected properly, with GND to the lug on the case that connects to the TT.
The power supply unit has a screw near the power socket that you are supposed to connect the AC earth to. As I see it the AC earth only connects to the transformer screen currently.
The system will hum if the TT ground is not connected to the VSPS ground lug.
One thing to be careful with is those black anodized chassis. The individual panels are often not in electrical contact with each other, so your box is not, electrically speaking, a metal box. You have to file off the coating at the parts that touch each other to ensure electrical contact.
The main VSPS looks to be connected properly, with GND to the lug on the case that connects to the TT.
The power supply unit has a screw near the power socket that you are supposed to connect the AC earth to. As I see it the AC earth only connects to the transformer screen currently.
The system will hum if the TT ground is not connected to the VSPS ground lug.