Since I already use Gmail, I had a quick look at Sites. I don't think this will work for the simple reason that I don't appear to be able to upload content.
I have the whole website already. Basically I'd just want to ftp the files over to a web host server and register a domain name. Maintenance via ftp and the good'ol unix account will be fine.
If I'm missing something with what Google has to offer please let me know. I never found an "upload HTML file" button... or any equivalent to the Geocities file manager.
/R
I have the whole website already. Basically I'd just want to ftp the files over to a web host server and register a domain name. Maintenance via ftp and the good'ol unix account will be fine.
If I'm missing something with what Google has to offer please let me know. I never found an "upload HTML file" button... or any equivalent to the Geocities file manager.
/R
Subject: VSPS
Howdy.
I think I need alot of help.
A layout pic (mspaint)
Its a LM4562
Those input caps 220pf I added before and got rid off all the noise and hum, they did something with the VSPS.
I hooked it up with a Fisher turntable and nothing. Deadsilent when it suppose to play some Enya.
Checked and rechecked. nothing.
I remove the input caps and still nothing. =(
Some new measurement. Crazy
input shorted: 2000mV
input open 8000mV
I declare it R.I.P for now. =(
Howdy.
I think I need alot of help.
A layout pic (mspaint)
Its a LM4562
An externally hosted image should be here but it was not working when we last tested it.
Those input caps 220pf I added before and got rid off all the noise and hum, they did something with the VSPS.
I hooked it up with a Fisher turntable and nothing. Deadsilent when it suppose to play some Enya.
Checked and rechecked. nothing.
I remove the input caps and still nothing. =(
Some new measurement. Crazy
input shorted: 2000mV
input open 8000mV
I declare it R.I.P for now. =(
Sorry.
Too much troubleshooting is not good for your health. eheh.
I desolder those input caps, but nothing changed. =(
After some time with frustration, I found the problem that cause the high dc offset.(8000mVdc on the output.)
A microscopic space between the power rail and the power pin on the LM4562 did that. But now I dont know if the input caps where any good.
All the changes makes the pcb card looks more like a warzone every time I make a change
The dc offset is back to "normal" 50mV and 210mV: shorted input.
And I hooked up the Fisher turntable again and I can hear Enya =)
There is one thing I want to know, why did the input caps cause the dc offset to rise to 1822 mV on both channels.
soo long...
Too much troubleshooting is not good for your health. eheh.
I desolder those input caps, but nothing changed. =(
After some time with frustration, I found the problem that cause the high dc offset.(8000mVdc on the output.)
A microscopic space between the power rail and the power pin on the LM4562 did that. But now I dont know if the input caps where any good.
All the changes makes the pcb card looks more like a warzone every time I make a change
The dc offset is back to "normal" 50mV and 210mV: shorted input.
And I hooked up the Fisher turntable again and I can hear Enya =)
There is one thing I want to know, why did the input caps cause the dc offset to rise to 1822 mV on both channels.
soo long...
Hi rjm,
my provider Tiscali.it, gives for free email address and 100Mb webspace.
It is an Italian site (the language should be a problem for you), but there is also the British site www.tiscali.co.uk and it seems it does the same thing: for free email and 100Mb web space
Renato
Thzar said:
The op amp was probably oscillating, and the DC offsets got jacked up as a result. That can happen.
Next time save yourself some frustration and just buy the boards / parts from SkyCoral. Much cleaner.
Hey Rjm.
1 pcs of VSPS pcb for 7 USD, wow thats cheap. =)
Its the same price I payed for a naked pcb with "coppar islands"
"The op amp was probably oscillating "
But the output were dead silent. no hum, noise or crackling sound whats so ever.
I think I will try the input caps again and I gonna lower the gain a little.
Thanks.
1 pcs of VSPS pcb for 7 USD, wow thats cheap. =)
Its the same price I payed for a naked pcb with "coppar islands"
"The op amp was probably oscillating "
But the output were dead silent. no hum, noise or crackling sound whats so ever.
I think I will try the input caps again and I gonna lower the gain a little.
Thanks.
Almost finished with my VSPS, will post photos soon.
I used the board from Skycoral, however I made some changes, most of which were clearly audible:
1. changed the NE5532 to LM4562. This was the first one to change and made the VSPS sound interesting. NE5532 was not bad, but a bit dull.
2. added 47uF electrolytics as coupling capacitors from opamp V+/V- to power supply.
3. used 2 12V, 1.2A batteries instead of building a power supply. I cannot commend on impacts of this change since I have not tried a power supply. However, I suppose that this is the easiest way to provide clean power to the opamp.
4. changed the output capacitor(a Nichicon 4.7u, non-polar electrolytic) to 4x1.0uF russian, millitary PIOs. This provided the biggest improvement, after changing the opamp! Dynamics are much better, voices sound crisp and naturall, highs are smooth.
5. biased the opamp to class-A by adding a current source, i.e. a 2SK170 with gate and source shorted, between the opamp output and V- in each channel. Not much improvement, the sound became a little "rich" and the opamp much warmer!
Still, there's room for more and serious improvements. I plan to change the RIAA MKT caps to silver micas, add input caps to match the cartridge's output capacitance, improve stability of the current source.
And, last but not least, fight humming which, started puzzling me again. I plan to separate power ground from signal ground. Has anyone tested this?
I used the board from Skycoral, however I made some changes, most of which were clearly audible:
1. changed the NE5532 to LM4562. This was the first one to change and made the VSPS sound interesting. NE5532 was not bad, but a bit dull.
2. added 47uF electrolytics as coupling capacitors from opamp V+/V- to power supply.
3. used 2 12V, 1.2A batteries instead of building a power supply. I cannot commend on impacts of this change since I have not tried a power supply. However, I suppose that this is the easiest way to provide clean power to the opamp.
4. changed the output capacitor(a Nichicon 4.7u, non-polar electrolytic) to 4x1.0uF russian, millitary PIOs. This provided the biggest improvement, after changing the opamp! Dynamics are much better, voices sound crisp and naturall, highs are smooth.
5. biased the opamp to class-A by adding a current source, i.e. a 2SK170 with gate and source shorted, between the opamp output and V- in each channel. Not much improvement, the sound became a little "rich" and the opamp much warmer!
Still, there's room for more and serious improvements. I plan to change the RIAA MKT caps to silver micas, add input caps to match the cartridge's output capacitance, improve stability of the current source.
And, last but not least, fight humming which, started puzzling me again. I plan to separate power ground from signal ground. Has anyone tested this?
busoni said:
1. LM4562 wasn't around when the VSPS was first drawn up. It would seem to be an excellent choice.
2. Ideally 100uF would be soldered from the power pins to the out- wirepads, and C6,7 would be left off the board. This is the main problem with th current layout; C6,7 are too far away from the op amp.
3. Batteries don't sound as good as a good linear supply.
4. 2x1.0uF should be sufficient. I suspect the Nichicon nonpolar sounds rather poor, though its OK in a pinch.
Hum? With a battery supply, the issue would have to be related to the turntable motor... signal, power grounds are already separated on the SkyCoral layout, i.e. already correct for a noninverting layout.
Thanks for your detailed comments.
Richard
rjm said:
Thanks for the reply Richard
So you think that I should invest in a good power supply? I'll certainly check it. Would an R-core transformer be better than a torroidal?
I'll also test 2.0uF, maybe less capacitance in combination with the output resistance. My intention is to try teflon caps which are available in smaller capacitances, in combination with the output resistance in order to keep the frequency of this output filter as low as possible. Input resistance of my opamp is around 200k, so I suppose there's still room to increase resistance and lower capacitance in the VSPS output. Nichicon does not sound bad at first. I didn't give it time to evaluate, so I can not comment more. But compared to the PIOs, what was "interesting" in sound now becomes "involving".
I haven't noticed separate grounding on the skycoral board. I'll check it again. Thanks for pointing out.
"I plan to separate power ground from signal ground."
signal ground is any noninverting returns (R1, in C0), which connect together on the right side of the board before meeting the inverting return (R2) followed by the output return (R7, out)
power and signal grounds meet at the output return, power grounds are, in order, first the bypass caps, then the regulators, finally power supply COM
power/signal grounds are seperated, except for where the join... and you have to join then somewhere!
that's everything except for the case, and there is some leeway in the stereo VSPS board with regards to where you connect the case to the VSPS common. You could do it at on of the the inputs, or, as I usually do, the COM pad... it shouldn't make a big difference, but its worth trying a both if you are having problems.
/R
signal ground is any noninverting returns (R1, in C0), which connect together on the right side of the board before meeting the inverting return (R2) followed by the output return (R7, out)
power and signal grounds meet at the output return, power grounds are, in order, first the bypass caps, then the regulators, finally power supply COM
power/signal grounds are seperated, except for where the join... and you have to join then somewhere!
that's everything except for the case, and there is some leeway in the stereo VSPS board with regards to where you connect the case to the VSPS common. You could do it at on of the the inputs, or, as I usually do, the COM pad... it shouldn't make a big difference, but its worth trying a both if you are having problems.
/R
A few pictures finished set with enclosure:
1. http://www.fotosik.pl/pokaz_obrazek/pelny/540d2d8d5f0cd65b.html
2. http://www.fotosik.pl/pokaz_obrazek/pelny/5296a1bec0d685be.html
3. http://www.fotosik.pl/pokaz_obrazek/pelny/46c607a4ed853cba.html
4. http://www.fotosik.pl/pokaz_obrazek/pelny/efc5de380882be7b.html
Chassis is from Modus Shop, Italy (http://www.modushop.biz/ecommerce/index_l2.php).
Very good quallity.
Regards K
1. http://www.fotosik.pl/pokaz_obrazek/pelny/540d2d8d5f0cd65b.html
2. http://www.fotosik.pl/pokaz_obrazek/pelny/5296a1bec0d685be.html
3. http://www.fotosik.pl/pokaz_obrazek/pelny/46c607a4ed853cba.html
4. http://www.fotosik.pl/pokaz_obrazek/pelny/efc5de380882be7b.html
Chassis is from Modus Shop, Italy (http://www.modushop.biz/ecommerce/index_l2.php).
Very good quallity.
Regards K
Web Page
For the record:
After a bit of searching around I chose webhostingpad as my web hosting service for the new RJM Audio website. It seems to be cheap, and more than enough for my relatively simple needs.
Have a look for yourself,
www.phonoclone.com
I will be dismantling the old Geocities site shortly.
For the record:
After a bit of searching around I chose webhostingpad as my web hosting service for the new RJM Audio website. It seems to be cheap, and more than enough for my relatively simple needs.
Have a look for yourself,
www.phonoclone.com
I will be dismantling the old Geocities site shortly.
You don't need a regulated power supply with any of the VSPS and Phonoclone projects, just a transformer and rectifier.
Please read the Construction Guide.
The guide is still confusing on this point, and a thorough re-write is on the top of my priority list. There are three components to each project: the phono circuit, regulators, and the power supply. The phono circuit and regulators are on the circuit boards, the power supply is not. If you are using the circuit boards, you don't need to worry about the voltage regulators or even the filter capacitors, it's on the board already. The problem is not everyone building these projects is going to use the circuit boards provided ... so when I'm talking about the VSPS circuit as described on the
VSPS page I have to say "you need to provide regulated +/-12 V voltages for this" and when I'm talking about the VSPS circuit boards I have to say "you need the rectified output from 2x 12 VAC secondaries for this"...
I'm trying to be consistent with the following convention, though the guide is not updated to follow them yet:
V++, V-- is the "raw" rectified DC from the 12 V AC transformer output and the rectifier diodes. It measures about 18 V and -18 V respectively once its connected to the filter capacitors. This is the power supply input marking on the (latest revisions of the) circuit boards.
V+, V- is the filtered, regulated DC used to power the phono circuit. It typically measures 12 V and -12 V but depends on which regulators are being used. This is used internally on the schematics as the power for the phono circuit.
Confused yet?
Please read the Construction Guide.
The guide is still confusing on this point, and a thorough re-write is on the top of my priority list. There are three components to each project: the phono circuit, regulators, and the power supply. The phono circuit and regulators are on the circuit boards, the power supply is not. If you are using the circuit boards, you don't need to worry about the voltage regulators or even the filter capacitors, it's on the board already. The problem is not everyone building these projects is going to use the circuit boards provided ... so when I'm talking about the VSPS circuit as described on the
VSPS page I have to say "you need to provide regulated +/-12 V voltages for this" and when I'm talking about the VSPS circuit boards I have to say "you need the rectified output from 2x 12 VAC secondaries for this"...
I'm trying to be consistent with the following convention, though the guide is not updated to follow them yet:
V++, V-- is the "raw" rectified DC from the 12 V AC transformer output and the rectifier diodes. It measures about 18 V and -18 V respectively once its connected to the filter capacitors. This is the power supply input marking on the (latest revisions of the) circuit boards.
V+, V- is the filtered, regulated DC used to power the phono circuit. It typically measures 12 V and -12 V but depends on which regulators are being used. This is used internally on the schematics as the power for the phono circuit.
Confused yet?