Mpp - Page 339 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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
Reply
 
Thread Tools Search this Thread
Old 11th December 2011, 03:21 PM   #3381
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Do not worry too much Rüdiger. It´s all my fault. I did simply not find the time to look more deep into this because i was too busy. I am sure your solution works fine. You got it working in your circuit in the first place. I ship you the modules next week. If you get them working i know somebody that will be happy. Plus me of cause.
  Reply With Quote
Old 11th December 2011, 04:11 PM   #3382
masag1 is offline masag1  Germany
diyAudio Member
 
Join Date: Dec 2008
don't worry be happy
  Reply With Quote
Old 11th December 2011, 06:47 PM   #3383
FdW is online now FdW  Netherlands
diyAudio Member
 
FdW's Avatar
 
Join Date: Feb 2009
Location: Both feet on the ground (near Gouda)
Quote:
Originally Posted by Joachim Gerhard View Post
Yes, that is also what i would try. The LM317 is also no good over 10kHz. One could also cascode the LM317 with another LM317 ( aka Walt Jung ) for a big improvement but then we drop over 6V. Has anybody the patients to modify the JHW ( Joachim, Holger, Werner ) that way? I think you, Hesener have done that already so may i ask for a contribution ?
Rüdiger, i check that out.
Finding the question (I could read it like that ) of someone looking into cascaded usage of the LM317 (as Jung) I thought to give it a go. The schema and FFT (as attached) gives the result of my try (research).

The cascade version shows a 75dB improvement over the non-cascoded usage.

For this test I use a 15Vac transformer * sqrt(2) for a nominal voltage of 21Vdc. Added to the supply voltage is an noise signal of 4Vpp sinus. The load is a voltage source with an Rser of 1Ohm.

The voltage across the LM317 (including one Vbe and the current set resistor (12.5Ohm for 100mAmp)) is kept constant by using a zener diode, the circuit functions with a minimum value, for the zener, of 5.6Volt. The sample shows a 6.2Volt zener for some headroom.

Let me know what you think of it, and if improvements should be made, but keep it simple.

Anyway, I hope this input was useful.

Happy lurker,
Frans de Wit.
Attached Images
File Type: jpg Cascoded LM317.JPG (200.5 KB, 209 views)
File Type: jpg SSA Inp Pwr Sup.JPG (158.3 KB, 213 views)

Last edited by FdW; 11th December 2011 at 06:58 PM.
  Reply With Quote
Old 11th December 2011, 07:03 PM   #3384
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
That is a huge improvement and it is simple. Good work as far as i can tell. We need of cause a negative version too and the output voltage should be around plus-minus 24V when we take MiiB´s suggestion. The INA217 can take only plus-minus 18V so we need a little local drop for it.
  Reply With Quote
Old 11th December 2011, 08:04 PM   #3385
FdW is online now FdW  Netherlands
diyAudio Member
 
FdW's Avatar
 
Join Date: Feb 2009
Location: Both feet on the ground (near Gouda)
Quote:
Originally Posted by Joachim Gerhard View Post
That is a huge improvement and it is simple. Good work as far as i can tell. We need of cause a negative version too and the output voltage should be around plus-minus 24V when we take MiiB´s suggestion. The INA217 can take only plus-minus 18V so we need a little local drop for it.
Here it is +/- 24Volt. Currently I am building my SSA IGBT version, and that is going to use a +- 15Volt version of this power supply for the input stage. But it is not build at this moment, so it is a proposal only (to be continued).

As Jung noted, no need for the LM337, the LM317 will do and has a better performance.

P.s. my build will take place during the upcoming seasons holidays. All stuff is sitting here on my desk, and the cabinet is being machined (will be delivered next week).

Regards,
Frans.
Attached Images
File Type: jpg 24Volt(+-) Proposal.JPG (180.1 KB, 208 views)
  Reply With Quote
Old 11th December 2011, 08:19 PM   #3386
diyAudio Member
 
Onvinyl's Avatar
 
Join Date: Aug 2002
Location: Germany
I want to throw my last jfets on something decent.
This time, I want current input and balanced operation (with option for unbalanced at the output).

Was there a balanced starless or the like in this thread?

Rüdiger
__________________
"I can feel what's going on inside a piece of electronic equipment. I have a sense that I know what's going on inside the transistors." Robert Moog
  Reply With Quote
Old 11th December 2011, 08:28 PM   #3387
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Thanks Frans. I would like to use your PSU for the Paradise Lost if you do not mind.
I like it a lot. I assume that the transformer should be plus-minus 18V. I would then add the common mode coils before the bridge like in the little schematic i post. Does your circuit need only a 10uF cap at the output ? That would be really fine. There are small Wima foils with 10uF or does that have too low ESR ?
I will build it and try it out.
Attached Images
File Type: jpg Circuit Example common mode choke ac.jpg (56.5 KB, 190 views)
  Reply With Quote
Old 11th December 2011, 08:31 PM   #3388
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Rüdiger, the Starless can be modified for balanced when you use the output stage of the Paradise Lost. Should i draw up something that could work ?
  Reply With Quote
Old 11th December 2011, 08:47 PM   #3389
FdW is online now FdW  Netherlands
diyAudio Member
 
FdW's Avatar
 
Join Date: Feb 2009
Location: Both feet on the ground (near Gouda)
Quote:
Originally Posted by Joachim Gerhard View Post
Thanks Frans. I would like to use your PSU for the Paradise Lost if you do not mind.
I like it a lot. I assume that the transformer should be plus-minus 18V. I would then add the common mode coils before the bridge like in the little schematic i post. Does your circuit need only a 10uF cap at the output ? That would be really fine. There are small Wima foils with 10uF or does that have too low ESR ?
I will build it and try it out.
The simulator gives (nearly) equal numbers with or without the 10u, so I guess it is not needed at all. Initially I added the 10u to see if adding a capacitive load would destabilize it (it does not). I think I will add a 1u poly in my version (I do have a lot of those).

P.s. I feel honored

P.s. Yes the transformer should be 18Volts (the simulated transformer uses sqrt(2) for ac/dc conversion so there is some headroom)

Last edited by FdW; 11th December 2011 at 08:50 PM.
  Reply With Quote
Old 11th December 2011, 09:03 PM   #3390
FdW is online now FdW  Netherlands
diyAudio Member
 
FdW's Avatar
 
Join Date: Feb 2009
Location: Both feet on the ground (near Gouda)
Quote:
Originally Posted by FdW View Post
The simulator gives (nearly) equal numbers with or without the 10u, so I guess it is not needed at all. Initially I added the 10u to see if adding a capacitive load would destabilize it (it does not). I think I will add a 1u poly in my version (I do have a lot of those).

P.s. I feel honored

P.s. Yes the transformer should be 18Volts (the simulated transformer uses sqrt(2) for ac/dc conversion so there is some headroom)
Just did a quick check, the original simulation uses a 24Volt transformer and a sqrt(2) ac/dc conversion (that is what I like to use). Recalculating for a 18Volt transformer and a sqrt(3) ac/dc conversion gives a raw voltage of about 30Volts. The LM317 needs 2Volts, Rset 1.25Volts and the transistor Veb 0.7Volts giving about 4Volts, then add some headroom gives a zener of about 6Volts add another 4Volts for Vce and you need 15Volt + 10Volt is 25Volts of DC from the capacitor bank.

So, yes an 18Volt transformer would do (given sqrt(3) ac/dc conversion) if the transformer and capacitor bank is a bit over dimensioned. Anyway I normally would use and (loaded) ac/dc conversion of sqrt(2), and then you will need a 22/24Volt transformer. I hope that clears thing up

P.s. When using an 18Volt transformer then you need to change R5/6/13/14 to around 820Ohm (for 2mA about)

Last edited by FdW; 11th December 2011 at 09:09 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 06:05 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright İ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2