KWAK: Who is malichiconstant? I never heard of him .. let me explain: R14 and C7 is a normal RC filter.
Can you explain me, which part of the RC filter you find intriguing?
The R or the C ?? And what does it have to do with this thread??? OK i will help you out on that one ..
The next version of XO3 it will actually have an implementation of the 'lownoise regulator' on board instead of the AD. With a few other upgrades..... But no BG caps cheers
Power Supply Regulators
Hi, In the good old days Tom Colangelo came up with the PLS-150 supply for the Mark Levinson ML-1 preamplifier. We were shocked by the abundance of parts and by the fact it was not potted. I reverse engineered the supply and found it is somewhat similar to the PLS154 used for the ML-7 preamplifier of the same brand.
The PLS150 is not a dual-tracking supply and has two 1N5526 zeners that are filtered and one is used for each supply (positive/negative)
The PLS154 is using the same reference, also filtered and used as a reference for the positive supply. The negative supply is then obtained by inverting the positive supply with an unity gain inverting amplifier.
So far so good as I am inclined to believe Tom is convinced a dual tracking regulator is better than a conventional dual supply.
But the Mark Levinson company went down for about a year and Mark Levinson (the person) founded a new company Cello. His favourite engineer Tom moved with him. And what do I see as the regulator of the Cello Encore preamp? A LM317/337 STEEL (TO-3 case) from National.
Anyone can shed light on this?
Attached picture is of the PLS150 supply.
Hi, In the good old days Tom Colangelo came up with the PLS-150 supply for the Mark Levinson ML-1 preamplifier. We were shocked by the abundance of parts and by the fact it was not potted. I reverse engineered the supply and found it is somewhat similar to the PLS154 used for the ML-7 preamplifier of the same brand.
The PLS150 is not a dual-tracking supply and has two 1N5526 zeners that are filtered and one is used for each supply (positive/negative)
The PLS154 is using the same reference, also filtered and used as a reference for the positive supply. The negative supply is then obtained by inverting the positive supply with an unity gain inverting amplifier.
So far so good as I am inclined to believe Tom is convinced a dual tracking regulator is better than a conventional dual supply.
But the Mark Levinson company went down for about a year and Mark Levinson (the person) founded a new company Cello. His favourite engineer Tom moved with him. And what do I see as the regulator of the Cello Encore preamp? A LM317/337 STEEL (TO-3 case) from National.
Anyone can shed light on this?
Attached picture is of the PLS150 supply.
Attachments
Funny?
Is everybody funny here?
And your quote using my name is certainly out of context and does not apply to Nelson Pass, Fred, Jocko, Jonathan Carr a.o.
The examples I gave are not the whole story. The PLS150 supply is dead quiet and the PLS154 also which cannot be said of a LM317/337 setup. The latter is simply not quiet enough powering a MC-cartridge preamp.
I did see some extra circuitry around the LM317 in the Cello so maybe Tom Colangelo designed something along the lines of Fred' s suggestion........(Improving the LM317 regulator thread).
Here perhaps:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28579&perpage=10&highlight=&pagenumber=1
There also do exist many versions of the Cello preamp. I did not spot the LM317/337 in earlier versions.
Funny?analog_sa said:
Is everybody funny here?
And your quote using my name is certainly out of context and does not apply to Nelson Pass, Fred, Jocko, Jonathan Carr a.o.
The examples I gave are not the whole story. The PLS150 supply is dead quiet and the PLS154 also which cannot be said of a LM317/337 setup. The latter is simply not quiet enough powering a MC-cartridge preamp.
I did see some extra circuitry around the LM317 in the Cello so maybe Tom Colangelo designed something along the lines of Fred' s suggestion........(Improving the LM317 regulator thread).
Here perhaps:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28579&perpage=10&highlight=&pagenumber=1
There also do exist many versions of the Cello preamp. I did not spot the LM317/337 in earlier versions.
Well, bub...........
I warned you...............
Found this in my inbox..........
"A message from the Space Wanderer (Malichi Constant):
Another pic of the finished regulator. Output +/-5 V to +/-22V (or 0/+44V) up to 1 Amp (with bigger heat sink with some resistor value changes and higher voltage caps on input. Drop out voltage about 5 or 6 volts. the dual op amp uses the regulator's output for it's rails but is decoupled from the supply starting at the point its PSRR starts to drop. RC output decoupling for best stability and no noise peaking. All the filter caps after the Voltage reference circuit and for op amp decoupling are polypropylene. The voltage reference is tapped for 5 10 12 and 15 volts. Op amp runs AC unity gain and the Mosfets are preloaded for decent transconductance. This took only three days to design and build. This is real straight forward stuff and not that hard. The posted design is not even up to doing the basic stuff right as outlined in the original Sulzer op amp supply article in TAA nearly a quarter of a century ago! The best part is not putting a gate resistor on the power mosfet. Something that is known to anyone who would dare call himself an audio designer would know better than to do."
End of message. Stop.
We hate Malachi Constant because..........
I warned you...............
Found this in my inbox..........
"A message from the Space Wanderer (Malichi Constant):
Another pic of the finished regulator. Output +/-5 V to +/-22V (or 0/+44V) up to 1 Amp (with bigger heat sink with some resistor value changes and higher voltage caps on input. Drop out voltage about 5 or 6 volts. the dual op amp uses the regulator's output for it's rails but is decoupled from the supply starting at the point its PSRR starts to drop. RC output decoupling for best stability and no noise peaking. All the filter caps after the Voltage reference circuit and for op amp decoupling are polypropylene. The voltage reference is tapped for 5 10 12 and 15 volts. Op amp runs AC unity gain and the Mosfets are preloaded for decent transconductance. This took only three days to design and build. This is real straight forward stuff and not that hard. The posted design is not even up to doing the basic stuff right as outlined in the original Sulzer op amp supply article in TAA nearly a quarter of a century ago! The best part is not putting a gate resistor on the power mosfet. Something that is known to anyone who would dare call himself an audio designer would know better than to do."
End of message. Stop.
We hate Malachi Constant because..........
Attachments
Elso, are you really sure about the specifictions?
30 mV load regulation seems very much. Has Lars' stated this or have you measured? If Lars has those specs, maybe he have stated this to be on the safe side (much better in real life)?
My "bad" regulator has 16 uV noise using a "bad" 431, Ok with filter.
30 mV load regulation seems very much. Has Lars' stated this or have you measured? If Lars has those specs, maybe he have stated this to be on the safe side (much better in real life)?
My "bad" regulator has 16 uV noise using a "bad" 431, Ok with filter.
Maybe Elso will get DC on the output of his op-amp in case one rail draws 1 A and the other 0 mA. But i am pretty sure it doesn't come from the 30 mV of rail difference
Read: 30mV = insignificant...
Fred: If you have some solutions you would like to share, why not publish the schematics also? I did .. ;-)
Lars
Read: 30mV = insignificant...
Fred: If you have some solutions you would like to share, why not publish the schematics also? I did .. ;-)
Lars
protection
There is a possible improvement for you: built in some protection to prevent the supply voltage from exceeding the +/- 22V at the opamp.
If everthing works the way it should this is a fine design, and perform(ed) very well in my system. However a fault in my mains power supply caused temporary 380V instead of 240VAC in the wall socket. As a result the opamp died.
Lars Clausen said:
3..Well the NE5532 may be old, but as i often tell my employees, just because something (or someone) is old, doesn't mean it's useless.
So it makes no sense to use a lower noise op-amp.
And it has one great advantage over any ultra low noise opamp: it can operate on +/- 22V (Philips brand).
Lars
There is a possible improvement for you: built in some protection to prevent the supply voltage from exceeding the +/- 22V at the opamp.
If everthing works the way it should this is a fine design, and perform(ed) very well in my system. However a fault in my mains power supply caused temporary 380V instead of 240VAC in the wall socket. As a result the opamp died.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.