Keantoken's CFP cap multiplier
Sorry for out of topic...
I changed the output caps and rail bypass caps on my Marantz SA11S1 and now it sounds very neautral and very smooth at high frequencies. My scope shows that the rails are very clean for high frequencies, BUT, I found 120Hz ripples at around 3mv p-p. I don't think the Marantz HDAM modules have any PSSR so no wonder the player does not sound as smooth or details as other high end CD players at lower frequencies!
Unfortunately I can't fit a CCS-shunt reg there because the heat within the chassis will quickly build up.
Which is the best series regulator circuit available? I have tried the Jung Supereg but at the time I did not have sufficient build experience to build it right, I guess. But then somebody reported that the phase margin is really low with that one. Any recommendations? my requirement is that the input is about +/-15V? output is about +/-11V.
Thanks in advance.
One of the Teddy-Regs regulators (see "Pink Fish Media" website) will do a pretty good job for this, is simple and doesn't take up much room - worth a look, and easy to knock one up to find out.
I have not found any high-performance series reg designs online except the Jung regs. There are discrete direct pin replacements for 7805-type regulators that can be bought, but they are hard for me to find on google.
I've done tons of sims with high-performance discrete series regulators, and I believe one could achieve better performance in a Jung-type regulator using discrete components rather than opamps, but that is an arena for another thread.
A full shunt reg might not work, but I think it's possible to hang a shunt reg off of a chip reg, for lower power and good performance.
However most of this is experimental, I haven't heard of anyone else using these techniques.
Do the boards use their own regulators, and if so, what type? Knowing this would make it easier to recommend a design with better specs, so as to avoid accidentally downgrading.
Thanks, jh. I will do some searches on that one.
I forgot to mention, one requirement is that the regulator must allow high capacitance at the load. In the original Marantz circuit, 6 x 470uF for each rail at the load (after the regulator, of course), which is huge. The Jung regulator would not like that.
The Marantz uses a very simple series regulator at that place. I have the schematic but due to copyright reason I can't post it.
With the Ikoreg, I did find running on 213mA gives a better sound than running on 170mA. At 213mA it dissipates up to 12W (30V x 0.213A x 2), and that is as hot as the music it delivers. The CD player won't last long for that sort of heat generated within the encloser.
would it look OK to locate the FET heatsinks outside (on the lid of) the CD player?
mount the CCS part outside and locate the Shunt part next to the circuit.
The LME49600 application sheet has schematics for a regulator design cooked by Bob Pease and Mark (Audioman 54) I believe they presented a paper on the design. I've built it, it works well, and can share express pcb files if you desire. Mark references the paper in the thread National Opamp Inflation http://www.diyaudio.com/forums/solid...inflation.html see post #5,#63 and #68. Somewhere I've seen a reference to the paper they presented, but, can't find it...
Bill, there's a very simple circuit which you'll be amazed by what a difference it can make. The resistor values will have to be changed to your liking. This is not a regulator.
some more options
another one, Vout can be adjusted
or HERE , everything on left side from C12 can be omitted
or mini shunt (more LEDs=higher Vout)
if you want shunt reg and don't want to dissipate heat, you can use clever idea from Wenzel Finesse Voltage regulator to build your own clean-up shunt reg: FINESSE REG.
Or Maxim's design idea: NOISE CANCELATION
all above regs are from different authors, pick up your poison :D
But be aware, with high output Z regulators, big capacitance with low-ESR, ESR can dominate over regulator into audio band. Capacitor sound :p
this might not be popular, but for your purposes here, I would recommend just using a linear technologies IC linear reg with simple surrounding circuit. such as the LT1764A or LT1963A. the ICs really are superb, the guys at linear really know what they are on about and the datasheets and app notes are very comprehensive. I have been using the 1763A and 1185 with very good results so far in a simple follower i'm working on and use their 176X series small LDOs in my portable sabre
low drop out V, low noise and low heat. not quite up there with a discrete shunt, but leagues ahead of any other ICs i've used before. also if you can use one of the fixed Vout versions (wont suit u here, too low V) they have a sense/force kelvin connection, but this is the same pin that is the adj pin in the adjustable versions.
just make sure to use a nice polymer cap in parallel with te datasheets ceramic at the output. or you could use film.
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