The simplistic Salas low voltage shunt regulator

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I will try to replace my existing power supply in Dispre preamp from PMA (you can find in diyaudio).

Hi lgabco,
I have a dispre II myself and I'm planning to feed it with salas shunt. Did you ask PMA's opinion about this ? At his site he says that " Power supply requirements - 2 x 15V stabilized, at least 2 x 200 mA ".
That makes me believe that we need a lot more than 200 ma from salas shunt ...
 
Dispre on CCS + Shunt reg

Hi,
I think the dispre is a push pull amplifier.
That will draw variable current from the supply rails, even while still in ClassA.

Can anyone confirm the quiescent current, the max ClassA output current and what happens if a higher than max ClassA current is demanded by the load?
 
I have a dispre II myself and I'm planning to feed it with salas shunt. Did you ask PMA's opinion about this ? At his site he says that " Power supply requirements - 2 x 15V stabilized, at least 2 x 200 mA ".
That makes me believe that we need a lot more than 200 ma from salas shunt ...

Marinos,
It depends whether you use Dispreas preamp, or as headamp. If you use Dispre just as preamp, then you need about 70 mA for both channels. Headamp is another case ...

Ladislav
 
Which opamp do you use for the dc servo that withstands +-24 V? The 15V specified by PMA is because of this limitation

Marinos, nice question. I am experimenting with Dispre a little bit. As a servo I use LF411, however there is 15V zener at each rail to keep it OK.

There are some discussion in slovanet forum (in Slovak) about the best opamp for servo, especialy for power amps. There are a lot of opinions, some are prefering OP177. It is bipolar opamp, however with high input resistance. If you want to experiment you can try this one.

Ladislav
 
Did you test the V1 reg and dispre together yet? What is it its before reg exactly?

I did not try it yet. I am busy and my diy activities are taking place very slowly :crying: .
My listening experience in comparing products is limited. My percepcion of my present system is that I feel little bit tired after 20-30 minutes of listening. This was not the case with Bal-zen preamp. On the other hand Dispre provide me more details and clarity than Bal-zen. So my present plan is to improve power supply for Dispre and remove "something" that make me feel tired. The next step will be changes in power amp. Anyway I will inform you but it will take some time.
Ladislav
 
I really tried to look through the thread, but unfurtunately the search-function is not of too much use as I can't find all the different references mentioned in the posts.
Fortunately I found a hint that I might just post my requirements and a pro would then direct me to my best bet(s) for the specific requirements.
I ll still keep on reading through this interesting thread, but if someone is willing to help me before I'm totally confused with all the posts, it would be really appreciated.

I want to power three different circuits with independent supplies:
1.) The first board is a USB-highspeed receiver with CLPD and Tent-XO that should provide a very clean I2S-signal from my computer (that's my own design and I will open another thread on that one later, when I have something to show of). It requires 3,3V and around 150mA.
2.) The next is a Buffalo II DAC (5V 400mA)
3.) The last one is the IVY III I/V (+-15V 150mA)

As I already understand there are different versions if the "simplistic salas", some using remote sensing others not doing so.
I haven't read through all the pages of this thread, so I can't really say which ones I favor, but perhaps someone could point me to the right direction – best yet if board layout would be available.

Many thanks in advance
THKL
 
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The versions are two. V1.0 and V1.2. The various schematics are configurations.
Remote sensing is just connecting with four Kelvin wires and is applicable to all.
To go 3.3V you will need to substitute the shunt Mosfet with a BJT. Mosfet has large Vgs for such. V1.2 is best. +/- 15V 1.2 you can find on page 190. Same thing can be adjusted for +5V. +3.3V has been done with V1.0 and MJE350 instead of 9240 shunt element for turntable DC motor and #26 DHT 1.5V filament with another BJT. Maybe when I will have some time I can gather the specific drawings and set values for you, but keep on reading, its very easy to grasp how to set for consumption, connect, etc.
 
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