Thanks Salas.
lessons learned:
Next time, I'll build, measure, then order the correct R's. Can't rely on theoretical specs for this. For some reason, I had spec'd the V at 2.3 from spreadsheet so I had those 3.9r for about ccs 600ma
In essence, I need to order 1.2 and 1.55 r to get .600 from both bibs.
so 2x2.4r and 2x3.1r in 5W
.72/600 = 1.2
.93/600=1.55
thanks all for support
lessons learned:
Next time, I'll build, measure, then order the correct R's. Can't rely on theoretical specs for this. For some reason, I had spec'd the V at 2.3 from spreadsheet so I had those 3.9r for about ccs 600ma
In essence, I need to order 1.2 and 1.55 r to get .600 from both bibs.
so 2x2.4r and 2x3.1r in 5W
.72/600 = 1.2
.93/600=1.55
thanks all for support
...Or simply sub a stronger LED that will make up for the difference, or, or...
The calc makes some assumptions, but if you will feed it your measured LEDs total Vf and specific Mosfet's VGS it will guess better. This is not a very easy to grasp initially reg for its inner works and fine points, its very individual. Using passive voltage reference with no local feedback loop holding its value even...But it pays in tone I hope. That part was the focus of the design.
Some pictures after you are finished are always welcome to the shunt family album.
The calc makes some assumptions, but if you will feed it your measured LEDs total Vf and specific Mosfet's VGS it will guess better. This is not a very easy to grasp initially reg for its inner works and fine points, its very individual. Using passive voltage reference with no local feedback loop holding its value even...But it pays in tone I hope. That part was the focus of the design.
Some pictures after you are finished are always welcome to the shunt family album.
question:
has anyone used caddock 30w at these positions?
I have plenty of sinking for them.
MP930s are said to be the dog's...ears in this
Yup, these are MKT made by Taiwanese manufacturer Carli and are commonly used in XO projects. $1.80ea at MadisoundChinese MKT like those used in speaker kits maybe.
MP930s are said to be the dog's...ears in this
tx220S (S-Foil power resistors) arent bad either =) gotta love surplus cleanups around here. bagged a bunch of these including some 4.7R and 10R, perfect for salas regs with a little heatsink. with teflon cap, makes for a stupidly OTT shunt reg
I am looking for a cheap but good quality MKP caps to replace shunt electrolytic capacitors at speaker crossover - at mid and woofer shunt position
I have made a test replacing only one mid speaker shunt electrolytic cap of 22uF with four Bennik XPP 5,6 uF and It bring Improvement
now I need a recommendation for a other values 100uF and 68uF and 150uF
anyone tryed erse MKP
I have made a test replacing only one mid speaker shunt electrolytic cap of 22uF with four Bennik XPP 5,6 uF and It bring Improvement
now I need a recommendation for a other values 100uF and 68uF and 150uF
anyone tryed erse MKP
Thanks.Nice. What is the config you supply exactly?
The 3 regs are supplying -15V, -5V, and +5V to a TDA1541A running at 44.1/16. The +5V reg is also supplying 2mA of current to bring the voltage on the analog output of the DAC to 0V (so far stable to about +-2mV).
The output stage is the CEN current conveyer circuit published by EUVL. The DAC sees about 6-7 ohm impedance keeping it roughly under the Philips' spec of +-25mV.
Question: I've built a pair of Salas shunts to supply +- 30V for a headphone amplifier project (that got seriously sidetracked by too many other things to be built first). Both are working flawlessly into their dummy loads but exhibit very different voltage ramp up behaviour (in need of a better way to describe this...).
Both are built exactly the same way BUT the colour of the 3-LED string and the make of the 5K trimmer. When I switch them on one will start at about 27V and then slowly creep up to about 30V (my desired voltage), the other starts at 29,7V and finally hits 30V. I am suspecting the trimmers, both being 64W types from Vishay...(?), but one side sports the creme housing and the other side blue (see pic).
Is this of any concern... is it the different trimmers... since in the end (after about 5 min. my voltage is at +- 30V as desired. ?
Both are built exactly the same way BUT the colour of the 3-LED string and the make of the 5K trimmer. When I switch them on one will start at about 27V and then slowly creep up to about 30V (my desired voltage), the other starts at 29,7V and finally hits 30V. I am suspecting the trimmers, both being 64W types from Vishay...(?), but one side sports the creme housing and the other side blue (see pic).
Is this of any concern... is it the different trimmers... since in the end (after about 5 min. my voltage is at +- 30V as desired. ?
Attachments
the smoothing before the regs use very wide tolerance caps.
That would be part of any difference in start up speed.
The CCS then charges the regulator and any capacitance in the load.
That CCS into capacitance is a ramp up. IT is NOT instant.
The speed of the ramp up depends on CCS current and capacitance This would be the second contributor to difference in start up speed.
I suspect the 27V & 29V7 are simply you not being able to "see" the ramp slope differences.
That would be part of any difference in start up speed.
The CCS then charges the regulator and any capacitance in the load.
That CCS into capacitance is a ramp up. IT is NOT instant.
The speed of the ramp up depends on CCS current and capacitance This would be the second contributor to difference in start up speed.
I suspect the 27V & 29V7 are simply you not being able to "see" the ramp slope differences.
I prefer Auricap vs Obbligato gold.
would you please explain why you think that
Are different taste and construction both are polypropylene but:
Obbligato are aluminium foil
Auricap are metallized
Objectively foil is better than metallized so more resolution, Auricap are non inductive, always comparisons with the same rated voltage if you compare different voltages surely you prefer the more rated voltage.
Obbligato are aluminium foil
Auricap are metallized
Objectively foil is better than metallized so more resolution, Auricap are non inductive, always comparisons with the same rated voltage if you compare different voltages surely you prefer the more rated voltage.
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