hi.
why it's that bad to thight thermo-couple the transistors? That is what I understand by using a thin strip of copper. My solution is to fasten all the transistors in each stage in a bouquet with a strip of copper, soldering them to a little pcb, then to the main pcb.
why it's that bad to thight thermo-couple the transistors? That is what I understand by using a thin strip of copper. My solution is to fasten all the transistors in each stage in a bouquet with a strip of copper, soldering them to a little pcb, then to the main pcb.
and if the paradise goes balanced, what with the amplifier.? I think already to add balanced inputs to my amplifier because my Oppo has balanced outs, but I can't figure it how. Is it worth to add a balanced input stage to an amplifier that is not designed in this way?
emil
emil
Sort off, just go there. I'm sure Stefano will be a good host 🙂 ohhh ehhh the name is Frans 🙂
I use this thread now for an off topic question related however to the shunt regulator. Sorry!
The question: how could I get 26 -27 volts from the shunt regulator used in the paradise? I need a shunt to supply the voltage for a preamplifier.
Which are the differencies between Salas shunt and this one? Bref, I want to supply the preamp stage in my integrated NAD 375 from a shunt instead the simple regulator that is used. The NAD 165 preamp use a shunt instead, but it's a classic design, with a zener diode, not with leds and other spices. So, what do you recommend?
Ricardo, do you hav an ideeea what kind of improvements DYNAVOX.CH brings to the Swiss version of NAD they sell?
The question: how could I get 26 -27 volts from the shunt regulator used in the paradise? I need a shunt to supply the voltage for a preamplifier.
Which are the differencies between Salas shunt and this one? Bref, I want to supply the preamp stage in my integrated NAD 375 from a shunt instead the simple regulator that is used. The NAD 165 preamp use a shunt instead, but it's a classic design, with a zener diode, not with leds and other spices. So, what do you recommend?
Ricardo, do you hav an ideeea what kind of improvements DYNAVOX.CH brings to the Swiss version of NAD they sell?
I have seen some revamped Myryads and it seems they have better psu's and caps, but I had not the opportunity to compare.
Add more LED's to the chain of LED's or replace them all with a zenerdiode of the desired voltage - 600mV or replace one LED with a zenerdiode(26V) - LEDcount * 1.8V - 600mV.
Thank you Ricardo, it seems that a modified NAD or Myrriad, sounds way better than the original.
Thanks Frans, I didn't get your point right now, I have to think a little bit more of what you wrote. (I don't get the point in electronics in general, but I try) But why did you use all that bunch of leds if a single diode would have done the same?
If in the paradise regulator are 9 led (as in the schematic)*1,8V - 600mV=15,6 V , how do we have 18,2 V?
What relation is between the input and the output voltage? So, Right now we have 25 V to obtain 18,2 V with the radiator quit warm. What voltage do I have to apply at the input in order to have the 26 or 27 V I need.
In this case the power BJT and MOSFET are enough in terms of power handling?
Thanks a lot. I don't want to pollute this thread with questions out of the paradise topic. Just tell me if you think it's not OK.
Emil
Thanks Frans, I didn't get your point right now, I have to think a little bit more of what you wrote. (I don't get the point in electronics in general, but I try) But why did you use all that bunch of leds if a single diode would have done the same?
If in the paradise regulator are 9 led (as in the schematic)*1,8V - 600mV=15,6 V , how do we have 18,2 V?
What relation is between the input and the output voltage? So, Right now we have 25 V to obtain 18,2 V with the radiator quit warm. What voltage do I have to apply at the input in order to have the 26 or 27 V I need.
In this case the power BJT and MOSFET are enough in terms of power handling?
Thanks a lot. I don't want to pollute this thread with questions out of the paradise topic. Just tell me if you think it's not OK.
Emil
Don't forget about the series resistor and potentiometer and there you have the difference 😉
Because we can 🙂
9 led (as in the schematic) * 1,8V + 600mV = 17.8 V (There is also a trimmer)
Vin = Vout + 7V...8V
Yes, but the MOSFET gets a bit hotter and you should use a somewhat larger heat sink.
My pleasure 🙂
Hi all!
I've received the last batch of transistors from SOS > from Diotec. 700+700. When I saw all that little black things I thought: I had to be mad, what a man can do for his passion. Well, I extended the testing circuit from the guide in order to measure 16 transistors at the same time, so this evening back to sorting.
Two important things:
I've changed the two 150 k resistors to 10 k each. And as described in a former post the readings changed accordingly:
Right channel
RIAA: -1,90 V wandering 100mV around
OUT: wandering between -15 mV and + 15 mV
Pin 6: -900mV wander 100 mV
Left channel:
RIAA: -2,2 V wander 100mV
OUT: +/- 10 mV
pin 6: - 200mV wander 100 mV
So quit a difference between the channels at pin 6 but I see a big improvement. Before, with the 150 k resistors I had-5 V for a channel and -13V for the other.
At OUT the both are pretty the same, and again an improvement, before I had wandering readings at - 200mV.
At RIAA the readings didn't change from the former situation.
Am I getting closer to the Heaven?
Thanks for your help
I've received the last batch of transistors from SOS > from Diotec. 700+700. When I saw all that little black things I thought: I had to be mad, what a man can do for his passion. Well, I extended the testing circuit from the guide in order to measure 16 transistors at the same time, so this evening back to sorting.
Two important things:
I've changed the two 150 k resistors to 10 k each. And as described in a former post the readings changed accordingly:
Right channel
RIAA: -1,90 V wandering 100mV around
OUT: wandering between -15 mV and + 15 mV
Pin 6: -900mV wander 100 mV
Left channel:
RIAA: -2,2 V wander 100mV
OUT: +/- 10 mV
pin 6: - 200mV wander 100 mV
So quit a difference between the channels at pin 6 but I see a big improvement. Before, with the 150 k resistors I had-5 V for a channel and -13V for the other.
At OUT the both are pretty the same, and again an improvement, before I had wandering readings at - 200mV.
At RIAA the readings didn't change from the former situation.
Am I getting closer to the Heaven?
Thanks for your help
The drifting goes away when the input transistors are thermally coupled. The easiest solution is to build a liitle box from paper and slight it over the input section.
Little wenting holes are ok.
Little wenting holes are ok.
Thats a pretty low value. Some volts on pin6 are OK, e.g. less than +/-5. Please try and see if 50k does the trick for you
I'll change to 50 k and report back. Also I'll try to implement my "extreme thermo-coupling".
with 47 k
RIAA: as usual -1,9 volts
OUT: wandering +/- 80 mV
pin 6: -3,5 V with little variation
It doesn't help me a lot. I mean not at all. It looks like that at Fraunhofer Institute they tried to build a quantic phono stage made of graphene but it's not for me. I'll stick with the Paradise.
RIAA: as usual -1,9 volts
OUT: wandering +/- 80 mV
pin 6: -3,5 V with little variation
It doesn't help me a lot. I mean not at all. It looks like that at Fraunhofer Institute they tried to build a quantic phono stage made of graphene but it's not for me. I'll stick with the Paradise.