Reflektor-D builds

[Salas]

With the RR 100Ω you secure moderate current even if you chance on a higher IDSS JFET.

Because they are SMD parts i.e. tiny you want to avoid extra dissipation in them, so use the 100Ω if not wanting to install various resistors and measure ID in circuit and then rework to home in.

 

[dahlberg]

I found this comment written by Mr. Kazuo Ozawa in a different thread.

As Bunpei precisely reports, my first interest for GaN
started from the study of Taylor Follower type Regulator.
When I replaced MTP3055VL with GS66502B for shunt on the
regulator, I found great improvement. Then I decided to apply
this GaN to Power amplifier particularly the Amazing Circlotron.

post 9
Applying GaN transistor as a replacement of SiC rectifier

Now I wonder if anyone here have tested this for the ReflektorD ?

 

[Salas]

I don't remember anyone reporting about having used GaN in this thread

 

[dahlberg]

I haven't seen it either but I sent Kazuo a PM asking about it. Dont know how often he reads here though.

 

[merlin el mago]

@Salas

Could I use only one bridge rectifier + one 10.000uF AC mains cap to power simultaneously one Reflektor set to 5VDC 350-450mA & one BiB 3.3VDC 625mA, the power transformer it's 9V 30VA?

TIA
Felipe

 

[Salas]

Yes, the loss to AC ripple across the main capacitor should not be that much for 1A total. Measure the DC across it to be not less than 10V at work. Use local decoupling capacitors on each regulator's DC input.

 

[merlin el mago]

Wich value 100nF? There is better SQ using one rectifier & one AC mains cap filter for each reg? I will do the question better? BiB is powering Amanero USB-I2S board + one part of I2S isolator. Reflektor is powering Cronus re-clock board + the other part of I2S isolator. The mains power transformer is a Selectronic R-Core with dual 0-9VAC secondary 30VA rated. As I more see it become more complicated. I forget the isolator need two isolated 3.3V, and I have only one 3.3V the other is 5V for the Cronus. Wow what a shock, I read the the IC USB-I2S isolator to know the working voltage & the Recommended Operating Conditions min. 3V & max. 5.5V and max. rating 7V Attached a couple of figures, I guess I have to use fig. 1?

TIA
Felipe

 

[Salas]

As figure 1 for the DC inputs and as figure 2 for the loads

 

[merlin el mago]

One reg. 1st load Amanero & 2nd load one side USB-I2S isolator?

Second reg. 1st load Cronus & 2nd load the other side USB-I2S isolator?

4 wires to 1st load and two wires for 2nd load?

 

[Salas]

4 wires to 1st load and two wires for 2nd load?

Yes, but shortest possible cables between loads.

About those digital circuits you have I don't know in what pairs they combine best if there is any best pairing for sharing PSU.

 

[merlin el mago]

Thanks Salas. The only I know for sure is that the USB-I2S isolator needs to be powered with two separate regs. to be isolated the I2S line. Could be a problem to isolate the I2S line to share the rect. & mains AC cap? I used BiB with Amanero a lot of years with great result, I prefered the SQ of BiB over Reflektor because I only listen DSD. So BiB for Amanero & Reflektor for Cronus. I have to left you Salas, today is the happy birthday of my wife and we will go to the restaurant to celebrate.

 

[Salas]

The only I know for sure is that the USB-I2S isolator needs to be powered with two separate regs. to be isolated the I2S line. Could be a problem to isolate the I2S line to share the rect. & mains AC cap?

Yes you lose the isolation. Must have a psu + reg all alone with own Tx if isolation is an issue.

Have a nice time with her. Bye!

 

[merlin el mago]

Thanks for all suport Salas.

 

[dahlberg]

I got this old link about the R6 mod from a friend the other day (it's called R5 though) and I have since then searched for the first 50 pages in this thread for a similar approach. Found nothing about alternative values for this position, any comment would be great. The short review by "pietjers" made me curious.

The simplistic Salas low voltage shunt regulator

Post 5820

 

[Salas]

Yes its influential. You could try other values but we usually put a K177GR JFET with G+S shorted in its place if we are looking for maximum effect.

 

[ggetzoff]

Salas,

I've got one Reflektor D for 2 very small loads, 30 mah for both. R1 is set correctly. But as far as hookup goes, Reg - 4 leads to first load, then parallel off of that for the second?

Thanks,

Greg

 

[Salas]

Parallel off of that to the second but with just two somewhat thick wires between them loads

 

[ggetzoff]

Parallel off of that to the second but with just two somewhat thick wires between them loads

K. Thank you.

 

[Mull3t]

Couldn't find an answer to all my questions via search, so here we go...


What is the tradeoff if wiring in normal two wire mode... not kelvin? My wiring won't be that long.


If wiring in Kelvin and then going to a terminal strip, do I need to continue with Kelvin wiring to final destinations. I have 3 destinations (isolation/re-clocking) that will be close to terminal strip.


Thanks in advance.

 

[Salas]

With two wire mode you avoid exposing sense runs to external interference and it can be a logical choice when killing little added short thick cable's resistance isn't a priority for the client circuits. Kelvin works best when all destination nodes come to a star arrangement with short copper lanes at a common terminal.