Building a symmetrical psu B1 buffer

[regiregi22]

Originally Posted by Algar_emi

Just for information to some of you guys, I bought 100 led to match them for the Shunt Reg and out of the 100, this is what I got:

Led YEL, Mouser 593-VAOL-3HCE4
Tested using 9V supply, 1K resistor
DVM FLuke 87, 4-1/2 digits meter

Led-Vf QTY
1.91V = 5
1.92V = 1
1.93V = 32
1.94V = 53 (Most 1.936-1.937V)
1.95V = 8
1.96V = 2

It happens the same with my bag, it comes already matched, more or less.For the ones who haven't bought it yet these are good news, because they dont need to buy soooooo many leds.

[woodturner-fran]

yep, I think thats what we all got Sylvain! Too bloody consistent!


Anyway, tonight I swapped in some Bennic 4.7uF caps instead of the Carli caps. These caps sounded really good as output caps in my phonoclone - and I rolled quite a few. So, I'll let them run in for a little and see how they go. Next up after these are smaller value GE caps.

All caps so far are from Madisound.

Fran

[Salas]

[Algar_emi]

Regarding the cap mods suggestion (100uF, 5X Led) to be replaced with a MKT of MKP cap, did anyone try to install a small MKP bypass cap on the 100uF cap instead, soldered from the bottom for example?

Also, do you have the part number, manufacturer, etc, of the matching connectors that fits the Mesmerize Selector Switch PCB outline, (and the IN/OUT connectors as well)?

[Algar_emi]

Also Woodturner-fran, I can see on your picture that you installed a jumper instead of one of the 5 led. What is the total 5X led voltage we are trying to reach as target?

[regiregi22]

Originally Posted by Algar_emi

Also Woodturner-fran, I can see on your picture that you installed a jumper instead of one of the 5 led. What is the total 5X led voltage we are trying to reach as target?

And could you tell as woodturner, what values are your CCS (R1) resistors and how many voltage are dropping?

[woodturner-fran]

Algar-emi:

in/out - I just used some old sockets from an old pcb and just pushed the wires into them. Very easy to remove that way - important on a tweakers board!! They are here:
mouser #575-113120

As regards using a bypass cap...eh nope - its just monkey see monkey do 'round here!

No jumper on the 5 x LEDs - I think what you're seeing is a much smaller LED that might look like a jumper cos of my crappy camera phone! I used all sorts of different LEDs to try and get the drop right. I think it was 9V for the 5 leds and 5.4V for the 3 LEDs we aimed for.


regiregi22: my resistors are 68//68//10 which I think works out at 7.2R. Voltage IIRC is about 1.6v and 1.9V which gives 230 and 270mA- have a look a few posts back and I link it to much earlier in the thread (post 1030)about page 102-104 i think).


Fran

[Salas]

Originally Posted by Algar_emi

Regarding the cap mods suggestion (100uF, 5X Led) to be replaced with a MKT of MKP cap, did anyone try to install a small MKP bypass cap on the 100uF cap instead, soldered from the bottom for example?

It will not take down chemical cap's distortion. Its not an ''instead'', it will alter ESR, and will have some other effect. Results are a mixed bag in my experience. Small good caps for there are the non celebrated PPS also, IMHO.

[Algar_emi]

Thanks Salas, yes, I know that film caps always have lower distortion that electrolytic ones.
I have in stock some very nice MKT Vishay (Polyester, Digikey BC1626-ND), 1.5uF, 63V. I'll installed two in parallel for 3uF total each.
They are very small, and will fit nicely. No offense, but much nicer that the big ones I saw
I'll try that.

Still no part number for the Selection and In/Out connectors?

Thanks.

[Algar_emi]

Here the caps installed.