Author Topic: ROG Thiunderbird supply voltage folly's  (Read 216 times)

petey twofinger

ROG Thiunderbird supply voltage folly's
« on: March 07, 2021, 08:27:27 PM »
next up a ROG thunderbird with a "cash box" chassis with a 5$ class D amp board , more 18650 li ion battery packs to power the circuits . one dozen 18650 for the amp = two three packs in parallel ( double capacity )wired in series for 24 volts to run the embarrassing class d amp . then a separate (3x) battery pack to run the thunderbird .

 i built a similar amp last year with a pal 800 (jfet marshal preamp) circuit and also a spring tank reverb driver/ blue acutronix tank shrill sounding over-rated chinese class d board . that unit uses a 7809 vreg powered off three 18650 so its like 12.5 down to 9 , not a dumble , not a ms2 .

 i am  considering fowling up the supply voltage powering the ROG Thunderbird . perhaps i could use 3 18650=12.5 volts and run that thru a 7809 to hit around 9 v

if i were to use just two 18650 cells thats maybe 8.3 volts and then three 18650 comes out to 12.5 .

my question is can i get away with just two 18650 (8.3vdc) or how about three of them @12.5vdc .

 ultimately using the vreg along with three 1650 would get me closer to proper operation , hitting it with around 9 volts dc , but i was curious if it matters running a bit low or high , (8.1 or 12.5vdc) what effects this would have , as the circuit has a lt1054 . i really have no idea and i am certainly able to use the 3 18650 thru the vreg but i am also curious about options and what the effect would be if i tried it on lower and higher voltages .

im learning , we'll thats what i keep telling myself


Re: ROG Thiunderbird supply voltage folly's
« Reply #1 on: March 07, 2021, 11:46:44 PM »
Have not seen you in a while Petey. Hope you have been OK.

The T-bird runs on +24V. Why do you want to convert the 24V which you already have, down to 9V, then convert back to 24V? Just use a 220 Ohm and 470uFd R-C power filter to keep power amp hash and thrash out of the preamp.

petey twofinger

Re: ROG Thiunderbird supply voltage folly's
« Reply #2 on: March 14, 2021, 03:31:39 AM »
i guess its always been a point to keep amp power supply's separate from everything else because in my mind -

it makes it run quiet w/o interference

i have run into heterodyne osc before and i guess i would rather have separate power because i can .

i recycle li ion battery's and have more than i know what to do with . like a ridiculous number of working 18650 cells i pulled from lap top power supply's  i find at resale . 

by the was i knew you were going to say this and by you i mean specifically i thought to myself prr is going to tell me to run the thundie off 24vdc . 

so i am planning to "just" use a 7809 vreg on a 3 pack of 18650 cells to give me 9 for the thunderbird . sorry to bug ya . thanks for the reply . i have come to realize when i have a question , there tends to be a very good reason for this meaning - there is not a good answer . as far as trying to have funny post titles like "the boy with two fathers who could aslo not comprehend data sheets " well i dont think any one deserves this sort of thing . i missed you too .
im learning , we'll thats what i keep telling myself