I have these caps as pairs and slightly soldered but with original lead uncut for sale pm me for details

Thanks

hi erwin

i may offer a built up pcb module. no point in putting out a kit. too many components to solder and mostly surface mounted!  necessary, imho, to maintain the shortest path possible.

my main problem is pricing.

yeo

yeo

how do you describe the sound from Monica variations ? Does it give a giant leap in terms of everything?

i'm guessing the high price mostly because you have to hand matched the resistors is it?

what you think having a kit consist of all smd soldered except the resistors to keep cost down. minus the psu section so that we can choose according to ones taste. 

a group buy is a best way to get matched resistors IMHO...

hi nikita

as for va calculation, remember, transformers aren't 100% efficient, so account for its losses.

say you need 30va, for you isolation trans, go for 60va. if efficiency is 80%, then 60va*0.8*0.8 so your resultant isolation trans combo is now only 38.4va.

see what i mean? so losses compound very quickly.

yeo

well said...

thanks for the advice Yeo

I mean  3 trans in total.
This is how i wire my isolation trans. My ac here is 230 V ac.

the first 2 tran are 230 v in and 18 0 18 vac out. The 18 0 18 v are tied together but only the 0 point of the first tran is taken to ground.  These 2 trans constitute the isolation trans set up.

The 230 V ac out of the 2nd trans will be tied to your input of the step down trans just before the rectifier

regards

kp93300

yes i understand. i just show the one representing the isolation part only.


I still stuck with the VA calculation though...

Hi
My isolation trans is  0   230V ac  in and 18 0 18 V ac out. I have 2 of this wired back to back.
From the   0 230 V out of the 2 nd trans , i connected the step down trans before the rectifier.

Remember live ac is very dangerous . Please ask for help if you are not sure

regards

kp93300

this is what you mean right kp93300.......

0----------------18---------------------18--------------0

                       0--- com                  0                     

230------------180---------------------18------------230


what possibly be be wrong if we do this correctly

I'm still stuck calculating suitable VA for the isolation traffo for my DAC requirements. My DAC needs around 50VA to works best...

hi nikita

i'll grab both of the same type, with center tap though i'll only ground the first tran's center tap.

dacs don't need more than 30va. to account for efficiency of transformer, for the isolation trans, i'll use 2 pieces of 60va, followed by a 30va step down trans.

yeo

yeo

do you mean using 3 traffo back to back is far more efficient than 2 traffo ?

So I read through this section today

http://diyparadise.com/web/projectsto-keep-you-busy-mainmenu-26/77-build-a-cleaner-power-supply

Yeo point out that building a cheap version of isolation transformer takes 2 identical transformer from any kinda of output and be connected back to back.

Question is does both needs to have a center tab of just one because if you look at the last diagram it's a center tab connected to a non center tab traffo. Noob question but please bare with me.

And how many VA of traffo seams seasonably adequate for filtering of single equipment like a dac?

kp93300

for a 12v out regulator using this shunt, how much capacitance I need after the rectification?

hi nikita

i got the pcb in already. the parts are pretty generic stuffs. refer to schematic on my site.

i may offer them for sale soon since there are so many folks asking for this pcb.

yeo

hi Yeo

gong xi fa cai

when will the pcb ready? i hope it won't have any dispute on copyright claim.

just keep it quiet....!!!

Hi Yeo

Now there's a good news. Can't wait to get my itchy hands on the pcb.


audi0

You're lucky too since you don't need $400-ish to have a simple frequency generator....

Hi

After reading this article I wonder will there be a discussion on how to build this plus maybe a kit. Would love to kill my excessive holidays with this project.

Yeo if you could hear this maybe you could lend me a hand specially for the parts.

http://diyparadise.com/web/projectsto-keep-you-busy-mainmenu-26/154

yes there is...re badged from digikey usa....

how much does the newava cost in digikey malaysia?

Hi Yeo

In the latest posting regarding mojo2 http://diyparadise.com/web/learn-learn-learn-mainmenu-27/155 you've mention different configuration to impliment mojo2 with various of digital sources....I2s, usb or spdf to eiaj to mojo2 to amp...BUT where's the DAC....?   

Hi everybody,

Been reading a lot about a good & simple I/V stage for PCM1798/4 dac and thinking is Modjo is suitable for the job?

Just like the subject, my plan is to use PCM1798/4 --> Modjo --> passive buffer stage like output traffos as a single ended output.

If this possible can anybody tells me what sorta of mod need to be done to the Modjo boards.

Thanks