Vout approx. 15 - 15.5
Hi here.
I'm building DimDim's dual AK4490 DAC, and i need 15 - 15.5 vout (100mA) for the output stage.
I have the chance to buy an R-core transformer with 20-0-20 / 30VA (2x15w), for cheap, but ideal would ofcourse be a little lower.
The outputstage should be running in class A 100mA so i will be setting the ultrabib to ~175-200mA range.
Lucky me i have the pf5102's from my other shuntbuild some years age.
Any considerations with this transformer, or is it good to go?
Rgds; Jesper.
Hi here.
I'm building DimDim's dual AK4490 DAC, and i need 15 - 15.5 vout (100mA) for the output stage.
I have the chance to buy an R-core transformer with 20-0-20 / 30VA (2x15w), for cheap, but ideal would ofcourse be a little lower.
The outputstage should be running in class A 100mA so i will be setting the ultrabib to ~175-200mA range.
Lucky me i have the pf5102's from my other shuntbuild some years age.
Any considerations with this transformer, or is it good to go?
Rgds; Jesper.
Set it to 200mA is better. If you have the space to sink 2W dissipation for each M1 successfully, that R-Core's secondary voltage isn't a problem.
Hi Salas... Long time no see 🙂
I sink the transistors/fets to 3mm. big mounting-plate on my chassis, so a lot of heat will be able to dissipate there, n.p! 200mA i will do 🙂
DCG preamp is running perfectly still Salas btw... Long term succes's i guess, Thanx.
Jesper.
I sink the transistors/fets to 3mm. big mounting-plate on my chassis, so a lot of heat will be able to dissipate there, n.p! 200mA i will do 🙂
DCG preamp is running perfectly still Salas btw... Long term succes's i guess, Thanx.
Jesper.
Hey Jesper, nice to know are doing alright, cool. Nice about the long term diy satisfaction too.
Yes doing allright here, but last year was most looking in diyaudio.
// Been collecting stuff to do SMD soldering (DimDim forced me 🙂 haha... )... Quite a challenge but i am getting good at it 😀
Anyway no more offtopic Salas, but again thanks.
Jesper.
// Been collecting stuff to do SMD soldering (DimDim forced me 🙂 haha... )... Quite a challenge but i am getting good at it 😀
Anyway no more offtopic Salas, but again thanks.
Jesper.
Question of the day, won't thermal cycles at screw terminals (getting less tight over time then) ruin the output impedance?
You may solder the output cables in a permanent application. Screws are screws they may loosen with time.
I often place smaller orders and so negates the free delivery. I know I should wait and place a big order! Is mouser UK offshore/ come from the States?
yeah, comes from US. Delivery takes roughly 1 week from ordering which seems fairly quick, though RS will always be quicker too.
Hi...
I got the trafo for my ultrabib's build i ordred from Audiophonics today!
(along with my Amenero usb board 🙂)...
This is a little embarrising to ask, but i have had some problems before with trafo hookup's.
It's a centertapped R-core transformer and i plan to just hook it up, like i would have hooked up an dual secondary except, the positive and negative shunt would share the centertap on theyre AC-inputs.
Is it okay ?
Rgds; Jesper.
I got the trafo for my ultrabib's build i ordred from Audiophonics today!
(along with my Amenero usb board 🙂)...
This is a little embarrising to ask, but i have had some problems before with trafo hookup's.
It's a centertapped R-core transformer and i plan to just hook it up, like i would have hooked up an dual secondary except, the positive and negative shunt would share the centertap on theyre AC-inputs.
Is it okay ?
Rgds; Jesper.
Attachments
I do not think you can share the common '0' as the neutral on both the Ultra BiB boards. These boards accept independent secondaries from the transformer. So I think you either need to buy another transformer with 0-20v, 0-20v dual secondaries or just use one of the white and black for a single BiB board.
Unless someone makes an own dual polarity UBiBs board where he uses single bridge configuration, or outsourcing the rectification sections to a single bridge external raw DC unit, the normal boards need independent secondaries. Two bridges and dual secondaries are the better (and more expensive) choice of course.
Wrong transformer
Hi there 🙂
They sent me the wrong transformer.
I just wrote to them, what to do now.
I've been reading about the center tapped type, and i see that it's not usefull for two full rectifier as Salas also pointed out.
Jesper.
Hi there 🙂
They sent me the wrong transformer.
I just wrote to them, what to do now.
I've been reading about the center tapped type, and i see that it's not usefull for two full rectifier as Salas also pointed out.
Jesper.
Do your own rectification section with four diodes only, link the C1 reservoirs zeroes.
Top cap (-) pin with bottom cap (+) pin. The loads represent the rest of regs circuits.
Top cap (-) pin with bottom cap (+) pin. The loads represent the rest of regs circuits.
An externally hosted image should be here but it was not working when we last tested it.
Hi Jesper,
In toroid transformers it's usually very easy to find where the center wire connects to both secondaries and separate them. However, I don't know if this applies to R-core, but if returning is not an option, you could check that.
In toroid transformers it's usually very easy to find where the center wire connects to both secondaries and separate them. However, I don't know if this applies to R-core, but if returning is not an option, you could check that.
I did have a look, but i cannot see excatly how they are winded up; think it's on two bobbin's. one with primary windings, and the other with two layers of secondarys.
I will see what they have to say, they proberly first reply monday, but again i have no rush; haven't got mine boards yet 🙂
Nice to hear from you guy's btw...
Jesper.