No a bit beyond me to track down, a friend is going to take look who I am sure will sort it out.
DAC Kit - what else do I need? #2
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No a bit beyond me to track down, a friend is going to take look who I am sure will sort it out.
Once the new dac is running I could let the old giga dac pass on to someone else. But I want to hang onto it right now as I may have another attempt at a repair should I get bored with having no dac. Right now its busted and looks like the converter chip is knackered but I could not be sure the fault is not closer to the dacs input side.
orangeart
KJF Audio Ltd.
But they are marked in yellow below
That's great Tony, thanks for that, looking at the final pic could you just tell me which end of each yellow line is the anode end, i think i can work everything else out just fine then.
Cheers
Stefan
The rectifiers wont fit the pads if the wrong way.
On the rectifier
Anode is one of the legs, the other leg is not connected in the rectifier but its ok to solder it down with the anode leg
Cathode is the body
On the board
Anodes are on the left cathodes on the right.
You will see the two large cathode pads are connected togeter and go to the +tve output.
The anodes are not connected to each other they are connected one to each end of the transformer secondary.
Your diodes should be something like below
http://docs-europe.electrocomponents.com/webdocs/0895/0900766b80895f82.pdf
Place your regs on the board and post a picture.
orangeart
KJF Audio Ltd.
great, got you now. So i looking at the data sheet the dpak bit is not essential merely the package it diode is in? so i could use some of the qspeed diodes i got in the recent gb? Also the traffo code i've got is from farnell, i'm not getting anything else so won't hit moq fir a while. if i post a link to what looks equivilent at rs ir elsewhere would you mind giving the thumbs up or down?
cheers
stefab
cheers
stefab
The dpack is a small surface mount hexfred no a through hole like the qspeeds from the gb.
The qspeed are as good as the hexfreds but you will strugle to get them to fit.
The farnel transformer was the best of the small transformers by far, most others at this size had far to high a winding resistance and would reduce startup time a lot.
I used smt diodes to get the package nice and small, sort of flea sized.
The qspeed are as good as the hexfreds but you will strugle to get them to fit.
The farnel transformer was the best of the small transformers by far, most others at this size had far to high a winding resistance and would reduce startup time a lot.
I used smt diodes to get the package nice and small, sort of flea sized.
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Rich very kindly sent me a Fleabite board a while ago but I wasn't sure what to do with it; I've searched PFM for info. but I can only find the odd reference to it. Is it something I could use in my DAC d'you think?
It is used to power a flea when doing clock (XO) duty.
A flea driving a clock works best when powered from its own winding, mainly due to all the crud that the XO sends back up the power supply line which if using a shared transformer would permeate into all the other bits and that not so good as it tends to dilute the advantage of the flea.
It uses a tiny pcb mounted trough hole transformer, the Farnell one is prefered as it has the lowest secondary impeadence of the bunch Ilooked at, a pair of dpack smt rectifiers mounted under the board and a single through hole electrolytic above the board and some nice screw terminal board connectors.
I believe your UTC flea is already on its own winding.
Now should you run the XO fom a flea in your other dac, the opamp one, then the flea bite would be handy as you have no spare winding.
Tony
A flea driving a clock works best when powered from its own winding, mainly due to all the crud that the XO sends back up the power supply line which if using a shared transformer would permeate into all the other bits and that not so good as it tends to dilute the advantage of the flea.
It uses a tiny pcb mounted trough hole transformer, the Farnell one is prefered as it has the lowest secondary impeadence of the bunch Ilooked at, a pair of dpack smt rectifiers mounted under the board and a single through hole electrolytic above the board and some nice screw terminal board connectors.
I believe your UTC flea is already on its own winding.
Now should you run the XO fom a flea in your other dac, the opamp one, then the flea bite would be handy as you have no spare winding.
Tony
Suffolk Tony
Aim low, achieve your goals, avoid disappointment.
Ta Tony - I'll see about fitting it into DAC Mk 2.
The bom I used for the flea bite was, I think...
Transformer Farnell 1214 584
Rectifiers RS 650-3303 same at Farnell looks like 1298428
Capacitor RS571 111
Terminal headers RS 710-0100 and 220-4260
The parts were optimised for running the gigadac XO module via Martins flea.
Transformer Farnell 1214 584
Rectifiers RS 650-3303 same at Farnell looks like 1298428
Capacitor RS571 111
Terminal headers RS 710-0100 and 220-4260
The parts were optimised for running the gigadac XO module via Martins flea.
Happy for you toogood that you didn't give up the baby.
I'll get my own ^^
Just got fed up with the dac in the SBT so it had to be fixed, so long as its a cheap fix.
Not quite sure how long it will be before its naughty again though
BuffaloII is going to hapen though.
orangeart
KJF Audio Ltd.
Wooopeeeedoooo.
Reflowed all the joints around the converter and bingo, bobs your uncle, I am a happy bunny again.
Oh this dac is just soooo much better than the dac stage in my SBT that I have been using sinc it buggered up.
amazing isn't it, i lived in blissfull ignorance of just how shite the DAC in the squeeze box was for ages
orangeart
KJF Audio Ltd.
Right then, a little advice on proposed box layout would be appreciated.
In the first pic everything is labeled. I have put the flea and flea bite by the USB as i don't use this very much and it seems to be the shortest path. The STRs for the op amps are over there as well although i could possibly put them on top of the dac board once i have removed the onboard regs and smoothing, i'd appreciate some help with what i could remove here.
The generic rectifier i have to power them has got 3300uf caps on it, i'm not sure what to do for either the L or R. What is the best way to work this out?
In one of the pics you'll see the other generic rectifier board is populated with a mix of standard nichion 2200uf and fine gold 2200uf for the B4 with a 12V traffo, probably best over in the B4 thread but i know you guys will comment on what is the best L or R here as well......
Oh and the DAC's decommisioned until i get this all sorted so i'm in the same squeeze box crappola dac territory Tony has been living in.
Cheers
In the first pic everything is labeled. I have put the flea and flea bite by the USB as i don't use this very much and it seems to be the shortest path. The STRs for the op amps are over there as well although i could possibly put them on top of the dac board once i have removed the onboard regs and smoothing, i'd appreciate some help with what i could remove here.
The generic rectifier i have to power them has got 3300uf caps on it, i'm not sure what to do for either the L or R. What is the best way to work this out?
In one of the pics you'll see the other generic rectifier board is populated with a mix of standard nichion 2200uf and fine gold 2200uf for the B4 with a 12V traffo, probably best over in the B4 thread but i know you guys will comment on what is the best L or R here as well......
Oh and the DAC's decommisioned until i get this all sorted so i'm in the same squeeze box crappola dac territory Tony has been living in.
Cheers
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