sam_cat
C'est Crounchifique!
Pics were provided by Gigaworks, along with instructions saying exactly the same.. DONT run the stock chip with the DIR9001 mod. Gonna make it a switch on mine so I can easily A/B it.
Sam
DAC Kit - what else do I need?
- Thread starter Suffolk Tony
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Pics were provided by Gigaworks, along with instructions saying exactly the same.. DONT run the stock chip with the DIR9001 mod. Gonna make it a switch on mine so I can easily A/B it.
Sam
I think Tony, that both our schematics and boards are different to each other! Here we are talking like we know what each others on about and we're talking about different things
hehe...
Ok, it looks like the board circuit underwent some changes between me and you guys getting one. On my board RPX3 (pin 1) is connected to the 68uH inductor pad which in turn follows all the way back to the 5V high current reg. Pin 2 (RPX2) is connected to the USB output. Below is a very murky pic showing what I mean. (sorry for the photo quality Sam, I've asked for a Nikon for Xmas!)
Sam on your pic it looks like pin 1 is connected to the USB output. So have you linked this to both the 5V rail and the USB? Can you use the USB now, presuming you wanted to?
Edit: As far as I can tell my board already has this mod and is running the stock chip fine.
hehe...
Ok, it looks like the board circuit underwent some changes between me and you guys getting one. On my board RPX3 (pin 1) is connected to the 68uH inductor pad which in turn follows all the way back to the 5V high current reg. Pin 2 (RPX2) is connected to the USB output. Below is a very murky pic showing what I mean. (sorry for the photo quality Sam, I've asked for a Nikon for Xmas!)
Sam on your pic it looks like pin 1 is connected to the USB output. So have you linked this to both the 5V rail and the USB? Can you use the USB now, presuming you wanted to?
Edit: As far as I can tell my board already has this mod and is running the stock chip fine.
Yeah, we should draw up our own schematic!
I found out something interesting - Snow 46_8 (Wei Zhou), one of the suppliers of the board, is the original designer of the DAC. So possibly her revisions have not been carried through to the schematic files. Giga sells the new boards but distributes the old documents?
Wei Zhou is also very attractive by the way ( hands off lads I saw her first...)
I found out something interesting - Snow 46_8 (Wei Zhou), one of the suppliers of the board, is the original designer of the DAC. So possibly her revisions have not been carried through to the schematic files. Giga sells the new boards but distributes the old documents?
Wei Zhou is also very attractive by the way ( hands off lads I saw her first...)
One of my fleas that I added a BC547 pass transistor to ran out of steam you might remember. I ordered up some heavy weight tansistors in order to see what mght happen.
They arrived today after quite a wait from RS.
I have just fitted them and the flea got all hot and bothered and only the AD797 did not seem to regulate.
Maybe I am getting better but it did not take long to find out that fitting BD140's was a stupid thing to do.
BC547 -npn
BD140-pnp
Duh why did I do such a thing?
Maybe Martin made a typo?
"The power handling limit is still only about 80ma, maybe a little more, due to the BC547s dissipation limit. Remember this also affects the gyrator at the input to the Flea! If you must have more it could be worth trying, say, a BD140 instead but"
So what is the complement of a BD140 and will it tak me another two weeks to get them
Martin please confirm I am not up the usual small dark hole.
They arrived today after quite a wait from RS.
I have just fitted them and the flea got all hot and bothered and only the AD797 did not seem to regulate.
Maybe I am getting better but it did not take long to find out that fitting BD140's was a stupid thing to do.
BC547 -npn
BD140-pnp
Duh why did I do such a thing?
Maybe Martin made a typo?
"The power handling limit is still only about 80ma, maybe a little more, due to the BC547s dissipation limit. Remember this also affects the gyrator at the input to the Flea! If you must have more it could be worth trying, say, a BD140 instead but"
So what is the complement of a BD140 and will it tak me another two weeks to get them
Martin please confirm I am not up the usual small dark hole.
martin clark
pinko bodger
Eeek! sorry fella. Yes, BD139 is what you want; or any convenient power transistor with reasonably high Hfe and Ft (I've spare D44H11 I could send you..)
sam_cat
C'est Crounchifique!
Just to clarify, I havent fitted the DIR9001 as my DAC is still misbehaving.. Optical input drops out after a few seconds. Havent had a chance to look at it since I originally reported the problem and on investigation found a broken leg or two on the CS8416, and probably wont get a chance to think about fixing it until tomorrow evening..
Ordered the DIR9001 as I was also getting a relacement CS8416..
Ordered the DIR9001 as I was also getting a relacement CS8416..
Aha D44H11, I have some of those, thanks for the offer, anyway BD139's should land in the morning so no worry.
Actualy there is no rush at all as I hve been breaking this dac for quite some months now
Dont feel bad Martin, its quite pleasing in a way to find out that Martin Clark has made a little slip-up
and I mean that in the nicest posibe way, Acoustica is a great site that helps my bodging so much. Also I found this problem on my litte ownsome so maybe I is bodging better? tONY
So now the Dac is back in the land of the living I have a flea with a BD139 pass transistor in the position that feeds 5v0 to both up-sampling module and S/PDIF receiver chip. Also upgraded the fleas gyrtor transistor to a BD139.
93mA load on the circuit and no start-up problems.
Of course it did not all go to plan, never does these days with this dac, no worky dacy on powering up the first time and I spent some time tracing the problem, getting closer to the reciever chip all the time. Eventualy found the optical input had gone down so I am now running on coax I have looked no further but suspect its the same problem as Sam. I expect a new optical to digital reciever would be the order of the day and take it from there. Did we ever source one for Sam?
Just recaping on the reg front.
STR +15v / 0v -15v - Analog.
Flea twin reds 3v3 - Up-sampler.
Flea 5v0 BC547 pass transistor - Converter.
Flea 5v0 BD139 pass transistor - Reciever.
Tony
Edit
Rich , package is posted
93mA load on the circuit and no start-up problems.
Of course it did not all go to plan, never does these days with this dac, no worky dacy on powering up the first time and I spent some time tracing the problem, getting closer to the reciever chip all the time. Eventualy found the optical input had gone down so I am now running on coax I have looked no further but suspect its the same problem as Sam. I expect a new optical to digital reciever would be the order of the day and take it from there. Did we ever source one for Sam?
Just recaping on the reg front.
STR +15v / 0v -15v - Analog.
Flea twin reds 3v3 - Up-sampler.
Flea 5v0 BC547 pass transistor - Converter.
Flea 5v0 BD139 pass transistor - Reciever.
Tony
Edit
Rich , package is posted
I'm pretty sure its a Toshiba TORX147. Check the datasheets for the right footprint and get one of these:
http://uk.farnell.com/jsp/search/br...arch_001&Ntt=toslink&Ntx=mode+matchallpartial
Edit: Cheers Tony
http://uk.farnell.com/jsp/search/br...arch_001&Ntt=toslink&Ntx=mode+matchallpartial
Edit: Cheers Tony
Yep thats the fella.
I'd chip in on the Farnell order except I'm tight for funds until some invoices get paid. Do they still have a minimum order quantity?
On a different subject - I'm thinking of starting a GB for generic rectifier boards, been getting some quotes so keep an eye on the forum.
I'd chip in on the Farnell order except I'm tight for funds until some invoices get paid. Do they still have a minimum order quantity?
On a different subject - I'm thinking of starting a GB for generic rectifier boards, been getting some quotes so keep an eye on the forum.
Thanks for the heads up, do you ever sleep? It will give you some good experiance for when my boards become better! I will take some of those if it goes ahead but they are also a real easy diy etch, no small pads.
Farnell still seem to have a £20 minimum order, I like RS as I can get a one penny item delivered for free
Dont worry about chipping in, I have not forgotten all the chips you sent which reminds me that I still have not got around to checking out that last package you sent.
But back to the thread,
So some listening has been done and there has been a further gain on SQ, not as profound as the other supplies but still worth while. I think the gain is somewhat diluted with this position as there are so many miscellaneous circuits attached. Maybe the real gains will come through when this circuit is sub divided with further regulators. Hmmmph more fleas?
SQ gains are related to the extremes, HF can now really make the hairs on the back of the neck stand up, LF just pounds your stomach out with more precision and the sound stage is a little wider, maybe still a little floaty though. Perhaps the most noticeable to me is the quietness of this dac now. Most of the back ground noise has gone there now being just the tinniest of a hint of noise at silly listening levels during track starts and ends.
Big thanks to Martin for helping me though the three flea variants that have helped this dac so much.
Tony
Farnell still seem to have a £20 minimum order, I like RS as I can get a one penny item delivered for free
Dont worry about chipping in, I have not forgotten all the chips you sent which reminds me that I still have not got around to checking out that last package you sent.
But back to the thread,
So some listening has been done and there has been a further gain on SQ, not as profound as the other supplies but still worth while. I think the gain is somewhat diluted with this position as there are so many miscellaneous circuits attached. Maybe the real gains will come through when this circuit is sub divided with further regulators. Hmmmph more fleas?
SQ gains are related to the extremes, HF can now really make the hairs on the back of the neck stand up, LF just pounds your stomach out with more precision and the sound stage is a little wider, maybe still a little floaty though. Perhaps the most noticeable to me is the quietness of this dac now. Most of the back ground noise has gone there now being just the tinniest of a hint of noise at silly listening levels during track starts and ends.
Big thanks to Martin for helping me though the three flea variants that have helped this dac so much.
Tony
Hi all,
I'm going to purchase DIY DAC kit but I have no experience in DYI at all. I reviewed the topic and decided to follow Rich's recommendations in this post #343 , but probably w/out Output transformers for now.
Could somebody update this post to the latest mods&upgrades I should do to make this kit sing?
BTW, there are many kits on ebay (from gigawork, raindrop_hui, kikitronic and diyaudiokit), what kit can be recommended?
Thanks a lot!
Regards,
Oleg
I'm going to purchase DIY DAC kit but I have no experience in DYI at all. I reviewed the topic and decided to follow Rich's recommendations in this post #343 , but probably w/out Output transformers for now.
Could somebody update this post to the latest mods&upgrades I should do to make this kit sing?
BTW, there are many kits on ebay (from gigawork, raindrop_hui, kikitronic and diyaudiokit), what kit can be recommended?
Thanks a lot!
Regards,
Oleg
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