Sorry slow response... I'm beta-testing some tweaks being developed by poster 'Soundcheck'. See these threads for some info on what he is doing:
http://www.diyaudio.com/forums/pc-b...-picore-linux-raspberry-pi-squeezelite-3.html
http://www.diyaudio.com/forums/digi...ry-dac-pro-hw-mods-anybody-7.html#post4713884
I expect Soundcheck plans to release these in some form at some point. As a beta-tester I agreed to keep them confidential. But he has made some public in those threads.
Greg in Mississippi
I have four LT3042's, two BAL BAL, and one SE SE.
First, I apologize for my lack of knowledge and these may be dumb questions.
I have two questions
First question is how would I power the BAL BAL with the LT3042, the preferred way anyhow. BAL BAL has V- , GND, and V+, but the LT3042 has only two outputs per rail.
I have a trafo for the BAL BAL and SE SE that is
15V - 0 1A(two secondary's)
and
15V - 0 .8A (two secondary's)
I would really appreciated it if someone could help with this one. I understand the LT3042 is able to be run as a bipolar psu, can someone confirm the proper way to configure this lt3042 psu for this?
but the one i'm really stumped with is how to power my DAC project with the LT3042 board, i'm guessing it's going to be similar to the BAL BAL.
I'm powering TWO Soekris DAM1021 dac boards. They have four power connections per board. they need a bipolar input, or v+ gnd and V- in the (preferred) regulated DC range of 7.5-12V. I figure 10V is good, and I have a trafo I would like to use
O-core 54VA
12V - 0 - 12V - 1A
12V - 0 - 12V - 1A
I originally got this trafo thinking I would pair it with a PSU design that I was going use some belleson regulators on a bipolar PCB that would of been great...although it WILL NOT FIT. the LT3042 looks appealing, yet I don't know if it's possible to use with my situation. I would really appreciate some help!
again, I apologize if i'm asking a stupid question. I understand the LT3042 can be a bipolar psu, and would like to know how to do so.
And thank those who take a moment to help me out! I'm on this forum for a good reason! most of the time I've found excellent help. I'm hear to learn and come here to get the knowledge!
-Tim
First, I apologize for my lack of knowledge and these may be dumb questions.
I have two questions
First question is how would I power the BAL BAL with the LT3042, the preferred way anyhow. BAL BAL has V- , GND, and V+, but the LT3042 has only two outputs per rail.
I have a trafo for the BAL BAL and SE SE that is
15V - 0 1A(two secondary's)
and
15V - 0 .8A (two secondary's)
I would really appreciated it if someone could help with this one. I understand the LT3042 is able to be run as a bipolar psu, can someone confirm the proper way to configure this lt3042 psu for this?
but the one i'm really stumped with is how to power my DAC project with the LT3042 board, i'm guessing it's going to be similar to the BAL BAL.
I'm powering TWO Soekris DAM1021 dac boards. They have four power connections per board. they need a bipolar input, or v+ gnd and V- in the (preferred) regulated DC range of 7.5-12V. I figure 10V is good, and I have a trafo I would like to use
O-core 54VA
12V - 0 - 12V - 1A
12V - 0 - 12V - 1A
I originally got this trafo thinking I would pair it with a PSU design that I was going use some belleson regulators on a bipolar PCB that would of been great...although it WILL NOT FIT. the LT3042 looks appealing, yet I don't know if it's possible to use with my situation. I would really appreciate some help!
again, I apologize if i'm asking a stupid question. I understand the LT3042 can be a bipolar psu, and would like to know how to do so.
And thank those who take a moment to help me out! I'm on this forum for a good reason! most of the time I've found excellent help. I'm hear to learn and come here to get the knowledge!
-Tim
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Sorry for any confusion. I was assuming since its posted in the wire section it would be the lt3042 pcb DIY board that OPC sells.
I have for of them. All the components needed to build them.
I'm waiting to confirm how to set the board up for bipolar output. I'm hoping OPC will respond or someone else who has set these boards up to power their wire amp. The bal bal and SE SE both take bipolar power input and I believe opc said he is using the lt3042 pcb kit to power his bal bal. I would love to know get confirmation on how to do this. I apologize for this question seemingly sounding dumb to some people. I'm fairly new with this and this is my first project.
I've built two SE SE board's and finishing the BAL BAL boards as I type. But I'm not worried much about the soldering part, I just need to be sure I'm assembling these lt3042 kits for my needs. I just posted another thread about this in hope that someone can help me! Thank you.
Bimmer,
To use Owen's Dual Paralleled LT3042 as a +- supply, you connect the side that will be the positive supply with the + to the positive input and the - to the ground of your powered component. Then for the negative supply you connect the - to the negative input and the positive to ground.
To do this with Owen's boards it wil work best if you use a transformer with two separate secondary windings or two separate transformers, with a separate secondary feeding each half of Owen's regulator board.
According to the Wiki, Ian uses this setup for his Bal-Bal headphone amp. Also, he uses the same configuration for his latest version of his NTD1 power supply/regulators.
And based on my experience reported above, I bet you'll find this very good!
BTW, do see my post a few pages back on my setup and process for soldering up these boards. Note that you MUST have either a hot-air rework station or a SMD reflow oven to assemble these as you cannot solder the LT3042 ground pad on the base of the package to the circuit board any other way.
Greg in Mississippi
P.S. Your question made perfect sense to me! I was just slow replying as I was slaving over a hot soldering station most of the day on one of my WAY too many projects! And it is only in the first stage of mods and tweaking and already has exceeded my expectations!
To use Owen's Dual Paralleled LT3042 as a +- supply, you connect the side that will be the positive supply with the + to the positive input and the - to the ground of your powered component. Then for the negative supply you connect the - to the negative input and the positive to ground.
To do this with Owen's boards it wil work best if you use a transformer with two separate secondary windings or two separate transformers, with a separate secondary feeding each half of Owen's regulator board.
According to the Wiki, Ian uses this setup for his Bal-Bal headphone amp. Also, he uses the same configuration for his latest version of his NTD1 power supply/regulators.
And based on my experience reported above, I bet you'll find this very good!
BTW, do see my post a few pages back on my setup and process for soldering up these boards. Note that you MUST have either a hot-air rework station or a SMD reflow oven to assemble these as you cannot solder the LT3042 ground pad on the base of the package to the circuit board any other way.
Greg in Mississippi
P.S. Your question made perfect sense to me! I was just slow replying as I was slaving over a hot soldering station most of the day on one of my WAY too many projects! And it is only in the first stage of mods and tweaking and already has exceeded my expectations!
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NTD1 power resistors...
Received a new NTD1 board, thanks Owen!
Anyway, I wish I could purchase Reidon resistors in 200R/400R, any source for these guys?
I can get Caddock no problem, and they are affordable enough to purchase a few and match them tightly, but it seems to me a thin film part would be an advantage here.
I know some people talked about using TO-220 style z-foils and trimming the tab, has anyone actually done this? Very expensive, of course... but are folks sure that soldering the tab would be OK on these resistors?
any ideas for the best resistors which are actually available and possible sources?
Received a new NTD1 board, thanks Owen!
Anyway, I wish I could purchase Reidon resistors in 200R/400R, any source for these guys?
I can get Caddock no problem, and they are affordable enough to purchase a few and match them tightly, but it seems to me a thin film part would be an advantage here.
I know some people talked about using TO-220 style z-foils and trimming the tab, has anyone actually done this? Very expensive, of course... but are folks sure that soldering the tab would be OK on these resistors?
any ideas for the best resistors which are actually available and possible sources?
Greg, I know you know this, but just to be sure: in this configuration you should not connect anything to ground at the transformer or reservoir caps. The ONLY ground point will be the point where the negative side of the pos supply is connected to the pos side of the negative supply.
Jan
I have both a hot air rework station and a hot plate/reflow oven.
I havent used the reflow oven much, and wondered how this process would vary from your instructional process you posted about a couple pages back?
I'm "pretty good" at soldering, or would like to think so anyways. but this project has be a slight bit intimidated due to the cost of components and potential for error. I'm taking it on as a challenge anyhow. I plan to order more of these boards if Owen has them. Need at least 3 or more actually. So Hopefully I can get this process down and they all are built effectively and efficiently after the first attempt.
I've got a large collection of different solder paste i've in mind to use. I've got some 247 solder paste that i've had some good luck with. I've been able to set my air station to around 150-160C
and the size of the particles are a bit smaller than most. Best of all, it's 10bucks a tube on amazon. Otherwise i've typically used SRA low temp silver solder paste, and the more difficult to work with stuff from MG chem (SAC305 green tube, silver solder paste)247 Solder:
Low Melting Point Solder Paste
T4 new industry standard
Contains Silver for less brittle joint
137C 278F Melting Point (Eutectic)
Two dispensing tips 16g and 20g
---------------
so if I was to use the oven reflow oven... what would be the ideal approach.?
I would think the oven might be easier possibly?
---------------
some photos of my BAL BAL build - w/o resistors as i'm not sure which ones to use yet. I'm using dual dam 1021 soekris dac, with normunds board to connect the two, and will have a 10K pot hooked up to the normunds board to control volume. But i'm not sure if this means i'll need...
10K RI, and 47.5K RF for a 22.5dB gain.
but it has 1K Ri and 1K Rf on the BOM, and the SE SE has 10K Ri and 1K RF?? why is this? both I assume are for 0dB gain? My outputs from the Soekris dam1021's will be unbuffered output. So I would think I would want to set my gain somewhere between 18-22dB ?
Here's my first attempt a the BALBAL board, but no resistors yet.
later, I realized I didn't need to install the heatsinks... although I'll be using 15V secondaries from the trafo. I'm not sure what I should set up the Lt3042 for maximum performance of the BAL BAL and SE SE.
the trafo is
15V - 0 - 1A
15V - 0 - 1A
15V - 0 - .8A
15V - 0 - .8A
was planning somewhere between 12V-14V output depending on what the psu will do. not sure the dropout voltage. any suggestions for max performance?
-------------
@Jan - thanks for the comment about not connecting ground at the transformer/resevoir cap side. I'm pretty sure you mean they just hookup as normal on that side of the PSU. +/- and +/- (~/~)
or
-------------
And would I be able to power the SE SE and BAL BAL with the same LT3042 PSU? I recall reading somewhere the BAL BAL is 500mw per rail? that would be 1000mW. I figured the LT3042 should be able to do at about 1600mW configured the above way?? I plan to use heatsinks on it too.
-------------
I apologize for all the questions, as I know many of them may sound stupid to most people on this forum. I'm happy to get the knowledge I need to complete my first project. Hopefully in time I will catch on more to this stuff. But i'm definitely only a "builder" and not a designer. I'm a beginner too
I chose a project to be a challenge with hopes of receiving guidance along the way!
thank you very much for your input Greg Stewart, and also Jan for commenting too. And many thanks to Owen / OPC for creating some great diy boards. I'm hoping to order some more if you plan to ship another batch. please let me know!
Awesome! I appreciate it Greg. I'm glad to hear any advice you can give me to complete this project with success. This is a big deal to me as it's my first full dac+ headphone amp build.
other than the O2 amp, which was so easy it took less than an hour to build.
All my experience is just in simple modding of dacs, amps, swapping out regulators, oscillators, trafos, caps etc. simple stuff.
I'm building this whole dac/amp for my wife actually. She is also into audio like I am. She has an NFB28 from audio-gd right now, and we plan to sell that after i'm done with this project. With some help, i'm sure this project should be complete hopefully in the next month or so
She's probably more excited for it to be done than I am.
This LT3042 psu pcb is so perfect for this project since it's so tiny. My only problem is I needed 5, and got 4. I've placed an order for 3 more, and hope Owen has a few laying around he can sell me. I've got one other project that could use them. My big hurdle is being able to build one of these sucessfully. The rest should be a breeze after that.
haha right.The max temp of 10sec @ 260C worries me. as the BAL BAL was no issue to do, yet installation of the heatsinks requires more heat... i'm hoping that didn't cause issues with these boards. I almost think it would be better to do the heatsinks first and deal with the awkwardness of installing the lme49610ts second. I would imagine It took another 10sec to get those heatsinks on the boards per chip. I preheated the heatsinks with my airgun to assist in a faster mating to the board. But 10 seconds per heatsink is 4 times the heat spec'd per chip. albeit about 200C was needed to do it. I should of planned this better.
I still think I screwed up the board if those specs are strict. I have one more BAL BAL board and will build it differently. With the heatsinks done first with higher melting temp solder, and use lower temp solder with the lme49610TS. those little lme49990's can witstand 20sec each, which is TONS of time to solder. easy! can do in 4-5sec.the little LT3042's are 10sec each @300C. which seems doable. I can get them to solder with low temp solder at 150C, so hope this isn't an issue. they say they can get up to 150C under load...so using low temp solder seems to be OUT OF THE QUESTION. seems MG solder paste may be needed for this project :/ oh well. I'm most interested to know what you used for solder paste. I prefer low temp as it's easier to work with imho.
thanks for all the help and look forward to hearing from you or anyone else that would like to comment!
I saw your update as I was posting...
Bimmer,
First, your builds look very nice. Yup, you are good at soldering. Nice build pix… but you should resize your pix smaller before linking.
Second, look at buying the LT3042 direct from Linear Tech… as I remember the price was a bit better in moderate quantities than Digikey or Mouser.
Third, I won’t venture a guess on the gain structure. I don’t have headphones, aren’t familiar with those boards, and really can’t help on this.
Fourth, on your drawings, on the input side for both the BAL-BAL and Soekris DAM remember Owen’s LT3042 board has a diode bridge on each side, so you want to take the AC from the transformer directly into the board, which you got right on the revised drawings.
Then on the output side, on the BAL-BAL drawing, you need to connect both sides of the LT3042 board to each channel’s grounds. I suspect strongly that board is dual mono, so there is likely no ground connection between each channel. Using one LT3042 board to power both channels will work ok, but your connections will be
- LT3042 positive side + to both +V
- LT3042 negative side – to both V-
- LT3042 positive side – and LT3042 negative side + to both G’s
The output side of the LT3042 -> Soekris DAM looks good. You won’t need to connect between the two ground inputs on the Soekris DAM as they are connected on the board, but it won’t hurt.
Fifth, on rework station versus reflow, I recommend the rework for two reasons. First, you really MUST check the connections of EACH LT3042 as you add it to ensure you don’t have un-noticed shorts. Remember, once they are on most pins are in parallel on all of the LT3042, so finding a short becomes a serious chore. Reflow (to me) makes sense when you are using a stencil, adding all of the components, and reflowing once. That makes checking each as you add it pretty impossible.
Also, positioning is key to successful soldering of each LT3042… again, harder to do with the reflow, although I suspect easier with a stencil. OTOH, I don’t have ANY experience doing reflow, so I may be entirely off-base here.
Sixth, your awareness of soldering time is good and using your rework gun to preheat is a good technique. I DOUBT you hurt the board and likely did not damage the components doing it as you described. Still, preheating with the rework gun and then using a serious iron to solder on something like the headsinks helps you localize heating.
Seventh, I AM very partial to the thin Wonder Solder, partly because of its workability, partly because of the sonics (I know I’ll get flack for this, but for those that are so inclined to provide flack, if you haven’t tried it yourself, don’t give me any SH*T about it!).
Eighth, I’d use a separate LT3042 board for the SE-SE and another for the BAL-BAL. Sounds like you’d be pretty close to the edge of the rating for a single board… and my experience has always been that getting close to the edge like that never helps sonics.
Finally, not sure which version of the Soekris you have. I have a couple of Rev 1 boards and did the VREF fixes/mods this weekend. DEFINITELY A REVELATION!!!!! If you have Rev 1’s and haven’t done this yet, you need to do so. I’ll be posting about mine at some point over in the main DAM thread. I am in the lucky/fortunate position to have stocked up on Black Gates back before they became hyper-expensive unobtainium. I have had seen some movement toward alternatives other than the industry-standard ceramic caps on the analog side of DACs… I’ve seen use of SMD PPS on Ayre, K&K Audio, Sony’s HAP Z1-ES, and DIYAudio’s EUVL builds, and have some experiences using these caps instead of ceramics on some of my mods. And I’ve found the stock Rev1 boards to be pretty special, so I wanted to maximize the potential and use what in my experience are the best components available (yet still appropriate for small tightly-packed builds). So I’m replacing the VREF .1uf ceramic cap at each shift register with a .68uf PPS SMD film and adding bulk capacitance using Black Gate 33uf at each shift register and 2x220uf at each VREF circuit. So far I’ve added the VREF caps and 2 of the 5 shift register cap sets and listened to one of the boards. The difference was pretty darned good. Yup, I’ll never be able to compare directly to a build using the stock ceramic caps with bulk capacitance added using conductive polymers. And I doubt ANYONE else will either have the quantity of Black Gates to do a Soekris board (28 per board) much less two OR spend the bucks to get them at current BG market prices… that’s about $900USD per board in caps! Of course when I got them it was only a fraction of that, though still about 5-10x the cost of the typical conductive polymers people use here. Still, if yours are Rev1 boards and you haven’t done VREF fix/mods, go over to MOREDAMFILTERS.info and DIMDIM’s blog to read up on what you need to do.
I hope this all helps!
Greg in MIssissippi
Bimmer,
First, your builds look very nice. Yup, you are good at soldering. Nice build pix… but you should resize your pix smaller before linking.
Second, look at buying the LT3042 direct from Linear Tech… as I remember the price was a bit better in moderate quantities than Digikey or Mouser.
Third, I won’t venture a guess on the gain structure. I don’t have headphones, aren’t familiar with those boards, and really can’t help on this.
Fourth, on your drawings, on the input side for both the BAL-BAL and Soekris DAM remember Owen’s LT3042 board has a diode bridge on each side, so you want to take the AC from the transformer directly into the board, which you got right on the revised drawings.
Then on the output side, on the BAL-BAL drawing, you need to connect both sides of the LT3042 board to each channel’s grounds. I suspect strongly that board is dual mono, so there is likely no ground connection between each channel. Using one LT3042 board to power both channels will work ok, but your connections will be
- LT3042 positive side + to both +V
- LT3042 negative side – to both V-
- LT3042 positive side – and LT3042 negative side + to both G’s
The output side of the LT3042 -> Soekris DAM looks good. You won’t need to connect between the two ground inputs on the Soekris DAM as they are connected on the board, but it won’t hurt.
Fifth, on rework station versus reflow, I recommend the rework for two reasons. First, you really MUST check the connections of EACH LT3042 as you add it to ensure you don’t have un-noticed shorts. Remember, once they are on most pins are in parallel on all of the LT3042, so finding a short becomes a serious chore. Reflow (to me) makes sense when you are using a stencil, adding all of the components, and reflowing once. That makes checking each as you add it pretty impossible.
Also, positioning is key to successful soldering of each LT3042… again, harder to do with the reflow, although I suspect easier with a stencil. OTOH, I don’t have ANY experience doing reflow, so I may be entirely off-base here.
Sixth, your awareness of soldering time is good and using your rework gun to preheat is a good technique. I DOUBT you hurt the board and likely did not damage the components doing it as you described. Still, preheating with the rework gun and then using a serious iron to solder on something like the headsinks helps you localize heating.
Seventh, I AM very partial to the thin Wonder Solder, partly because of its workability, partly because of the sonics (I know I’ll get flack for this, but for those that are so inclined to provide flack, if you haven’t tried it yourself, don’t give me any SH*T about it!).
Eighth, I’d use a separate LT3042 board for the SE-SE and another for the BAL-BAL. Sounds like you’d be pretty close to the edge of the rating for a single board… and my experience has always been that getting close to the edge like that never helps sonics.
Finally, not sure which version of the Soekris you have. I have a couple of Rev 1 boards and did the VREF fixes/mods this weekend. DEFINITELY A REVELATION!!!!! If you have Rev 1’s and haven’t done this yet, you need to do so. I’ll be posting about mine at some point over in the main DAM thread. I am in the lucky/fortunate position to have stocked up on Black Gates back before they became hyper-expensive unobtainium. I have had seen some movement toward alternatives other than the industry-standard ceramic caps on the analog side of DACs… I’ve seen use of SMD PPS on Ayre, K&K Audio, Sony’s HAP Z1-ES, and DIYAudio’s EUVL builds, and have some experiences using these caps instead of ceramics on some of my mods. And I’ve found the stock Rev1 boards to be pretty special, so I wanted to maximize the potential and use what in my experience are the best components available (yet still appropriate for small tightly-packed builds). So I’m replacing the VREF .1uf ceramic cap at each shift register with a .68uf PPS SMD film and adding bulk capacitance using Black Gate 33uf at each shift register and 2x220uf at each VREF circuit. So far I’ve added the VREF caps and 2 of the 5 shift register cap sets and listened to one of the boards. The difference was pretty darned good. Yup, I’ll never be able to compare directly to a build using the stock ceramic caps with bulk capacitance added using conductive polymers. And I doubt ANYONE else will either have the quantity of Black Gates to do a Soekris board (28 per board) much less two OR spend the bucks to get them at current BG market prices… that’s about $900USD per board in caps! Of course when I got them it was only a fraction of that, though still about 5-10x the cost of the typical conductive polymers people use here. Still, if yours are Rev1 boards and you haven’t done VREF fix/mods, go over to MOREDAMFILTERS.info and DIMDIM’s blog to read up on what you need to do.
I hope this all helps!
Greg in MIssissippi
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