chobint said:
Ferrous metal will tend to shield or redirect magnetic fields. Should help, as opposed to Aluminum which wouldn't do anything to mag fields. Any conductive materiel, will shield the electric fields, when connected to a ground. Of course it will vary due to how much shielding, where is the shielding in releation to the source, etc. A full box is best, but having a plate wall between will go a ways in shielding between the two sides.
So to answer your question is... the purpose of the plates is to allow for the shortest possible signal path while minimizing the interference between the power and signal sections of the DAC.
edit: and yes the plates are ferrous, as verified by the "does my magnetic screwdriver stick to this" test
edit2: and I lied the Buffalo didn't need shielded wiring, I just forgot to ground the case
Ah, but my real question is what the heck are those plates!!
Just curious, I keep guessing answers, and talking myself out of them...My original wonder about the transformer right next to a ferrous plate was more about power losses into the plate, rather than conducting noise into what's on the other side. And the more I think about it, the more I doubt it's an issue with a toroid transformer.
JonPike said:
Ferrous metal will tend to shield or redirect magnetic fields. Should help, as opposed to Aluminum which wouldn't do anything to mag fields. Any conductive materiel, will shield the electric fields, when connected to a ground. Of course it will vary due to how much shielding, where is the shielding in releation to the source, etc. A full box is best, but having a plate wall between will go a ways in shielding between the two sides.
Ah, but my real question is what the heck are those plates!!
My original wonder about the transformer right next to a ferrous plate was more about power losses into the plate, rather than conducting noise into what's on the other side. And the more I think about it, the more I doubt it's an issue with a toroid transformer.
Ah I see. Well, you're probably going to laugh but...they are cabinet dishes from Parts Express that I drilled various mounting holes into. Cabinet dishes, as in the things you mount on your DIY speaker cabinets to mount bindings posts, or w/e you want. How did I get the idea to mount PCB boards on these things??? I donno b/c I'm nuts and I have very contemporary art tastes. Links to the plates used below.
bijou back plate
bijou front and mid plates
buffalo mid and back plates
buffalo front plate
edit: and thanks for the physics clarification, I HATED E&M. I'm more of a mech type guy.
Aha, I see... I kept thinking a indented handle for pro audio gear, only it didn't have the right shape to be a good handhold. Looks like I was close.
Very cool, though... I love seeing "creatively unusual" uses for things.
Planning on some kind of wraparound shell, or just the bare, industrial look?
Very cool, though... I love seeing "creatively unusual" uses for things.
Planning on some kind of wraparound shell, or just the bare, industrial look?
#41 is ALIVE!!!!
And in other news... #41 LIVES!!! As of about 1:30am, the Buffalo Sings!!! And for a hairy, humpbacked bovine, it has a heck of a voice!
Been so busy at work that I'd put together the IVY and one PS the weekend after the sale, then didn't get close to it till this weekend.
I discovered many things, amongst them...
1. Even an old veteran kit builder like myself can forget basics like "stuff the shorter/smaller parts first".
2. Would have been good to order some transformers during busy week, so they'd be here by this weekend.
3. A pair of 9v batteries is NOT sufficient to run a IVY power supply, OR the + side of a Buffalo...
4. Been too long since I've built something... Almost forgot how fun it is...
5. Serious dedication can get you where you didn't think you could go... (or get you finding spare transformers and wall worts for PS parts)
Anyway, thanks to Russ and Brian for a clean, well packed and well done set of kits! So far, have only listened to them on a pair of moderate quality headphones, (Koss KSC-35's) but WOW. Even on these you can hear a large difference in dynamics, imaging, etc.. compared to the (ahem) Creative Labs SB24 USB that I am using for a SPDIF source. Can't wait to get it on my system for a good listen tomorrow.
A few technical questions, notes, and observations:
The Buffalo is syncing on 44.1 and 48k, but not 96. I get brief, occasional flashes of the lock LED, and tiny pops. I will get out the scope and take a look at the pre and post comparator data. OTOH (considering the source ) it could be the SB24 isn't doing good or any 96K output. I'll try another source tomorrow. Should I be trying different switch settings? They are currently all ++++. Also found that if I have something playing, I can switch to 96k and have it sync. If no source is playing and I switch, no lock. When the playing stops, lock drops, then picks up when it starts again.
BTW, is there any significant preference sonically to one or the other setting? (I imagine the answer may depend on input source CD or 24/96 files, etc...)
I'm also noticing that I get uneven current draw on the IVY PS.
Measuring across the 10 ohm resistors, I see .47v (47mA) and .63v (63mA) on the + and - sides. Is this normal? I guess I was expecting something, well, more symmetrical.
On the Buffalo's PS's, I get +175mA and -67mA.
Again, a wonderful part, design, kit, and effort to get it out to us all... Kudos to Dustin, Russ, Brian, and their associated long suffering others that brought it to us! I raise a fine, hop flavored beverage in salute to you all!!
And in other news... #41 LIVES!!! As of about 1:30am, the Buffalo Sings!!! And for a hairy, humpbacked bovine, it has a heck of a voice!
Been so busy at work that I'd put together the IVY and one PS the weekend after the sale, then didn't get close to it till this weekend.
I discovered many things, amongst them...
1. Even an old veteran kit builder like myself can forget basics like "stuff the shorter/smaller parts first".
2. Would have been good to order some transformers during busy week, so they'd be here by this weekend.
3. A pair of 9v batteries is NOT sufficient to run a IVY power supply, OR the + side of a Buffalo...
4. Been too long since I've built something...
Almost forgot how fun it is...5. Serious dedication can get you where you didn't think you could go... (or get you finding spare transformers and wall worts for PS parts)
Anyway, thanks to Russ and Brian for a clean, well packed and well done set of kits! So far, have only listened to them on a pair of moderate quality headphones, (Koss KSC-35's) but WOW. Even on these you can hear a large difference in dynamics, imaging, etc.. compared to the (ahem) Creative Labs SB24 USB that I am using for a SPDIF source. Can't wait to get it on my system for a good listen tomorrow.
A few technical questions, notes, and observations:
The Buffalo is syncing on 44.1 and 48k, but not 96. I get brief, occasional flashes of the lock LED, and tiny pops. I will get out the scope and take a look at the pre and post comparator data. OTOH (considering the source
) it could be the SB24 isn't doing good or any 96K output. I'll try another source tomorrow. Should I be trying different switch settings? They are currently all ++++. Also found that if I have something playing, I can switch to 96k and have it sync. If no source is playing and I switch, no lock. When the playing stops, lock drops, then picks up when it starts again.BTW, is there any significant preference sonically to one or the other setting? (I imagine the answer may depend on input source CD or 24/96 files, etc...)
I'm also noticing that I get uneven current draw on the IVY PS.
Measuring across the 10 ohm resistors, I see .47v (47mA) and .63v (63mA) on the + and - sides. Is this normal? I guess I was expecting something, well, more symmetrical.
On the Buffalo's PS's, I get +175mA and -67mA.
Again, a wonderful part, design, kit, and effort to get it out to us all... Kudos to Dustin, Russ, Brian, and their associated long suffering others that brought it to us! I raise a fine, hop flavored beverage in salute to you all!!
Re: #41 is ALIVE!!!!
1) My only recommendation there would be to try the higher DPLL bandwidth setting. As you say, it could be the source itself dropping out. I have an older SB card that does the same thing.
2) It generally best to match the SPDIF output to the source content. That way no conversion is required.
3) Perfectly normal. The difference is because of the current bias coming into the I/V stage.
4) Thanks a lot! Hops.... Yum.... 
Cheers!
Russ
JonPike said:And in other news... #41 LIVES!!! As of about 1:30am, the Buffalo Sings!!! And for a hairy, humpbacked bovine, it has a heck of a voice!
1) The Buffalo is syncing on 44.1 and 48k, but not 96. I get brief, occasional flashes of the lock LED, and tiny pops. I will get out the scope and take a look at the pre and post comparator data. OTOH (considering the source
2) BTW, is there any significant preference sonically to one or the other setting? (I imagine the answer may depend on input source CD or 24/96 files, etc...)
3) I'm also noticing that I get uneven current draw on the IVY PS.
Measuring across the 10 ohm resistors, I see .47v (47mA) and .63v (63mA) on the + and - sides. Is this normal? I guess I was expecting something, well, more symmetrical.
On the Buffalo's PS's, I get +175mA and -67mA.
4) Again, a wonderful part, design, kit, and effort to get it out to us all... Kudos to Dustin, Russ, Brian, and their associated long suffering others that brought it to us! I raise a fine, hop flavored beverage in salute to you all!!
1) My only recommendation there would be to try the higher DPLL bandwidth setting. As you say, it could be the source itself dropping out. I have an older SB card that does the same thing.
2) It generally best to match the SPDIF output to the source content. That way no conversion is required.
3) Perfectly normal.
The difference is because of the current bias coming into the I/V stage.4) Thanks a lot!
Hops.... Yum.... Cheers!
Russ
Re: #41 is ALIVE!!!!
Russ,
I also measured about 175mA drawn by Buffalo's VD, but the heatsink on the LCDPS gets too hot to touch for more than 2 seconds. I tried swapping the two halves of the LCDPS but, once again, the half connected to VD got too hot. Am I missing something?
Jon,
how hot does yours get?
JonPike said:
Russ,
I also measured about 175mA drawn by Buffalo's VD, but the heatsink on the LCDPS gets too hot to touch for more than 2 seconds. I tried swapping the two halves of the LCDPS but, once again, the half connected to VD got too hot. Am I missing something?
Jon,
how hot does yours get?
Beefy said:
agree with that . . . russ says 9 - 15 V secondaries - but without a doubt the lower the voltage the cooler the regs will run.
yours sound like they are at about 75 degrees C which is not terrible but if ur planning to put it all in an enclosure u you will have to make sure u have good ventilation.
Torroids for Buffalo and IVY
Yes, from 15 Volt secondaries, you will get quite a bit of heat on the regulator. While I think this is acceptable (I run it for 10 days continuous this way), I just felt more comfortable after changing to a torroid with 9 Volt secondaries, where I can feel almost no heat when touching the heatsink. Ideal for putting it into an enclosure. Both 9 or 10 Volt secondaries would be just fine.
However, for the IVY, the 15 Volt secondaries are very much ok. Very small temperature rise on the heatsinks there.
I was looking around for a transformer with something like dual 15 Volt and dual 9 Volt secondaries, but found nothing. The idea here was to save some space by having only one torroid instead of two. Seems the only way for this is custom made, which may not be worth the extra expense.
Yes, from 15 Volt secondaries, you will get quite a bit of heat on the regulator. While I think this is acceptable (I run it for 10 days continuous this way), I just felt more comfortable after changing to a torroid with 9 Volt secondaries, where I can feel almost no heat when touching the heatsink. Ideal for putting it into an enclosure. Both 9 or 10 Volt secondaries would be just fine.
However, for the IVY, the 15 Volt secondaries are very much ok. Very small temperature rise on the heatsinks there.
I was looking around for a transformer with something like dual 15 Volt and dual 9 Volt secondaries, but found nothing. The idea here was to save some space by having only one torroid instead of two. Seems the only way for this is custom made, which may not be worth the extra expense.
Thank you guys, you have confirmed what I already suspected was the problem. My concern is the temperature increase when I put it in a case. Tonight I will try wiring the primaries of the transformer connected to the LCDPS in series, which should cut in half the secondary voltage. I’ll see if the LCDPS will still deliver the 6.0 VDC and 6.6 VDC needed.
Hello folks,
Rest assured that even with the 15V secondaires the VREGs will not over heat if you use the heat sinks provided. yes they will get up to 60-65C (that's how hot mine measured with an IR thermometer) But that is perfectly fine.
What I have done, and other have suggested if you would like them to run cooler is to run the primaries in series as some have already suggested. Make sure if you do this that you account for the drop accross the 10R resistor. You may either need to jumper this R or reduce it.
All things considered, I would leave the 15V secondaries as they are and just let them run warm, they should be just fine.
Cheers!
Russ
Rest assured that even with the 15V secondaires the VREGs will not over heat if you use the heat sinks provided. yes they will get up to 60-65C (that's how hot mine measured with an IR thermometer) But that is perfectly fine.
What I have done, and other have suggested if you would like them to run cooler is to run the primaries in series as some have already suggested. Make sure if you do this that you account for the drop accross the 10R resistor. You may either need to jumper this R or reduce it.
All things considered, I would leave the 15V secondaries as they are and just let them run warm, they should be just fine.
Cheers!
Russ
fmak said:
Hi Fred, I have been discussing this with Brian and I think that the comparator selection is the entire issue.
The comparator we are using is the LMV7239 which is apparently just too slow for > 48khz.
I actually meant to use the LMV7219 (which ESS used) which has the same pinout but is around 6 times faster. I think the part swap arose because the LMV7239 was included in my PCB CAD program in its standard libraries, and the LMV7219 was not. I honestly don't remember. It was probably just me forgetting to change the part type in the BOM after designing the PCB.
In any case, I am going to try swapping the parts and see if that make 192khz achievable with the on-board comparator.
Cheers!
Russ
Re: Torroids for Buffalo and IVY
Hello Javin5
I have ordered R-core transformers from
http://www.analogmetric.com/store/goods.php?id=84
I have taken 26-34 (2x 9V, 2x 15V)
They are 50VA, are very silent and stay cool.
Hello Javin5
I have ordered R-core transformers from
http://www.analogmetric.com/store/goods.php?id=84
I have taken 26-34 (2x 9V, 2x 15V)
They are 50VA, are very silent and stay cool.
Re: Torroids for Buffalo and IVY
We carry the 15V trafos because they would work pretty well for all of our stuff, so one size fits all. I will, however, start carrying 9V trafos as of next week. This is primarily to support our new Placid shunt regulated power supply, but will also work well for Buffalo VD.
Javin5 said:
We carry the 15V trafos because they would work pretty well for all of our stuff, so one size fits all. I will, however, start carrying 9V trafos as of next week. This is primarily to support our new Placid shunt regulated power supply, but will also work well for Buffalo VD.
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