Way to 'ring in the New Year', guyz
@curlew I found qusp's initial answer totally convincing and went to sleep. Trust the aussies on this one -- ALL the signal info is in the differential and as long as the DC is equal the effect on that difference will be zero.
Why Russ added all those resistors izOT here so I should not have brought it up. The Opus is undergoing redesign; we can wait and see if the resistors are still there.
@curlew I found qusp's initial answer totally convincing and went to sleep. Trust the aussies on this one -- ALL the signal info is in the differential and as long as the DC is equal the effect on that difference will be zero.
Why Russ added all those resistors izOT here so I should not have brought it up. The Opus is undergoing redesign; we can wait and see if the resistors are still there.
THANKS OPC 
+ how to get more gain with the BAL-SE
Hey all, I built the Wire BAL-SE, all I can say is BEAUTIFUL! Thanks OPC So grrrrreat!
And yes, OPC is correct, with any recorded music in your collection, unity gain for the BAL-SE is more than enough. Having said that, if you are in a recording studio situation (where the signals feeding The Wire are-cue mixes which aren't yet mastered), the levels going into The Wire might not be hot enough to get your headphones to a happy level. This isn't The Wire's fault, it's just that the incoming signals are low.
So, I am going to try boosting the gain on the BAL-SE version - and although I saw some suggestions for the SE-SE, as far as I could search, nothing has been posted about values for the BAL-SE version. I think I can figure out the values myself, but just to be sure, I wanted to run it by the collective expertise.
So, I'm looking for a gain of about 1.6X (even 2X is needlessly too much for my purposes). For BAL-SE, I would love to know which ONE of the following would result in maintaining the best performance of this superb headphone amp:
1) Decreasing R1,R5,R7,R11 to 620ohms
2) Increasing R2,R6,R8,R12 to 1.6kohm
That is assuming my calculation is correct, that we want to increase the ratio of R2/R1 (and the other 3 pairs) to about 1.6 Another option would be to reconfigure U1-A, U2-A, U5-A, U6-A to run at gain of 1.6X, but I am going to rule that out since it would require re-designing the PCB.
Any thoughts?
PS see attached photo of my Wire
+ how to get more gain with the BAL-SEHey all, I built the Wire BAL-SE, all I can say is BEAUTIFUL! Thanks OPC
So grrrrreat!And yes, OPC is correct, with any recorded music in your collection, unity gain for the BAL-SE is more than enough. Having said that, if you are in a recording studio situation (where the signals feeding The Wire are-cue mixes which aren't yet mastered), the levels going into The Wire might not be hot enough to get your headphones to a happy level. This isn't The Wire's fault, it's just that the incoming signals are low.
So, I am going to try boosting the gain on the BAL-SE version - and although I saw some suggestions for the SE-SE, as far as I could search, nothing has been posted about values for the BAL-SE version. I think I can figure out the values myself, but just to be sure, I wanted to run it by the collective expertise.
So, I'm looking for a gain of about 1.6X (even 2X is needlessly too much for my purposes). For BAL-SE, I would love to know which ONE of the following would result in maintaining the best performance of this superb headphone amp:
1) Decreasing R1,R5,R7,R11 to 620ohms
2) Increasing R2,R6,R8,R12 to 1.6kohm
That is assuming my calculation is correct, that we want to increase the ratio of R2/R1 (and the other 3 pairs) to about 1.6 Another option would be to reconfigure U1-A, U2-A, U5-A, U6-A to run at gain of 1.6X, but I am going to rule that out since it would require re-designing the PCB.
Any thoughts?
PS see attached photo of my Wire
Attachments
Threee attaboyz!
Nice BAL-SE, fualcr. That is the third, the first of the new year.
Remarkably good judgement
Nice BAL-SE, fualcr. That is the third, the first of the new year.
Remarkably good judgement
nice!! yeah the BAL-SE is a very nice little amp
much of a muchness,
1) Decreasing R1,R5,R7,R11 to 620ohms
will have lower voltage noise, but increase current noise
2) Increasing R2,R6,R8,R12 to 1.6kohm
will have lower current noise, but increase voltage noise
neither presents enough of a change to be noticed, apart from the desired effect
much of a muchness,
1) Decreasing R1,R5,R7,R11 to 620ohms
will have lower voltage noise, but increase current noise
2) Increasing R2,R6,R8,R12 to 1.6kohm
will have lower current noise, but increase voltage noise
neither presents enough of a change to be noticed, apart from the desired effect
I haven't received my SE->SE boards yet, either, in the US. opc shows it all shipped on Dec 22. Most likely the typical postal thing for a letter from Canada to the US:
2 days Canadian post -> 2 weeks customs -> 7 days US post -> misrouted to China -> 3 weeks customs -> 5 days US post -> misrouted to Turkey -> 2 weeks customs -> 6 days US post -> stuck in letter sorting machine in Los Angeles for 2 months -> found by maintenance crew and dropped in a letter box -> 7 days US post -> received sometime in June.
2 days Canadian post -> 2 weeks customs -> 7 days US post -> misrouted to China -> 3 weeks customs -> 5 days US post -> misrouted to Turkey -> 2 weeks customs -> 6 days US post -> stuck in letter sorting machine in Los Angeles for 2 months -> found by maintenance crew and dropped in a letter box -> 7 days US post -> received sometime in June.
the thread would indicate that only a lucky few people so far have received their pcbs, so i wouldnt worry about it, agdr's post is probably not too far from the truth. In all other GB's from opc i have been involved in, the pcbs have taken 2.5-3.5 weeks to arrive here in OZ. It was the same with GBs from Peter Daniels and I also had some custom transformer orders from Richard Sumner that took 14 weeks!! (sumR), so it would appear as if the Canadian postal system is not so swift. i've had issues sending packages back the other way too.
it's always got here in the end however, so i'm trying not to think about it, although i would love it if my kits arrived this week.
it's always got here in the end however, so i'm trying not to think about it, although i would love it if my kits arrived this week.
[very] Small bug on the BAL-SE, nothing major...
Hey Guys - I forgot to mention in my post yesterday what I believe is a super-minor bug in the BAL-SE PCB (and I'm hoping OPC will be able to confirm this)...
Like I said, it is very minor, but one of the two "G" headphone output pads on the PCB isn't connected to anything on the PCB at all, it appears to be 100% floating pad (unless it goes to a mysterious floating 4th inner shield layer). I discovered this by accident when at first I wired only one of the G pads to my headphones, and it happened to be the one that was floating. The remedy is very simple, just use the other "G" pad when connecting to your headphones (or probably what OPC intended, use both)!
I have another blank BAL-SE PCB, and confirmed via multimeter continuity test that the pad is indeed floating one. I have attached photos to show which one is the floating one, as well as my lazy fix (until I wire it into a proper enclosure). I would NOT go so far as to call this bug... I just wanted to document it here in case anyone else like me gets stumped as I was for 5 minutes (trying to figure out why the amp sounded so wonky).
OPC has done a seriously great job with this project, best headphone amp I've ever heard, and so simple, so satisfying. Wow!
PS Regarding those who are patiently waiting, my PCB was part of the Dec.22 batch, but I am also in Canada like OPC... still pleasantly surprised at the speed considering holiday madness with the postal system
PS #2 [edit] thank you qusp for your thoughts on the resistor values for adjusting the gain! going to give it a shot very shortly!
Hey Guys - I forgot to mention in my post yesterday what I believe is a super-minor bug in the BAL-SE PCB (and I'm hoping OPC will be able to confirm this)...
Like I said, it is very minor, but one of the two "G" headphone output pads on the PCB isn't connected to anything on the PCB at all, it appears to be 100% floating pad (unless it goes to a mysterious floating 4th inner shield layer). I discovered this by accident when at first I wired only one of the G pads to my headphones, and it happened to be the one that was floating. The remedy is very simple, just use the other "G" pad when connecting to your headphones (or probably what OPC intended, use both)!
I have another blank BAL-SE PCB, and confirmed via multimeter continuity test that the pad is indeed floating one. I have attached photos to show which one is the floating one, as well as my lazy fix (until I wire it into a proper enclosure). I would NOT go so far as to call this bug... I just wanted to document it here in case anyone else like me gets stumped as I was for 5 minutes (trying to figure out why the amp sounded so wonky).
OPC has done a seriously great job with this project, best headphone amp I've ever heard, and so simple, so satisfying. Wow!
PS Regarding those who are patiently waiting, my PCB was part of the Dec.22 batch, but I am also in Canada like OPC... still pleasantly surprised at the speed considering holiday madness with the postal system
PS #2 [edit] thank you qusp for your thoughts on the resistor values for adjusting the gain! going to give it a shot very shortly!
Attachments
Last edited:
Hi Guys!
I'm finally back from Christmas vacation, and it looks like I've got some catching up to do on the thread! Lots of good discussion, and a few more pictures of builds which is good to see.
fualcr:
Great work on the build! Your BAL-SE looks excellent.
As soon as I saw your note about the second ground pad I grabbed a board and gave it a measure, and you are indeed exactly correct, it is not connected!
I also double checked the the gerber files and for some very strange reason, that pad didn't get any spokes despite being on the GND net. I have no idea why it happened, but it did.
Anyhow, as you mentioned, it's really not a big deal since it's purely a 3-pin system. I just need to make sure peope know to avoid using the floating pad!
I'll update the construction wiki and add a note. Thanks for the good catch!
fredlock:
Your kits shipped out with the others on Dec. 22nd. You did, however, choose surface shipping so your kit might take a little longer than the others which were mostly air mail. I would guess that you'll have it by the end of the week.
agdr:
I have had pretty good luck in the past when shipping to the US, but you're definitely correct, sometimes things just go badly and it takes forever. I once had a mouser order shipped with Purolator that was supposed to be "next day" delivery and ended up taking three weeks to get here!
Cheers,
Owen
I'm finally back from Christmas vacation, and it looks like I've got some catching up to do on the thread! Lots of good discussion, and a few more pictures of builds which is good to see.
fualcr:
Great work on the build! Your BAL-SE looks excellent.
As soon as I saw your note about the second ground pad I grabbed a board and gave it a measure, and you are indeed exactly correct, it is not connected!
I also double checked the the gerber files and for some very strange reason, that pad didn't get any spokes despite being on the GND net. I have no idea why it happened, but it did.
Anyhow, as you mentioned, it's really not a big deal since it's purely a 3-pin system. I just need to make sure peope know to avoid using the floating pad!
I'll update the construction wiki and add a note. Thanks for the good catch!
fredlock:
Your kits shipped out with the others on Dec. 22nd. You did, however, choose surface shipping so your kit might take a little longer than the others which were mostly air mail. I would guess that you'll have it by the end of the week.
agdr:
I have had pretty good luck in the past when shipping to the US, but you're definitely correct, sometimes things just go badly and it takes forever. I once had a mouser order shipped with Purolator that was supposed to be "next day" delivery and ended up taking three weeks to get here!
Cheers,
Owen
As the luckiest of the lucky (but who hadn't yet uncovered the gerber goober) I am feeling a little guilty. There was no mail delivery today at my location in US so there is a good chance a clot of them will pour out Tuesday.
Early in 2011 a small package from Vilnius took three and a half months to arrive but it got here. If, after a month or two, you see smiling postal workers wearing headphones you should begin to worry.
Early in 2011 a small package from Vilnius took three and a half months to arrive but it got here. If, after a month or two, you see smiling postal workers wearing headphones you should begin to worry.
which one? might i suggest you read the thread. most are sold out, actually all now i think; so you are out of luck unless someone has a spare they will let go