Sorry for repeatedly posting in the wrong thread since we have the conglomerate build thread… but here goes.
Last weekend I also took the advice of OPC and qusp and went to improve the wiring on my “Wire”. So I managed to twist the wires from the mini XLR to the board at least twice (I was afraid of actually breaking contacts off the mini XLR…) and fabricated a new umbilical to the psu using bigger gauge wire and braiding them like my daughters blonde hair
.
The result is interesting… I am under the impression that the treble region changed… to the better.
I am not sure whether this is due to the improved wiring or other… I also seem to observe that the amp is so transparent that I can feel (hear) the influence of mains pollution. In the evening “The Wire” simply sounds better. Time to think of a mains filter or resurrecting the isolation transformer that is sitting in a corner of the room. ..?
Did I say that this amp is utterly transparent? Oh yes… it brings you very close to the music with fantastic resolution and a big open soundstage but also merciless reveals any flaws in the recording , hiss of the recording gear and so on.
Compared to my favourite tube amp the tonal balance is a tad leaner (on Sennheiser HD800) but it pairs very well with my Sennheiser HD650 that gives male voices a bit more chest. Sound is full and has beautiful impact (--> PRAT although I don’t have a clue what it actually means… maybe you guys can enlighten me). One of my test tracks lately is “Ton sur Ton” on Marc Johnsons ‘Shades of Jade’… what can I ask more?
Last weekend I also took the advice of OPC and qusp and went to improve the wiring on my “Wire”. So I managed to twist the wires from the mini XLR to the board at least twice (I was afraid of actually breaking contacts off the mini XLR…) and fabricated a new umbilical to the psu using bigger gauge wire and braiding them like my daughters blonde hair
.The result is interesting… I am under the impression that the treble region changed… to the better.
I am not sure whether this is due to the improved wiring or other… I also seem to observe that the amp is so transparent that I can feel (hear) the influence of mains pollution. In the evening “The Wire” simply sounds better. Time to think of a mains filter or resurrecting the isolation transformer that is sitting in a corner of the room. ..?
Did I say that this amp is utterly transparent? Oh yes… it brings you very close to the music with fantastic resolution and a big open soundstage but also merciless reveals any flaws in the recording , hiss of the recording gear and so on.
Compared to my favourite tube amp the tonal balance is a tad leaner (on Sennheiser HD800) but it pairs very well with my Sennheiser HD650 that gives male voices a bit more chest. Sound is full and has beautiful impact (--> PRAT although I don’t have a clue what it actually means… maybe you guys can enlighten me). One of my test tracks lately is “Ton sur Ton” on Marc Johnsons ‘Shades of Jade’… what can I ask more?
Added PRAT value
Pace, Rhythm, Attack & Timing apparently ... but if you think of it from a musicians point of view, pace, rhythm & timing of a piece of music are pretty much the same thing. From an amps point of view, these terms describe it's ability to convey the feel of the music to the listener, ideally giving correct delineation of each individual part without hiding or adding to it artificially ...
I find the album Tourist History by Two Door Cinema Club to be have a lot of immediacy about it, with The Wire it feels like your being draged along by the scruff of your neck with hardly a chance to catch your breath. The same album played through my A/V system lacks the drive it had with the Wire. Details are lost due to various reasons and different aspects of the music can be heard giving it a more mellow feeling...
A lot of personal preference is involved...
Paul
Pace, Rhythm, Attack & Timing apparently ... but if you think of it from a musicians point of view, pace, rhythm & timing of a piece of music are pretty much the same thing. From an amps point of view, these terms describe it's ability to convey the feel of the music to the listener, ideally giving correct delineation of each individual part without hiding or adding to it artificially ...
I find the album Tourist History by Two Door Cinema Club to be have a lot of immediacy about it, with The Wire it feels like your being draged along by the scruff of your neck with hardly a chance to catch your breath. The same album played through my A/V system lacks the drive it had with the Wire. Details are lost due to various reasons and different aspects of the music can be heard giving it a more mellow feeling...
A lot of personal preference is involved...
Paul
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LOL... no problem, wasn't to sure so went for overkill
I always find these threads a great source of usefull info. After the talk on wiring I've gone back to my own and implemented some of the suggestions. Already using sheilded twisted pairs for the audio signal, but hadn't done anything with the transformers wires... so shortend & twisted 'em, can't say I can here any difference, it was already silent at full folume with all the components connected and turned on.
One very happy camper...
I always find these threads a great source of usefull info. After the talk on wiring I've gone back to my own and implemented some of the suggestions. Already using sheilded twisted pairs for the audio signal, but hadn't done anything with the transformers wires... so shortend & twisted 'em, can't say I can here any difference, it was already silent at full folume with all the components connected and turned on.
One very happy camper...
It's been a year and a half since I completed the Wire headphone amp. I love it but now that I live in the city (seven stories up) I get radio noise.
I know the wiring could be optimized a bit (a la Owen's post a couple pages back). I don't get any 60hz hum, just scratchy radio ads and trending songs.
Here is my layout as it stands.
The chassis is connected direct to mains ground (screw near the back of the divider). I have tried both connecting the PCB ground to the chassis and leaving it floating but I didn't notice a difference in noise.
I'm using a USB dac + B1 for my pre, my RCAs are about 12" long.
I will definitely twist the signal pair but I doubt that will fix all my problems. Do I need to shield my RCA cables? My headphone cable? I can reduce or increase the interference by moving the headphone cable around. I never have this issue with my speakers connected to the same source (I know it's not the best test b/c of different sensitivity).
Any advice?
-Nelson
I know the wiring could be optimized a bit (a la Owen's post a couple pages back). I don't get any 60hz hum, just scratchy radio ads and trending songs.
Here is my layout as it stands.
The chassis is connected direct to mains ground (screw near the back of the divider). I have tried both connecting the PCB ground to the chassis and leaving it floating but I didn't notice a difference in noise.
I'm using a USB dac + B1 for my pre, my RCAs are about 12" long.
I will definitely twist the signal pair but I doubt that will fix all my problems. Do I need to shield my RCA cables? My headphone cable? I can reduce or increase the interference by moving the headphone cable around. I never have this issue with my speakers connected to the same source (I know it's not the best test b/c of different sensitivity).
Any advice?
-Nelson
twisting the input wiring is the single biggest thing you can do, it always baffles me why people dont do it... twist ALL signal and power pairs; if you havent done that, that is why you are picking up noise.
its a DC coupled wideband amplifier, without twisting the input and output wiring you are turning the input connections and the headphones and headphone voice-coil into an aerial, which is why iut changes when you move the headphone cable around.
its a DC coupled wideband amplifier, without twisting the input and output wiring you are turning the input connections and the headphones and headphone voice-coil into an aerial, which is why iut changes when you move the headphone cable around.
I'm almost finished with "the wire" headphone amp. I just have to wire up the jack and power switch.
I have a led rocker switch, that I might swap out. It requires 12vdc to power up the led when it's switched on (I believe). I guess I can't wire it directly to the incoming ac.
What are the trim pots on amp for again? I'm certain I've already set them and forgot about them.
I have a led rocker switch, that I might swap out. It requires 12vdc to power up the led when it's switched on (I believe). I guess I can't wire it directly to the incoming ac.
What are the trim pots on amp for again? I'm certain I've already set them and forgot about them.
Much of the above is a little scary, but let's see what we can do:
1. No, 120VAC across an LED is probably not a good idea. If you have a spec sheet you can check how they implemented the LED in the switch. If it needs 12V, you can probably wire a resistor in series and power it off the +12-15V rail from the PSU. It's best to err on the side of caution.
2. The trimpots are on the PSU and they set the rail voltage for the +/- rails that supply the amp. You want to adjust them to get the +/- voltage you decide to run. In your case, if you don't need extra high output voltage swing, I would simply set it at +/-12V and be done. That way you can power your LED directly
Cheers,
Owen
I was going to come back and edit my post, don't need to now
I would like to add one thing though, please, when you're building anything electrical, look at the schematic and the datasheets while you build it and then double (or tripple check) your wiring before hooking anything up to power.
Chris
I would like to add one thing though, please, when you're building anything electrical, look at the schematic and the datasheets while you build it and then double (or tripple check) your wiring before hooking anything up to power.
Chris
I'm quite sure you had your PSU set at +/-15V by the trim pots
Never wire the incoming AC to the LED unless your rocker switch is rated for live potential for the LED part and you know how to wire live circuit to the safety codes.
Owen's idea about the LED wiring is good. Just wire it to one of the rails with a resistor of 4k7 in series. LEDs are diodes that will pass a current one way. If it doesn't light up reverse the polarity. Experiment with the resistor value for a desired brightness. I had my front panel LED powered across the rails at 30V with a 27K resistor in series. There is only about 1mA current and the LED gives a quiet, subtle glow, yet still stands out the mess on my desk.
I dont think you will find a switch with LED rated for AC, it would need to have separate power for the LED, or some crazy step down from mains to 5-10vdc, aint gonna happen. most LED switches are momentaries
that and LED dont work with AC ever, they need DC voltage
actually DC current. I guess the LED replacement light bulbs that are becoming more widespread have some sort of rectifier in them and maybe a zener? maybe i'm wrong, I have just never heard of an LED that takes AC anything voltage or current
that and LED dont work with AC ever, they need DC voltage
actually DC current. I guess the LED replacement light bulbs that are becoming more widespread have some sort of rectifier in them and maybe a zener? maybe i'm wrong, I have just never heard of an LED that takes AC anything voltage or current
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x2^^
I think its more likely it has an LED and hes seen them used for mains...as momentaries controlling relays. lots of PC tuning websites and ebay shops sell them. they take 12vdc normally and do NOT like mains AC across them
but yes pic + datasheet or part # or we cant really help.
I think its more likely it has an LED and hes seen them used for mains...as momentaries controlling relays. lots of PC tuning websites and ebay shops sell them. they take 12vdc normally and do NOT like mains AC across them
but yes pic + datasheet or part # or we cant really help.
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