The DAC that I had that did balanced out died.
(Don't wanna talk about it =( )
Does this headphone amp need balanced input?
If not, tell me how? (Without a SE to Balanced converter)
If so, it's now officially for sale for the same price that I paid. (Whatever that was)
EDIT: kit is untouched. bag just opened to examine.
Thanks
(Don't wanna talk about it =( )
Does this headphone amp need balanced input?
If not, tell me how? (Without a SE to Balanced converter)
If so, it's now officially for sale for the same price that I paid. (Whatever that was)
EDIT: kit is untouched. bag just opened to examine.
Thanks
negative pole input tied to ground will work. its not ideal, but will do till you get around to getting another balanced output dac
I am not entirely sure when that will be.
Thus, I am going to put it up for sale.
It seems like there is enough demand that someone will be able to take it off my hands.
It's a PCB + parts
Exact contents I received from opc.
Cost: $95, same price that I paid.
BOM:
http://www.diyaudio.com/forums/head...e-headphone-amplifier-pcbs-8.html#post2416740
i just need to knock up a power supply and i'm ready to listen to this amp, will report back with pics tomorrow
Hi
I just listened some music with my new headamp and it's sounding good to my ears. Punchy, clean, detailed and noise free at idle.
Having no balanced pre, the amp sits on top of a volume control card made of two MAS6116 (same as WM8816) in balanced configuration and four OPA627 in inverting mode. Output offset of this combo is well below 1mV at different levels and all was fine at power on. I'm still waiting for some connectors and caps that are out of stock at my local shop.
It's my first try with this volume control chip and some further comparisons will be needed. I plan to build a balanced stepped attenuator in front of "The Wire".
Thanks for your effort Owen
Cheers,
Francis
I just listened some music with my new headamp and it's sounding good to my ears. Punchy, clean, detailed and noise free at idle.
Having no balanced pre, the amp sits on top of a volume control card made of two MAS6116 (same as WM8816) in balanced configuration and four OPA627 in inverting mode. Output offset of this combo is well below 1mV at different levels and all was fine at power on. I'm still waiting for some connectors and caps that are out of stock at my local shop.
It's my first try with this volume control chip and some further comparisons will be needed. I plan to build a balanced stepped attenuator in front of "The Wire".
Thanks for your effort Owen
Cheers,
Francis
Attachments
Hi guys,
I have been quite busy lately between destructive earthquake and nuclear disasters, but today I managed to find time to remove the balliste from the legato and try "The wire".
I still have this strange bias problem, removing the legato did not change anything. With only one channel connected I have no bias, with both I have 125mV on the output of the headphone amp.
Any more test or measurement that I can do ?
Thanks,
Davide
I have been quite busy lately between destructive earthquake and nuclear disasters, but today I managed to find time to remove the balliste from the legato and try "The wire".
I still have this strange bias problem, removing the legato did not change anything. With only one channel connected I have no bias, with both I have 125mV on the output of the headphone amp.
Any more test or measurement that I can do ?
Thanks,
Davide
do the 2 channels of legato use separate supplies?
glad you are ok, seems to be a fair bit of disaster making the rounds this year and i actualy was thinking of you the other day when i was watching the coverage. i dont trust tokyo electric at all
glad you are ok, seems to be a fair bit of disaster making the rounds this year and i actualy was thinking of you the other day when i was watching the coverage. i dont trust tokyo electric at all
No, I have only one power supply for both channels. I also tried to power both "The wire" and the legato with the same power supply, but nothing changes.
Also with a load, nothing changes.
I think I'll give up for now and try again with the D1, when it will be.
Actually, I spent more time that I wanted inside that reactor. I feel very sorry for the people I have worked with and that probably are now risking their lives.
D.
Also with a load, nothing changes.
I think I'll give up for now and try again with the D1, when it will be.
Actually, I spent more time that I wanted inside that reactor. I feel very sorry for the people I have worked with and that probably are now risking their lives.
D.
i should qualify that statement, i dont trust tokyo electric management and their statements that everything is ok at all. i think they are out of their depth, i also feel sorry for those on the front line taking all the risk for little money compared to the boss, it is hard to see how you could not walk out of there with life long effects at a minimum. my thoughts are with you and your family; an earthquake that shifts the planet 20cm off its axis permanently and moves the entire coastline several meters is pretty awesome power. (numbers spat from memory, cant remember exact detail, but they arent far off)
sorry i cant be more help, i dont know the cct at all and we have covered all the usual suspects. i'm back on track with matching now with new voltmeter, so will be chewing through tc matching again this week. i will try out with 75ohm bnc cable and connectors this weekend for the measurements (it didnt come with any leads), but have 50 ohms parts arriving on monday.
i hope to have some good news and better estimate by next weekend and hopefully all done before the next one.
just wiring up my 'the wire' to my buffalo 2 now, will be having a listen shortly.
intermission:
edit: Omg!!! Opc mate i just had several eargasms, lashed it together with buff 2 and ivy3 fed by aku-20 and this things diminutive size belies its absolutely massive sound!! this is one of (at a minimum) THE BEST headphone amps i've ever heard and it has pretty good synergy with hd600 (300 ohms), jh13 (28 ohms) and um3x (28 ohms), you would have to throw some pretty silly headphones at this thing to run out of juice, but at the same time, i use sabres volume, so the amp is wide open and even with 28 ohms highly sensitive iems and the knob turned all the way on pause, its just black. i just sent this to a friend who asked me to report
the detail retrieval is just huge for a single ended amp and the bass is so clean that its capable of some of the best 'sub bass snarl' i have heard from headphones, anyone who knows the term, will know that for it to happen there cannot be any type of distortion in the transducers or the distorted, modulated edge on the note is corrupted by mechanical distortion.
cant wait to try this out on the d1, great job Owen!! you may not be so responsive lately, but my god this litte amp is
sorry i cant be more help, i dont know the cct at all and we have covered all the usual suspects. i'm back on track with matching now with new voltmeter, so will be chewing through tc matching again this week. i will try out with 75ohm bnc cable and connectors this weekend for the measurements (it didnt come with any leads), but have 50 ohms parts arriving on monday.
i hope to have some good news and better estimate by next weekend and hopefully all done before the next one.
just wiring up my 'the wire' to my buffalo 2 now, will be having a listen shortly.
intermission:
edit: Omg!!! Opc mate i just had several eargasms, lashed it together with buff 2 and ivy3 fed by aku-20 and this things diminutive size belies its absolutely massive sound!! this is one of (at a minimum) THE BEST headphone amps i've ever heard and it has pretty good synergy with hd600 (300 ohms), jh13 (28 ohms) and um3x (28 ohms), you would have to throw some pretty silly headphones at this thing to run out of juice, but at the same time, i use sabres volume, so the amp is wide open and even with 28 ohms highly sensitive iems and the knob turned all the way on pause, its just black. i just sent this to a friend who asked me to report
the detail retrieval is just huge for a single ended amp and the bass is so clean that its capable of some of the best 'sub bass snarl' i have heard from headphones, anyone who knows the term, will know that for it to happen there cannot be any type of distortion in the transducers or the distorted, modulated edge on the note is corrupted by mechanical distortion.
cant wait to try this out on the d1, great job Owen!! you may not be so responsive lately, but my god this litte amp is
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well i havent heard this amp in push pull format, but its at least as good as many push pull amps i have heard. i wouldnt say better, just different. it has many of the attributes i would normally associate with balanced drive, probably having to do with the fact its being driven by a balanced dac and the amp has a fully balanced input stage, so pretty much all of the balanced goodness is folded down into the se signal
did you read my post? on the previous page? second half gives my impressions with hd600 and a couple of high end iems
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also unity voltage gain on 3vrms @ 250ma per channel makes it around 750mw per channel, or 1.5w total. thats ear bleeding territory with hd600, but at the same time to get to a nice listening level does not require the digital pot on sabre to be turned down too far. besides, if for some crazy reason its not enough power for you, change a couple of resistors and hey presto, higher voltage gain
the above is assuming you are using it with sabre or a dac with similarly rated output, because of course with unity gain, what voltage you put in is what voltage comes out, but the lme49600/10 up the current considerably. its designed for a balanced input.
the above is assuming you are using it with sabre or a dac with similarly rated output, because of course with unity gain, what voltage you put in is what voltage comes out, but the lme49600/10 up the current considerably. its designed for a balanced input.
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Hello,
A direct answer;
HD-600’s work well with a “unity” gain amplifier.
At first thought I was reluctant to even try unity gain but I hooked up a tube buffer (unity gain) => para feed transformer then HD-600's this is plenty loud with10 ~ db to spare.
I have not yet purchased the BOM to complete “The Wire”.
DT
All just for fun!
it does depend on the source though, unity gain on a single ended dac with passive iv may not be enough
So, I managed to chase the DC bias problem, that is not a DC bias problem, but HF oscillation.
I started to suspect that when I saw that the position of my hands had effect on what I was measuring as a bias. Scope confirmed that.
10 nF at the input signal to ground had a huge effect, but I still have some.
What's the best way to avoid it ?
The output of the legato has coupling caps 100uF and bleeder 220K.
Thanks,
Davide
I started to suspect that when I saw that the position of my hands had effect on what I was measuring as a bias. Scope confirmed that.
10 nF at the input signal to ground had a huge effect, but I still have some.
What's the best way to avoid it ?
The output of the legato has coupling caps 100uF and bleeder 220K.
Thanks,
Davide
hf oscillation of legato, or 'the wire' ? if its the wire try lifting the BW pin (pin 1) on one of the output buffers. this will lower the bandwidth and hopefully get rid of the oscillations for you. try one channel first and then if its a success, the other. just lift it and leave it floating. otherwise you may try shielding the connecting wires, casing it up in a grounded metal case, or placing some filter capacitance in the input opamp inverting fb loop. i guess you live in a high rf area and this amp is VERY wide bandwidth and with no filter of any kind this keeps it very linear, at the risk of oscillation in areas with high interference
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