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Post by PinkFloyd on Jan 31, 2009 20:54:34 GMT
krisno, the X-Can V2 produces 1.5 watts of power way more than the K701 need. I have a hard time understanding what you mean by lack of drive. I hope the Little Pinkie provides you w/ what you are missing. Also there is a tweak replacing the two power supply transistors inside the X-Can V2 which I and others have implemented. I personally am very happy w/ the results of the tweak. I also "seriously" cannot understand this "lack of drive" or "harshness" that Kris describes.... this couldn't be further from the truth with my experience of v2's being they are extremely capable on the driving front (1 watt Miguel) and one of the smoothest "MF house sound" listens I have come across in a head-amp. I'm not saying that kris is wrong but it would be good to understand just "why" he is experiencing these unwelcome effects........ Kris, have you double checked all your solder connections? If any of them look a bit "dry" / not shiny then rework them and flood a bit of fresh solder in with a high temperature bit.... all it needs is one joint to be a bit "iffy" and it can throw the entire thing out of true. If you've got the time (ie: can wait a few weeks) then you can send the PCB's to me and I'll compare them with my ELNA v2.... that way we can rule out any mechanical / component faults (and rectify them if they exist)..... I'll do this free of charge as long as you cover the postage. The v2 is a wonderful little amp (It's what got me into this hobby) and always has that "old glove" safe sound.... many amps have come, many have gone but the v2 is always there doing what it does best..... making music. I want you to experience the v2 the way it should be Kris so don't be shy to take me up on my offer  Mike. |
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Vallejos
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Post by Vallejos on Jan 31, 2009 21:06:25 GMT
I´m following this thread with great interest.
Kris,
I have not listened through the V2 but I have a V3 and I´m more than satisfied with the sound. Even though it is unmodified. I´m having a hard time imagine the V2 sounding like you describ. Must be something completly wrong with your specific amp or the source does not live in synergy with the amp. I think you ought to try a different source and maybe different interconnects.
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Post by PinkFloyd on Jan 31, 2009 21:26:48 GMT
I think you ought to try a different source I've been suggesting this for a few months now...... |
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insomniac
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Post by insomniac on Jan 31, 2009 21:45:06 GMT
I think you ought to try a different source I've been suggesting this for a few months now...... Krisno A different source may be the best option as suggested. Have you still got the yulong? If so try the DAC out from it into the V2 as it uses the BurrBrown OPA2134's and is a bit darker. |
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Post by dejanm on Jan 31, 2009 23:30:12 GMT
Sorry guys, but I had the very same problem as krisno. After upgrading PSU this problem disappeared. Therefore I believe that krisno should try the same thing. Anyway, Pinky is on its way ... If that does not help, I think that Pink Floyds offer cannot be refused and all of us would be very keen to see what Mike is going to find out ...
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Post by Deleted on Feb 1, 2009 1:55:54 GMT
Miguel Do you have a fire extinguisher, or kitchen fire blanket ?  Alex |
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Post by Deleted on Feb 1, 2009 5:16:46 GMT
Miguel The top one could make things very hot without even plugging in the modded unit. Alex |
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Post by dejanm on Feb 1, 2009 7:25:01 GMT
They all need robust power supply ...  |
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Post by PinkFloyd on Feb 1, 2009 8:10:24 GMT
They all need robust power supply ... I don't think I've got enough power to satisfy those particular models  |
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Post by dejanm on Feb 1, 2009 8:17:35 GMT
They all need robust power supply ... I don't think I've got enough power to satisfy those particular models In this case you need to put more secondaries in parallel -> that gives that necessary kick ... ;D |
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Vallejos
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Post by Vallejos on Feb 1, 2009 16:08:33 GMT
Looks more like firestarters to me... Hot |
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Post by krisno on Feb 1, 2009 16:20:42 GMT
First off are the tubes. These are $110 at tube monger. Stamped HONVEDSEG is military approval stamp, rare tubes and very underrated. Made in 1971.    1: Regarding the ferrite bead input transistor 'mod'. Does this ferrite bead not affect the sound at all? Are we 100% sure there is no distortion with this?? ** Are we sure that no dacs has DC on the output... 2: I changed the source, from the NOS dac to a cheap panasonic CD player. My £50 sony is not here at the moment. It did not sound bad, but the sharpness was still there. It really is sharp as the Yulong never was, the v3 was a bit darker also. PSU might help somewhat, we will see.. Still, when I compare SS and this tube v2, for instance when a car drives by on a movie trailer I had, it sounded good with the yulong(using built-in ad1955 dac). When using yulong + nos dac that trailer sounded just freakin amazing. VERY musical, 'dark', 100% non-fatiguing, very fast, good drive... intens but beatufil experience. This experience is kinda 'gone' with the V2, but its more realistic, and much more fun than the stock v8, though the v8 was a bit lusher. But then again, the v8 was also run with a Pinkie... I never heard MF headphone amps without that pinkie PSU, so maybe this is what is killing it... I am not sure. But if you guys are using £10K Wadia CD players, of course my DAC is the weak link. I want to use my computer as source.... it will never be as good as pure CD player, since Vista somewhat changes the sound, and jitter is increased. But still, it is brighter than what I am used to. If I had used the X-dac v3 and not the NOS dac I think I would have been completly killed.... I am getting a new NOS btw, using chassis as heatsink and much shorter signalpath. Lets hope 150hour burn-in + psu is what is needed for the V2.. BUT PLEASE CONFIRM the 'iron bead' mod is safe to implement and really good. Those big iron beads must somehow cause distortion? no?? K P.S. I will maybe take your offer if it won't behave... hehe P.S.S I think my soldering is OK, as it sounds better now than before modded, and it was bright as FunKadelic CoWpat also pre-mod. P.S.S thanks guys! |
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Post by Deleted on Feb 1, 2009 20:25:43 GMT
Krisno The ferrite beads are quite small, and only affect radio/TV frequencies. It is quite common practice with phono preamps to use several turns of thin enamelled copper wire through them to reduce RFI. In this case it is only slipped over the wire. I doubt that any commercial DAC would be putting out any DC of a magnitude of more than a few mV. Some of these DIY DACs could be a different story.  Any residual DC would only get as far as the potentiometer, where it would be noticed as a rustling sound as the potentiometer is rotated. After the potentiometer, there is another capacitor, anyway. SandyK |
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Post by krisno on Feb 1, 2009 22:51:18 GMT
SO that is what is creating the 'rustling' sound. I remember having that problem alot with different hifi stuff many years ago. Probably was DC coming from the soundcard on the pc into the amps. I thought the potentiometer had some dust in it..... excellent getting to know that now.
I will remove those caps and solder in the iron beads if Mike will send them to me. But still, this V2 is brighter than the average MF x-can v3/v8. Even with the russian tubes... Really annoying... but anyways, I might be SS kind of guy, atleast when using that NOS. That NOS + Yulong was just so amazing at times.
I i got this multimeter thingy, how can I measure if the (Almost DIY dac) has DC on the output??
K
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Post by Deleted on Feb 1, 2009 23:45:14 GMT
Krisno
The potentiometer noise can also be caused by the internal wipers of the potentiometer as they "wipe" over the carbon (usually) track. This usually indicates a worn potentiometer, although a little spray of WD40 , CRC26,Servisol etc. into the innards,often restores operation, after quite a few complete backwards and forwards motions of the potentiometer. This sometimes helps, even without the spray.
To measure any residual DC voltage out of the DAC , the easiest way is to unplug the RCA leads from the amplifier, turn the meter on to DC Volts scale, and connect the meter's probes across the inner and outer of the RCA plugs. If the voltage is fairly small, you can then set the DMM to the millivolts range for a more accurate reading.
SandyK
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Post by PinkFloyd on Feb 2, 2009 14:31:42 GMT
First off are the tubes. These are $110 at tube monger. Stamped HONVEDSEG is military approval stamp, rare tubes and very underrated. Made in 1971. Very expensive valves, how do they sound in the v2? The axial ferrites will certainly not add any distortion and help eat any RFI that may have found it's way in.... as Alex says, there is another cap in the chain so the 10uF is NOT required and the v2 WILL sound a lot better without them in circuit. I will send you a couple when I return home. Safe and good  How to measure DC here: www.rock-grotto.co.uk/dcoffset.htm |
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Post by krisno on Feb 5, 2009 14:18:47 GMT
Got the Littlepinkie now. It sounds still sharp, no difference.... I use laptop as source now.
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Post by dejanm on Feb 5, 2009 16:07:57 GMT
Got the Littlepinkie now. It sounds still sharp, no difference.... I use laptop as source now. With Tungsram as well ? |
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Post by krisno on Feb 5, 2009 17:18:48 GMT
No, not tried the Tungsram, using the NOS russian tubes. The thing was bright when I got it also. But the thing is really 'mint', so the amp had probably hardly been used. And I read that the V2 is known to be bright. The V3 is a totally different animal when I had it.
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Post by dejanm on Feb 5, 2009 18:28:36 GMT
Try Tungsram first ... give them some time to burn in ... Tubes do need some time to settle down. If then you still have very bright and sharp sounding amp then I would accept very gentle offer from Pink and send him PCBs.
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Post by krisno on Feb 5, 2009 18:35:55 GMT
I am selling the tungsram, won't try them as saleprice might go down. It won't be that much difference, the map was bright also with stock jan philips.
It is burning in now, running sepultura chaos AD FLAC, with headphones unplugged and volume pot at 12oclock. Will leave it for some days.
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Post by PinkFloyd on Feb 5, 2009 18:56:51 GMT
I am selling the tungsram, won't try them as saleprice might go down. It won't be that much difference, the map was bright also with stock jan philips. It is burning in now, running sepultura chaos AD FLAC, with headphones unplugged and volume pot at 12oclock. Will leave it for some days. Try the other tubes.... nobody will know |
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Post by krisno on Feb 5, 2009 19:00:37 GMT
it cannot be the tubes, the russians are known to be laid back also.
it is good looking so I can't think its something wrong with it... But why I have this experience vs you other guys is shocking. It really is nothing like the $250 Yulong, which was a DAC, pre-amp, digital vol controller and lehmann clone, all in one. ... incredible.
I will not btw pay £500 for a opamp Slee solution. So then there is only one more thing to try, Burson HA-100 headphone amp.
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Post by PinkFloyd on Feb 5, 2009 20:11:14 GMT
Kris, This may be stating the perfectly obvious but why don't you have the $250 Yulong instead of the X-Can? You seem to really like it so it's the amp you should go with at the end of the day.... this is what it's all about at the end of the day..... going with your ears tell you is "right". The X-Can on this occasion doesn't suit your tastes so find an amp that does....... from what you've reported in previous reports, that won't be a hard task! The Yulong |
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Vallejos
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Post by Vallejos on Feb 5, 2009 20:51:58 GMT
If you like Kris, you can always ship the V2 to me for compasion to my V3. Though I can´t guarantee I will send it back to you ;D
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Any residual DC would only get as far as the potentiometer, where it would be noticed as a rustling sound as the potentiometer is rotated. After the potentiometer, there is another capacitor, anyway.