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Review: Violectric HPA V200 amp - Page 150

post #2236 of 2660

i questioned, some time ago, violectric ceo about the fact that my devices, v800 and v200, and all those pictured in the reviews, where set to lift by default, while in the manual gnd is stated as being the "ex works" setting

 

it turned out that was the configuration of the prototype only, i didn't question why they changed that however i think they tried to maximize thd+n figures, while i can clearly hear how going from lift to gnd, and from ac to dc, somehow enhance, a lot in my case, the driving capabilities, and balance, extension on both ends, and purifies the mids
 

edit: oh, and yeah, lcds + dc coupling, shake it baby


Edited by roskodan - 4/26/13 at 2:51am
post #2237 of 2660
Quote:
Originally Posted by kkl10 View Post

Hey guys, could someone please help me get a grip on a mystery?

 

To begin with, I would like to ask you guys if anyone has found their V200 or V100 to impart some channel imbalance on any headphone connected to it?

 

I have a V100 and just recently found that on any headphone hooked up on it the physical left channel always sounds slightly louder than the right channel...

I've noticed this imbalance months ago but I thought that it was coming from the headphones themselves, but recently I actually verified that the problem was coming apparently from the amp.

 

I've tested all possible variables: digital sources, interconnects, software (channel reverse), pre-gain settings (of course!, I used the same for both channels duh!), volume knob position, etc... and the imbalance remains always the same regardless of the above configurations... The left channel of the headphones sounds louder than the right one.

So it seems that it's an issue within the amp....

 

My ears detect this imbalance mostly on the upper midrange - treble frequencies, on the lower frequencies I'm not sure I was able to discern any imbalance as strange as it seems...

I'm not sure if it's right to call it an imbalance, it's a sort of sound image shift to the left channel...

As if a sound that was supposed to appear in front center position of the sound field appeared to be coming slightly from the left (channel)... it's like a slight incoherence between the channels, and the left channel always seems to sound a bit more dynamic or detailed? than the right channel which sounds comparativelly kinda dead... but this could just be the impression caused by the volume mismatch.

 

This is not simple to describe.

I hope I'm making sense here... frown.gif

 

My amp is currently at Lake People instalations undergoing inspection, but they already informed me that they measured the channel imbalance to be within norms, nothing major, way below 0,5 dB...

But the difference I hear is most certainly of several dBs it's quite apparent in the higher frequencies...

I'm not sure if they tested it at 1000Hz tone only though...

 

I don't get this channel imbalance from my other sources my PC integrated HP-out nor my Sansa Clip+, so it seems to be a real issue with my V100...

 

Note that this is not the usual low volume channel imbalance, this is omnipresent regardless of how loud the sound/volume knob position is.

And it's always the left physical channel of the headphone that sounds louder.

Even if I reverse channels through software (foobar2000, for example) and swap channels in my head it's the left channel of the headphone that sounds louder, regardless of being routed the left or right channel stereo signal from software.

 

I'de like to ask if anyone has noticed this behavior with their amps Violectric or not?

Is this a normal occurence with amps?

What could possibly be causing this issue on my V100?

AFAIK the previous owner didn't mess within the amp, but could this be caused by DC coupling issues or incosistency between the opamps/transistors used for each channel?

 

Any help or clarification would be much apprecciated.

I own a V100 with HD800 and I think there is some merit to your points. I experience some channel imbalance to the right sometimes and a power off/on seem to solve the issue. I don't know.. Persistently there seems also to be a slight shift to the right.. I can't really confirm. It could be my ear or headphone too, but it's annoying I know.


Edited by smoothtalker - 4/26/13 at 11:49am
post #2238 of 2660

listening feedback anyone? about ac/dc and lift/gnd comparison
 

post #2239 of 2660

i see that very few took the time to try the v200 set to dc (and gnd)

 

probably from fear to bust their cans

 

however if you have the hd800 or beyer t1 or lcd or such high resolution cans the difference is huge

 

Quote:
Originally Posted by fdg View Post

At least, DC operation is a little bit ingenuity and a bigger portion marketing so we can say " we can do that " - but to say it frankly, it is not very reasonable.

 

lol i almost fell for that

Quote:
Originally Posted by project86 View Post


I'd check with Violectric before doing that just to get a feel for their opinion. I guess if you know the specs of your source then it might be worth trying though. If you are the type to believe a single capacitor can greatly color the sound.

who said there's only a capacitor, the change in performance is huge, did you try it? no? to bad, the review is not complete than...

 

Quote:
Originally Posted by theophile View Post

Since that warning comes from the manufacturer, it is worth repeating.

 

Let anyone who read my post weigh my observations via the warning. I'm not going back to AC however.

amen

post #2240 of 2660

Since a few weeks I connected my V200 with a Lessloss original power cord. In my revealing system (Zodiac gold dac and audeze LCD2vs2) it is like listening to a new, better amp. Everything sounds now much more natural and more  like real music...better timbres, much more holographic stage better bass, etc. A very, very worhwile improvement...

post #2241 of 2660
Quote:
Originally Posted by kindval View Post

Since a few weeks I connected my V200 with a Lessloss original power cord. In my revealing system (Zodiac gold dac and audeze LCD2vs2) it is like listening to a new, better amp. Everything sounds now much more natural and more  like real music...better timbres, much more holographic stage better bass, etc. A very, very worhwile improvement...

I recently had a chance to try the V200 using a ZTRON Python Power Cable, and boy was I impressed with the bass and soundstage improvement.
post #2242 of 2660

Both my V800 & V200 are (internally) stock: V800 at default gain (6dB); the V200 is factory default as well (has no jumpers set to DC/"Lift" mode.  The V800's pot is always fully open in my system.. up until now, I had kept the V200 set to unity (0dB) gain.. the pot rarely (if ever) traveled past 12pm when using any of my phones.

 

Playing around with the V200's (external) gain settings..  I noticed my FA-002w "High Edition" really sing when the V200's gain is set to -12dB.  The 002w HE is one. picky. phone. when it comes to finding ideal upstream synergy.. it's practically on par with the HD800 in this regard.  The V800/V200 functioned admirably with the HE.. but there was a certain 'roughness' to the sound (when I had the V200's gain at 0dB)... and roughness is certainly not something one typically associates with the V200 (unless the tracks recording quality possesses it).

 

Dropping the V200's gain to -12dB allowed me to use the pot in the 12pm to 3pm range more freely.. and, boy, did the 002w-HE clean up!  I'm hearing noticeably better control and smoothness now from the HE now.  In particular, dynamic swings sound more fluid and articulate.  With the lowered gain, I sense better balance in the freq. presentation.  It's less tipped toward the upper mids & now possesses a more neutral, even tone.  The soundstage appears more coherent, as well.  I'm simply relieved to be able to capture a sense of 'calm' with this (wily) phone now.. something I wasn't able to (consistently) attain when the V200's gain was set to 0dB.  I've been enjoying the results so much that I haven't even glanced at the HD800 (for the past two days)... LOL.

 

So, as has been previously mentioned in this thread by some other members (spkrs01, etc.), the V200 does seem to have a sweet spot in the 12pm-3pm range... at least with the couple of phones I've used (so far).

post #2243 of 2660

the harshness has something to do with the dc decoupling filter and ground lift high pass rf filter

 

are you using v800 balanced out into v200 or rca? cos v800 balanced out is at 15dBu default while you are probably using rca out which is at -9dBu in regard to the balanced output, so 6dBu

 

with the ac operation and lift settings there seems to be a tremendus amount of peak, musical power

 

i'm using v800 balanced out at the default 15dBu into the v200 at 0dB pre-gain but with ground jumper set to gnd and dc coupling, jumpers set to dc

 

the dc offset with the v800 v200 combo is almost non measurable,

 

i measured the max, while heaving the v200 pot at max, dc offset

 

of 5mV for left and right channel while set to ac operations

 

and of 0mV and 3mV for the left and right channel respectively when set to dc operations !!!!!! eek.gif

 

try setting the v200 to 0dB pre-gain, dc operation, and the ground lift jumper to gnd on both the v200 and v800, and be amazed

 

 

 

i know this is a hopeless monolog but is there anyone who want to share more in depth impressions about the v200 set to gnd and dc, 0dB pre-gain, vs ac lift settings


Edited by roskodan - 5/13/13 at 4:49pm
post #2244 of 2660
Quote:
Originally Posted by roskodan View Post

the harshness has something to do with the dc decoupling filter and ground lift high pass rf filter

 

are you using v800 balanced out into v200 or rca? cos v800 balanced out is at 15dBu default while you are probably using rca out which is at -9dBu in regard to the balanced output, so -6dBu

 

with the ac operation and lift settings there seems to be a tremendus amount of peak, musical power

 

i'm using v800 balanced out at the default 15dBu into the v200 at 0dB pre-gain but with ground jumper set to gnd and dc coupling, jumpers set to dc

 

the dc offset with the v800 v200 combo is almost non measurable,

 

i measured the max, while heaving the v200 pot at max, dc offset

 

of 5mV for left and right channel while set to ac operations

 

and of 0mV and 3mV for the left and right channel respectively when set to dc operations !!!!!! eek.gif

 

try setting the v200 to 0dB pre-gain, dc operation, and the ground lift jumper to gnd on both the v200 and v800, and be amazed

 

 

 

i know this is a hopeless monolog but is there anyone who want to share more in depth impressions about the v200 set to gnd and dc, 0dB pre-gain, vs ac lift settings

 

Appreciate the insights, roskodan.  I forgot to mention: I am using balanced cables between the V800 & V200... so the V800's gain is running at 15 dBu, in this case?

 

I'll take a shot at tweaking the jumper settings tonight.  So aside from changing the ground lift jumper to "GROUND" on the V800, nothing else needs to be changed on the DAC side?  On the V200, I will change it to GROUND as well, and change to DC operation.

post #2245 of 2660

that's right groundlift jumper from lift to gnd for the v800 and v200, plus for the v200 set the two jumpers that are near the pot from ac to dc

 

before you disassemble the devices, while still at their default settings, you may want to try connecting the v800 and v200 by rca, with the v200 at 0dB pre-gain, and comparing with the balanced interconnections

 

which gives really a different experience

 

default for the v800 is 15dBu for balanced outs, and the rca outs are at 6dBu, -9dBu lower

post #2246 of 2660

Dug into the V800 & V200's internal settings tonight.. upon opening them, I was surprised to see the XLR-GROUND settings (on both devices) to be set to GND.. so I've been listening to both devices in this 'experimental' mode.  Coupling on the V200 was set to AC, though (I changed it to DC).  I left the V800's internal (XLR) gain at 15 dBu.

 

I'm not sure I hear any change after switching the V200 to DC coupling... I'll need more time listening & comparing.  But when I changed the V200's gain to -6dB, the HD800 most certainly yielded some very pleasing results.  The resulting improvement in sound was much like what I heard when I dropped the gain to -12 dBu (for the FA-002w HE):  the HD800 had (noticeably) more fluid dynamic swings.  Gone was the harshness I experienced (when the gain was at 0 dBu).  With the V200's gain at -6 dBu, the HD800 still tilts to the bright side (as it's natural tuning dictates).. but the upper mid-through-treble freq. sound less peaky and unruly.  It's smoother in that region without losing any of the detail and resolution I'm accustomed to.  In fact, those qualities seems heightened as there's less stridence muddying up things.  Bass sounds distinguishably more linear, better extended, and cleaner.  I've gained a renewed appreciation for just how fast the HD800's bass really is, too.  Moving through the pot range, the sonic balance remains even over a much larger area (than what I heard when the gain was at 0 dBu).  With well recorded tracks, I can comfortably reach between 2 and 3pm.. the sound has a silky "decadence" that I'm more than willing to indulge in.

post #2247 of 2660

Ha I'm willing to try this, but have been holding off as I'm fairly sure I won't be able to hear any difference.  :)

post #2248 of 2660
Quote:
Originally Posted by FlySweep View Post

 I was surprised to see the XLR-GROUND settings (on both devices) to be set to GND.. so I've been listening to both devices in this 'experimental' mode.

nope, thats the default setting

 

i was refering to the groundlift jumper not the xlr ground, try again

 

when just adjusting to dc the difference is less noticeable but still substantial

 

Quote:
Quote:
Originally Posted by roskodan View Post

 

 

 

 

 

Quote:
Originally Posted by roskodan View Post

 

first turn off and unplug the power mains cables and all the other cables as well

 

for the v800 one should first remove the metal cylinder of the volume pot and the nut underneath it, that holds the pot to the case,

than the two hex, upper left and right screws on the front panel

than the four corners hex screws from the back panel

than slide the back panel (the pcb on which it's screwed on comes along) straight out about 5mm

than lift the upper cover starting from the back

 

for the v200 lift the two hex, upper left and right screws on the front panel

than the four corners hex screws from the back panel

than slide the back panel (the pcb on which it's screwed on comes along) straight out about 5mm (not more cos there's a patch cable holding the pcb to the pot and the front panel)

than lift the upper cover starting from the back

 

enjoy messing with all the configurable settings

 

Quote:
Originally Posted by roskodan View Post

 

 

V800-E Manual.pdf 954k .pdf file

 

 

 

V200-E Manual.pdf 542k .pdf file

 

 

did you change the groundlift jumper or just thought i was referring  to the xlr?

 

did you try the single ended rca interconnection from the v800 to v200 with the v200 at 0dB pre-gain?

 

Quote:
Originally Posted by FlySweep View Post
I'm not sure I hear any change after switching the V200 to DC coupling...

 

make sure v200 is at 0db pre-gain, i don't know , setting the v200 to gnd, for the groundlift jumper (not xlr ground), plus to dc operation, yielded a huge difference in my case, maybe my devices are faulty confused.gif

 

 

Quote:
Originally Posted by Kendoji View Post

Ha I'm willing to try this, but have been holding off as I'm fairly sure I won't be able to hear any difference.  :)

 

well, would appreciate your feedback, the change is so evident on my shure se530, beyer t1 and audeze lcd2v2

 

remember groundlift jumper to gnd (not the xlr ground), both for v800 and v200, and pot jumpers from ac to dc for v200, everything else default, v800 xlr out 15dBu and v200 0dB pre-gain

 

with gnd and dc i can go v200 pot to the metal with any recording, without getting any bad harshness

 

the bass is very much more extended, low mids and mids with much more body and space, highs smooth and ultra detailed and airy


Edited by roskodan - 5/14/13 at 3:52am
post #2249 of 2660

Thanks for the clarification, roskodan.. When I read GROUND-LIFT jumper.. I assumed XLR GROUND-LIFT jumper: since I don't use the RCAs and thought changing the (non-XLR) GROUND LIFT jumpers would have no effect (or be tied to the RCA inputs.. which I don't use).

 

I'll try using the RCA inputs (with V200 at 0dBu) before changing the (non-XLR) GLJ to "GND."

post #2250 of 2660

if you like the v200 at -6dB pre-gain, you will like the v800 rca out into v200 0dB pre-gain too, than you can try lowering the v800 xlr out from 15dBu to 12 or 6, into the v200 at 0dB pre-gain

 

i tried all the options and in the end the default along with the dc/gnd was the best for me, between the two i don't know yet, i find myself going back and forth

 

edit: but ofc the objective best is always all default with just a touch of +6dB pre-gain on the v200... seriously beyersmile.png

 

oh... and for rising +3dB, leave v200 at 0dB pre-gain and rise v800 from the default 15dBu to 18dBu beyersmile.png

 

actually i'm starting to like this better

 

omg... this is so...

 

 

for those who didn't get it...

 

it's so fascinating...

 

what's next from Violectric i wonder...


Edited by roskodan - 5/16/13 at 4:49am
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