Discussion in 'Modifications and Tweaks' started by Ksorota, Aug 6, 2020.
Ill have to dig one up of the completed version, but here are the new caps vs. the originals!
@Ksorota Even though you haven't spent a great deal of time with the amp in its stock form, I would say your descriptions of what the mod does is pretty accurate. I didn't hear any of this distortion you're describing with 650s, but I'm aware of the one member on Headfi who claimed he was hearing distortion with his Ether 2s which are lower impedance headphones.
All my impressions of the stock version are with stock & Tungsram PCC88. For the modded version I've only been able to use the stock tubes because of an extremely annoying issue that revealed itself.
The gear that was used: HT Omega Fenix S/PDIF out, Schiit Gungnir Multibit A2, and HD650.
Summary - The mod improves the Liquid Platinum in a lot of ways, but has its own drawbacks that might be a deal-breaker for some. If you have a warmer and/or darker DAC, the mod will probably work very well in your system. If your DAC is on the leaner and/or brighter side, this mod might not be a good match.
Stock caps sound very liquid, no pun intended, and non-fatiguing with better bass extension than modded. It just does very little wrong and works well with any type of music. Some say it's a boring amp because of how laid back it is. While I can understand their perspective and why they think that, I came to appreciate that aspect of the amp because I could listen for hours and hours and not get fatigued while also enjoying what I was hearing.
The cap mod improves sound stage depth, bass impact (punch), transparency, incisiveness, dynamics, and perceived differences between tubes.
The negatives that come with the mod; dryness, less bass, less bass extension (less slam), thinner tone, and sharpness.
I'm not sure what this is called, maybe layering, but one thing I found the mod to improve is how instruments and sounds are spread out more and don't overlap or bury one another in placement and in volume. I was noticing sounds and instruments that were more in the background of a song or mix a lot more, whereas before, they were getting drowned out or almost canceled out by the other sounds or instruments that were louder in the song or mix.
It's sort of like a correct full RGB signal vs an incorrect (crushed) full RGB signal. Or how some TVs and monitors aren't able to display correct shadow and/or highlight detail in the lowest and/or highest luminance of grayscale, which results in crushing. While some are able to, even without calibration.
The main issue that I have is this extremely annoying high pitched mosquito noise that seems to be incorporated with the added sharpness the mod brings. It's extremely prevalent with the Tungsram tubes, making the sound unlistenable and the tubes unusable. This has been the most disappointing aspect of all of this because the Tungsram's were my daily driver when the LP was stock because of the increased bass and soundstage the tubes bring. I thought the high pitch noise could be coming from the tubes, but this issue didn't exist when the amp was stock and it's still present with the stock tubes, just not as severe.
I have thought, perhaps, the increased transparency might be revealing something wrong with my source, which is possible. I'll have to try out the Gen 5 USB on my Gungnir MB A2 to see it's still there or if my soundcard is causing the issue.
Of course IMO, YMMV.
Thanks to @Ksorota for providing the unit for this tour. It’s a rare thing for me to have two of the same amp in the house, my wife probably thinks I’m crazy.
Anyway, to the mod itself, I found that overall the LP is still the LP whether modded or unmodded, but there were some notable differences in the sound. This is more a matter of inches than miles in every respect, so I guess the first thing I noted right off the bat is that the mod does not produce a night and day difference as some on HF have claimed.
Let me back up and list the gear I used. Both amps used stock tubes. For sources, I ran a GOV2+ balanced and SE, an Xduoo XD-05+ via line out, and a Gungnir Multibit via balanced out, fed coax by an RPi with a 502DAC hat. For headphones I used only my modded HD580s.
One thing to note is that in balanced out mode on the GOV2+, the modded LP produced a loud hum at any volume with no music playing. The hum was present with music playing and could be heard at all times. This remained even when I used the grounding trick with the SE port on the GO. The stock LP did not do this. Balanced in from the Gungnir was silent on both amps, and using the SE out only from the GOV2+ resolved it on the modded unit.
I would say the mod produces the following changes: Slight boost in clarity and attack, slight reduction in bass impact, medium reduction in sweetness/euphony/“tube-ness”, flattening of layering and staging. It is possible the reduction in the tube-ness could also create a perceived boost in clarity and attack. The mod made the amp feel more like the SS in the hybrid whereas the stock feels more like a tube amp.
The reduction in that tube like sound was not to my taste, although I could certainly see why those who prefer maximum clarity would prefer the mod. In a way the modded LP sounds like a souped up Jotunheim. Very clear, very clean, flat staging, SS dominant sound.
To be clear, the mod still sounds very good. And for some it may be worth the trade offs. I never disliked listening to it, and plenty of times found myself bobbing my head along with the music. But the consistency of engagement wasn’t there for me like it is with the stock.
I very much appreciate the chance to hear the mod and I look forward to reading more impressions. More people should sign up for the tour!
Going back to my stock LP, I think the biggest change I was trying to describe is harmonic resonance. This may mean that the stock LP has more harmonic distortion than the modded one, but if that’s the case it’s an even order distortion that creates those seductive mids and generally euphonic presentation. In terms of clarity, I am either at the limits of my ability to perceive small details, at the limit of the HD580 to resolve small details, or there is no significant difference between the modded and stock amps in terms of clarity. The stock definitely sounds thicker, which might be perceived by veiled as some, but part of what I love about this amp is how it offers clarity while offering that “thicker” sound. It’s been very interesting to hear these two side by side.
I spent some time with a modded one and my stock one side by side. I posted about it briefly somewhere I thought.
I came away the same as you @Merrick
Thinking about it later however I would listen again with Bifrost 2. At the time I was using modius and that's already thinner and clearer sounding dac. Might have doubled the effect perhaps ? To much of a good thing ? I do love the liquid mids and character of the stock LP however especially with HD600/650. I think dac and headphones matters a lot as usual. I think most the guys with different tubes and the mod are detail chasers and the amp does respond well to the mods. It definitely sounded more less liquid sort of like it removed that slight harmonic distortion. At the same time though it does deliver details and has great instrument placement even stock and I didn't think the mod added anything there. I noticed a lot of the guys with the mod had real low ohm headphones. Probably makes a difference I suppose.
Hmm, you mention low ohm headphones, I should have tried the modded LP with the FDX1, which I thought sounded just so-so out of the stock LP. Oh well.
In terms of synergy, you’d think the Gungnir MB A1 would nicely balance the characteristics of the modded amp, but I find it’s a better match with the stock amp. Go figure.
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