[Bonddam]

I measured by touch. With the stock op back in it feels a little warm. When I had Sparkos in at idle it got really warm. Being that Fried has never measured a op roll to give us fact that this increase won't hurt the amp, I'm not going to be the guinea pig who does. It's a shame because there was a difference in sound that I liked.

 

[111MilesToGo]

Sparkos roll update.

One V281 and one V 280 owner rolled them in their lower deck signal path. Both rolls produced more heat than either owner remembered when the stock op amps were in. There was a positive sonic change but the risk of damage was not warranted at this point.

I apologize for hijacking the V281 thread with my enthusiasm for my assumption that what worked in a V200 would work in a V280/281.

I will go back to under the rock where the V200 people live.

Sorry!

@Pharmaboy and @Geezer Rock 001, and to all others contributing to this topic of op-amp rolling: Thank you so much for all your ideas and efforts, and in particular for sharing your experiences in as cautious a way as is needed.

I'd like to put in my "less than 1 cent". Out of mere speculation, I think

1. that due to the higher power dissipation of the Sparkos op-amps,
2. one might find oneself considering to beef up the power transformers in order to make the new op-amps really shine,
3. which in turn might lead to an even higher power dissipation and temperature rise inside the V281 case which (at least mine) has no vents at the top.

So op-amp rolling might lead us towards a vicious circle in this instance.

Myself, I am so very happy with the V281 as-is.

 

[sahmen]

@Pharmaboy and @Geezer Rock 001, and to all others contributing to this topic of op-amp rolling: Thank you so much for all your ideas and efforts, and in particular for sharing your experiences in as cautious a way as is needed.


Myself, I am so very happy with the V281 as-is.

And here's my own less than 1 half, errr, less than 1 quarter of a cent : "me too"

 

[Geezer Rock 001]

And here's my own less than 1 half, errr, less than 1 quarter of a cent : "me too"

The results in the V100 were stunning. The results in the V200 were significant to my ears. That is why I tempted my friend Pharmaboy with it.

With the cost of a V281 in the equation, the additional heat is not worth the risk until someone can determine how much heat is too much heat.

Back to the rock pile for me. I will be sticking with the V100 and the Sparkos roll.

 

[Christoph]

With the cost of a V281 in the equation, the additional heat is not worth the risk until someone can determine how much heat is too much heat.

Fully agree.
Upgrading the heat sinks might be more difficult and to get the additional heat out of the enclosure without ventilation slits or holes. And I don't want to cut the lid for this.

However, the exact temperature increase would be interesting. Pharmaboy measured 90°C at the heatsink of the stock version in idle. His measurements after the opamp rolling are not useable as the opamps on the lower deck were not changed.

 

[Fegefeuer]

The results in the V100 were stunning. The results in the V200 were significant to my ears. That is why I tempted my friend Pharmaboy with it.

With the cost of a V281 in the equation, the additional heat is not worth the risk until someone can determine how much heat is too much heat.

Back to the rock pile for me. I will be sticking with the V100 and the Sparkos roll.

No rock pile at all. V100 and V200 are legends and the foundation of today's LP amps, even if the performance jumps don't tell because they are huge and designs improved a lot over time. Look how far everything came, up until the Niimbus line.

 

[3083joe]

Hey guys. I just have a question. I tried using my v281 as preamp and is unbalanced in sound. Concentrated on the right side.

balance on front is level and dip switches on back are level, any thoughts. Purchased in 2016 but never used as preamp just HPA

thanks. joe

 

[Pharmaboy]

Hey guys. I just have a question. I tried using my v281 as preamp and is unbalanced in sound. Concentrated on the right side.

balance on front is level and dip switches on back are level, any thoughts. Purchased in 2016 but never used as preamp just HPA

thanks. joe

Can we assume you did all the logical stuff already--ie, unplugging/replugging the interconnect from V281 to next device downstream? Make sure the balance in front is actually working (vs somehow not working properly)?

Beyond the simple stuff, I can only think of 4 possibilities:

1. There's something wrong w/either the interconnect coming out of the V281, or a channel imbalance in the next device downstream (ie, amp, integrated amp, powered speaker pair, etc). The latter is possible if the next device has its own balance controls
2. There's something wrong w/either the interconnect coming into the V281, or a channel imbalance in the next device upstream (ie, DAC). That's unlikely, since you would've heard that via headphones
3. There's a malfunction of the V281's line-out function
4. Or for some reasons, the internal/line-out dipswitches (entirely separate from the ones on the back, which control headphones only) are not in alignment.

I know it's a PITA, and you need a 3.0mm hex wrench to do it, but this means removing the top cover and checking the 2 internal dipswitches. From pg-22 of the V281 manual:

"LINE-OUTPUT LEVEL
can be set by means of internal DIP switches located on the line-out circuit board. See page 33 for further details.

Generally, the level at the unbalanced output will equal the input level in pre-fader mode, or with the level control set fully clockwise in post-fader mode. By means of the DIP switches however, relative attenuation/gain can be set to –12, -6, 0, +6 or +12 dB.
Please note that output level at the balanced output is generally +6 dB higher than at the unbalanced output."
​

The 4th scenario is pretty unlikely, too. But you wouldn't know unless you checked.

 

[sahmen]

No rock pile at all. V100 and V200 are legends and the foundation of today's LP amps, even if the performance jumps don't tell because they are huge and designs improved a lot over time. Look how far everything came, up until the Niimbus line.

So now, by all rough estimates, what is the delta of sq/performance between the niimbus line and the v281, formulated as carefully as one can in words? I have always thought of the Niimbus as something outside my budget range, at least for purposes of making any instant purchase, but, like almost every component in this hobby, the purchase of the niimbus as a long term goal is always doable. i have been wondering for some time now, whether I should place the niimbus on my mid-to-longterm to-buy list, and have not been able to make a firm decision about it, which is why I need a clearly formulated sense of just what the delta in performance and SQ is... It is difficult to decide, since I already enjoy my v281, both as an HPA, and a preamp, not to mention also enjoying the "safe" ignorance of not knowing what I am missing, not having ever heard a niimbus.

 

[Fegefeuer]

It will take a few weeks until I can give you more info in how the Niimbus ascends from the V281 but from tonality alone the Niimbus distinguishes itself as being more liquid unlike the more square V281 and is overall more refined, especially in the treble and bass. The amazing feat of the US4+ is how it can be both powerful, visceral, hard hitting and yet effortless and composed at all times, especially in the treble. I never heard the HD 800 so good before (on a solid state) and so detached from its reputation of being dry and square.

Now the HD800 was great and powerful from the V281 already of course, sure: Extension to both sides, fast, tactile transients, grand soundstage great punch and kick which the HD800 can do very well.
The US4+ goes further than here though and this is where the key difference comes into play. I could talk about bass lines, breath, the smacking of lips and the tiniest details but that's something for another time. Let me just mention the most important feat that the US4+ brings to the table:

Where the V281 has a slight inner warmth at hand to support its strong technical foundation and presentation, the Niimbus "counters" with liquidness from its very core. This does not mean the following: soft, warm, subdued, rolled off, smearing or even forgiving. It's simply effortless, it leaves no gaps, it simply flows and runs. I think Bruce Lee would understand me best right now.
The V281 tries to overachieve starts and stops like the best solid states, the US4+ knows better how to transition (or let's say dance) from one move to the next, yet never blur at all or decay unnaturally.

To me that's the most important difference.

 

[sahmen]

It will take a few weeks until I can give you more info in how the Niimbus ascends from the V281 but from tonality alone the Niimbus distinguishes itself as being more liquid unlike the more square V281 and is overall more refined, especially in the treble and bass. The amazing feat of the US4+ is how it can be both powerful, visceral, hard hitting and yet effortless and composed at all times, especially in the treble. I never heard the HD 800 so good before (on a solid state) and so detached from its reputation of being dry and square.

Now the HD800 was great and powerful from the V281 already of course, sure: Extension to both sides, fast, tactile transients, grand soundstage great punch and kick which the HD800 can do very well.
The US4+ goes further than here though and this is where the key difference comes into play. I could talk about bass lines, breath, the smacking of lips and the tiniest details but that's something for another time. Let me just mention the most important feat that the US4+ brings to the table:

Where the V281 has a slight inner warmth at hand to support its strong technical foundation and presentation, the Niimbus "counters" with liquidness from its very core. This does not mean the following: soft, warm, subdued, rolled off, smearing or even forgiving. It's simply effortless, it leaves no gaps, it simply flows and runs. I think Bruce Lee would understand me best right now.
The V281 tries to overachieve starts and stops like the best solid states, the US4+ knows better how to transition (or let's say dance) from one move to the next, yet never blur at all or decay unnaturally.

To me that's the most important difference.

Now that's what I call a mouthwatering presentation of an HPA, especially, since you mention the "liquidity" of the niimbus US4+ more than once. The pun couldn't be more appropriate. At any rate, you have almost single handedly persuaded me to place the US4+ on my to-buy list, as my end-game HPA. Now I can't wait to hear how my HD800, my Audeze LCD-4, LCDi4, and LCD-X, not to mention my Hifiman he-1000SE might all sound on the US4+. Admittedly, I have considered other options before in pondering end-game HPAs, but it now appears that the US4+ is a strong, unavoidable contender, if not the only contender. Ironically, it is the fact I already have and know the v281's performance so well, which makes the US4+ so irresistibly attractive. So talking about "mouthwatering," I would like to hear more about the US4+, but when you get the chance to do more listening to nail down the differences even more. No rush necessary. I have a lot of time to strategize about how to get the US4+.

 

[Fegefeuer]

Do you have the Yggdrasil Analog 2? My absolute dream combo as of right now would be PI2AES/Lynx AES -> Yggdrasil Analog 2 -> US4+.

Yeah, obviously I've also looked at other amps but the vast requirement differences of my headphone collection (like yours) don't fit in with most amps on the basis of superseding the V281's qualities. The only amp that I would really consider would be a DNA Stellaris but that's simply impossible and insecure from a European perspective. Huge customs bill, probably warranty issues, sending back and forth (in the worst case of course). A nightmare. Other than that none other than the US4+. Or I would go passive preamp and a high gain First Watt, but then I'd miss the HD800 and the 650. Impossible. That's why I will stay here.

Anyway, being a refined V281 is too simple of a description, it could serve as a warning though not to expect universes in difference. There's a saying by Voltaire though: "le mieux est l'ennemi du bien" meaning the best is the enemy of good and it never applied so well like here. Most of the users that are still active in this thread have their V281 for years and hold it very dear for its qualities:

The V281 has a very black background, strong macro- and microdynamics, gets you involved with the music and invites you deep into it. It's the tiniest differences, refinements and the very drive of the US4+ where the differences are. Where the V281 simply wants to punch through by all means, the US4+ knows how to conserve its energy and use of it through better technique.
The US4+ is a seasoned veteran, a silver shield of Alexanders Army, the finest of all Hoplites, the V281 is a young hoplite who while highly trained, chosen and disciplined by those very silver shields, is not on the same rank because he has yet reach the experience, the same finesse and the awareness of the veteran.

 

[sahmen]

Yes, I have the Yggy A2, and I have been pairing it with the V281 for a long time. I have called the pairing my "reference" system (especially since they were both servicing my main HT 2.1/5.1/7. speaker system). I do not have the US4+ yet, but I already feel the needle moving toward it... So to Voltaire's "le mieux est l'ennemi du bien," I feel like responding "le mieux vaut bien la peine," exclusively in hommage to the US4+, of course

 

[Fegefeuer]

That's a terrific system already. V281 hugely rewards DACs and scales off them.

 

[Pharmaboy]

Yes, I have the Yggy A2, and I have been pairing it with the V281 for a long time. I have called the pairing my "reference" system (especially since they were both servicing my main HT 2.1/5.1/7. speaker system). I do not have the US4+ yet, but I already feel the needle moving toward it... So to Voltaire's "le mieux est l'ennemi du bien," I feel like responding "le mieux vaut bien la peine," exclusively in hommage to the US4+, of course

Great quotations!

I couldn't do without my V281. I have a number of other amps, but the V281 stands above all others, both as preamp (it's my day-to-day preamp) and headphone amp (same comment). I paired it with an NOS DAC (MHDT Labs Orchid), which is a very good match, indeed. An arranged marriage that became a love match...

My only doubt regarding your second quote ... (I google-translated it to French for the occasion):
"Le meilleur aujourd'hui est juste moyen l'année prochaine"

(an idea that hovers over all my obsessive audio moves)