has anyone tried plugging 2 headphones into the nimbus at the same time? does it work at all? if so, could this harm the device or the headphones? I plan to use xlr and 4.4 outputs at the same time when my other headphones arrive.
Niimbus Ultimate Series US4/US4+/US5/US5 Pro Headphone Amps - by Lake People
- Thread starter Fegefeuer
- Start date
drummerdimitri
500+ Head-Fier
After finding out that my Niimbus US5 Pro was fitted with lower grade Nichicon capacitor as the gold series specifically designed for audio was out of stock when the unit was being manufactured, I took it upon myself to switch them out to the high quality KW series capacitors as seen in the older US4+ units.
They are physically quite a bit taller and look way better fitted in my unit.
If there is no sound quality improvement, at least it wouldn't degrade it so I thought it was worth the risk.
Success!
They are physically quite a bit taller and look way better fitted in my unit.
If there is no sound quality improvement, at least it wouldn't degrade it so I thought it was worth the risk.
Success!
And you warraty goes away!
Success!
Success!
mitchb
1000+ Head-Fier
- Joined
- May 13, 2007
- Posts
- 1,345
- Likes
- 484
One of the Headfi members claimed that he replaced the caps in his 5 Pro to better caps like the ones in the 4+. He claims that the people at Niimbus did not have the best gold caps for the 5 Pro as in the 4+ as they were not available. My question is that is there much difference between the caps in the older Niimbus and the newer ones. The Headfi member who noticed the difference claims that he replaced the caps in his 5 Pro to the better gold caps. Is there much difference between the caps used in the 4+ and the caps in the 5 Pro which according to this Headfi member are a lower quality and used due to availability issues.
So US5 is really a downgrade? Fried should explain this.
has anyone tried plugging 2 headphones into the nimbus at the same time? does it work at all? if so, could this harm the device or the headphones? I plan to use xlr and 4.4 outputs at the same time when my other headphones arrive.
drummerdimitri
500+ Head-Fier
Fried claims that they are of the same quality however, I must respectfully disagree.
I've measured the capacitance of both the original caps and the new gold ones and there is a big difference in capacitance.
They are both within the 20% tolerance spec, however the original ones are on the lower side (2740-3110 uF) vs 3670 uF for the gold series.
There is a reason why they are physically larger in size and my testing proves that the larger ones have quite a bit more capacitance (25% more on average) which is better from a filtering point of view.
I've also noticed a lower equivalent series resistance (ESR) at difference frequencies meaning that they don't attenuate the frequency response as much as the former ones.
How does all that translate into sonic improvements? Not sure I will ever know without another US5 Pro with the stock capacitors for quick A/B testing but it seems to have improved the bass quantity by a very slight amount. This could just be a placebo effect as I cannot know definitively.
That being said, it just makes it easier to sleep at night knowing that on paper, the capacitors installed in my unit are measurably better and to me that's good enough.
Now time to break them in and enjoy the music!
Last edited:
I can't find a review in which a forum participant replaced operational amplifiers (circled in red in the photo) with Burson operational amplifiers. Are you planning to experiment with operational amplifiers?After finding out that my Niimbus US5 Pro was fitted with lower grade Nichicon capacitor as the gold series specifically designed for audio was out of stock when the unit was being manufactured, I took it upon myself to switch them out to the high quality KW series capacitors as seen in the older US4+ units.
They are physically quite a bit taller and look way better fitted in my unit.
If there is no sound quality improvement, at least it wouldn't degrade it so I thought it was worth the risk.
Success!
drummerdimitri
500+ Head-Fier
No I won't be experimenting with op amps because Fried mentioned somewhere that inserting different ones may cause oscillation in the circuit and eventually fry the amplifier so not a risk I am willing to take.I can't find a review in which a forum participant replaced operational amplifiers (circled in red in the photo) with Burson operational amplifiers. Are you planning to experiment with operational amplifiers?
Last edited:
adeadcrab
1000+ Head-Fier
- Joined
- Jan 30, 2008
- Posts
- 1,201
- Likes
- 843
I was just about to ask the same thing - looks similar to the Violectric V550 amplification stage, which would be 4 * single opamps that could be swapped. NE5534 are not the best and discrete opamps would most probably withstand the voltages and oscillation put out by this amp.
I would be more likely to swap opamps than the capacitors!
drummerdimitri
500+ Head-Fier
Yes the amplification stage on the V550 is very similar indeed.I was just about to ask the same thing - looks similar to the Violectric V550 amplification stage, which would be 4 * single opamps that could be swapped. NE5534 are not the best and discrete opamps would most probably withstand the voltages and oscillation put out by this amp.
I would be more likely to swap opamps than the capacitors!
If you ever decide to swap opamps, please do post your findings after hundreds of runtime hours as others might be interested in doing the same.
On what gain you guys listen IEMs on Niimbus?
mikel
New Head-Fier
- Joined
- Jan 3, 2005
- Posts
- 28
- Likes
- 17
Hi there
I have a question i could not see answered so for in this thread. I received a Niimbus US5 pro for trial from a very nice dealer who let me have the unit for one week.
Although i really loved the sound, the thing that made me send it back was the mechanical hum from the PCB TOROIDAL TRANSFORMER PTC25.
Especially when the unit was cold, the hum could be heard outside close to the enclosure.
I also own a V281 that is actually totally silent. So due to the hum, I sent it back. Now I wonder if any here in the forum have observed something similar?
These are highly rated special transformers, so they should not really be heard through that very massive case.
Comments?
I have a question i could not see answered so for in this thread. I received a Niimbus US5 pro for trial from a very nice dealer who let me have the unit for one week.
Although i really loved the sound, the thing that made me send it back was the mechanical hum from the PCB TOROIDAL TRANSFORMER PTC25.
Especially when the unit was cold, the hum could be heard outside close to the enclosure.
I also own a V281 that is actually totally silent. So due to the hum, I sent it back. Now I wonder if any here in the forum have observed something similar?
These are highly rated special transformers, so they should not really be heard through that very massive case.
Comments?
I have not heard any transformer hum from my Niimbus US 5 Pro.
Users who are viewing this thread
