NuForce Mods

rustydoglim · « **on:** 7 Aug 2005, 11:38 pm »

We take a neutral stance on various NuForce modifications and we support them on a case by case basis. If you want to get into the NuForce mod business, talk to us first.

Don't ask us whether we think any mod really sounded better than the original or whether it is worth getting the mod. Talk to the people who do the mods.

We try to maintain backward compatibility for the same series (Reference series for example) of NuForce amp and customer can choose to get the mod if they're convinced that it will sound better or spend the money on circuit board upgrade in the future.

Ric Schultz from Electronic Visionary Systems has been working on NuForce mods and we welcome him to move his topic here. Again, we don't comment on the listening aspect of mods but will be happy to provide measurement or technical comment from time to time.

NealH · « **Reply #1 on:** 8 Aug 2005, 02:02 am »

What op-amp are you using and, do you think changing it really improves the amp? I would have thought this aspect of your amp would have already been thrashed out by your people. Compared to the cost of you amp, op-amps are not exactly expensive these days and, it somewhat disturbs me when a modder says they change it to improve the sound.

Beano · « **Reply #2 on:** 8 Aug 2005, 04:02 am »

Not sure about the effects of changing opamps on the Nuforce, but I have heard changes of opamps made to a tripath based amp and to CD players.

My 2 cents is that it changes the sound characteristics but it may not necessarily be better for everyone. With the tripath based amp opamp mod , the owner wanted more warmth in the sound and swapped opamps until he found one which seem to provide that effect, but in doing so, I thought that the amp lost a bit of bass "tightness" and "airiness". But he was willing to sacrifice those attributes to get the warmth....so I guess some opamp mods may just be the tailoring of listening preferences (assuming the key measurements aren't impacted).

Is the opamp on the Nuforce soldered into the board or chip socketed? If it is socketed, then it would be quite easy to swap around various Opamps to see the effects.

rustydoglim · « **Reply #3 on:** 8 Aug 2005, 06:49 am »

Replacing with the so called "expensive" opamp doesn't necessary improve the sound. Even though the circuit board is small, there are more than 100 components in there and tuning the performance of the modulator (especially gain), feedback, switching freq and dead time, all made a big difference. Opamp is a critical component and if you want to give it a try, check the spec carefully to make sure it at least outperforms current opamp. Unless you're an authorized dealer, you should refrain from going with trial and error approach

When we make any changes to the circuit, listening test is the last thing we do as we're getting better at correlating the science with what people hear.

_scotty_ · « **Reply #4 on:** 9 Aug 2005, 03:29 am »

Jason, what are the minimum bandwidth,slewrate and stability requirements
that a replacement OP-amp must meet. Does the op-amp need to be unity gain stable.
Scotty

nuforce-casey · « **Reply #5 on:** 10 Aug 2005, 01:09 am »

Hi,
We do not recommend replacing the factory opamps.
The opamp TL082 is used as an attenuator, and must not be replaced, or the amplifier may self-destruct. Almost all the 'audiophile' opamps is not capable of working with gain < 1.

radiobird · « **Reply #6 on:** 10 Aug 2005, 02:26 am »

Casey-I believe modder Ric Schultz's L2 mods include an imput op amp change-are we talking about the same Op amp here?

nuforce-casey · « **Reply #7 on:** 10 Aug 2005, 06:47 am »

Quote from: radiobird

Casey-I believe modder Ric Schultz's L2 mods include an imput op amp change-are we talking about the same Op amp here?

I trust Ric has good ears. On the other hand, I haven't heard any of his modified units, and we do not want to find out what he did (to stay clear from any IP conflicts). Along with the $90 capacitors, it is entirely possible to find some exotic opamps that works well.

My position and with all the positive reviews and users' experience, are that modding the opamps is not necessary, but hey, audio is a about obsessive nonetheless!

radiobird · « **Reply #8 on:** 10 Aug 2005, 01:43 pm »

Casey-what are the fuse values and how many fuses are there in the Nuforce amps? I've used the gold plated Isoclean fuses in my Exposure 2010 Integrated and Power Amps and they made a huge improvement in terms of higher highs,lower lows and more detail overall

nuforce-casey · « **Reply #9 on:** 10 Aug 2005, 06:31 pm »

Quote from: radiobird

Casey-what are the fuse values and how many fuses are there in the Nuforce amps? I've used the gold plated Isoclean fuses in my Exposure 2010 Integrated and Power Amps and they made a huge improvement in terms of higher highs,lower lows and more detail overall

Ref8 has built-in fuse that's soldered to the SMPS PCB, not user replaceable. Ref9 has an external fuse in the IEC connector as well as the soldered fuse on the SMPS.

rustydoglim · « **Reply #10 on:** 11 Aug 2005, 08:17 am »

Don't you dare to replace these:

Ric Schultz · « **Reply #11 on:** 28 Aug 2005, 08:08 am »

Finally finished my more extensive mod on the Nuforce. I've got an ad on Audiogon and will put a post on Marketplace in a few minutes. I will answer questions in either thread. Thanks, Nuforce for letting me post here.

Ric Schultz
EVS