need to choose opamp for X-fi Forte

CyberJunk

CyberJunk

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i was wondering what a good opamp would be for the forte

i was thinking of getting the OPA637AU ?
 
Well two things:

1) The 627 and 637 and single channel opamps. If the Forte uses stereo opamps, you'd have to get two of them, and get a browndog adapter to use two in one socket or teh like.

2) The 637 is an uncompensated opamp, meaning it is only stable at gains of 5 or more. Unless you know the gain of the card, I wouldn't try it.
 
Ok, well if they sell it to you, you can assume it'll work.
 
I'm just asking out of thos which would be the best option given the price

i don't want to spend $250 on the SM's

has anyone upgraded their forte ?
 
Well the TI 637s are some of the best opamps on the market. They really are more for high bandwidth things like DSL or the like. They are way overkill for audio. They work well though. I built a headphone amp with them. It was flat from DC out to 1.5MHz and was down 6dB at about 6MHz. Bit overkill for a 20kHz audio signal :D.
 
what would you suggest then? I just want the best audio i can afford that was the most i could afford that would work with the board. that is the OPA637AU
 
Is there something wrong with the way the card sounds now?

I have never seen any real proof that these actually improve sound quality. Has anybody compared RMAA results pre and post opamp replacement? What about A/B testing?
 
I'm not saying there's anything at all wrong with the 637. It is pretty much the best JFET opamp in the world. I am just saying it is overkill. Not saying there's anything wrong with overkill, just stating the fact of the matter.
 
well i just wanted to improve the sound or change the sound while using headphones and stuff and ive read alot of threads at Headfi.org but i have not seen much for people doing this to their forte's there is a youtube video
but i dunno just wondering if anyone else has done this
 
TBH it's probably too limited by other aspects of the circuit for you to get a really huge improvement. OTOH IMO if it can be modded and it won't take you a silly amount of time or effort to do, then mod it for the fun of it and find out for yourself how it affects things.

Don't know how people learn anything without tinkering with stuff to find out for yourself. Osmosis maybe? But there's no substitute for first-hand experience.
 
i would like to know if anyone else has upgraded the opamp

the installation is easy for the forte all you do is pull it out and put the new one in the same way. Auzentech already has them soldered onto the adapter boards so they have 2 opamps for stereo L/R . I just want to change it mostly for headphone sound output where you can really hear . The card does not sound bad at all but i wanted to maybe increase its power or range with a hgiher end opamp
 
Problem is, it is unlikely to affect power at all, and many other things will be constrained by other circuit elements and possibly the headphones used (directly, or indirectly via power / etc).

Sounds easy to do though, and op-amps are cheap (well, some are). Try it, why not.
 
the opa637AU is like $69.99 from Auzentech and $50 from browndog

both are all put together and with the right adapter

do you think it will be worth it? people on headfi.org seems to think so as they have done it with other sound cards and stuff
 
Damn, what's this $70 op-amp crap? Nah, I wouldn't pay that. Like I said, the benefits are likely to be very, very constrained assuming there are any meaningful differences to begin with. There's no way it's cost-efficient, and if you're even considering spending $70 on an op-amp then you'd be much better off saving it to spend towards something more substantial later.
 
thanks for the articles i think after reading the guru3d review i will go for the OPA637AU

i think it will do what iam looking for
 
I think you'd have a better time of using your Forte as a DAC, and building an amplifier yourself to play around with opamps.

Hell, you could build a hybrid amplifier. Then you can mess with opamps and tubes.
 
would that cost more money than just trying out an opamp ?
i love my forte soundcard i just wanted a little richer sound out of it

figured this might be the best way
 
Look at it this way. A solid state amp is going to use at least two op-amps. And then you have to deal with getting a clean, reliable power source built. Others are cheaper. Tubes, who knows. They range from dirt cheap to whatever...I've paid $5 for several good tubes as well as nearly $100 for a pair of low-noise power-stage tubes. To soundly beat it, you'll probably need $100+ in parts plus electronics equipment (soldering iron & DMM at least) and the skills to use them.

Rolling is a good way to get some control over such tweaks without actually building the amp yourself from scratch.
 
brown dog only has the OPA627AU for $49

it has 2 opamps on the correct adapter
 
National LM4562 will be cheaper and better than the TI 6x7 series, IMHO. I've upgraded a M-audio Revolution with all SMT 4562 opamps. But your limiting factor for the sound card is probably in the PSU noise, DAC output, SMT coupling capacitors, SMT resistors, and output cable (sheilding on most 3.5mm cables/plugs sucks). A good external DAC might be a worthwhile improvement, but honestly, most people's biggest limitiation is in the speakers and room. Put your money there first and worry about op-amp tweaks last.
 
the sound card already has a dedicated headphone amp i just wanted to tweak the sound
 
If you just want to play with your soundcard, get some opamps and be happy. Some people love to go nuts with DYI which is fine for them, but don't feel like you have to.
 
Fenris_Ulf said:
I love Pete's stuff. He really knows his electronics. I'm doing a similar junkbox amp but with a Broskie "power triode" design.
Click to expand...

I might try this in a few months...still working on learning some stuff related to circuits with sinusoidal signals. Also soldering, although part of that is futzing around to figure out how to set my iron to get it to match the eutectic point of the solder.
 
i wish brown dog had the OPA637AU for $50

i would have to pay $79 with shipping from auzentech to get a complete part

i can get the OPA627AU from brown dog for $50

i really wanted the opa637au though
 
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