[ROBSCIX]

Quote:

Originally Posted by Mphile /img/forum/go_quote.gif Hello, I was wondering what the differences are between OPA2277P, OPA2277PA, OPS2277PAG4 and OPA2277PG4. All are DIP-8 sockets, boasting the same specs. Confused

In many cases they will have the same specs because they are basically the same chip. Somtimes these codes denote no lead, temperature ratings, package type. They usually vary from company to company so you would have to check the spec sheets. To see exactly what each letter in the coding represents.

Hope that helps.

 

[ROBSCIX]

Quote:

Originally Posted by dextersventures /img/forum/go_quote.gif I ordered two opa627ap to put into my asus xonar stx card for my headphone listening. When I put them into the card, the headphone volume is so very low and it distorts a little. I only bought two of them, one for each slot for the headphones. I have no clue what is wrong, I installed them correctly. I heard somewhere, somebody said that these are only single channel and that I need an adaptor or something. Im not sure. So does that mean I need to buy some adaptors and two more. Im so confused, all help will be greatly be appreciated.

I answered this in another thread. The OPA627's are single channel opamps and the circuit requires dual channel units. If you have DIP8 you will not be able to use themin the circuit without some handy work.
You need the smaller SOIC8 chips mounted on the adapters, these fit fine and work in this circuit.
You could get the dual DIP8 adapter and use the 627 for a buffer opamp, if your using line out.

 

[johnzz4]

I have been running the stock op amps and have found the highs to be fatiguing. I'm running the Presonus HP4 as my amp and the HD650's.

Any recommendations on an op amp combination to smooth out the highs, maintain the bass, and widen the soundstage?

 

[garbulky]

I am about to buy an essence STX or an ST. A few burning questions affecting my purchase decision. I am going to be using an Emotiva UPA-2 2X amplifier for my axiom speakers when they come. This amplifier does not have a volume control and requires a pre-amp. Will the essence be able to act as this pre-amp? AFAIK the UPA-2 requires 1.4V to to be driven to maximum power with an input impedance of 47k ohms.
Second question: Can I use the H6 add-on board with the STX as well? My impression is that the H6 is PCI-e only right? That's the reason I want to go for the ST as I have only one free PCI-e slot available on my current mother board.
Third question: If I buy the ST, will PCI slots be obsolete in about 3-5 years when I upgrade my motherboard? Is it on its way out already?

 

[dex85]

1. ST/STX can act as a preamp since they have variable outputs. they put out 2.16V when set to 100%.

2. only with ST, if they are available. last time i heard they were hard to get, but that could have changed.

3. no, at least some motherboards manufacturers will keep PCI alive for next 8+ years. even if that meant they would have to put an additional chip on the motherboard.

 

[johnzz4]

I see that some people are putting the LME49710HA in the buffer instead of the LME49720HA... Should I order the 49710 now? I thought we needed 2-channel in the buffer??

 

[KingFiercer]

I'm thinking about what better for buffer with 2xLME49720NA - 49720NA or 49720HA?
Some peopels say that 49720HA have good bass, but muffed treble... But what will the result of their combination?

 

[garbulky]

Thanks for the info Dex. I will most probably buy the Essence ST then. I've been searching for the answers to my questions for a couple of weeks and I was stumped! I had no idea a PC sound card can act as a preamplifier!

Two more questions, if I may, if I put the line out to my headphone amplifier (Xenos 3HA) and then to my stereo amplifier. Will I be damaging the amplifier if the voltage goes to high or will I actually be helping to enhance the dynamics (just like in a headphone) and produce better sound?

Second: I want to hook up the line out to my speakers (via amplifier). I also want to use my headphones at the same time and use the xenos 3ha to amplify the signal and not the inbuilt amp on the essence. Is there anyway to hook my headphone amp to the headphone out and sort of disable the inbuilt amp so I can run my headphone amplifier? Or is it safe to set it to low impedance output and then use my headphone amplifier anyway.Will that affect the sound quality?

 

[ROBSCIX]

Quote:

Originally Posted by garbulky /img/forum/go_quote.gif Thanks for the info Dex. I will most probably buy the Essence ST then. I've been searching for the answers to my questions for a couple of weeks and I was stumped! I had no idea a PC sound card can act as a preamplifier! Two more questions, if I may, if I put the line out to my headphone amplifier (Xenos 3HA) and then to my stereo amplifier. Will I be damaging the amplifier if the voltage goes to high or will I actually be helping to enhance the dynamics (just like in a headphone) and produce better sound?

No, both cards lien outputs, operate on standard line level voltages. Even if the card is fully cranked it is still within line level specs so it will not damage anything. If you conencted the HP out to the amplifer and then cranked that you could possibly damage the input section on the amp.
Quote:

Originally Posted by garbulky /img/forum/go_quote.gif Second: I want to hook up the line out to my speakers (via amplifier). I also want to use my headphones at the same time and use the xenos 3ha to amplify the signal and not the inbuilt amp on the essence. Is there anyway to hook my headphone amp to the headphone out and sort of disable the inbuilt amp so I can run my headphone amplifier? Or is it safe to set it to low impedance output and then use my headphone amplifier anyway.Will that affect the sound quality?

You can driver another headphone amplifer with the HP out of the Essence, others have tried it. Just make sure you keep the Gain low on the Essence.
I would recommend that you use the line outs to your can amp though.

 

[Bojamijams]

Quote:

Originally Posted by johnzz4 /img/forum/go_quote.gif I see that some people are putting the LME49710HA in the buffer instead of the LME49720HA... Should I order the 49710 now? I thought we needed 2-channel in the buffer??

ROBSCIX made the adapter for me with two of us on there. Is quite nice.

 

[ROBSCIX]

The LME49710HA seems to be a great buffer amp for these cards.

@Johnzz4, you're right. Every socket on the STX/ST requires dual channel opamps.
To use the LME49710 HA requires an adapter, a dual To-99 to dip 8.

 

[dex85]

Garbulky: Rob has answered your questions, i just might add that i would connect the line-outs of ST/STX straight to your power amp, if you listen mostly to the speakers. your headphone amplifier is not really meant to be used as a pre-amp for the speakers (2x 3.5mm output jacks meant for headphones). the less components in the signal path the better.

on the other side, analog volume pot is more convenient than software based volume control. be careful at first with Xenos volume pot, to see how loud signal you will get when soundcard is set 100%. and you can use Xenos out of the headphone output of ST/STX, it will be Xenos driving the headphones, only sound can have a little different flavor compared to line-outs. it's up to your likings, keep experimenting

 

[garbulky]

Thank you to both Robscix and dex. You guys give out some great information. VERY VERY helpful and very specific. You both might laugh, but I went to radioshack with these questions and they hadn't a CLUE.
I will connect the line out (RCA) to my power amplifier and then if the xenos amp has better dynamics connect the headphone out at low impedance to the xenos. Or if the HP out on the essence is indeed better I shall just directly connect my headphones to the HP out. Fantastic.
Unless the quality becomes remarkably better, I would refrain from hooking the line-out to my Xenos. This is because I would have to switch the output from headphone amp to power amplifier often. But, I do value good quality headphone audio so if the difference is quite significant I shall do just that.

 

[ROBSCIX]

Well this type of information can be very specific especially for a salesmen. Some know their electnroics and basic audio standards and other just sell the gear!
Not to mention many of us have used similar system at one time or another. PC soudncards can be connected to pretty much any other consumer electronics goods because they are bult to line level standards. Cards with can amplifer would be the exception as driving an amplifer using another amplifer is not really recommended although can be done if you're carful.

Test it out and let us know how it goes.

 

[ManuLM]

has someone ever tested AD797 in lieu of the JRC's (using DIP adapter) on the STX ?

Did'nt see this combination posted in the first post of the thread

Single-to-dual Op-AMP Adapter - DIP version (p/n 021001)