[ROBSCIX]

Quote:

Originally Posted by gurubhai /img/forum/go_quote.gif using an adapter would have been easier (the soldering should take less than a couple of minutes ). But I was not sure if it still would fit the shield and since the adapters were not available locally so I just decided not to wait and went ahead with HA fitting. I was very careful though to place the legs in their correct respective positions and not just to poke them. I think it was worth the effort though unless the audiophile placebo is taking me over

As I suggested, if you are 100% sure these are the opamps for you, then you would remove the Dip socket and install the TO-99 in a adapter straight to the PCB. Soldering those would be a snap.

 

[leeperry]

Quote:

Originally Posted by gurubhai /img/forum/go_quote.gif I am guessing it means that HA version goes through tighter quality control measures. Is that so?

don't bother, he made that up...read the datasheet and the link from diyaudio I posted in the previous pages, a National engineer says that all measurements are IDENTICAL between NA/HA.

 

[ROBSCIX]

Quote:

Originally Posted by gurubhai /img/forum/go_quote.gif I am guessing it means that HA version goes through tighter quality control measures. Is that so?

Yes, they are usually the top of the line for whatever chip part line.
You can get TO-99 version of most audio opamps. They are also less suceptible to interference from EMI/RFI.

 

[ROBSCIX]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif don't bother, he made that up...read the datasheet and the link from diyaudio I posted in the previous pages, a National engineer says that all measurements are IDENTICAL between NA/HA.

Yes and these chips show the same measurments and spec sheets as the LM4562NA. BTW, the guy is a EX-National engineer well know on DIYaudio. If your going to post information make sure it is correct.

 

[leeperry]

well whatever, he used to be an engineer there..he said that the metal packages sound better, and several ppl have confirmed that they indeed do! including fzman & me

if National was lazy and put the same specs for 4562/49720/49860 is another story altogether....the point is that most everyone will agree that 49720HA is where the money is

I was looking for other TO99 op-amps, but couldn't locate much : TO-99 opamps - Google Search

anyway, these sound out of this world...my upgraditis hunger is over, for now

 

[ROBSCIX]

I never said anything about their sound quality. -Try reading before you start trolling.
The point was they are considered high spec devices. Usually refered to as Mil Spec.
Two device can measure the same but still have different tolerances and suceptibity to noise either EFI/RFI. This is part of the reason they are in metal cans.

 

[Cynips]

Just got my free 49720NA samples in the mail today. Placed my order on the 6th, so that's pretty fast if you ask me. We'll see when I can manage to make some time for switching them out for testing.

 

[leeperry]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I never said anything about their sound quality. -Try reading before you start trolling. The point was they are considered high spec devices. Usually refered to as Mil Spec. Two device can measure the same but still have different tolerances and suceptibity to noise either EFI/RFI. This is part of the reason they are in metal cans.

then my simple question to you is : where does it say that the TO99 49720 measures any different from the DIP8/SOIC8? does it say ANYWHERE that it's indeed "mil spec"? don't bother searching, it simply isn't the case.

these are metal cans coz TO99 is metal cased to begin w/....the added interference shielding is the icing on the cake, turning a great chip into a stellar one.......and it renders the STX simply astonishing

 

[ROBSCIX]

It is not the fact they measure any different it is the fact they are less susceptible to interference. There are usually other factors for mil spec also. TO-99 packages are usually refered to as Mil Spec opamps. Sometimes companys will have yet a higher version such as TO-99 with gold leads etc.
LM4562 and LME49720 opamps measure the same, right? -Yet you say they sound different why is that?
You also say the TO-99 version sound better then the chip version, why? -they measure the same, you said the spec sheets are exact. -Yet there is something better about the TO-99, that is what you have been saying?

 

[ROBSCIX]

Here check these out:

Standard Mil-spec opamps wil gold leads.

 

[ROBSCIX]

Quote:

Originally Posted by Cynips /img/forum/go_quote.gif Just got my free 49720NA samples in the mail today. Placed my order on the 6th, so that's pretty fast if you ask me. We'll see when I can manage to make some time for switching them out for testing.

Remove the shield, use a small knife or screwdrive to lift on one end then the other until they are free. If you loft one end too mcuh you will bend the leads. Look on the chip there is a indent or dot ont he one end. That goes in the direction of the same indent on the DIP socket. Be 100% sure the orientation is correct, if not you will usually blow the opamp and possibly damage the card as soon as power is applied.

 

[Cynips]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif Remove the shield, use a small knife or screwdrive to lift on one end then the other until they are free. If you loft one end too mcuh you will bend the leads. Look on the chip there is a indent or dot ont he one end. That goes in the direction of the same indent on the DIP socket. Be 100% sure the orientation is correct, if not you will usually blow the opamp and possibly damage the card as soon as power is applied.

Ok, thanks for the advice. Sounds pretty straightforward once you know what to look for.

Currently listening to maudlin of the Well's latest free web release in the 24-bit FLAC quality. Amazing what a good quality recording can do for music. I just want to familiarize myself a bit more with this piece before I do the swap.

 

[leeperry]

I switched to 49720NA first before ever using the card, and it sounded really bad....you'd be better off letting the card burn in for a few days before doing the swap IMHO.

 

[Cynips]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif I switched to 49720NA first before ever using the card, and it sounded really bad....you'd be better off letting the card burn in for a few days before doing the swap IMHO.

Well, I got my card even before you did, so I think it's burned in by now

 

[leeperry]

hah, that's what I thought...so I'm not sure of what you meant by "I just want to familiarize myself a bit more with this piece"