Modding the RME PAD

[Iron_Dreamer]

Not just yet, since I don't know how compatible they'd be, I'm waiting to hear from Glassman again on that issue.

 

[Iron_Dreamer]

Well I've been looking up opamp info for a while, and it seems there are a number of different ones that are pin and voltage compatible with the stock JRC/NJM 4580.

I'm thinking install a socket and get a bunch of opamps and try them all to achieve the best SQ. Would it be possbile to put a socket in where that lowermost, leftmost opamp is?

 

[Wodgy]

You'd need some sort of DIP to SMD adapter if you wanted to put in a socket. Not a bad idea, but I haven't seen one before. Maybe someone else has?

 

[Edwood]

Would one of those Brown Dog adapters work? They're pretty small. Would make future upgrades alot easier.

I have a chip puller, so a dip socket would be OK too.
-Ed

 

[Wodgy]

I dunno if Brown Dog sells a DIP to 8 lead SOIC adapter. Someone probably does though.

 

[Glassman]

I don't know of any DIP->SOIC adapters.. SOIC leads are a lot smaller than DIP, I can't imagine mounting any adapter there..

as for the opamps, you can use pretty much every dual opamp in SOIC package you can find, I've just listed one of the most appealing candidates..

to be honest I don't see anything special on RME cards other than their low jitter oscilators instead of using simple pierce oscilator.. AD1852 is one of the better DACs, but there's nothing special in the following analog circuitry.. the card seems to lack any kind of power conditioning for the opamps and also nothing special for DAC and ADC.. There's a lot more inside waiting to be revealed in this card

 

[Edwood]

What would you replace on it?

Would it be worthwhile to mod the RME digi96/8 PAD?

Which sound card is significnatly better than the RME?

-Ed

 

[Iron_Dreamer]

Quote:

Originally posted by Edwood Which sound card is significnatly better than the RME?

The only ones generally thought to be better are the Digital Audio Labs CardDeluxe ($400) and Lnyx Audio 2 ($1000) and L22 ($700).

I think if I changed the opamp, I'd go with the AD8620, since it has the highest slew rate of the ones I've looked at.

 

[lan]

Quote:

Originally posted by Edwood Which sound card is significnatly better than the RME?

To me it doesn't make any sense to get a better soundcard since the higher end pro ones just have more features which you don't use. The $ is better spent on getting a better external DAC.

 

[Wodgy]

Not to beat a dead horse, but the transformer output mod gets around most of the limitations Glassman was talking about, as it bypasses the entire analog output stage. You can't get around the DAC's power supply being "underwhelming" but it's good enough.

I'm not sure the AD8620 would be the most synergistic choice. You'd be taking a DAC that's already on the brighter side of neutral and hanging one of the most "lively" op-amps onto it. If you can find a socket that works, that's a much better option.

 

[Iron_Dreamer]

Holy moly, hold the fort, I think I found a workable adapter: http://www.cimarrontechnology.com/in...PROD&ProdID=20

Could I simply put a socket on this puppy (no pun intended) and solder it down?

 

[Wodgy]

Good find! That's what you need. You'll also need a socket to mount on to it.

If you want to be able to use single op-amps, you'll also need the single-to-dual Browndog adapter, as well as two sockets for that adapter. It's probably worth the couple extra bucks, so you can try the OP627 and AD797, etc.

 

[Iron_Dreamer]

True, the AD797 looks like a hell of an opamp. I just ordered the Blackgates, the only ones that had the right specs and sould fit, the PK series 22uF 50v. Looks like the big challenge will be getting the stock opamp off, and the adapter on safely. Should end up being a next week project once I recieve all the parts.

 

[Iron_Dreamer]

Well I did some measuring, and the dual browndog adapters with sockets, to enable me to use two single-channel DIP8 opamps will not work, becuase the single-dual DIP8 adaoter is too wide, and it would contact the PCI slot when the card is inserted to the PC.

So, my plan is to go with dual AD797's in SOIC form on the browndog single-dual SOIC adapter, to upgrade the opamp. My reasoning for the AD797 is twofold. One, the AD797 is known to be a rather analog-sounding opamp (as compared to the AD8610) from direct comparisons people have done with the Ray Samuels amps. Two, the reference design for the AD1852 DAC uses the AD797 for its' output stage, so I'd think the AD folks think it is the best opamp for that DAC.

Anyone have specific tips for soldering SOIC opamps without burning thiem up? SHould I order backups, in case of a mishap?

 

[lan]

Quote:

Originally posted by Iron_Dreamer SHould I order backups, in case of a mishap?

Another soundcard?

Good luck man! Let us know how it turns out.