[patricklang]

I'm curious, has anyone seen any NAD mods? I've been curious about throwing a pair of 627's or ad8610's in my C520 and was wondering if it was worth the upgrade.

Or, would I be better off getting a DI/O? The DI/O would be nice at work to replace my sonica's weak analog section as well.

 

[Megaptera]

That might be interesting. Do you know what opamp is in there now? If you were going to do that, it'd probably be worth upgrading the caps and adding sockets for the opamps, too (assuming they're not surface mount).

As far as your Sonica goes, you've already got a pretty decent DAC right there; it just needs an amp section, since its analog out is strictly line-level. I'm pretty impressed at the sound you get by pairing it with a simple headphone amp like a MINT -- that's my work setup -- so if you're not amped yet, I'd say that will make a huge improvement for not a whole lot of money.

 

[Jose Garcia]

and transport was a modified NAD C540. This one was modified by Dan Wright
when he first start doing mods as a living. Some of the changes were:

1- addition of an IEC
2- internal damping ( lid and transport)
3- damping to the clock
4- New OpAmps ( 2604)
5- new caps from Nichicon Gold, Sanyo and Cerafine
6- new rectifiers
7- better RCA's

Those changes get the analog stage better as well as the transport section.

Jose.

 

[recephasan]

i'd say forget the DIO unless you send it in for mods. my $150 Sony cdp is much better than it

 

[the_villain]

OK. Today I finished modding my 521BEE - replacing the caps in the power supply and the output stage and soldering sockets and changing the opamps from NE5532 to OPA2604. To tell you the truth the difference is not that much. I already know that the single biggest difference is opamp rolling and if you are not satisfied then you have to try some DIY DAC. I think the DAC will have significant impact on the sound. Now thinking of building my DAC - passive and using TDA1543.

 

[patricklang]

Quote:

Originally Posted by Megaptera That might be interesting. Do you know what opamp is in there now? If you were going to do that, it'd probably be worth upgrading the caps and adding sockets for the opamps, too (assuming they're not surface mount). As far as your Sonica goes, you've already got a pretty decent DAC right there; it just needs an amp section, since its analog out is strictly line-level. I'm pretty impressed at the sound you get by pairing it with a simple headphone amp like a MINT -- that's my work setup -- so if you're not amped yet, I'd say that will make a huge improvement for not a whole lot of money.

I run the sonica with a meta42 right now actually. My NAD520 currently sounds better than the Sonica to me already, which is why I've considered using a different dac with it. I think the NAD's higher P-P output makes the difference. Maybe I'll just rip out the crummy dc blocking caps they have in the sonica and jumper them since my amps have blocks already and see how that goes, its a free mod.

I just opened the 520, and it has the same 5532 opamps. I think my local Fry's carries the good round copper amphenol sockets, so I'm probably going to try some opamp rolling

I noticed that there's also some fets or transistors labeled just D655, a pair per channel, physically between the opamps and RCA's, so I assume they're in the signal path, but haven't examined the traces yet. Anyone familiar with NAD's output sections?

 

[Jose Garcia]

Quote:

Originally Posted by the_villain OK. Today I finished modding my 521BEE - replacing the caps in the power supply and the output stage and soldering sockets and changing the opamps from NE5532 to OPA2604. To tell you the truth the difference is not that much. I already know that the single biggest difference is opamp rolling and if you are not satisfied then you have to try some DIY DAC. I think the DAC will have significant impact on the sound. Now thinking of building my DAC - passive and using TDA1543.

My experience was that you need to give the modified unit about 160 hours of break-in. You will hear weird changes on the run but it will get much better after that.

Enjoy it,

Jose.

 

[Megaptera]

Quote:

Originally Posted by patricklang I run the sonica with a meta42 right now actually. My NAD520 currently sounds better than the Sonica to me already, which is why I've considered using a different dac with it. I think the NAD's higher P-P output makes the difference. Maybe I'll just rip out the crummy dc blocking caps they have in the sonica and jumper them since my amps have blocks already and see how that goes, its a free mod.

Ahh, good -- I was hoping you weren't judging the Sonica by its unamped output. Incidentally, if you're at all interested in modding the Sonica, there's a few threads about it in the DIY forum. One thing I've noticed is that it's very dependent on the quality of the power it's getting over the USB; mine sounds great at home and pretty blah at work -- you might find improvement there simply by switching it to battery power. Of course, the NAD would probably be a funner project

Quote:

I just opened the 520, and it has the same 5532 opamps. I think my local Fry's carries the good round copper amphenol sockets, so I'm probably going to try some opamp rolling I noticed that there's also some fets or transistors labeled just D655, a pair per channel, physically between the opamps and RCA's, so I assume they're in the signal path, but haven't examined the traces yet. Anyone familiar with NAD's output sections?

I don't know it at all, but a quick Google investigation suggests they might be Hitachi's 2SD655 transistors. Is this what you're looking at?