6 channel pre amp fun!

[lbstyling]

I just recieved one of these-
6Way M62446 LCD Volume Remote Control Preamplifier Kit on eBay (end time 29-Oct-10 02:12:33 BST)

For a bit of fun realy.

It has 3 NE5532 op amps for the 6 channels. Could you guys suggest what I could swap them for to improve the preamp? The ad mentions changing the for JRC4556 op amps for headphone application- dont know why.

Or any other mods I could play with?

Damn cheap isnt it!

[MJL21193]

Looks like a good deal, especially for someone building a 6 channel amp for an active system or home theatre.
4556 op amps have higher current/lower impedance output (I think) so would be better suited to drive headphones.

[AndrewT]

I would not waste time looking up the price of JRC opamps.

[abraxalito]

Originally Posted by lbstyling

Or any other mods I could play with?

Damn cheap isnt it!

Yep, looks like it has tremendous potential for the price. Probably the grounding will be the weakest point - fixing that would be my first port of call before rolling opamps. I get excellent results from NE5532s but they do need care and attention to layout and decoupling.

[sumaudioguy]

Try an NJM2068. Very good sounding and cheap. I use a lot of them. Also swap out those cheap caps for Panasonic FM type.

I think you made a real find and may buy one myself and do exactly as I have suggested. Remote control bargin!

I have no idea why AndrewT does not like Japanese Radio Corp. They make a lot of great stuff like the 2068 and the common ones like the one you mention not sounding as good. Maybe he likes the shrill sounding Analog Devices parts as he did not say the issue. A lot of people do use those shrill opamps by AD and then tell me how great their THD is. True enough but that one measurement certainly does not cover all aspects of performance.

[paulb]

NE5532 is still a pretty good choice for a preamp.

[sumaudioguy]

Lots of people like the NE5532 as it works but it really does not sound very good. Let me say it this way, if I never hear another it will be to soon. Everything that comes in with a 5532 is replaced by some other part, usually the NJM2068. Many manufacturers have moved to the 2068 from the 5532 as a better choice. Rane, Symmetrix, Garmin (navigation and avionics), Peavey, and the list goes on. Why use a 36 year old design when there is something that works better in every way in real circuits, not test circuits. Is it not time to retire a 36 year old solid state device? What about the old 709 and 741? Anyone not using a modernized version of one of those? That original is long gone or are there still some who do? Where do they purchase those old ones? Obsolete.

[gil1]

Originally Posted by lbstyling

I just recieved one of these-
6Way M62446 LCD Volume Remote Control Preamplifier Kit on eBay (end time 29-Oct-10 02:12:33 BST)

For a bit of fun realy.

It has 3 NE5532 op amps for the 6 channels. Could you guys suggest what I could swap them for to improve the preamp? The ad mentions changing the for JRC4556 op amps for headphone application- dont know why.

Or any other mods I could play with?

Damn cheap isnt it!

So how does it sound?

[abraxalito]

Originally Posted by sumaudioguy

Lots of people like the NE5532 as it works but it really does not sound very good.

What application does it not sound very good in for you? To my ears it sounds fine so long as attention is paid to power supplies, common mode distortion and the like. Samuel Groner's tests don't reveal anything bad about it, given the low price.

Let me say it this way, if I never hear another it will be to soon. Everything that comes in with a 5532 is replaced by some other part, usually the NJM2068. Many manufacturers have moved to the 2068 from the 5532 as a better choice.

Please do explain what makes the NJM2068 better - both technically and sound-wise. Here in China ostensibly its no cheaper than the NE5532 - both are around 1RMB each.

[sumaudioguy]

How about make a circuit which can switch between the 5532 and the 2068 using the same circuit in a typical application. Here, several sample circuits are used to listen to opamps in various configurations and switch between several. If you cannot tell the difference then it is clearly not important. To me on my system and in our professional equipment it is the difference between rotting fish and fresh fish. The 2068 has lower drift, less offset, will drive a low Z load better, has complementary instead of quasi comp output stage, and phase response using feedback is much better in real circuits.

Is this enough?

Regards, =SUM