replacing opamps in a Symetrix 522

changeng · 1st March 2010

Help me, O Mighty Lords of Geekslutz!

Taking the sage advice of the posters here, I've decided to send my Aphex 651 in to Jim Williams to mod and make it magical.

So I have an old Symetrix 522 that has a bunch of socketed opamps and I'd love to see what changes newer opamps make. Looking online, this is way over my head. As I slowly learn this stuff, could you kind, brilliant people tell me what would be excellent upgrades to the following opamps in the 522?

NEC C456OC 4428 – (12 pieces) 8 pin

HCF 4066BE 88415Y – (4 pieces) 14 pin

LM339N RCA H.427 – (6 pieces) 14 pin

HCF4017BE 88442Y – (2 pieces) 16 pin

Here's a link to the schematics - Where can I find Schematics for the 522 Compressor / Limiter / Expander ?

Thanks in advance for any help you can give me!

Stuart

mbrebes · 1st March 2010

The only ones to change would be the 4560 opamps. Standard dual opamp in an 8 pin DIP configuration. Plenty of threads with recommmendations for replacing TL072's, 5532's, etc. Do a search. Other IC's are CMOS logic and a comparator.

Jim Williams · 1st March 2010

The upc4560 is the Mackie opamp, the one that made them famous. You can try swapping them but if there are not phase feedback caps nor local psu bypass caps they may not be stable. Use a scope to check. A National LME49720NA would possibly be a good swap if...

Jim Williams
Audio Upgrades

changeng · 2nd March 2010

Thanks, guys. If anyone has other choices, please let me know (at $5 a pop, those National LME49720NA's start to eat away at my mac n' cheese money!) Provided that oscillation isn't a problem, has anyone done this swap who can say what type of difference I'll hear? It's not bad now, just a little slurry.

changeng · 5th March 2010

I'm getting opamp recos from teh prodigy board - would any of these be a good choice for simple "plug and play"? I realize that a cap change would be in order down the road, as well as a power supply upgrade. I'm just learning to mod, so I'd like to do one thing at a time - so I guess the best thing would be to use the opamps with the lowest current pull for now? Is that correct? With that in mind, along with the suggestions already made, are these also good and safe choices?

LME 49860
TLE 2072
OPA 2604
OPA 2134

Part of my learning process is to read up on these chips and understand better what I'm putting in the unit. So I want to research the most likely suspects.

Thanks for your input !

changeng · 8th March 2010

So I'm trying to learn as I go along -

On the prodigy-pro board, for example, someone said to go with the TLE 2072's. Looking at Mouser, it appears (tho I could be wrong) a standard 4560 opamp has an input offset voltage of 0.5v, an input bias current of 500 nA and a supply voltage of +/- 18v.

Looking at the TLE 2072 on Mouser - there are several types for a PDIP-8 setup - one has an input offset voltage of 3.5mV @5V and the other has an input offset voltage of 6mV@5V - both have an operating supply voltage of 38V- are these pushing too much current for a proper replacement without doing other mods to the unit? Even tho I'll eventually upgrade the caps (this will be my frankenstein unit to learn on) I want something right now that I can just plug in and hear an improvement in clarity and transient response, without blowing up my apartment or the unit. I realize that with older circuitry, that's like getting in a Porsche and driving on the 405 during rush hour, still I want to learn.

Thanks for all the input, guys, I really appreciate it.

1st March 2010	#1
changeng Lives for gear Joined: Jan 2006 Posts: 884 Thread Starter 3 Reviews written	replacing opamps in a Symetrix 522 Help me, O Mighty Lords of Geekslutz! Taking the sage advice of the posters here, I've decided to send my Aphex 651 in to Jim Williams to mod and make it magical. So I have an old Symetrix 522 that has a bunch of socketed opamps and I'd love to see what changes newer opamps make. Looking online, this is way over my head. As I slowly learn this stuff, could you kind, brilliant people tell me what would be excellent upgrades to the following opamps in the 522? NEC C456OC 4428 – (12 pieces) 8 pin HCF 4066BE 88415Y – (4 pieces) 14 pin LM339N RCA H.427 – (6 pieces) 14 pin HCF4017BE 88442Y – (2 pieces) 16 pin Here's a link to the schematics - Where can I find Schematics for the 522 Compressor / Limiter / Expander ? Thanks in advance for any help you can give me! Stuart

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1st March 2010	#2
mbrebes Lives for gear Joined: May 2006 Location: Los Angeles, CA Posts: 593	The only ones to change would be the 4560 opamps. Standard dual opamp in an 8 pin DIP configuration. Plenty of threads with recommmendations for replacing TL072's, 5532's, etc. Do a search. Other IC's are CMOS logic and a comparator.

1st March 2010	#3
Jim Williams Voiding warranties Joined: Feb 2004 Location: beautiful Carlsbad, CA Posts: 10,054	The upc4560 is the Mackie opamp, the one that made them famous. You can try swapping them but if there are not phase feedback caps nor local psu bypass caps they may not be stable. Use a scope to check. A National LME49720NA would possibly be a good swap if... Jim Williams Audio Upgrades

2nd March 2010	#4
changeng Lives for gear Joined: Jan 2006 Posts: 884 Thread Starter 3 Reviews written	Thanks, guys. If anyone has other choices, please let me know (at $5 a pop, those National LME49720NA's start to eat away at my mac n' cheese money!) Provided that oscillation isn't a problem, has anyone done this swap who can say what type of difference I'll hear? It's not bad now, just a little slurry.

5th March 2010	#5
changeng Lives for gear Joined: Jan 2006 Posts: 884 Thread Starter 3 Reviews written	I'm getting opamp recos from teh prodigy board - would any of these be a good choice for simple "plug and play"? I realize that a cap change would be in order down the road, as well as a power supply upgrade. I'm just learning to mod, so I'd like to do one thing at a time - so I guess the best thing would be to use the opamps with the lowest current pull for now? Is that correct? With that in mind, along with the suggestions already made, are these also good and safe choices? LME 49860 TLE 2072 OPA 2604 OPA 2134 Part of my learning process is to read up on these chips and understand better what I'm putting in the unit. So I want to research the most likely suspects. Thanks for your input !

8th March 2010	#6
changeng Lives for gear Joined: Jan 2006 Posts: 884 Thread Starter 3 Reviews written	So I'm trying to learn as I go along - On the prodigy-pro board, for example, someone said to go with the TLE 2072's. Looking at Mouser, it appears (tho I could be wrong) a standard 4560 opamp has an input offset voltage of 0.5v, an input bias current of 500 nA and a supply voltage of +/- 18v. Looking at the TLE 2072 on Mouser - there are several types for a PDIP-8 setup - one has an input offset voltage of 3.5mV @5V and the other has an input offset voltage of 6mV@5V - both have an operating supply voltage of 38V- are these pushing too much current for a proper replacement without doing other mods to the unit? Even tho I'll eventually upgrade the caps (this will be my frankenstein unit to learn on) I want something right now that I can just plug in and hear an improvement in clarity and transient response, without blowing up my apartment or the unit. I realize that with older circuitry, that's like getting in a Porsche and driving on the 405 during rush hour, still I want to learn. Thanks for all the input, guys, I really appreciate it.