# zapco studio op amps



## drumcrusher (May 4, 2008)

hey guys, i was thinking about replacing the op amps in my zapco studio 100 and a z300s2vx. they both use TL074cn i believe. does anyone know if the burr brown OPA 4227 is a direct drop in upgrade for these? or if there are other options to go with? or for that matter, are there any other mods anyone has done as far as SQ is concerned? i also have the elna and panasonic fc caps that will be needed to recap both. both work fine as they are now, just having an OCD moment.


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## thehatedguy (May 4, 2007)

Yeap, should.

Not many good quads out there, but there are a few.


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## ATOMICTECH62 (Jan 24, 2009)

thehatedguy said:


> Yeap, should.
> 
> Not many good quads out there, but there are a few.


Exactly.
The main difference is the TL074 is a JFET and the BB is not.You need a scope to really see what is going on after its replaced.Also should compare current consumption if there are a lot of them.I have had to add a small cap soldered directly to the V+/V-for oscillation problems.

If the BB does not work the LT1058 should.It is a JFET upgrade made to replace the TL0XX series.The cheapest I found them was $5 at Digikey.


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## drumcrusher (May 4, 2008)

So you're saying there could be some problems with the burr browns huh? Not sure if i wanna deal with that in the bigger amp. Ill try the one out in the studio 100 and see how it works. Im wondering if ill even tell a difference. My ears aint what they used to be.


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## drumcrusher (May 4, 2008)

Ha... I won't ever claim to be able to make anybody happy. Much less everybody. I did notice that the 4227 is the 14 pin version. Im needing the 8 pin. Anybody know which I should get between the opa227 of opa228, 2227 or 2228? They are All 8 pin versions....


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## drumcrusher (May 4, 2008)

The 2227 and 2228 are duals, and the 227 and 228 are singles, if that helps anybody. Thanks for your help.


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## drumcrusher (May 4, 2008)

So are you saying that this is probably going to be a big waste of my time? Ha... You sound like you would know better than me. I just got my test bench up and running and im sortof itching to try some unnecessary sound upgrades. I want them to be as easy and problem free as possible though. Now i see that there are a few different versions. Unless somebody can tell me which would be my best bet i may just try the jfet chips that somebody mentioned earlier.


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## ATOMICTECH62 (Jan 24, 2009)

The TL07 series is an OK op amp.I feel the worst thing about it is the noise floor.
The NE5532 and the NJM2068 are the go to lower cost upgrades if they will work in the circuit.
You might not even hear any difference,but then you might.
There are tons of sites on the subject of "this op amp sounds better then that one".

Just Google TL072 upgrade.

Just last week I tried replacing some BA4560's with NE5532's and got worse results.


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## drumcrusher (May 4, 2008)

Cool man thanks for the help. The studios aren't noisy amps to begin with but im gonna try out some different ones just to satisfy my curiosity. Im gonna google the upgrades and see what options i may have.


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## Richv72 (May 11, 2012)

So did you ever swap them out?. If so what were the results?.


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## drumcrusher (May 4, 2008)

i sure didnt man, not yet at least. i just had to buy a new solder gun, and im about to recap the studio 100 tonight. im looking for schematics if anyone has them for these zapcos.


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