dickiefunk
New member
Hi Chessrock. Are the LT 1469 and OP275 OpAmps better/more suitable for the output stage only? Would either of these be better than the OPA2134 for the MIC or Line In stages?
Hi Chessrock. Are the LT 1469 and OP275 OpAmps better/more suitable for the output stage only? Would either of these be better than the OPA2134 for the MIC or Line In stages?
Well, it's not like building a house.
You spend (hopefully) a few hours on it, you're done and you move on.
Generally speaking. It's talking about it in threads like this one that burn a lot of hours.
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OK you need to understand some very basics about opamps before you go crazy with swaps. First off is the package you are replacing (I assume it's DIP-8?). If the opamp you are thinking about isn't 8 pin DIP, it will be a much bigger hassle to swap.
Second, 4580 is a dual opamp. AD845 in the DIP-8 package is single, OPA627 is single. OPA2132 is dual.
Finally, superfast, wide bandwidth opamps can oscillate under the wrong conditions. If the VTB's circuitry isn't set up to deal with that, it's a potential problem.
Also you need to make sure you are swapping in a FET input opamp, which 2134 is (and the others mentioned above too, but double check). You don't want a BJT input opamp in the place of a FET input unless you really know the circuit and what you are doing. You can *usually* swap out a BJT input and replace with FET input on a mic input stage, but elsewhere in a circuit (especially in a mixer), the BJT opamps could be necessary to drive the required outputs.
Is it easy to swap opamps? Well, can you solder? Can you desolder without lifting traces? How robust is the VTB1's PCB? Are the holes plated-through? I don't know the answer to any of those questions, but I've swapped many opamps, even when I wasn't that experienced, and it isn't too difficult, but you should get some experience before you jump in. Find an obsolete PCI card with thru-hole components (an old modem should be good for that) and desolder it for fun.
I have swapped the x134 series into many units, always with little trouble and good results. I've used 2604 too, which chess mentioned. They are fairly similar parts, I think 2604 is a bit quieter and 2134 is lower distortion. Both are good, and much better than 4580.
You're done until you have the burning desire to replace that op amp with a "better" one just one more time....just for that ever so slight improvement in sound. LOL.
Anyone had any experience with the TL072 OpAmps?
Thanks. The reason why I'm asking about the TL072's is someone from Studio Projects has recommended that the OPA2134's and TL072's would be the most suitable to use I have had different messages from them saying either don't replace the OpAmps at all, use OPA 2134's at the input stage to use an OPA 2134 and TL072's?
What are they actually doing in the circuit though?I'm surprised that the TL072's are not much of an upgrade because Rane are fitting their current MS-1b's with these
You know if you’re that interested in how different opamps sound you should really get a load of the ones recommended or any that will work in the circuit and just spend some time comparing. Getting opinions on the net is valuable to an extent but you’re never going to get all the answers unless you listen for yourself.QUOTE]
Hi, yeah I agree with you but some people have told me that it's not advised to simply swap different OpAmps in because I could permanantly damage the circuit?
The Rane Ms-1b also use MC 33078 OpAmps with the TL072
What are they actually doing in the circuit though?
I'm shit at reading shcematics but it looks to me as if they're not in the audio path at all (maybe something to do with the overload circuit)?