Fender Frontman 25R op amp replacement

[DavesNotHere]

Hi, newcomer here. I've got a Fender Frontman that I'm upgrading. I replaced the reverb tank and am replacing a bad pot next. While looking up other mods, I saw that replacing the op amps is popular for upgrading the sound and reducing the noise floor, so I'm planning to do this using the NE5532 op amp. I'm pretty experienced with microelectronics, and have done a lot of wiring on guitars and other micro projects, but this is my first time working on an amp. I've seen the process for desoldering and replacing the stock op amps, it looks pretty straightforward, but I've also heard there can be problems with messing up the board, etc. I'm pretty confident in my skills but don't want to brick my amp. What tips or other advice do you have for me? Is this as straightforward as it looks, or should I just leave it alone?

thanks,
-Dave

[Jazz P Bass]

Personally, I don't think a 5332 op amp is going to drastically change the amp sound.
I would recommend NOT replacing the IC's as board damage is a given.
The traces are paper thin.
If you really want to change the dynamics of the amp , look at a better speaker.

[DavesNotHere]

I already dropped a Raging Cajun in. Big improvement in sound but it's still noisy at the floor. The op amp replacement seems to be pretty popular. I would desolder rather than pull.

[J M Fahey]

Being popular means nothing.
people copy each other ... the blind leading the blind.

5532 will have a *somewhat* lower noise floor, but pull twice as much current, have lower in put impedance (bipolar vs FET), in all not much advantage, if at all.

Not sure about your "desolder rather than pull."

In my book both go together.

[joecool85]

At the very least, if you are going to pull the stock IC, I highly recommend putting in a socket so you can swap ICs and play with different ones to see in real time if it changes anything and by what degree.

ICs you could try:

TL072
OPA2604
LM4562

[vintagelove]

Hi, newcomer here. I've got a Fender Frontman that I'm upgrading. I replaced the reverb tank and am replacing a bad pot next. While looking up other mods, I saw that replacing the op amps is popular for upgrading the sound and reducing the noise floor, so I'm planning to do this using the NE5532 op amp. I'm pretty experienced with microelectronics, and have done a lot of wiring on guitars and other micro projects, but this is my first time working on an amp. I've seen the process for desoldering and replacing the stock op amps, it looks pretty straightforward, but I've also heard there can be problems with messing up the board, etc. I'm pretty confident in my skills but don't want to brick my amp. What tips or other advice do you have for me? Is this as straightforward as it looks, or should I just leave it alone?

thanks,
-Dave

Might I suggest rather than swapping opamps, you figure out sticking a "master volume" pot somewhere around u3b or u4a. I know at least one guy successfully put an fx loop right after u3b.

That little amp is ridiculously loud, and the reality is you're probably playing it at like 1, in a quiet environment, and the idle noise is bothersome in that setting.

You could easily knock off a few db with a master volume, that would lower the noise floor to where it's barely noticeable. It would still have plenty of power set like that, and if you wanted full power, just turn the master up all the way. In that kind of setting (jamming with others), the stock noise floor would be barely noticeable.

My 2 cents... Anyway... maybe someone can chime in with the best place to put it. Here's the schematic.

[joecool85]

Hi, newcomer here. I've got a Fender Frontman that I'm upgrading. I replaced the reverb tank and am replacing a bad pot next. While looking up other mods, I saw that replacing the op amps is popular for upgrading the sound and reducing the noise floor, so I'm planning to do this using the NE5532 op amp. I'm pretty experienced with microelectronics, and have done a lot of wiring on guitars and other micro projects, but this is my first time working on an amp. I've seen the process for desoldering and replacing the stock op amps, it looks pretty straightforward, but I've also heard there can be problems with messing up the board, etc. I'm pretty confident in my skills but don't want to brick my amp. What tips or other advice do you have for me? Is this as straightforward as it looks, or should I just leave it alone?

thanks,
-Dave

Might I suggest rather than swapping opamps, you figure out sticking a "master volume" pot somewhere around u3b or u4a. I know at least one guy successfully put an fx loop right after u3b.

That little amp is ridiculously loud, and the reality is you're probably playing it at like 1, in a quiet environment, and the idle noise is bothersome in that setting.

You could easily knock off a few db with a master volume, that would lower the noise floor to where it's barely noticeable. It would still have plenty of power set like that, and if you wanted full power, just turn the master up all the way. In that kind of setting (jamming with others), the stock noise floor would be barely noticeable.

My 2 cents... Anyway... maybe someone can chime in with the best place to put it. Here's the schematic.

Alternatively you could place an attenuator at the speaker output.  I did this by way of a couple large resistors on my Dean Markley for the reasons you mentioned.  I was always running it at 1-2 on volume and there was still noise.  By attenuating the overall output it allowed me to increase the preamp volume and lower the noise floor.

I chose to do an attenuator even though it is less power efficient because of two reasons:
1. I rarely use this amp as I'm normally playing my Positive Grid Spark Mini
2. I was able to put in a switch with the attenuator so I can go from <1w to 20w at the flick of a switch and make a meaningful difference, all without modifying the circuit at all.  This was important to me because I've already played around with this a lot and didn't want to keep doing this haha.

[Loudthud]

I was wondering what it would be like volume wise to have four 16 Ohm speakers and be able to select one, two or four in parallel with a footswitch ?

[J M Fahey]

It will certainly change volume, but I guess variation will not be that big, probably a few dB.

For bedroom playing we need, say, something between 20dB and 30dB or so.

Tiny Terror offers a 7W-15W switch, Mesa Boogie a 60W-100W one (cutting 2 x 6L6 out), neither as effective as it seems.
One modern Mesa offers a 50W-5W-0.5W switch ... now THAT one is useful.

[joecool85]

It will certainly change volume, but I guess variation will not be that big, probably a few dB.

For bedroom playing we need, say, something between 20dB and 30dB or so.

Tiny Terror offers a 7W-15W switch, Mesa Boogie a 60W-100W one (cutting 2 x 6L6 out), neither as effective as it seems.
One modern Mesa offers a 50W-5W-0.5W switch ... now THAT one is useful.

My K20-X mod brings it down to about 0.6w when switched, and honestly I probably should have brought it to about 0.25w to be ideal.  It does work well enough for me that I'm not going to change it though.