fender frontman 65r op amp upgrade issue

[jimiamd]

Hi everybody i'new to this forum
After some research on google couldn't find a solution to my problem :
I've recently bought a used fender frontman 64r. Everything was OK and i've recaped big part of it plus some new resistors. Anyway the sound quality was better and decided to upgrade opamps. U3 and U4 with ne5532 and again big improvement in audio quality but. These 2 chips are overheating. But still working when replacing with previous one ba4560 no more overheating.
There a little distorsion with the new one very low and from time to time not permanent. Since i'm satisfied (money for nothing sounds like money for nothing. On the drive channel cannot roll back) with the new audio quality i really want to keep it with ne5532 chips but i'm worried about this overheat.
I have one last question isn't the 47uf (c69. C70). Very low value to supply 7 opamps. ? Can i add some juice without grilling components ?
Any help will be highly appreciated

[loudthud]

Can you provide a link to the correct schematic or attach a copy ? Since you have less than 5 posts, you may not be able to attach a large file, but a link is OK.

[g1]

schematic attached

Where did you get the 5532's from?

[The Dude]

The NE5532 is good to around 70°C according to datasheets. Do they run hotter than that? I'm not sure why they'd get hot in this amp unless your supply rails were high (open 16V zeners or something of the sort). Check the 16V rails and make sure they aren't high. Changing the filter caps for larger values won't "add some juice". It might give you better filtering, but the rails are clamped at 16V by the zener diodes. If you don't hear any 60 cycle hum, I'm not sure what would be gained.

[jimiamd]

Hi, and thanks everybody for your help.
Yes sorry for the wrong. Schematics but my quota is limited and couldn't upload the good one.
All the voltages that supply the opamps are correct. 16,5v. like i said when put back the ba4560 no overheat.
I've choosen the ne5532 because i knew it support up to 22v max, the datasheet electrical characteristics are even better than ba4560 And they are not fake , they were taken from rotel preamp (hifi) and totally working no overheat.
And for the 60 cycle hum. Yes it'd louder than before changes. But i've Replaced all componants with same values , except for the U3 and U4. Opamps.
Oh yes last detail that might help i've put all opamps on dip8 socket to swap them easily i first thought it was bad contact but rolling back to ba4560 didn't show any overheat.

[Helmholtz]

The 5532 draws about twice the supply current of a 4560, so increased dissipation and case temperature.
Higher supply current also increases power supply ripple and thus hum.

[Mark Hammer]

My advice would be to use the 5532 chips for other aspects of the circuit (U1 and U2 should be fine) but NOT the reverb driver (U6, I believe), since reverb circuits need and draw more current. But, that said, U3 and U4, being further downstream, should not really benefit much, from replacement. And given that Fender used two different op-amps (TL072 and 4560 types), I'll assume that there was some logic underlying their choice and application.

[g1]

It's interesting they were running cooler in the Rotel. What are the supply voltages there? Maybe 12 or 15 rather than the 16.5 in the Fender?
Or perhaps running in lower current circuits?

[jimiamd]

Hi, thanks to the two last answer and for you interest to my issue.
I wouldnt put the ne5532 if i wasnt sure of its compatibilty in this design.
In the rotel design it was supplied with 19,5. Volt and was working fine.

[jimiamd]

Hi, i've just found an interesting video about modding a fender fm 25 with ne5532. At the end it gives the link of this site and Mark Hammer (small world) about adding some capacitors and resistor to the new chip ne5532. I didn't find the original post here .
Here the video link https://m.youtube.com/watch?v=0xGPvYxexE0
.regards

[g1]

At the end it gives the link of this site and Mark Hammer (small world) about adding some capacitors and resistor to the new chip ne5532. I didn't find the original post here .

I think it will be this one: https://music-electronics-forum.com/...it-or-ditch-it

[jimiamd]

Ho, everybody and thanks for your time and help