Question about putting aftermarket caps in a receiver

[Adam]

Hey, all. I have two questions for the amp gurus here. Please pardon my semantics below - I'll do my best to describe the situation.

Back in 2007, I talked myself into buying an amp because my receiver at the time (a Pioneer VSX-1015) would seem to lose dynamic range at higher volumes (it sounded "muffled," I'd call it). At my normal listening volumes, it sounded great. It was only when I turned it up much louder than normal that I could tell that it wasn't playing everything quite correctly (some transient details like guitar plucks lacked the full range that they had at lower volumes). It played plenty loud for me, but it lacked the details. When I added an amp, I don't think that it was any louder overall, but things at louder volumes still sounded as detailed and crisp as they did at lower volumes. So, it was the receiver/amp and not something else in my system. My questions:

1. Is it likely that the lack of detail at the higher volumes was due to the capacitance being too small in my receiver?

2. If so, would it be enough to swap out the capacitors in the receiver for larger ones to overcome that issue?

Thanks!

 

[Bryceo]

Ridikas would be Abel to answer this question

 

[fuzz092888]

1. Is it likely that the lack of detail at the higher volumes was due to the capacitance being too small in my receiver?

2. If so, would it be enough to swap out the capacitors in the receiver for larger ones to overcome that issue?

Thanks!

I don't think it is a question of only capacitance, but yes that would definitely help.

Is there room for bigger caps in the receiver? Is there room for additional caps in the receiver? I know when I open up my Onkyo the damn thing is packed full. I'm not sure I could fit any additional caps in there, but your pio may be different.

As long as the receiver's amp section can handle the additional power that the additional caps will provide and there is room for bigger/more caps I think it may be a viable option.

Maybe I'm way off though. I know that once my Perreaux is fixed I plan on adding additional capacitors and may replace the original ones with bigger ones, but I've been told by the guy fixing it that all the other parts can handle the extra power that adding more caps brings.

 

[Swerd]

… At my normal listening volumes, it sounded great. It was only when I turned it up much louder than normal that I could tell that it wasn't playing everything quite correctly (some transient details like guitar plucks lacked the full range that they had at lower volumes). It played plenty loud for me, but it lacked the details. When I added an amp, I don't think that it was any louder overall, but things at louder volumes still sounded as detailed and crisp as they did at lower volumes. So, it was the receiver/amp and not something else in my system. My questions:

1. Is it likely that the lack of detail at the higher volumes was due to the capacitance being too small in my receiver?

2. If so, would it be enough to swap out the capacitors in the receiver for larger ones to overcome that issue?

I'm not an amp guy, but I had very similar experience to yours. Your sentence that I bolded spells out the difference I heard when I added an outboard amp to an AVR.

I'll hazard a guess to answer your questions. It's the receiver's power supply transformer and the capacitors, not the caps alone. Installing larger caps probably will not make the receiver more powerful, unless the manufacturer originally put in inadequately small caps. Because the power supply transformer is probably the most expensive part in any amp or receiver, if a manufacturer wants to hold down cost, it will choose a smaller transformer. Larger caps may make a small improvement, but not much.

 

[Adam]

Thanks, guys!

Just a bump to see if anyone else had thoughts on the matter. Thanks in advance.

 

[Bryceo]

I have a pioneer 5.1 amp in my parents sheed I could order some bigger caps and see if it works befor you try this Adam!!!

 

[Adam]

I have a pioneer 5.1 amp in my parents sheed I could order some bigger caps and see if it works befor you try this Adam!!!

Thanks, Bryce. That's a generous offer, but don't do it on my account. It's more of a curiosity for the future. I don't plan on upgrading that amp, at least not right away. I just figure that someone here knows the answer.

 

[Whitey80]

In pure honesty, I wouldn't trust your report on it.

 

[Bryceo]

Thanks, Bryce. That's a generous offer, but don't do it on my account. It's more of a curiosity for the future. I don't plan on upgrading that amp, at least not right away. I just figure that someone here knows the answer.

I might have a little play because I've seen recapped amps and upgraded fans and all the lights an stuff so a upgrade Capp should be a walk in the park

 

[Nestor]

Hey, all. I have two questions for the amp gurus here. Please pardon my semantics below - I'll do my best to describe the situation.

Back in 2007, I talked myself into buying an amp because my receiver at the time (a Pioneer VSX-1015) would seem to lose dynamic range at higher volumes (it sounded "muffled," I'd call it). At my normal listening volumes, it sounded great. It was only when I turned it up much louder than normal that I could tell that it wasn't playing everything quite correctly (some transient details like guitar plucks lacked the full range that they had at lower volumes). It played plenty loud for me, but it lacked the details. When I added an amp, I don't think that it was any louder overall, but things at louder volumes still sounded as detailed and crisp as they did at lower volumes. So, it was the receiver/amp and not something else in my system. My questions:

1. Is it likely that the lack of detail at the higher volumes was due to the capacitance being too small in my receiver?

2. If so, would it be enough to swap out the capacitors in the receiver for larger ones to overcome that issue?

Thanks!

Unless you have a clear understanding of the circuit design, simply swapping out for larger caps will be ineffective, at best, or damaging to your amp, at worst.

 

[Adam]

Unless you have a clear understanding of the circuit design, simply swapping out for larger caps will be ineffective, at best, or damaging to your amp, at worst.

Thanks. Are you willing to elaborate?

 

[TLS Guy]

Hey, all. I have two questions for the amp gurus here. Please pardon my semantics below - I'll do my best to describe the situation.

Back in 2007, I talked myself into buying an amp because my receiver at the time (a Pioneer VSX-1015) would seem to lose dynamic range at higher volumes (it sounded "muffled," I'd call it). At my normal listening volumes, it sounded great. It was only when I turned it up much louder than normal that I could tell that it wasn't playing everything quite correctly (some transient details like guitar plucks lacked the full range that they had at lower volumes). It played plenty loud for me, but it lacked the details. When I added an amp, I don't think that it was any louder overall, but things at louder volumes still sounded as detailed and crisp as they did at lower volumes. So, it was the receiver/amp and not something else in my system. My questions:

1. Is it likely that the lack of detail at the higher volumes was due to the capacitance being too small in my receiver?

2. If so, would it be enough to swap out the capacitors in the receiver for larger ones to overcome that issue?

Thanks!

If only life was that simple. I think you not only would waste your time, but would likely b low the amps output stages.

Basically the power amps in receiver s are just nasty. They have miserably small power transistors and only pairs. No nice large power transistors tripled or quadrupled.

In this money grubbing build to lowest price and race to the bottom, you can bet the sizing of the caps has something to do with saving the miserable power transistors at overload by reducing the voltage. Crude but cheap. Their is no depth low enough for the the designer of receiver amps to stoop.

Basically a multichannel receiver is an obsolete nonsense.

Pre pros, with active loudspeakers, I'm certain could deliver much better performance per dollar.

 

[Nestor]

Thanks. Are you willing to elaborate?

TLS's complaint about receivers aside, he's right. It's just not that simple.

 

[Adam]

Thanks, guys. I'm not in the camp that receivers are obsolete and they all suck , but I sincerely do appreciate the input.

My understanding was that capacitors are what provide the energy required for short-term transient power spikes for things like cymbal crashes. So, since what seemed to be lacking when I turned up the volume were those types of things, I thought perhaps adding in capacitance would help. Again, the overall volume was plenty loud. I also know a bit about electrical circuit design (no quizzes, please - I said a bit ) and figured that it might not be as easy as swapping out a cap...but I wanted to ask.

Thanks, again.

 

[Irvrobinson]

My understanding was that capacitors are what provide the energy required for short-term transient power spikes for things like cymbal crashes.

Actually, capacitors are used in power supplies to smooth the output from the rectifier stage. Capacitors can be used for energy storage, but it's the overall circuit design, from the transformer to the rectifiers to smoothing caps to the output stage that must be designed as a unit, as TLS Guy alludes to. Capacitors do age and degrade, and they are relatively expensive compared to other electrical components so corners are sometimes cut, but I think it is unlikely that just increasing the filter capacitance will increase performance noticeably. Also, higher value capacitors may have additional series resistance, which could degrade the amp's slew rate.

Since a receiver's transformer is sized for five channels, using it in two channel mode could mean you have the transformer capability to handle higher output, but if each channel has a separate rectifier that could be overloaded to charge the larger caps. And, as TLS Guy mentions, the output transistors could be under-sized for more filter capacity, but I'm guessing they'd probably handle higher peaks.

Bottom line though, I agree with everyone that says don't do it. If you want a better amp, buy a better amp.

 

[Irvrobinson]

If only life was that simple. I think you not only would waste your time, but would likely b low the amps output stages.

Basically the power amps in receiver s are just nasty. They have miserably small power transistors and only pairs. No nice large power transistors tripled or quadrupled.

In this money grubbing build to lowest price and race to the bottom, you can bet the sizing of the caps has something to do with saving the miserable power transistors at overload by reducing the voltage. Crude but cheap. Their is no depth low enough for the the designer of receiver amps to stoop.

Basically a multichannel receiver is an obsolete nonsense.

Pre pros, with active loudspeakers, I'm certain could deliver much better performance per dollar.

You've turned up the contrast so high my eyes are hurting!