Yamaha amplifier Upgrade

[zanash]

I can't hear different solders ...lead free 4% silver is pain to work with ...

as to the opamps ...ditch the 4559 and the ne5532 there pretty pedestrian these days ...

fit a good quality socket with berylium pins...

then try opa2604 as new standard

then there opa2227 thats interesting...and many others besides..

most should drop in and give you a flavor before you need change surrounding components.

But the biggest change will be if you fit good caps/better caps to any signal decoupling positions.

I use paper in oil for these ...and always get a huge jump in sound quality ....you just can't believe how bad some dc blockers can mess with the music signal !

 

[Macpibe]

Hi all:
Thanks zeppy and zanash for the opinions. I’ll evaluate all this.
And sorry, I’ve missed some of this post, I’m travelling in my winter holidays.
And for Chris (if you can) or anybody,
I can “swap” O.P. amps (i.e. 4559 for OPA2604 or NE5532), with the same associated components in the circuit, without worry about factors like gain and input and output impedances?
Thanks all.

 

[anatech]

Hi Macpibe,

I can “swap” O.P. amps (i.e. 4559 for OPA2604 or NE5532), with the same associated components in the circuit, without worry about factors like gain and input and output impedances?

Normally yes. You must be careful of some op amps that need their compensation adjusted to suit the circuit and supply bypassing. Try not to use sockets.

Always check for oscillation with an oscilloscope if you can.

-Chris

 

[Macpibe]

Clearly, Chris.
But, why "Try not to use sockets"?
Is it critical in low frequency systems, like used in audio?
Many thanks.
Carlos.

 

[anatech]

Hi Carlos,

Is it critical in low frequency systems, like used in audio?

Your intended signal is a low(er) frequency, but some devices will merrily oscillate at higher frequencies. You must be aware of this. If you ignore this you will learn it the hard way.

My experience has taught me to consider the audio bandwidth to extend up to the area of 1 MHz. I have seen circuits oscillate above this frequency. What do you consider the high frequency of audio to be? Unintended signals are every bit as important as the intended ones.

-Chris

 

[suzyj]

Re: OK.-

About the lead-free solder (the RadioShack mentioned earlier), i've used with my standard 25W or 30 W Goot solder iron, in RCA or TRS plugs and jacks involved in lots of audio connections, inside equipment, or making connection cables or extensions. it results in a firm sound, more detail in the wave shape..You'll can re-discover your existing CD's, the sound from your tuner and other sources of sound.
The difference in speaker connections is greater than the single ended (RCA-To-RCA) connections.
You need just to spend a few dollars in that lead-free solder, and try.

Barf!

This is tweaking of the highest order.



I only use 2% silver solder. It's a little more expensive than normal eutectic lead/tin, but melts a few degrees lower, flows better, and makes my tips last longer. I always add RMA flux (solder wire never contains enough) and make sure I clean the board after soldering to remove the flux.

Lead free solder is complete rubbish.

 

[anatech]

Hi suzyj,

Lead free solder is complete rubbish.

Agreed. It is documented rubbish!

The Telecom industry doesn't use it
The Military doesn't use it
I'll bet that any life support gear doesn't use it

I don't use it.

I have used the 2% silver stuff. It's okay.

I always add RMA flux (solder wire never contains enough) and make sure I clean the board after soldering to remove the flux.

Same here. Every single time.

I have noticed when working on equipment that I did work on over 10 years ago that my joints are still very good. The OEM joints deteriorate a fair amount. There must be something about a wave soldering machine that doesn't do as good a job. They always go crystalline and pull back from the component lead.

-Chris