Hello Gurus,
I have an audiosource amp seven t with tripath ta0104a chip.
I also have a carver hr 875 receiver which I am going to re-cap.
BOTH units have the 4558dd/jrc op amp in them.
The audiosource has 2 4558's and 1 ne5532.
I am about to buy some opamps for replacement in this and other gear also, and I am asking for elder's/experienced opinions on what to try/use.
I see OPA2** and LME4*** mentioned a lot here.
What is a good replacement for the Audiosource amp and carver receiver/what's maybe going overboard?
I drive ribbons with the audiosource.
I drive subs with the carver front channels.
Caps in carver receiver I was going to use either panasonic fc or nichicon.
Audiosource has elna, rubycon, kmg, and others in it. They good?
I know elna's are expensive.
I can include pictures depending on how helpful someone wants to be..
Many thanks,
paul
I have an audiosource amp seven t with tripath ta0104a chip.
I also have a carver hr 875 receiver which I am going to re-cap.
BOTH units have the 4558dd/jrc op amp in them.
The audiosource has 2 4558's and 1 ne5532.
I am about to buy some opamps for replacement in this and other gear also, and I am asking for elder's/experienced opinions on what to try/use.
I see OPA2** and LME4*** mentioned a lot here.
What is a good replacement for the Audiosource amp and carver receiver/what's maybe going overboard?
I drive ribbons with the audiosource.
I drive subs with the carver front channels.
Caps in carver receiver I was going to use either panasonic fc or nichicon.
Audiosource has elna, rubycon, kmg, and others in it. They good?
I know elna's are expensive.
I can include pictures depending on how helpful someone wants to be..
Many thanks,
paul
Opamps aren't always in the signal path, they could just as easily be in a PSU etc.
4558's are little different to just dual 741's so I find it hard to believe they are used in the audio path.
Be careful what you swap without studying the circuit first.
Caps, if you must replace them stick to top quality brands like you mention such as Rubycons Elnas or Panasonic etc.
4558's are little different to just dual 741's so I find it hard to believe they are used in the audio path.
Be careful what you swap without studying the circuit first.
Caps, if you must replace them stick to top quality brands like you mention such as Rubycons Elnas or Panasonic etc.
The 1458 is a dual 741; the 4558 is designed to be a better performing replacement for the 1458. Still, it is pretty aweful. Amazingly they are sometimes found in lower end gear, probably because they are very very cheap.
I'd be careful when replacing a 4558 with a one of the higher speed OPA and LME series often talked about here. You may end up with an oscillator instead of an amp. Your speakers won't like that.
The Panasonic FC are not specifically designed for audio, but they are of very high quality, and have a good reputation for audio. Something like Nichicon Muse (KZ is best, Fine Gold is good too) or Elna Silmic are specifically designed for Audio and also have a very good reputation, as far as 'lytics go anyway. As always, some people prefer one over the others, sometimes very strongly, but not everyone agrees. My opinion is that you won't go wrong in replacing the old, dried out generics with any of these.
I'd be careful when replacing a 4558 with a one of the higher speed OPA and LME series often talked about here. You may end up with an oscillator instead of an amp. Your speakers won't like that.
The Panasonic FC are not specifically designed for audio, but they are of very high quality, and have a good reputation for audio. Something like Nichicon Muse (KZ is best, Fine Gold is good too) or Elna Silmic are specifically designed for Audio and also have a very good reputation, as far as 'lytics go anyway. As always, some people prefer one over the others, sometimes very strongly, but not everyone agrees. My opinion is that you won't go wrong in replacing the old, dried out generics with any of these.
"Opamps aren't always in the signal path, they could just as easily be in a PSU etc.
4558's are little different to just dual 741's so I find it hard to believe they are used in the audio path.
Be careful what you swap without studying the circuit first."
In the case of the receiver, the 4558dd is absolutely in the path between the main board and front pre-output. There are 5 more of these opamps scattered about in various places on the mainboard and also cards.(for center/surround/phono/whatnot.)
I can't get a schematic for this thing as I'm having problems with the carver pages.
here is top and bottom of place in question:
JS01 is the front L+R Preoutput:
Here is a snap of the tripath(audiosource amp), the TA0104 chip and amp section is directly to the left off the photo, the white plug is pre in (no dang schematic for this one either):
Its a hell of a clean amp as-is, but if I can make it better by changing the op's I'd like to socket it and try it. Same for the carver rcvr...
Thanks for the help!
paul
4558's are little different to just dual 741's so I find it hard to believe they are used in the audio path.
Be careful what you swap without studying the circuit first."
In the case of the receiver, the 4558dd is absolutely in the path between the main board and front pre-output. There are 5 more of these opamps scattered about in various places on the mainboard and also cards.(for center/surround/phono/whatnot.)
I can't get a schematic for this thing as I'm having problems with the carver pages.
here is top and bottom of place in question:
JS01 is the front L+R Preoutput:
Here is a snap of the tripath(audiosource amp), the TA0104 chip and amp section is directly to the left off the photo, the white plug is pre in (no dang schematic for this one either):
Its a hell of a clean amp as-is, but if I can make it better by changing the op's I'd like to socket it and try it. Same for the carver rcvr...
Thanks for the help!
paul
If the 4558's really are in the audio path then I would definitely look to swap them.
You have loads of options... however don't underestimate the power requirements. Although we are only talking milliamps, 5 of them (4558's) at a couple of ma each is different to 5 NE5532's at say 15 ma each. Going from memory for those figures 🙂
The TL072 FET opamp is a very respectable performer... it will replace the 4558's directly and offer far superior performance. For one thing the slew rate of the 4558 is around 1v/us which is too slow to allow an undistorted full output swing at 20khz...
The TL072 may be ancient, but it's really good sonically.
If the PSU is up to it, the LM4562 is a top performer, and a favourite of mine the FET OPA2604
The 5532 and 4558 are also "unity gain stable" as are all the options mentioned... something to be aware of.
You have loads of options... however don't underestimate the power requirements. Although we are only talking milliamps, 5 of them (4558's) at a couple of ma each is different to 5 NE5532's at say 15 ma each. Going from memory for those figures 🙂
The TL072 FET opamp is a very respectable performer... it will replace the 4558's directly and offer far superior performance. For one thing the slew rate of the 4558 is around 1v/us which is too slow to allow an undistorted full output swing at 20khz...
The TL072 may be ancient, but it's really good sonically.
If the PSU is up to it, the LM4562 is a top performer, and a favourite of mine the FET OPA2604
The 5532 and 4558 are also "unity gain stable" as are all the options mentioned... something to be aware of.
I searched 'unity gain stable' and got a lot of information. Thanks for the hint!😀
The math is ahead of me at this point, I am more of a tactile prodigy.
Are the LM and OPA you mention 'not' direct replacements of the 4558?-
-(I am considering a buy-and-try with these in addition to your recommendation of tl072)
What sort of modifications would need to ensue, if not?
Is there a quick and dirty way to add current?(pardon ignorance plz)
In the third pic, what would you change of the 3 op amps there?
Thanks again,
paul
All the devices I mentioned should work with no modifications needed at all.
Nothing is 100% guarateed however, you should always study the circuit really to see exactly what the devices are used as... and I see what looks like a 1 meg resistor (R18) on pin1 of one of the 4558's in the last picture. That's a high value for a "normal" audio part of a circuit... is it a filter ? A DC servo ?
That said the TLO72 is pretty much sure to be OK.
The NE5532 is an industry standard device, purpose designed for audio, and the only real "upgrade" has to be something like the modern LM4562.
I would fit sockets and try first the TLO72, even using that for the 5532 and see what you think.
To add current to the PSU. Again would have to see circuit. The TL072 will be fine as is.
Nothing is 100% guarateed however, you should always study the circuit really to see exactly what the devices are used as... and I see what looks like a 1 meg resistor (R18) on pin1 of one of the 4558's in the last picture. That's a high value for a "normal" audio part of a circuit... is it a filter ? A DC servo ?
That said the TLO72 is pretty much sure to be OK.
The NE5532 is an industry standard device, purpose designed for audio, and the only real "upgrade" has to be something like the modern LM4562.
I would fit sockets and try first the TLO72, even using that for the 5532 and see what you think.
To add current to the PSU. Again would have to see circuit. The TL072 will be fine as is.
Have a look at this just to confuse you 🙂
I added some 'scope screen shots at around post #1017
Don't let it put you off... fit sockets... try the TLO72's for starters.
http://www.diyaudio.com/forums/chip-amps/154106-best-sounding-audio-integrated-opamps-51.html
I added some 'scope screen shots at around post #1017
Don't let it put you off... fit sockets... try the TLO72's for starters.
http://www.diyaudio.com/forums/chip-amps/154106-best-sounding-audio-integrated-opamps-51.html
One other thing... do you know how to unsolder the old IC's in double sided print ?
The safest way is to snip each leg at the body of the IC, then heat and pull each leftover pin out, then use braid/sucker and clear the hole.
A good trick once you get used to it is to use a small stainless wire and to use that to probe the hole when the solder is melted. Being stainless it won't stick to it... then use braid if needed to tidy it up.
And that's it for tonight 🙂
The safest way is to snip each leg at the body of the IC, then heat and pull each leftover pin out, then use braid/sucker and clear the hole.
A good trick once you get used to it is to use a small stainless wire and to use that to probe the hole when the solder is melted. Being stainless it won't stick to it... then use braid if needed to tidy it up.
And that's it for tonight 🙂
Wow thanks for the input!
"I see what looks like a 1 meg resistor (R18) on pin1 of one of the 4558's in the last picture. That's a high value for a "normal" audio part of a circuit... is it a filter ? A DC servo ?"
I believe that one 4558 (or both, I haven't looked closely at that yet) drive the power supply, so servo? Not sure w/o schematic I'm going to look harder for one.
"do you know how to unsolder the old IC's in double sided print ?
The safest way is to snip each leg at the body of the IC, then heat and pull each leftover pin out, then use braid/sucker and clear the hole.
A good trick once you get used to it is to use a small stainless wire and to use that to probe the hole when the solder is melted. Being stainless it won't stick to it... then use braid if needed to tidy it up."
Yes that is the method I use for removing IC's as you mentioned..
I have a vac and like 5 irons.
I have been soldering since ~12 years old when my Atari broke😀
A career tech, I also have Mr Babin's tutorial and successfully repaired amps with it.
Many Thanks, and for the Link, I will update...
paul
"I see what looks like a 1 meg resistor (R18) on pin1 of one of the 4558's in the last picture. That's a high value for a "normal" audio part of a circuit... is it a filter ? A DC servo ?"
I believe that one 4558 (or both, I haven't looked closely at that yet) drive the power supply, so servo? Not sure w/o schematic I'm going to look harder for one.
"do you know how to unsolder the old IC's in double sided print ?
The safest way is to snip each leg at the body of the IC, then heat and pull each leftover pin out, then use braid/sucker and clear the hole.
A good trick once you get used to it is to use a small stainless wire and to use that to probe the hole when the solder is melted. Being stainless it won't stick to it... then use braid if needed to tidy it up."
Yes that is the method I use for removing IC's as you mentioned..
I have a vac and like 5 irons.
I have been soldering since ~12 years old when my Atari broke😀
A career tech, I also have Mr Babin's tutorial and successfully repaired amps with it.
Many Thanks, and for the Link, I will update...
paul
Yeah, I figured they were probably not audio.. it wouldn't really make sense to have an ne5532 and 2 4558's all for audio
I received today a Carver C1 in the mail
I like what it does for the midrange/midbass, hearing another layer in pink floyd already.
It is also getting capped and it has 9(nine) 4136cp's in it.
I refer you to post #8 :
http://www.diyaudio.com/forums/solid-state/120496-replacement-4136cp.html
There, they are talking about replacing 7 of them but there are 9 in mine.
I am looking at RC4136, should I just wait til I can blow $50 on adapter boards?
paul
I think if you are going to swap them, go for something much more up to date.
Just keep the choices sensible... don't go for anything so hi speed that stability might be a problem.
Be prepared to add a small cap in the 0.01 to 0.1uf range across the supply pins too. That's good practice whatever 🙂
Just keep the choices sensible... don't go for anything so hi speed that stability might be a problem.
Be prepared to add a small cap in the 0.01 to 0.1uf range across the supply pins too. That's good practice whatever 🙂
Hi,
There are a lot of different types of Polypropylene caps alone.
What is the preferred type to use in this way?
Thanks,
p
You want something that can be fitted neatly by bending the leads (carefully so as not to damage the cap) to fit exactly across the pins. Most polys are the wrong shape and size so I use something like these. When you solder it direct to the IC use a minimum of solder and just connect to the top of the pin, that way the IC still goes perfectly in a socket.
Ceramic types are good for general decoupling where staility isn't an issue.
--|MCRR25104Z5UM0050|CAPACITOR, CERAMIC MULTILAYER | CPC
Capacitor types and their uses :: Radio-Electronics.Com
Ceramic types are good for general decoupling where staility isn't an issue.
--|MCRR25104Z5UM0050|CAPACITOR, CERAMIC MULTILAYER | CPC
Capacitor types and their uses :: Radio-Electronics.Com
Thanks!
I was working from this page...
I found some silk elnas on ebay for cheap... I guess its overkill but I can always use them elsewhere... 😀
I replaced ne5532 with an lm4562 in the audiosource with a .1 uf cap to pins 4+8....
wow
About all the harshness is removed, same clarity, no, more. (only listened to 2 recordings so far)
Set the eq flat again no fatigue immediately noticeable. 1-2kz area is not so grating as it was.
Also, the dc offset it had is gone.
I have not done anything to the other gear I have in the chain yet...
Thanks again for all your help!
wow
About all the harshness is removed, same clarity, no, more. (only listened to 2 recordings so far)
Set the eq flat again no fatigue immediately noticeable. 1-2kz area is not so grating as it was.
Also, the dc offset it had is gone.
I have not done anything to the other gear I have in the chain yet...
Thanks again for all your help!
That sounds like a bit of a result, pleased you are happy with it 🙂
Did you fit sockets in the end or solder the chip direct ?
Did you fit sockets in the end or solder the chip direct ?
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