Dear all,
I have a Musical Fidelity Nu-Vista 300 power amp which I really love.
Recently I recapped it and now I am looking for TL084CN upgrades.
The amplifier uses one TL084CN per channel.
Brown dog adapters has two adapters to help me with that.
First is SO to DIP adapter that I could use for OPA1644.
The second and more interesting adapter allows to integrate two OPA1612 as TL084 replacement.
Has anyone tried it?
I don't ask if it's worth it since this is a high class amplifier and deserves a better opamp.
If anyone like, I could provide with high resolution images of the pcb's.
Thanks
I have a Musical Fidelity Nu-Vista 300 power amp which I really love.
Recently I recapped it and now I am looking for TL084CN upgrades.
The amplifier uses one TL084CN per channel.
Brown dog adapters has two adapters to help me with that.
First is SO to DIP adapter that I could use for OPA1644.
The second and more interesting adapter allows to integrate two OPA1612 as TL084 replacement.
Has anyone tried it?
I don't ask if it's worth it since this is a high class amplifier and deserves a better opamp.
If anyone like, I could provide with high resolution images of the pcb's.
Thanks
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1) "deserves" is a moral/ethical/humanistic/sociological/legal qualification which has no meaning in a Technical sense.
As in: it belongs to a "Humanities" area of knowledge instead of a "Sciences" area, which includes Technology, so no use or meaning here.
2) define "better"
Non designers sometimes think that a product performance (in this case an amplifier) depends on individual parts quality, as in total quality is the sum or grand total of all individual parts "quality", so improving one, the whole will improve.
Reality is way more complex; a final product (in this case an amplifier) is a *system* , made out of individual parts, no doubt, but which are not simply "thrown together" but carefully, painstakingly mated to each other.
Even without defining "better", we can be certain that we are meaning a "different" part (or it would not make much sense replacing something by functionally the same).
The Million dollar question is: will the system (the amplifier) work better now?
* it might work better (by sheer chance)
* it might not change
* it might work worse
point is, a random replacement is not the way to go, and in any case we can´t answer that with any certainty ... we haven´t even seen a schematic.
And even if we did .......
Talking specifically about what you want to replace, and with the caveat that the schematic is unknown, so far:
* if new Op Amp has less noise but otherwise is *absolutely* the same, that looks "harmless" and can improve results.
* if it "distorts less" , again being *absolutely* the same on all other parameters, that might be "harmless" and still improve results. Although I guess Op Amp distortion, old or new, is already well below the threshold of audibility.
* if its "faster", has wider band, higher slew rate, etc. , think again, it might turn designer´s *careful* amplifier stability achieved by designer out of the window.
In a nutshell, not saying amplifier can´t be improved, anything can, but it´s not as simple as you seem to think.
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Thank you very much for your obvious statistical result of replacing an opamp. This is why I have specifically mentioned adapters and opamps. If someone tried something somilar regarding TL084 upgrade will have a more specific opinion. Regarding OPA devices are mentioned key points are, higher slew rate, lower input noiser, massivly less distortion (tl084 0.01% vs OPA 0.0000x%) higher bandwitdh.
So I suppose that if the upgrade will be succesfull without any issues then I will hear it for sure in a 8.500 euros amplifier. I heard the ELNA Silmic II capacitors after the recap. I am planning to put PDIP sockets for my experiments. So if there is no real gain I will just put back the ST TL084CN's.
So I suppose that if the upgrade will be succesfull without any issues then I will hear it for sure in a 8.500 euros amplifier. I heard the ELNA Silmic II capacitors after the recap. I am planning to put PDIP sockets for my experiments. So if there is no real gain I will just put back the ST TL084CN's.
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There is an discreet toroid transformer that powers the board, the board it self also contains the amplifier protection with it's relays. The rca input cables come first to this board and after wards to the line amp pcb (the nuvistor single board per channel) for each channel.
With the same logic I could leave also the Jamicon capacitors in their places.
I do appreciate TL084 because I am a 80's guy! But since then evolution occurred. I always loved the Burr Brown sound. It's just an experiment so nothing bad will occur. If it works then great, if not then back to the TL084's.
I always thought it was the other way around!
But looking at the datasheets, both op-amps have the exact same distortion and noise numbers and graphs!
On the other hand, TI, in the datasheet, suggests to use the TL07x chips for high end audio circuits.
Regards, Peter
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I don't know about 07x or 08x but I know that 08x of ST electronics have higher slew rate than TI. Maybe better in some other aspects too. There is a lot of mythology regarding 07x and 08x. Well undocumented mythology. There are also TLE207x and TLE208x which TI claims it's a direct replacement of 07x and 08x respectively. I have bought them too and I am planning to "listen" to them soon. Nothing though exotic than burr brown OPA series.
If I read this correctly, this Nu-Vista 300 also has a Nuvistor *tube*. This is SO 1959! There has been some evolution (at least change of fashion) since then.
I'll have No Opinion on swopping a TL07x. I do know that almost any commercial track has been through multiple TL07x in studio internal paths; one less seems trivial to me.
Tube sound is eternal and surely a matter of taste. This amplifier is an hybrid as you already read. SAP15 as output Nuvistor C6W4 as line amp. It also has chokes! Well if you prefer evolution in total then go to Class D. Or as I call it Class Frankestein.
It's a so magical amplifier and unique. The best of both worlds! Accurate but warm.
Well, in that case, it seems that TL084CN's are used for the signal processing, most likely to sum the phono input signal, and the feedback signal, into a single-ended output -> see attached.
If my assumptions are correct, you could try OPA4134 as a drop-in replacement. Just make sure that the Vcc / Vee are not greater than + and - 18V.
Do you listen to a turntable? If not, leave them alone. If you DO, you will notice a very nice improvement.
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I remember the same.
Been making amps since 1969, always an Op Amp lover, and my historical sequence, each step purportedly improving on the earlier one was: LM709 > uA741 > RC4558 > LF353 > TL082 > TL072 .
And stayed there, because tl072 still are good enough, plus inexpensive and readily available all over the World.
And having not much use for an Op Amp which does 0.001% instead of 0.1% distortion when I purposely add 5% to 80% of it elsewhere, nor great bandwidth when Guitar speakers drop like bricks (24dB/oct) above 2500 to 4500Hz anyway.
To boot, peaking 6 to 12dB just before that
Been making amps since 1969, always an Op Amp lover, and my historical sequence, each step purportedly improving on the earlier one was: LM709 > uA741 > RC4558 > LF353 > TL082 > TL072 .
And stayed there, because tl072 still are good enough, plus inexpensive and readily available all over the World.
And having not much use for an Op Amp which does 0.001% instead of 0.1% distortion when I purposely add 5% to 80% of it elsewhere, nor great bandwidth when Guitar speakers drop like bricks (24dB/oct) above 2500 to 4500Hz anyway.
To boot, peaking 6 to 12dB just before that
The pcb that holds the two TL084's has a discreet power supply from a discreet toroidal. At the pcb power supply there is a pair of 7812/7912 so the power supply it's 12V.
I guaranty you that there will be significant audible improvement even without turntable.
Not yet. But I am thinking soon to buy a decent one and start "collecting" records.
CD and it's derivatives are dead.
This is phono pre-amp.
How you can have "improvement even without turntable" ?
No. Nu vista 300 is a power amp, accompanied by Nu vista pre amp.
I mention "phono" but I just mean RCA input jack.
It's not an integrated amplifier.
I apologize for the misunderstanding.
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