Dear Forum,
The output stage of my ReVox B261 tuner is an RC4559 dual opamp. Being a 30-year old design I can just imagine there should be something better available in 2012..
As a direct equiv I saw a BB OPA2111AM but bloody expensive (Farnell approx 23 Eur) If this would be a real improvement I would even do it but sofar no proof..
Any good suggestion? I would use the OPA 627 but the board design does not allow 🙂
Leonard
The output stage of my ReVox B261 tuner is an RC4559 dual opamp. Being a 30-year old design I can just imagine there should be something better available in 2012..
As a direct equiv I saw a BB OPA2111AM but bloody expensive (Farnell approx 23 Eur) If this would be a real improvement I would even do it but sofar no proof..
Any good suggestion? I would use the OPA 627 but the board design does not allow 🙂
Leonard
I would suggest LME49720. Of course, the tuner being a thirty year
old design, you will have to check for stability after changing the op amp.
old design, you will have to check for stability after changing the op amp.
Let's be realistic.
A quality tuner of the day would still have had at least 0.2% THD + Noise in stereo FM mode. Even a pulse counting detector type will still have 0.1% at best.
It would be pointless to fit anything better than standard parts. However, the 5532 is still 2 orders of magnitude better, cheap, readily available and suitable for output applications.
A quality tuner of the day would still have had at least 0.2% THD + Noise in stereo FM mode. Even a pulse counting detector type will still have 0.1% at best.
It would be pointless to fit anything better than standard parts. However, the 5532 is still 2 orders of magnitude better, cheap, readily available and suitable for output applications.
I agree, throw an NE5532 in there - and that's already muchly better without being stupidly expensive. Yes, they're old design, but still excellent quality.
It's my feeling that theres just no point in using recent high-end opamps unless the circuit is designed for them.
It's my feeling that theres just no point in using recent high-end opamps unless the circuit is designed for them.
get your shelf a few 5532 different makes they are dirt cheap
Many people so far including me noticed quite a lot of difference between 5532 makes
Many people so far including me noticed quite a lot of difference between 5532 makes
Guys thanks for the responses, I ordered a TI NE5532AP for the ashtonishing cost of 69 Eurocents. Can't really experiment with different versions as once soldered in and done, I don't see myself opening everything again to try a new opamp. Will compare once with the original RC4559 see if it makes any difference at all. Sand is sand (yes I'm a thermionic fundamentalist) after all 🙂
Leonard
Leonard
Personally I would prefer to keep it original and use an RC4559. Apparently the designers have found it adequate for its job.
Regarding distortion: I've seen the inside of one professional Revox tuner and it had trimmed LC IF filters and a transmission line (coaxial cable) as the frequency to phase converter of the quadrature detector. That is, it was really designed for the lowest possible distortion, much more so than a typical consumer-grade tuner.
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