i've replaced NE5532 for high-speed AD826 in a buffer stage preamp
How do you know that it oscillates ?
Do you hear it or do you measure it with an oscilloscope ?
When i decouple the AD826 with BG 10uF//Wima mks0.1 , the sound is really faster but the midrange is crisp and harsh
I think that the Ad 826 isn't the best substitute. You must use OPA 627 or AD 825.
How many volts are the supply?
you can use AD 825 or OPA 627 because the max. supplyvoltage of the AD 825 is +/-15V.
although you could have oscillation at audio frequencies and hear it, most substitution based oscillations occur well above audible frequencies. Voltage rail bypassing will not fix this...contrary to other posts.
Crank it up...
I have replaced scores ofopamps with high speed ones and have never had oscillations. In fact, I have just done what you did on a Midiman Duo to good effect. This business of bypassing is just scare mongery. If the thing iscillates, you should hear the effects.
If the thing oscillates above audio frequencies, which is very possible, you won't hear it and it can damage things. While it is certainly true that we can hear things we cannot measure the converse is absolutely not true. Just because you can't hear it, doesn't mean bad stuff is not happening. Check the output with a scope to make sure.
Not as simple; you need a scope with sufficient bandwidth and good trigger. In twenty years of audio modification and construction, I have only seen oscillation in poorly designed equipment; even in the stock, Sony SCD 940 which has vigorous ground loops.
Less technically equipped people should not be worried; they just need to be careful. If there is oscillation, then there is usually some manifestation. Auidio is not rf engineering at the ouput stages.
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