Mod your Beresford 7520

[leo]

I have a 7520 and a access to a digital scope.

Then what you waiting for, get probing

[HighFidelityGuy]

Then what you waiting for, get probing

Someone to tell me what I'm looking for and how to look for it.
I know roughly how to use a scope but how should I set everything up to look for oscillation?

[leo]

The detail is excellent. Best I've heard so far. Just need to tame the top end a bit.

Its another chip that may have some HF ringing, this could be making it sound bright.
Problem is chips like this and 4032 are bloody fast and high bandwidth, they don't always work too well as a straight drop in replacement for a circuit designed to use say a NE5532 without some adjustments/modifications .

[trailer]

Its another chip that may have some HF ringing, this could be making it sound bright.
Problem is chips like this and 4032 are bloody fast and high bandwidth, they don't always work too well as a straight drop in replacement for a circuit designed to use say a NE5532 without some adjustments/modifications .

I'd say it was more revealing of a poor recording.

[leo]

Someone to tell me what I'm looking for and how to look for it.
I know roughly how to use a scope but how should I set everything up to look for oscillation?

If you've an idea how to use it I presume you know how to adjust the volt/div and time/div etc

Replay a test signal like a sine wave, these can be downloaded and burnt onto a disc.
Look at the signal on the op-amps input pins and compare it against the output pins

Heres some small ringing on a 1k sinewave


You can get much worse than that sometimes the output can look wild without any signal

[HighFidelityGuy]

If you've an idea how to use it I presume you know how to adjust the volt/div and time/div etc

Replay a test signal like a sine wave, these can be downloaded and burnt onto a disc.
Look at the signal on the op-amps input pins and compare it against the output pins

Heres some small ringing on a 1k sinewave


You can get much worse than that sometimes the output can look wild without any signal

That makes perfect sense to me, you'd make a good teacher if you're not one already. I should be able to set this up before the end of the week. Thanks!

[Covenant]

What a helpful bunch of people are on this forum.

[leo]

No problem! no better way to learn than to get stuck in

Funny thing is some people seem to like the effect of instability , it can give the impression of added air and detail, what your hearing is stuff thats not on the actual recording but caused by the HF ringing.
Nothing worse to my ears than this brightness/distortion, its not good long term for your kit either

BTW theres more involved with thorough testing but as a simple starter to at least give you an idea if the op-amp stands half a chance in there

[James G]

Leo,

How do find the 1364's? I'm pleasantly surprised.

If you like detail and forwardness I'm thinking you'll also like the AD8066's. I was using the 1364's for awhile and then switched back to the 8066 and noticed they were doing much the same thing but more of it. I'm liking that speed and clarity combined with my tube amp much better than the LME49720. My wife loves them too and says they sound totally different whereas the others sound mostly alike (to her).

Note that I'm running it in a TC-7510. Leo or Stan, you reckon there would be much difference in the sound for a 7520?

[rhmjmango]

No problem! no better way to learn than to get stuck in

Funny thing is some people seem to like the effect of instability , it can give the impression of added air and detail, what your hearing is stuff thats not on the actual recording but caused by the HF ringing.
Nothing worse to my ears than this brightness/distortion, its not good long term for your kit either

BTW theres more involved with thorough testing but as a simple starter to at least give you an idea if the op-amp stands half a chance in there

Hi Leo, are you referring to the 1364 chip?