It will be interesting to hear your listening impressions. and if you haven't already seen it then this is the kind of thing that can (sometimes) go wrong.
http://www.diyaudio.com/forums/anal...u-have-checked-see-its-stable-havent-you.html
http://www.diyaudio.com/forums/anal...u-have-checked-see-its-stable-havent-you.html
Dear Mooly,
Agree and the DAC is still on.... BY the way my DAC is the "famed" Xiang Sheng DA-01A which provides up to 24 bits and 192KHz sampling rate. Sure pray that the results will be better with the new OP amps as compared to the former which is an OPA2107AP. A "BB".
Just a question, ( a dumb one as i am very new in DIY). Can we detect oscillation just by hearing? If yes, what are the characteristics of an op amp in oscillations?
thanks...
Agree and the DAC is still on.... BY the way my DAC is the "famed" Xiang Sheng DA-01A which provides up to 24 bits and 192KHz sampling rate. Sure pray that the results will be better with the new OP amps as compared to the former which is an OPA2107AP. A "BB".
Just a question, ( a dumb one as i am very new in DIY). Can we detect oscillation just by hearing? If yes, what are the characteristics of an op amp in oscillations?
thanks...
Thanks to Esperado's recommendation on another thread I recently tried out the OPA260. But I'm fairly certain I had it oscillating at first - the characteristic was that the lowest level ambience detail was obscured as if by a fine 'mist'. I guessed it was oscillation due to too much capacitance on the outputs (I have a CCS on the OP to bias into classA) so I upped the number of ferrite beads on the output from 1 to 3. The misty background lifted and I could now hear into the recording. I figured the oscillation had stopped.
No way to reliably detect oscillation audibly. It could range from gross distortion through to just a slight worsening of overall distortion levels. It could appear as noise or noises (white 'phasey' type noise) or even the opamp drawing more current than normal and running warm.
A million and one possible scenarios
2604 is surely different from 4562 family. If you'd replace stock 4562 with say 49860 there's 99% chance it will never oscillate because they are very same i think, even though they sound different. But i guess it's easy to see with oscilloscope, if you don't have one (or good one) talk to local repair shops
OPA2604 is not very good - compared to other BB opamps it's the worst i tried when it comes to resolution, dynamics etc, but he does color sound in a pleasant way. I guess you get most of "BB sound" with this one
4562 and it's relatives may sound brittle and sterile at first, but it does burn-in noticeably. 49860 will have most bass as well as sort of laid-back signature which is easier to adapt to for those coming from BB opamps...
OPA2604 is not very good - compared to other BB opamps it's the worst i tried when it comes to resolution, dynamics etc, but he does color sound in a pleasant way. I guess you get most of "BB sound" with this one
4562 and it's relatives may sound brittle and sterile at first, but it does burn-in noticeably. 49860 will have most bass as well as sort of laid-back signature which is easier to adapt to for those coming from BB opamps...
hi
opa2604 is a fet and lm49860 is a bjt ...
for after D/A input impedance very important ... I favorite is lm49860 too. but for out put stage not for I/V stage after DAC!!!
I think one of the best selection of opa2604 is the sound chip is a part of the Secret in the data sheet. It is rejection noise.
Separation silence background music and realistic tools is in the past.
Because this chip has the ability to be a high performance AC by Amp Bipolar
Is launched.
The use filmcap for bypass PSU recommended. if you want kill pizo effect...
I would rather have it(opa2604) be longs Deck for opa627 chips!!!
this time I metod :
DAC192KBit wolfsun(wm8716) --> opa2604(I/V)---> LME49860(peri Out)---> MUSES 01(input amp)---> 23pic OPA627 (filtering and bufeer ) --> cable VDH (van Den Hul) for hifrecuancy clear Water ... for hi mid Snowline ... for low mid CS122 ... for buss cs122
an other good selection for I/V stage is Muses8920 ( is a Jfet )
I have here oscloscop . But when I think of the art sound ... No longer!
Here the sense of hearing is more important than oscloscop !!!
thanks .afshin
opa2604 is a fet and lm49860 is a bjt ...
for after D/A input impedance very important ... I favorite is lm49860 too. but for out put stage not for I/V stage after DAC!!!
I think one of the best selection of opa2604 is the sound chip is a part of the Secret in the data sheet. It is rejection noise.
Separation silence background music and realistic tools is in the past.
Because this chip has the ability to be a high performance AC by Amp Bipolar
Is launched.
The use filmcap for bypass PSU recommended. if you want kill pizo effect...
I would rather have it(opa2604) be longs Deck for opa627 chips!!!
this time I metod :
DAC192KBit wolfsun(wm8716) --> opa2604(I/V)---> LME49860(peri Out)---> MUSES 01(input amp)---> 23pic OPA627 (filtering and bufeer ) --> cable VDH (van Den Hul) for hifrecuancy clear Water ... for hi mid Snowline ... for low mid CS122 ... for buss cs122
an other good selection for I/V stage is Muses8920 ( is a Jfet )
I have here oscloscop . But when I think of the art sound ... No longer!
Here the sense of hearing is more important than oscloscop !!!
thanks .afshin
THank you for the great tips,
I have a USB oscilloscope and would be interested to know how i can take the measurement for oscillation. Also as mentioned in my earlier post to Mooly, i am using a
"Famed" xiang Shing DA-01A which only allow me to change only 1 OP amp.(socket) without doing any soldering. The DAC original changeable OP amp is the OPA2604 which I had rolled with OPA2134 then OPA2107. And now wanting to try the LMEs.. I had rolled to LM4562 and will intend to roll with LME49720HA and LME49860.
Yes i have heard that all the 3 LMes are identical but i just wanna try and experience with different OP amps.
I have a USB oscilloscope and would be interested to know how i can take the measurement for oscillation. Also as mentioned in my earlier post to Mooly, i am using a
"Famed" xiang Shing DA-01A which only allow me to change only 1 OP amp.(socket) without doing any soldering. The DAC original changeable OP amp is the OPA2604 which I had rolled with OPA2134 then OPA2107. And now wanting to try the LMEs.. I had rolled to LM4562 and will intend to roll with LME49720HA and LME49860.
Yes i have heard that all the 3 LMes are identical but i just wanna try and experience with different OP amps.
A USB scope may not have the bandwidth to show oscillation which is usually at very high frequency, typically 1MHz upward. To check for oscillation you need to look at the opamp outputs but beware, the capacitance of the scope test leads can either stop oscillation or actually cause it. You really need a low capacitance probe.
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