Hi
This Adam A7 come with D-K cap. Do anyone know what brand is it?
And I replace power amp cap to elna cerafine and blackgate
Preamp replace blackgate and cerafine too. And change to bc film cap. Opamp change to opa2107.
Power filter cap change to bc 146.
Do anyone can give me suggestion? What wrong?
This Adam A7 come with D-K cap. Do anyone know what brand is it?
And I replace power amp cap to elna cerafine and blackgate
Preamp replace blackgate and cerafine too. And change to bc film cap. Opamp change to opa2107.
Power filter cap change to bc 146.
Do anyone can give me suggestion? What wrong?
Looks like an active crossover with Gainclone amps. Better not change many things at the same time. D-K is cheap but very good sounding.
1) Make sure you have compared both opamps (other components being the same) to make sure the problem is not due to the opamp. There are many (SMD!) opamps, which one that you changed? All?
2) Small caps (mostly in nF) might be crossover elements. If so, you cannot replace them with different values. Tho may be they are the SMD ones.
1) Make sure you have compared both opamps (other components being the same) to make sure the problem is not due to the opamp. There are many (SMD!) opamps, which one that you changed? All?
2) Small caps (mostly in nF) might be crossover elements. If so, you cannot replace them with different values. Tho may be they are the SMD ones.
Guess I have to suggest, are you sure you did not get counterfeit parts?
By worse sound, what do you mean?
You modified two boards. Which is causing the problem? Both?
I agree, it is likely an oscillation has been introduced. It looks like some of the caps are physically much larger. Were the values changed? You need to get a scope on it.
By worse sound, what do you mean?
You modified two boards. Which is causing the problem? Both?
I agree, it is likely an oscillation has been introduced. It looks like some of the caps are physically much larger. Were the values changed? You need to get a scope on it.
Hi
I replace all the cap with same uf. S-K cap size small than normal cap. D-K cap sound very good?? You compare and get this result??
I stupid that I believe change all good componet will sound good. But I am wrong. I change all opamp to opa2107. My friend tell me original a7 sound better. I will know the result tomorrow.
How should I do now?
I replace all the cap with same uf. S-K cap size small than normal cap. D-K cap sound very good?? You compare and get this result??
I stupid that I believe change all good componet will sound good. But I am wrong. I change all opamp to opa2107. My friend tell me original a7 sound better. I will know the result tomorrow.
How should I do now?
Give the big electros plenty of time to stabilise. Some of the Audio Grade types are notorious for taking ages to stabilise.
Also, never do more than one modification at a time, and take the time to fully evaluate any audible changes.If in doubt, reverse the modification and listen again,
Also, never do more than one modification at a time, and take the time to fully evaluate any audible changes.If in doubt, reverse the modification and listen again,
What do you mean YOUR FRIEND told you the original was better??? Have you compared by yourself? You cannot compare 2 components in an audio system when the other components (speaker, amp, etc) are not the same.
Cerrafine and Black Gate is fine for power supply (decoupling). You may have done some mistakes (is it easy to solder smd chips? I heard it cannot be too hot), or the Cerrafine/Black Gate is not original. But if the cap is "in signal line" (coupling), yes both BG or Cerrafine may sound inferior in certain system compared to cheaper cap that is good for coupling (but bad for decoupling).
Hi
This Adam A7 come with D-K cap. Do anyone know what brand is it?
And I replace power amp cap to elna cerafine and blackgate
Preamp replace blackgate and cerafine too. And change to bc film cap. Opamp change to opa2107.
Power filter cap change to bc 146.
Do anyone can give me suggestion? What wrong?
Perhaps you have not used Blackgates before? Don't throw the baby out with the bath water, Blackgates take at least three weeks to burn in and will still do small changes for several more after that. Best regards Moray James.
i run the blackgate cap about 1000 hrs in my guitar pedal. i just find out the sound is more worse.
Didn't they stop making Black gate caps long ago? That would mean that these are old, and will probably need reforming. It's not a good idea to buy old caps. 🙂
By the way, burn-in is not a thing.
By the way, burn-in is not a thing.
The yellow cap is made by many companies. Here it is commonly called MKM capacitor. I don't know what it is made of, but it is cheap but good sounding. It is a good decision to use it for commercial offering as its performance-to-price ratio is very high. And it works in all positions.
The OPA is better than the JRC/NJM, I don't think the upgrade will reduce performance. The JRC can be used with lower voltage than the OPA, but I don't think they use below +/-10V (as it will degrade the performance).
I think you need to listen both amps. Who knows you have different taste than your friend. The original caps will tend to sound "thin" but quite transparent, so good at middle to high. Cerrafine and especially Black Gate, especially when it is in signal path, the sound can be "hard" with small speakers. Its bandwidth is wider, you can hear more bass, but the sound is not friendly to ears.
Check the cap in signal cap (usually in input and output to block DC). Cap in this position is usually used to "tune" the sound of a circuit. If it is an electrolytic (such as Cerrafine/BG), simply parallel them with your MKM/MKP. Or use smaller value if you have one. Or use the original cap
The OPA is better than the JRC/NJM, I don't think the upgrade will reduce performance. The JRC can be used with lower voltage than the OPA, but I don't think they use below +/-10V (as it will degrade the performance).
I think you need to listen both amps. Who knows you have different taste than your friend. The original caps will tend to sound "thin" but quite transparent, so good at middle to high. Cerrafine and especially Black Gate, especially when it is in signal path, the sound can be "hard" with small speakers. Its bandwidth is wider, you can hear more bass, but the sound is not friendly to ears.
Check the cap in signal cap (usually in input and output to block DC). Cap in this position is usually used to "tune" the sound of a circuit. If it is an electrolytic (such as Cerrafine/BG), simply parallel them with your MKM/MKP. Or use smaller value if you have one. Or use the original cap
as the blackgate. i bought it from partsconnextion before. it is just few year before.
as the opamp. i believe burr brown will sound better. in fact, i like ad8620 more. but it can handle 13v max. i guess my A7 run 15v in the opamp , so i use opa2107. and i like lme49720 too. it is good for monitor .
i will get my friend and my speaker today. i can do this test, if i think my A7 sound not good than original. i will install my friend A7 preamp board to my A7, so i can find out the power amp section or preamp serction problem.
last, i always mod the guitar pedal. i like BC 134 , 136 cap. it is very balance sound . i guess it may great in my A7. also, i like panasonic FC too. is it good idea to use it in A7?
last, cerafine and blackgate is good for power section only? how about silmic 2? is it better than cerafine???
thanks
as the opamp. i believe burr brown will sound better. in fact, i like ad8620 more. but it can handle 13v max. i guess my A7 run 15v in the opamp , so i use opa2107. and i like lme49720 too. it is good for monitor .
i will get my friend and my speaker today. i can do this test, if i think my A7 sound not good than original. i will install my friend A7 preamp board to my A7, so i can find out the power amp section or preamp serction problem.
last, i always mod the guitar pedal. i like BC 134 , 136 cap. it is very balance sound . i guess it may great in my A7. also, i like panasonic FC too. is it good idea to use it in A7?
last, cerafine and blackgate is good for power section only? how about silmic 2? is it better than cerafine???
thanks
Yes. One in +V, one in -V. Four for stereo.
In signal path, none of the cap ends goes to ground. They are usually in input or output of the opamp. So for opamp, check on pin#3 (or pin#2)
In attachment, input cap is circled in red. Sometimes, to save space, electrolytics (usually of too high value) is used there.
Attachments
Hi
As the power section filter cap. Should I use rubycon zlh, nichicon vz , Panasonic FC or Philips 136 instead of cerafine?? Cerafine for signal Path or power filter ?
I will check the preamp board. Anyways, blackgate not good in signal path, right? How about cerafine?
As the power section filter cap. Should I use rubycon zlh, nichicon vz , Panasonic FC or Philips 136 instead of cerafine?? Cerafine for signal Path or power filter ?
I will check the preamp board. Anyways, blackgate not good in signal path, right? How about cerafine?
As you can see from LM3876 above 3u3 input cap is sufficient. I don't know what IC in your amp is. If it is the LM3875, then the cap on pin#7 or #8. I can see that you have electrolytics there, around 47uF-100uF. Better is MKP 2.2uF but the size is big. If electrolytics, better use NP type (non-polar)
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