Thanks for your input Andrew, I'll take all your considerations into account.
Regarding the DC blocking caps, what would be your recommendation, value and type wise, if I decide to go on and try the 50K pot?
Regarding the DC blocking caps, what would be your recommendation, value and type wise, if I decide to go on and try the 50K pot?
film alone to set your "passive" filter to the frequency YOU want.
Or, a smaller film with a bypass consisting of a very large bipolar electrolytic.
Read Rane for their suggested implementation.
Or, a smaller film with a bypass consisting of a very large bipolar electrolytic.
Read Rane for their suggested implementation.
Sorry Andrew, I checked out Rane's page but couln't find exactly the info you are refering to. May you provide me with the link to that info?
Thanks again!
Thanks again!
I don't know the Rane document by name.
I'll give you the answer:
Rane suggest that the output cap be 220uF bipolar Panasonic and they quote the Panasonic part number. They say bypass this with 1uF film cap. They don't specify the film make nor part number.
This is placed in BOTH poles of the balanced impedance output. This requires that you measure and match the caps.
I turned that around. 1uF for the output cap bypassed with a bipolar electrolytic.
If you read recent literature you will find that best of all the electro combinations id a series pair of bipolar caps for least distortion that approaches film in performance.
A stereo balanced output would thus require 4 off 470uF bipolar. I suspect 4 off 220uF would be virtually as good. I adopted 1uF//100uF and that sounded clean.
I'll give you the answer:
Rane suggest that the output cap be 220uF bipolar Panasonic and they quote the Panasonic part number. They say bypass this with 1uF film cap. They don't specify the film make nor part number.
This is placed in BOTH poles of the balanced impedance output. This requires that you measure and match the caps.
I turned that around. 1uF for the output cap bypassed with a bipolar electrolytic.
If you read recent literature you will find that best of all the electro combinations id a series pair of bipolar caps for least distortion that approaches film in performance.
A stereo balanced output would thus require 4 off 470uF bipolar. I suspect 4 off 220uF would be virtually as good. I adopted 1uF//100uF and that sounded clean.
Thanks Andrew for providing straightforward information. 🙂
Will follow your advice and report back after implementation and tests.
Will follow your advice and report back after implementation and tests.
Input Capacitors
I hope this applies for the preamp section of any integrated as well...
Out of curiosity, I wanted to put it into practice by removing the two ceramic 100pF caps from one AUX line in, and replacing them with two 470pF. There was a noticiable cut in the lower frequencies and some boost in the mids. But no changes in the highs.
Just wondering if something like 47pF would alter the sound towards mid to lower freq.
I hope this applies for the preamp section of any integrated as well...
Out of curiosity, I wanted to put it into practice by removing the two ceramic 100pF caps from one AUX line in, and replacing them with two 470pF. There was a noticiable cut in the lower frequencies and some boost in the mids. But no changes in the highs.
An externally hosted image should be here but it was not working when we last tested it.
Just wondering if something like 47pF would alter the sound towards mid to lower freq.
After a lot of tests I found that it sounds the best - by a large margin- with no input capacitor.
I'm using a ground loop isolator as input DC blocker. Really sounds awesome, and far better than any input cap I tried. I tested several cap configurations and values of brands like Nichicon and Wima.
I'm using a ground loop isolator as input DC blocker. Really sounds awesome, and far better than any input cap I tried. I tested several cap configurations and values of brands like Nichicon and Wima.
Not surprising; as the saying goes, the best (coupling) capacitor is no capacitor.
I'll try later without the capacitors, too.
How do you do for a ground loop isolator as input DC blocker?
The ground loop isolator I believe he is referring to is a transformer, so no DC passes.
I hope I understood your question correctly.
A ground loop isolator will isolate the amplifier ground from the preamp ground preventing any DC offset at the amplifier's input terminals. You won't regret trying one.
input transformer?
Is this what you are talking about?
COUPLING TRANSFORMER 600:365 OHMS | All Electronics Corp.
Is this what you are talking about?
COUPLING TRANSFORMER 600:365 OHMS | All Electronics Corp.
May be sounds wrong but it's probably the way I described it 🙂
Grabbed this image from the net that is probably self explanatory.
An externally hosted image should be here but it was not working when we last tested it.
Not quite sure if that is for audio application. There 're dedicated ones.
An externally hosted image should be here but it was not working when we last tested it.
I just got a low cost Stinger SGN20 from ebay to try and it's unvelievable how good it is. I'm quite certain I can recommend it.
Amazon.com : Stinger SGN20 Ground Loop Isolator : Vehicle Amplifier Power And Ground Cables : Electronics
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WOW! Unbelievable!
WOW! Just took the caps out (AUX line in) and... what can I say? WOW! 🙂
The soundstage/imaging improved by a lot! It's LIVE!
Unbelievable that such a simple mod can do a HUGE improvement!!
Is this a general rule? Can this be applied for ANY preamp, including those very expensive?
Why do they put these caps, by the way??
Thank you very much, sextaafondo!
And thank you guys, too!
WOW! Just took the caps out (AUX line in) and... what can I say? WOW! 🙂
The soundstage/imaging improved by a lot! It's LIVE!
Unbelievable that such a simple mod can do a HUGE improvement!!
An externally hosted image should be here but it was not working when we last tested it.
Is this a general rule? Can this be applied for ANY preamp, including those very expensive?
Why do they put these caps, by the way??
Thank you very much, sextaafondo!
And thank you guys, too!
WOW! Just took the caps out (AUX line in) and... what can I say? WOW! 🙂
The soundstage/imaging improved by a lot! It's LIVE!
Unbelievable that such a simple mod can do a HUGE improvement!!
Is this a general rule? Can this be applied for ANY preamp, including those very expensive?Why do they put these caps, by the way??
In some circuits they really are necessary, but in many they are there mainly to assure equipment compatibility, etc. Capacitors are poor in performance, even the better ones. You tried a bypass test and found that out for yourself!
Thank you rayma.
I'll keep one source with the stock 100pF ceramic ones and later will take the CD and Tuner input caps out after some more listening...
Bass is full, sound is not harsh at mids. Very nice...
If you must use ceramic capacitors, the only decent ones have COG dielectric.
WOW! Just took the caps out (AUX line in) and... what can I say? WOW! 🙂
The soundstage/imaging improved by a lot! It's LIVE!
Unbelievable that such a simple mod can do a HUGE improvement!!
Is this a general rule? Can this be applied for ANY preamp, including those very expensive?
Why do they put these caps, by the way??
Thank you very much, sextaafondo!
And thank you guys, too!
LOL yes, it made an abyssmal difference in my amp also.
One of the reasons the input caps are there is to block any DC input on DC coupled amps (as I understand this..) So the risk of DC at the input terminal of a DC coupled amp is amplifying this DC value by the amp factor and sending this value to the speakers.
My amp is in fact DC coupled with LME49830 input stage, so to stay on the safe side is that I put a GLI between the amp and the preamp. Bass is full and powerful at 20Hz and subsonic frequencies. I can see the woofers in my JBL L7 speakers moving though I can't really hear such frequencies.
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