| adfairless |
Hi All
I have been replacing non polar caps in my Musical fidelity X-A1 NOT A1 amp. I have been using Blackgate's up till now in the circuit, and the amp keeps getting better. Now! The last two had to go, so I changed them for 100uf 16v N / NX non polar parts, and although the midrange sounds wonderful and the voices dreamy, where has all the treble gone. I used to get extreme height in the soundstage, and now it is like a wide letterbox format. Not bad, but high treble is now missing...
What can I do to get it back? I could put the old parts (cheapo) back in, but the midrange gets a little grainy...
Cheers in advance for any assistance. |
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| jnb |
My first thoughts are that a different cap will sound different. Have you used a larger cap than necessary?
You might try bypassing them with a small value of high quality polypropylene cap. That will almost surely make a difference. |
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| tinitus |
I dont know where you can use 16volt caps in a poweramp ??
The BG caps you may need is the NX Hi-Q types, 50volt 0,1-0.47uf
From what I have read you should never combine the BG caps with other types - I never seem to like any kind of paralelled components |
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| KBK |
| quote: | Originally posted by tinitus
I dont know where you can use 16volt caps in a poweramp ??
The BG caps you may need is the NX Hi-Q types, 50volt 0,1-0.47uf
From what I have read you should never combine the BG caps with other types - I never seem to like any kind of paralelled components |
Very very smart. It seems that one of the last things you learn in audio is that bypass caps don't work. They smear transients in 'time' (phase/smear) and lead to a false impression of detail and treble. Monolithic application of capacitors end up sounding best. Just put in the best you can. If not and bypass MUST be used, use the BIGGEST value possible, to drop the phase smear to as low a frequency as possible. That's my experience, over much experimentation. (25 years or so of experimenting with bypass caps on everything under the sun) The problem with bigger bypass caps..is that the transient smear issue then begins at lower frequencies and infects everything. Ug. What to do?
The same problem rears it's head in audio amplification circuits that use multiple output transistors on the same rail. Damaged micro transients, right were we concentrate most of our hearing to 'decode' the sound. Thus the liking of single ended amps and full range speakers.....
The most realistic sounds I've ever heard come from monolithic application of capacitance in a given point in a circuit. It just gets expensive, is all. Good caps cost money.
Real signals don't like bypass caps due to the fact that a music signal in a circuit is not a sine wave but a very complex harmonic. |
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| adfairless |
| Thanks for all the responses. I found out what was causing the problems. I wired up the speakers incorrectly. My baby now goes great guns. Soundstage and clarity are breathtaking. Organic is not the word. I am a very happy man. Blackgates are fab. :D |
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| analog_sa |
| quote: | Originally posted by adfairless
I wired up the speakers incorrectly. :D |
You should be guillotined for starting this thread |
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| adfairless |
| Yeah! just look at the random **** that was posted as a reply :rolleyes: |
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| analog_sa |
| Could have been worse. If you had given it another day there would have been a fist fight :) |
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| adfairless |
HAHAHAA ;)
Note to self. Mention caps at your peril. Nobody knows what they are talking about, and if they do then they baffle everyone else... |
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| Bernhard |
| quote: | Originally posted by KBK
It seems that one of the last things you learn in audio is that bypass caps don't work. They smear transients in 'time' (phase/smear) and lead to a false impression of detail and treble. Monolithic application of capacitors end up sounding best. |
Also decoupling PS rails of op amps ? |
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| jnb |
I haven't had much luck bypassing, myself. I know what I posted alluded otherwise but that was written in a diagnostic spirit and I was kind of glad when the O/P fixed the problem.
I especially don't like bypassing filter caps. I suspect that a main cap with a troublesome resonance will become worse when bypassed but what KBK says sounds plausible on its own.
I tend to prefer a single cap offering a rolled off top end rather than bypassing, and hold off 'till I can get my hands on a higher quality replacement. |
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