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Old 19th November 2007, 02:00 AM   #1
Barry1 is offline Barry1  United States
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Default Ono/ Xono Output coupling Caps

I'm think about ditching the 4 - 10uf Axon output coupling caps and swapping them for 3.9uf mundorf silver/oil temporarily. Into a 20K line stage input impedance this should give me a Fq -3 of about 2Hz.

Later on I'd plan to parallel these with 4 other 3.9uF bringing the the values to just under 8uF (when I can afford them!). The only reason I'm picking this value is space - I can't go larger.

Anyone see any problems with this? Anyone recommend any other film/foil/ poly? My other choices might be the Sonic Cap - Gen Is or the new Modwright metalized oil-impregnated polypropylenes. Recommendations anyone?

thanks for your help!

Barry
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Old 19th November 2007, 02:12 AM   #2
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I'm going with Wima MK4S 10 uF to start, and I'm going to
put space in my layout to bypass with Mundorf 1.0 uF silver/gold.
I'll fork over for the Mundorfs in a couple months or so.
First I have to get the amps going and that's a ways off
yet.

I have no experience with this - I'm just doing what seems to
make sense from a cost and space perspective.

Cheers.
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Old 19th November 2007, 08:45 AM   #3
h_a is offline h_a  Europe
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Well, I always try to stay away from exotic parts discussions, however this time I would like to point out that there are 'weaker' links in the chain than the output coupling cap.

For example, the mc-front end passes its signal via a 220uF elco; and as you've already found out for sure, the XOno uses again a 220uF elco to pass the signal from Q15 to the MM-stage, where in the predecessing Ono a 10uF film cap was used.

Just to give you the idea.

If this is relevant or not, you decide for yourself. All the best, Hannes
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Old 19th November 2007, 11:34 AM   #4
Barry1 is offline Barry1  United States
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Hannes Thank you!

So from what your saying there are 2 x 220uF electrolytics in the Xono signal path even before you reach the output coupling caps?

I think that does matter even more than the output! I'll consider replacing them with higher quality parts (BG Ns) and will try to find a schematic on the board here although the caps should be easy to find. As you may have guessed this is a commercial unit and I just purchased it used.

Any other suggestions or links would be helpful.

Kindest regards,
Barry
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Old 20th November 2007, 03:36 PM   #5
DaveM is online now DaveM  United States
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This is kind of the reference of Caps and their associated sound qualities. It appears that Tony Gee has spent more time listening to and notating the changes different caps make than anyone I know of.

http://www.humblehomemadehifi.com/Cap.html

Enjoy.

DaveM
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Old 20th November 2007, 05:25 PM   #6
Netlist is offline Netlist  Belgium
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By carefully trimming the output offset with a variable resistor which were replaced by fixed ones later, I managed to get rid of the output caps completely.

/Hugo
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Old 20th November 2007, 06:04 PM   #7
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Hannes is right. There are other weaknesses than the output capacitors.

I experimented with a number of choices and even bypassing the output capacitors as Netlist suggests. The bypassing leads to a "different" sound to my ears. I would not say categorically better.

I did replace two capacitors that Hannes referred to, as well as a number of other electrolytic (in fact, all except for the rail capacitance) with Black Gate NX. Again, listen for your self. One thing I'd recommend is not to skimp on the amount of capacitance, as I learned this early on. The one capacitor that was increased to 1000uF on the Xono was for a reason. It sounds better I ended up using 2x470uF here.

As for bypass capacitors on the coupling capacitors, I found the best (better than the Mundorf silver I tried) were the Vishay/Roederstein MKP1837.

Again, your opinion will vary. For example, everyone that listens to my equipment thinks it sounds bright and over-analytical. Perhaps it does. Things like Miles' trumpet, the 7th note that the solo violin plays on Lalo's Symphony Espagnole, or the upper register on Gould's decrepit old pre WW piano *should* sound harsh and bright in my opinion
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Old 20th November 2007, 06:07 PM   #8
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Quote:
Originally posted by DaveM
This is kind of the reference of Caps and their associated sound qualities. It appears that Tony Gee has spent more time listening to and notating the changes different caps make than anyone I know of.

http://www.humblehomemadehifi.com/Cap.html

Enjoy.

DaveM
I think this is a bit apples and oranges. I've found that caps sound different in DC coupling situations than in crossover situations.
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Old 20th November 2007, 06:41 PM   #9
DaveM is online now DaveM  United States
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Quote:
I think this is a bit apples and oranges. I've found that caps sound different in DC coupling situations than in crossover situations.
Quote:
As for bypass capacitors on the coupling capacitors, I found the best (better than the Mundorf silver I tried) were the Vishay/Roederstein MKP1837.
Certainly you are right about the application being different, yet you yourself suggested the same bypass that Tony Gee did so there must be some similarity.
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Old 20th November 2007, 07:14 PM   #10
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Quote:
Originally posted by DaveM

Certainly you are right about the application being different, yet you yourself suggested the same bypass that Tony Gee did so there must be some similarity.
yes, in both cases the MKP1837 is a bypass If there are other recommendations for good bypasses, then perhaps they would be applicable as well.
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