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Old 4th January 2004, 10:30 AM   #1
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Question zen V4 output caps question

I use cheapest 10 000uf nichicon, but decide to change it to 6800uf panasonic for audio. nelson said that I can use values close to orig. is 6800uf is enuoght to zen v4. first impresion was tht bass become very thin. but it was with nichicon too i think. after few mth of use bass apear.
any sugestions welcome
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Old 4th January 2004, 01:42 PM   #2
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Default Re: zen V4 output caps question

Quote:
Originally posted by elviukai
I use cheapest 10 000uf nichicon, but decide to change it to 6800uf panasonic for audio. nelson said that I can use values close to orig. is 6800uf is enuoght to zen v4. first impresion was tht bass become very thin. but it was with nichicon too i think. after few mth of use bass apear.
any sugestions welcome


What is the rated impedance of the speakers you drive with the V4? This can make a big difference in the delivered sound quality.
The output caps do not need to be 50v rated to live in the output. I used 35 volt for a long time. The maximum voltage is 42 volts, and it may not go that high.
I currently have a Jensen 4 pole cap, 10,000 ufd 63 volt bypassed with a 680 ufd 35 v BG NX. It replaced Nichicon audio grade cap. Everything seems better, highs, clarity, distortion, and bass.
I think the missing bass can be found in the front end of the circuit. Up the bias current on the buffer and try lowering the input impedance to 20 - 30K. I think this will yield bigger improvements than playing with the output caps.

George
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Old 4th January 2004, 02:26 PM   #3
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spekers read 4.4ohm- i think my speakers are 5-6ohm.

can I add pararel one more cap-one panasonic hq grade for audio 63V and 3300uf 42v elna for audio. I think that I will find all theese notes "for audio" is sh..

I find only one bad thing in zen v4-its output cap. i wish i have pcb which make my zen to outputless cap amp..

how can i rise ias curent. my zen lack of bass because I turn it direct to cdp.this is the reason i think. but now bass is very thin.. even for me..
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Old 4th January 2004, 09:00 PM   #4
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Quote:
Originally posted by elviukai
spekers read 4.4ohm- i think my speakers are 5-6ohm.

You most likely will need to keep the cap around 10,000 ufd.

can I add pararel one more cap-one panasonic hq grade for audio 63V and 3300uf 42v elna for audio. I think that I will find all theese notes "for audio" is sh..

There are two places on the boards from passdiy for output coupling caps. If they fit use them.

I find only one bad thing in zen v4-its output cap. i wish i have pcb which make my zen to outputless cap amp..

If learn something everyday, but I do not know how to build a dc coupled, singlended amp with single rails. If daul voltage rails are used it is fairly easy to dial out the dc and leave out the blocking caps. Look at the Alephs.

how can i rise ias curent. my zen lack of bass because I turn it direct to cdp.this is the reason i think. but now bass is very thin.. even for me..
The bias current is raised by lowering the value of R13. This is 4.75K listed. Changing to a 1 watt 2.2K resistor will crank the current from 7 - 8 ma to 15 - 17 ma.
BUT, your problem is the source. It is well documented here that the Zen V4 requires a very healthy source to drive it. Use one of the Pass preamps, or something else that has a real strong output and low impedance, and then you should find the missing bass.
Playing around on the output will not yield much until the input issues are addressed.

George
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