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Old 25th March 2009, 10:42 PM   #521
troystg is offline troystg  United States
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The device is for listening to the signatures of caps correct?

Well as long as each of the caps go through the same "spaghetti" in turn then the objective is met. Hearing the difference in the sound of each cap.
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Old 25th March 2009, 10:58 PM   #522
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Default Re: Re: Re: Cap switching box

Quote:
Originally posted by VictoriaGuy
Good idea- I'll free up a slot for a straight wire.
You're welcome John!

Tom, regarding C21, now I've 10nF MKS2 to directly compare to 100nF MKS2 originally used and I could confirm that value is a issue here.

The 10nF MKS makes voice closer, I would say in the right position comparing to my Marantz power section.

Next week I should have also the others values to fine tune.

I've tried also 10nF Wima MKP2 and they seems better than Wima MKS2, more transparent and bass is tighter.

So I would say the right value for C21 seems between 10nF and 68nF.

Both MKP2 and FKP2 are available from Mouser in these values.
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Old 25th March 2009, 11:36 PM   #523
udailey is offline udailey  United States
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Nice MCap Dario! I think John will choose the PIO but if he puts in a straight wire he will choose that. Just my bets. I like the idea of burning in the caps.
I dont know if I told you guys but I did DC couple a few days ago. Better soundstage, more transparency, better separation of instruments, .... muddy bass? Well I have to put it all back together again after messing with it last night. Give it a better listen then.
Uriah
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Old 25th March 2009, 11:51 PM   #524
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Quote:
Originally posted by udailey
I dont know if I told you guys but I did DC couple a few days ago. Better soundstage, more transparency, better separation of instruments, .... muddy bass?
Muddy bass?
Yes, it's the Panny FM in C9

a Wima MKP2/FKP2 (<100nF) in C21 helps a lot

Quote:
Originally posted by ClaveFremen
- Panasonic FM is quite good, dinamyc and involving, but has a bit of harshness and basses are a bit bloating
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Old 26th March 2009, 06:53 AM   #525
Tony X is offline Tony X  France
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Default Offboard caps

Just a note for anyone who may try some large caps off board. Keep them well away from the relays or they will pick up a lot of hum, buzz and hiss at the same time. It took me days of frustration to find that out.
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Old 26th March 2009, 09:00 AM   #526
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Default Re: Offboard caps

Quote:
Originally posted by ClaveFremen
I've tried also 10nF Wima MKP2 and they seems better than Wima MKS2, more transparent and bass is tighter.
Sorry, it's FKP2 in place of MKP2

Quote:
Originally posted by Tony X
Just a note for anyone who may try some large caps off board. Keep them well away from the relays or they will pick up a lot of hum, buzz and hiss at the same time. It took me days of frustration to find that out.
Hi Tony,

you were experimenting Obbligatos in C13, right?

Tried others caps?
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Old 26th March 2009, 12:49 PM   #527
Tony X is offline Tony X  France
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Quote:
you were experimenting Obbligatos in C13, right? Tried others caps?
Yes, Dario, It was the Obligatos. Mine are big brutes, 2.2uF 630v coppercase. They actually give already a nice sound once they are moved away from the relays. They will probably be great when I get the other things fixed. I have a Speedlight on order from Uriah and some Silmics are on the way from Germany. I am waiting for you guys to decide on the other pots before looking at C13 again if necessary.
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Old 26th March 2009, 03:54 PM   #528
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Quote:
Originally posted by Tony X
They actually give already a nice sound once they are moved away from the relays.
...
I am waiting for you guys to decide on the other pots before looking at C13 again if necessary.
Strange, other caps I'm trying doesn't seems sensible to position, it could be that copper body of Obbligatos has a role picking up noise...

If you are referring to C9,C21,C4,C5 and so on, yes, it's a long quest...
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Old 26th March 2009, 04:36 PM   #529
schro20 is offline schro20  United States
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Default hiss issue

So last night I connected the secondary ground(s) to chassis/earth. I know Troy doesn't like this because it mixed clean and dirty ground (I can see his point). I tried this first since my original setup (no case yet) was done that way and it worked well. (Also because this is recommended practice according to Rod Elliott.) That made the hiss essentially go away. I say essentially because if I really strain and with just the right setting of my pot I can still hear just the faintest version of this buried in what is otherwise the noise floor on my input. But with the speakers I have I barely go above the 9 o'clock position on the pot and then the speakers are dead quiet with source connected and active, but no signal running. So, for now this is good enough. For the next case build I will probably go the long shaft route to really separate sections more cleanly.

Next thing I gotta do now is find a D/A with lower noise floor. Right now I am running off an Entech 205.2 but I don't like the level of white noise. I have some other DACs. Let's see how much of a difference that makes.

peter
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Old 26th March 2009, 05:15 PM   #530
troystg is offline troystg  United States
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Mixing grounds is not a "BAD" thing, it is just old engineers being stubborn and saying proper engineered equipment shouldn't require it.

But if tying signal ground to earth ground quietened the amp then you have power ground issues between the amp and the source feeding it.

Connect your RCA cables between source and amp and measure the AC and DC voltage between the chassis of both and the RCA grounds of both.

That might also be contributing to the noise floor of the DAC as you mentioned.
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