[MASantos]

What do you guys think of using Elna Silmic II 47uF 6.3V? I am thinking of using these in all positions except for C2. Using these instead of panasonic FC's is only a few bucks.

Would someone be interested in a group buy?

 

[Sinbios]

Quote:

Originally Posted by MASantos What do you guys think of using Elna Silmic II 47uF 6.3V? I am thinking of using these in all positions except for C2. Using these instead of panasonic FC's is only a few bucks. Would someone be interested in a group buy?

I think the only position the Silmics would fit in is CL/CR...

 

[MASantos]

Quote:

Originally Posted by Sinbios I think the only position the Silmics would fit in is CL/CR...

I have used them in the first prototipe board.I used panasonic FC first and then Silmic II. I gave each 20 hours playing time before listening. The bass was more controled and there was less hiss when no music was playing. The mids sounded a bit less muffled and the highs were a also less muffled. Overwall the sound improved.

In the group buy board, they fit in every position except C2.

The Silmic II 47uf 6.3v has the following dimensions:
6.3mm diameter; 11mm length(it fits the smallest hammond case); pitch: 2,5mm, which fits to all positions

In terms of capacitance values, 47uf is a good choice for C13,C23,C33 and CL/CR, according to the suggested values by Alf in the parts list page.

Manuel

 

[Alf]

Quote:

Originally Posted by MASantos In terms of capacitance values, 47uf is a good choice for C13,C23,C33 and CL/CR, according to the suggested values by Alf in the parts list page.

C23, C33 positions accept capacitors up to 8mm. If you have a few extra dineros in your pocket, I would try 100uF Silmics here as the DAC may benefit from it.

 

[Sinbios]

MASantos: Ah, digikey doesn't carry a wide range for the Silmics so I didn't see the 10V. I'd certainly be interested in obtaining a few.

Alf, any thoughts on the power supply?

 

[Alf]

Quote:

Originally Posted by Sinbios The ideal situation for USB power would be to take the 5V from USB and step it up to 6.4V, and then regulating it to 5.4V and feeding it to the DAC. I looked up a few voltage converters today and this is certainly feasible, maybe for the next revision?

This approach has been part of the original design. After conducting some tests and doing more reading on the subject I removed the step-up section from the DAC.

Quote:

Originally Posted by Sinbios Assuming the USB gives perfect 5.0V (which mine does), …..

If you have a rock solid 5V (which you do), then you need no additional active regulation because your computer’s PSU does the job for you. Regulators are used to eliminate large swings of voltage. For everything else you should use passive filters. Have you noticed C1/C2/L11/L12? This is what they are there for. Do they do a perfect job? Unfortunately not, there is some space for improvement. If you have enough room in your enclosure, I suggest that you start with adding 5-6 boutique electrolytics (200-300uF) and a few 220nF film capacitors. Read a bit more about passive filtering and you can come up with more ideas. The board is very customizable in this respect and there is no excuse for not trying.

 

[Tedro]

With <3 from me

Quote:

Originally Posted by Tedro

 

[Whitewind]

So Alf, would you recommend stepping up the input voltage of USB by adding a 1.2v NIMH AA battery in series?

Thanks

 

[robzy]

Would people who have built it mind testing the "dc offset" between C18 and CR/CL?

If its low enough it might be best to take out CR/CL and use it as an output ground (assuming it has the current capacility).

Rob.

 

[doobooloo]

Quote:

Originally Posted by MASantos I have used them in the first prototipe board.I used panasonic FC first and then Silmic II. I gave each 20 hours playing time before listening. The bass was more controled and there was less hiss when no music was playing. The mids sounded a bit less muffled and the highs were a also less muffled. Overwall the sound improved. In the group buy board, they fit in every position except C2. The Silmic II 47uf 6.3v has the following dimensions: 6.3mm diameter; 11mm length(it fits the smallest hammond case); pitch: 2,5mm, which fits to all positions In terms of capacitance values, 47uf is a good choice for C13,C23,C33 and CL/CR, according to the suggested values by Alf in the parts list page. Manuel

This is very interesting. I am a bit skeptical though of the effect the Silmics had in the filtering positions (everything other than CL/CR) - perhaps the BEST performance can be had by leaving the higher capacitance (and still very low ESR) FM/FCs in all positions other than CL/CR and use the Silmics only in the signal path, CL/CR.

For me, I'm planning to use Black Gate NX Hi-Q bipolars in CL/CR as to minimize the negative effect of electrolytics in the signal path, and use Panasonic FMs in all other positions for low ESR and high capacitance for better filtering... IMO this should be quite close to ideal given the board limitations (no exotic film output caps, etc.)...

But I'd still like your opinion on having "audio grade" low-density boutiques in the filtering positions. By any chance have you tried swapping just the CL/CRs, or even better, everything BUT the CL/CRs? This should be a very interesting experiment.

[edit] went back and read your post again, did you actually try the silmics in positions other than CL/CR with the early proto board or are your impressions only for the output signal path position?

 

[00940]

Quote:

Originally Posted by Alf If you have a rock solid 5V (which you do), then you need no additional active regulation because your computer’s PSU does the job for you. Regulators are used to eliminate large swings of voltage. For everything else you should use passive filters. Have you noticed C1/C2/L11/L12? This is what they are there for. Do they do a perfect job? Unfortunately not, there is some space for improvement. If you have enough room in your enclosure, I suggest that you start with adding 5-6 boutique electrolytics (200-300uF) and a few 220nF film capacitors. Read a bit more about passive filtering and you can come up with more ideas. The board is very customizable in this respect and there is no excuse for not trying.

Be extremely careful adding capacitance on the USB bus without putting some resistance in serie before the caps. The USB specs don't allow much current to be drawn and at start up, too much capacitance could kill your USB bus. Of course, putting some resistance in serie is another evil...

At lowish frequency, high quality regulators are actually very good at cleaning the incoming DC. A combination of regulation and passive filtering is best, especially when lots of capacitors aren't recommanded (as here). At higher frequencies, only passive filtering will work.

 

[tomb]

Quote:

Originally Posted by Doobooloo For me, I'm planning to use Black Gate NX Hi-Q bipolars in CL/CR as to minimize the negative effect of electrolytics in the signal path, and use Panasonic FMs in all other positions for low ESR and high capacitance for better filtering... IMO this should be quite close to ideal given the board limitations (no exotic film output caps, etc.)...

I agree with that strategy, although I'm trying to find another source that would let me try all three that have been most mentioned for CL/CR:

1. Black Gate NX-HiQ
2. Elna Silmic
3. Nichicon Muse ES

I received four boards, so if someone has a fourth suggestion for CL/CR, please let me know.

 

[doobooloo]

Quote:

Originally Posted by tomb I agree with that strategy, although I'm trying to find another source that would let me try all three that have been most mentioned for CL/CR: Black Gate NX-HiQ Elna Silmic Nichicon Muse ES I received four boards, so if someone has a fourth suggestion for CL/CR, please let me know.

Is it most definately preferable to have bipolar electrolytics in the signal path? If regular electrolytics still "work" in this position, what is the exact reason for bipolars being useful here?

Also, where would you get your Muse ES series caps?

 

[tomb]

If you read the hype, the "bi-polars" put less noise in the signal path. The rationale is a little ridiculous it seems to me, so I won't go there. Nevertheless, I read the reviews because like most people, I'd like something that sounds the best after all the work put into building it. There are enough warnings floating around against using regular FM's or other popular power electrolytics in CL/CR to convince me there's something to it.

You can find a lot of this in Dsavitsk's capacitor review referenced by Alf in his Parts List page: Notes on Coupling Caps. I had found this review earlier from one of Dsavitsk's posts on the Millett's caps, so was a little familiar with it. Unfortunately, Alf's pages only references it with the simple word "here", so it's easy to miss.

Nichicon Muse ES's can be obtained at:
Handmade Electronics
Michael Percy
B&D Enterprises (they don't have the smaller ones - only the Millett's C7)

P.S. I'm thinking of trying Michael Percy, since he has both the Black Gates and the Nichicon's (KZ's, too). MisterX mentioned Parts Connexion, but they only have the Black Gates. Since all these outfits have a minimum order, I was trying to choose one that has more than one type. Before I get into another Kyoto-Electro fiasco, has everyone had good luck ordering from Michael?

 

[MisterX]

Quote:

has everyone had good luck ordering from Michael?

I waited a week to get a reply to my last order request.
The reply I got said they had nuked all of the emails they had got because they had to much backlog and I should re-send my request.
So I sent them another request.
Care to guess what the reply was to that inquiry as well?
Same thing.

I think you may get better results on the phone but I got sick of messin with them and ordered the Black Gates caps I needed from Parts Connexion.
They were here 4 days later.