X-Can V3 Mods

[tmaslar]

I am ordering the parts to upgrade my newly acquired X-can V3.

I see on your original cap upgrade page the 4X1000uF/35v caps were also replaced with 2200uF/35v caps. Now I see in your cap upgrade kit you are providing 1000uF caps for use in these positions. Was there an issue with increasing the capacitance from 1000uF to 2200uF in these positions?


I was looking at the Panasonic FC series cap listing in the Mouser Catalog. I see that there are two different 2200uF/35v caps available. One has an 18mm O.D.X25mm Height. The other a 16mm O.D.X 31.5mm Height. The ripple current on the 18mm is 2740mA and 3010mA on the 16mm cap. Is the 16mm cap with the higher ripple current a better choice? It looks as though either one would easily fit on the board.

I could not find a supplier in the USA for the Capxcon or Suntan Non Polar caps. I can get Black Gate Non Polar ones to use here. They are fairly pricey but not crazy in price. Do you think they would work well for the input and output caps?

As for the bypass caps on the output caps. I again could not find the Evox/Rifa that you now offer in the kit. I can get Wima MKP2 polypropylene in .1uF/250v and Wima MKS2 Polyester caps in .047uF/63V and .22uF/50v. Would these cap selections be sufficient for the output cap bypass caps?

I have also ordered an Avel toroid transformer for the supply. I have attached the picture. It is available at Parts Express. I am wondering about the grounding and wiring between the XFRM and the power supply filters and rectifier on the PC board.

I am assuming that I would wire the primaries in parallel and in phase for 120V operation. My guess is that the secondaries will be wired in series with a common ground between the two secondary windings?

I am unsure of what type of grounding scheme to use. Would I connect an earth ground from my power inlet cord to the common on the secondaries and to my metal chassis? Or should I just float the whole circuit from earth ground?

If I run a shielded cable from the XFMR to the PC board should I connect the shield to earth or common only on the XFMR side?

Thanks for putting up this great site!

Tom

[bennyboy]

Hey there, I've found good BP that I and others really like, Nichicon Audio Muse BP.
As far as the bypass caps go, I've tried with and without and can hear no change in SQ.

Have fun!

[tmaslar]

Thanks Bennyboy!

Do you know of a source for them in the US?

Tom

[PinkFloyd]

tmaslar said:

I see on your original cap upgrade page the 4X1000uF/35v caps were also replaced with 2200uF/35v caps. Now I see in your cap upgrade kit you are providing 1000uF caps for use in these positions. Was there an issue with increasing the capacitance from 1000uF to 2200uF in these positions?

No, perfectly fine to use 2200uF instead of the 1000uF, the extra 4800uF isn't going to blow any gaskets

I was looking at the Panasonic FC series cap listing in the Mouser Catalog. I see that there are two different 2200uF/35v caps available. One has an 18mm O.D.X25mm Height. The other a 16mm O.D.X 31.5mm Height. The ripple current on the 18mm is 2740mA and 3010mA on the 16mm cap. Is the 16mm cap with the higher ripple current a better choice? It looks as though either one would easily fit on the board.

16mm diameter is the one to go for as it's a perfect fit. The 18mm ones require a bit of leg bending and repositioning on the board so stick with the 16mm ones.

I could not find a supplier in the USA for the Capxcon or Suntan Non Polar caps. I can get Black Gate Non Polar ones to use here. They are fairly pricey but not crazy in price. Do you think they would work well for the input and output caps?

I tried the black gates and, to be totally honest, thought they sounded grainy and spitty. Sure, there are people who reckon they need weeks to burn in and then sound good but I'm not prepared to work with a cranky part like that. Of them all the CapXon, CD-71 and Nitai sound good (Capxon and CD-71 are both 105C rated too) I wish I did like the sound of the black gates in this application but I don't. The Nichicons that Benny mentions may be worth a punt, I've had good results with them in other amps, well worth trying. Generally though, if you've got no DC offset out of your source it's best to dispense with the input caps altogether and jumper over the pads with a zero ohm link.

As for the bypass caps on the output caps. I again could not find the Evox/Rifa that you now offer in the kit. I can get Wima MKP2 polypropylene in .1uF/250v and Wima MKS2 Polyester caps in .047uF/63V and .22uF/50v. Would these cap selections be sufficient for the output cap bypass caps?

Bypass caps are a matter of personal taste, some people love the sound with them in situ others don't. Others think bypassing is a bad idea others think it's a good idea, this is really an area best left down to personal taste and trial and error.... if you like it with them in place then leave them, if you prefer the sound without them then remove them. 470nF would be a good value to try if your output caps are 470uF... you could also use multiple values and parallel them onto the output caps, say a 100nF, a 220nF and a 470nF all paralleled together.... pure experimentation here and no one combination is necessarily better than another, it's all down to personal taste. There is a difference in the sound by the way Benny, specially if you mnake up some multivalue bypass caps

I have also ordered an Avel toroid transformer for the supply. I have attached the picture. It is available at Parts Express. I am wondering about the grounding and wiring between the XFRM and the power supply filters and rectifier on the PC board.

If you're housing the transformer in an ABS enclosure then you're just taking the secondaries to the input of the X-CAN. OV (zero volt) goes to the centre pin on the 3 pin DIN and the other two 12V goes to the two outer pins. You should measure around 15V between each outer pin to centre pin and around 30V when measuring between both outer pins.

I am assuming that I would wire the primaries in parallel and in phase for 120V operation. My guess is that the secondaries will be wired in series with a common ground between the two secondary windings?

for 115V operation the primaries are wired 0V-0V 115V-115V (jumpered) with live going to 115V-115V and neutral going to 0V-0V (well, that's the routine with the encapsulated types I use) The secondaries are wired 0V 12V-0V 12V with the jumpered 0V-12V acting as the centre tap, you connect the centre tap to the middle pin on the 3 pin input and the other two outputs to the outer pins. Hope this makes sense!

I am unsure of what type of grounding scheme to use. Would I connect an earth ground from my power inlet cord to the common on the secondaries and to my metal chassis? Or should I just float the whole circuit from earth ground?

Just connect the ground to the chassis of your transformer enclosure. All we want going into the V3 is 12 0 12V

If I run a shielded cable from the XFMR to the PC board should I connect the shield to earth or common only on the XFMR side?

Yes, only on the one side.

Thanks for putting up this great site!

[PinkFloyd]

tmaslar said:

Thanks Bennyboy!

Do you know of a source for them in the US?

Tom

Give me your address (in a PM) and I'll fire you some over.

Mike.

[tmaslar]

Mike,

YGMPM?

Tom