Components used in LEACH AMP !

[adrianbodor]

Hi to all,

I started a new thread only to talk about components used in LEACH AMP ...

Please post here all about compontents used or alternative that can be used in this briliant aaf ... also you can post questions and answers about connectors used and other stuff used ...

So I ask:

Is there any diference between using Wima Film Capacitors MKS 2 instead those listed by Dr. Leach ... i mean those caps that are film based ...

0.1uF/100V
0.1uF/50V
0.01uF/50V

If I use these tree values in Wima caps MKS 2 version at 100V all of them
would make any diference ?

I don't have the posibility to buy at 50V only at 100V ...

Thanks for any help !

Best regards, Adrian

 

[acenovelty]

Greetings Adrian,

The Leach amp seems to be extremely forgiving about the quality of components used. Having built more than a dozen using both new high quality and "surplus" cheap parts seems to make very little difference. While one might be able to measure the small differences,
what you hear is why we build these things. Tho some folks claim to hear differences between various poly (whatever) style and film caps. However substituting electrolytic for a poly/film cap is a bad idea. And do use mica caps per the destruction manual. As to the voltage rating of things like caps, if it is at least a large as the doc's recommend, all is well. Higher values will not hurt, but physical size may be a problem fitting in the space. The cost of board parts is miniscule compared to trannies, power supply caps (put your money here) and the case/heatsink.
If you think the amp does not put out enough bass, raise the bias current to 150 or 200. The improvement can be quite remarkable.


Prosit

 

[adrianbodor]

Hy,

I don't intend to change Mica caps with other types, just i want to know if i can use those Wima caps instead those listed on Dr. leach web site ...

1.

Ex:

MKS 2 100nf/100V instead 0.1uF/100V
MKS 2 100nf/100V instead 0.1uF/50V

and

MKS 2 10nf/100V instead 0.01nf/50V

These WIMA MKS2 are Metalised Polyester [Cubic Shape] and have a lead spacing of 5.08 mm

2.

Can i use low impedance 105 degrees elko caps for those 100uF/100V ? I think would be better ...

Best regards, Adrian

 

[acenovelty]

Adrian,
100nf/100V instead 0.1uF/100V

"# C2, C3, C15, C16, C23, C24, C25 - 0.1 uF, 100 V film (DigiKey P4725-ND, 0.4 inch or 0.2 inch hole spacing)
# C7, C12, C17, C18 - 0.1 uF, 50 V film (DigiKey P4525-ND, 0.2 inch hole spacing)"

It would seem you're asking me to do the math for you.
"The Leach amp seems to be extremely forgiving about the quality of components used. Higher values will not hurt, but physical size may be a problem fitting in the space."

The WIMA MKS2 caps you propose are extremely unlikely to let the magic smoke out of any other component on the board. If physical spacing is a problem, mod the board to fit as needed. The Leach amp board has meen modified in hundreds of configurations successfully by folks all over the world.

Isn"t this what you proposed?
"I started a new thread only to talk about components used in LEACH AMP..
Please post here all about compontents used or alternative that can be used in this briliant aaf ... also you can post questions and answers about connectors used and other stuff used ..."

1000pico-farad(pF)=1 or 1n nano-farad(nF)=0.001micro-farad
(mF,uF or mfd)


Prosit

 

[wigginjs]

An externally hosted image should be here but it was not working when we last tested it.

A complete list of all the components I used can be found in the leach amp guide on my website (sig).

 

[adrianbodor]

Hy,

One important thing i forgot to mention ...
SPACE ON tHE CIRCUIT BOARD IS NOT A PROBLEM because i'll design the board myself ...

so substitute film caps with MKS2 will not be problem ...

First i will choose what components to put on the circuit board then i will make the board ...

I know the transformation of capacitance, so i asked only if i can put a Wima MKS2 0.1uF/100V (100nf/100V) instead that Panasonic Cap 0.1uf/100V (100nf/100V) ... The reason is that i don't have the posibility to buy from digikey ... I'm from Europe, Romania ...

Hope you understand me now ...

Best regard, Adrian

 

[Damon Hill]

The Wima caps should be no problem; I'd prefer to use
polypropylene instead of polyester, but that's just me
and I haven't found a convenient source for them.

In general, using a higher voltage rating for a capacitor
doesn't hurt anything, though it may make installing
the part more interesting.

I also have used OnSemi MJ21193/94 output transistors,
as these are a bit faster and more rugged. These are
available in a plastic case as well with MJL and MJW part
numbers.

 

[pro]

Try this link for components.
http://www.rsromania.com/
Ciao.

 

[adrianbodor]

All resistors from Leach Amp PCB can be also 1/4W carbon film 5% ...

I want tu use all resistors at 1% metal film only for 1/4W type

It should be better ?

Can be any bad results ?

If tolerance is much smaller than carbon film why Dr. Leach had recomended carbon film resistors ?

I intend to use metal film ... (only for 1/4 W of course)

 

[BobEllis]

1% metal film types will be fine, I used them in mine. I haven't compared to carbons, but I am happy with my amp.

I suspect that Dr. Leach suggested 5% carbons because anything else is probably overkill. And way back when he originally wrote it up it may have been difficult/expensive for a hobbyist to source 1% metal film resistors.

 

[adrianbodor]

I was sure I can use those metal film 1/4 W 1% but what do you mean by that:

I suspect that Dr. Leach suggested 5% carbons because anything else is probably overkill.

Best regards, Adrian

 

[BobEllis]

meaning that the circuit is insenstive to minor variances in values. I may try exotic resistors in the feedback loop someday, but I am happy with the sound as is with Digikey and Mouser standard metal film resistors.