Yup. I'm building an F5! Here are my questions

[ouimetnick]

Hi everyone!
I'm really excited to get started on building an F5. i've heard nothing but great things about the amp, so I bought some boards from the DiyAudio store, and here we go.

P-F5-2V20 - Pair of F-5 boards (Makes 2 channels; Rev 2.0) - Boards

Anyways, the boards are V2.0 dated 2010-10-23 caviler layout

So I have the BOM

Attached is the BOM, and I have several questions. I plan on just throwing all the board components into a Mouser project, and ordering. They don't seem to have all the transistors, and I will discuss them later.

Just one questions for resistors... well two actually. I know K means 1000, so 100K=100,000

But what does R mean? Like 10R, 100R, 0.47R 150R, etc?

Also, I'm going to use metal film resistors? Is that okay?

As for the pots, P1, and P2 are both 5K. Can someone point me to the mouser part number (or digikey) for the pot? I can find a lot of 5K pots, but I need one that fits in the holes. One with the right spacing. :-)

As for the NTC thermistor, its 4.7K.. whats the wattage? Can someone point me a link or something?

Also, what about LED1? What should I use for that? Again, a link would help me.

Now onto transistors.

Q1: 2SK170
Q2 2SJ74

Aren't these transistors difficult to find? I heard one of them was discontinued with no replacement.. I have a source for them, but do they need to be matched? If they do, what is it for? Low DC offset?

As for Q3 and Q4, what website has them?

What brand should be used for them? Any matching needed for these? I know they are the outputs.

As for Q5 and Q6, Mouser has them.. nuff said. But do they need to be matched?

Now with all that done, heres the other set of questions.
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Transformer should be a 18-0-18. What VA would work? Can I simply wire up the power supply like in a Hafler DH-200?

I would simplify if though. I would get rid of the thermal breakers, as they would be on the PCB, and get rid of the high temp lamp.

The center tap of the transformer is connected to the ground bus between the two filter capacitors. For filter caps, would two 22,000µF work? Also, having an B+ and B- fuse for each channel. Thats my plan for the wiring. The ground of the RCA jacks is grounded to the bus bar, and so is the negative output for the speakers. Fuses will be put inline with the positive speaker output.

As for a chassis, I'm simply reusing an old Yamaha receiver.. Don't worry, the heatsinks are huge.
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Sorry for some of the stupid questions, but I'm not an electronics genius yet. I'm only 16, and money is an issue, so thats why I'm not going to buy fancy resistors and stuff. Just regular components.


Thanks so much for the help!
-Nick

[Woody1911a1]

why not just order the parts kit from Tech DIY Company Store ?

[Woody1911a1]

and for a transformer Antek - Transformers - Grid View[]=0

[ouimetnick]

I may do that, but it may be cheaper just to buy the components on my own.

Is a 400VA transformer enough to drive two channels?

Antek - AS-4218

[Woody1911a1]

yes

and the thing you're going to find out is that the jfets aren't available from mouser or digikey any more

[ouimetnick]

A guy still sells them. So I'll get them from him.

[ouimetnick]

Nevermind. Econimically, it would be cheaper to just buy from the DIY Company Store.

It looks like it does, but does it have EVERY component for my boards? And pots that fit?

[Woody1911a1]

whatever lol make sure that they are genuine , because they are 90% fakes on the net

was just trying to help .

Out ,
Woody

[Woody1911a1]

and if you need heatsinks , these are more than adequate 10.080" Wide x 7" Long Heatsink - HeatsinkUSA, LLC Store

[heinz1]

Have also a look at cviller's blog entry on the subject:

http://www.diyaudio.com/forums/blogs...version-2.html