• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

WTB Firstwatt Clone F2 PCB boards

Status
Not open for further replies.
Jump to Latest
#63
#66
F2 boards are already here, will start shipping out tomorrow.
 

Attachments

  • web2.jpg
    web2.jpg
    98.4 KB · Views: 462
#68
I am looking at various options for resistors for this project. I am interested in Kiwame resistors. Here in the UK they are difficult to get hold of and the stocks are fairly limited.

They come in 2W and 5W versions. I see that a lot of the resistors are rated at 3W. I will be using very sensitive speakers and will not be drawing much current, will 2W be ok?

Can you also confirm that on the schematic where it says a resistors like R7 & R8 are shown as 1, is this 1R? and R18 221R?

If I can't get the exact values is 2k2 ok for 2.21k and 220R for 221R?
 
#70
Puffin said:
I am looking at various options for resistors for this project. I am interested in Kiwame resistors. Here in the UK they are difficult to get hold of and the stocks are fairly limited.

They come in 2W and 5W versions. I see that a lot of the resistors are rated at 3W. I will be using very sensitive speakers and will not be drawing much current, will 2W be ok?

Can you also confirm that on the schematic where it says a resistors like R7 & R8 are shown as 1, is this 1R? and R18 221R?

If I can't get the exact values is 2k2 ok for 2.21k and 220R for 221R?
Click to expand...

Puffin,
I breadboarded one of these last year (and looking forward to building another with these boards!) and can say for certain the R7-R12 resistors run very hot. Another member said they ran around 83c. I would use 5 watts there if possible, or use 12 of the two watters.
 
#71
Peter. Thanks for your reply. I assume you meant to say that 2k2 and 220R were ok as substitutes for 2.21k and 221R.

What is the nearest value to .33R?

I had this incling in the back of my mind when typing my last post that Class A is a consistent current draw, but thought I would add it anyway.
 
#77
Peter. The codes above RN55 = Metal Film 0.1w
CMF55 = Metal Film 0.25w

I assume that the 3w resistors required for the F2 would be the Dale Silicone wire-wound?

Digikey don't have all the values I would require (I was hoping to order all parts from one source)

It is also quite confusing in that they have 3w, 3.25w and 3.75w wire-wound's and also they refer to "Power - wire-wound resistors". Would I be right in thinking that these are not Silicone,, but the white block resistors whiche most would say are to be avoided ?

I assume that Wattage values over 3w makes for a bigger package. Would they fit the board?
 
#78
Puffin, for R23-26 the 'virtual' L1, inductive WW are recommended.

I previously built this point to point.
I used these from Digikey. RSB-.33RCT-ND
The 'RS' are inductive, NS, non-inductive.

For all others I used Panasonic.

In my next iteration with this, R7-R12 I would recommend 5 watts if possible. Those ones run really hot.:hot:
 
Status
Not open for further replies.
Top Bottom