DIY Audio F4 Premium Resistors?

[Einric]

Are there any resistors needed in the DIY Audio F4 clone that would be well worth the splurge on Low Noise or High Stability premium resistors?

[The Space Egg Corp]

Hi Einric

You could try some nice 'old-school' wire-wounds.
The small green 'Welwyn 22 type' 3W are quite nice.

Not realy a 'high-end, audiofool' type product...
...thus, no 'splurge' required !

Just good wire & EXELLENT stability.

You could try giving them a nice 'heat-cycle' in the oven; before matching.
Values will NEVER change after that !

Low noise...?...
...I don't think there is anything lower in noise, than a coil of wire !...
...I don't imagine you would notice any 'noise' in an F4 anyhow...
...more the territory of phono-pre's...
...but wire-wounds are 'cool' anyhow.

I like 'em anyway.

Cheers.

Si.

No 'bling' kudos though...
...just 'plain wire'...
...no solid gold or platinum or unobtainium is used in the Welwyn 22's.

[Einric]

Funny thing.....Those Welwyn 3W .47Ω resistors were the ones I already had picked out.

Are any of the 1/4W resistors benefited by High Stability and better than 1% matching?

[The Space Egg Corp]

Hi Einric

I'm trying to use ALL wire-wounds EVERYWHERE !
( just a current obsession ( no pun intended ! )

Not sure about the F4 exactly, not familiar with the circuit.
I fancy a BA-3 at present with all wirewounds for the 1/4W's as well.

Using a bigger 1W metal-film, where 1/4W's go could be good ( less reactance to heat, perhaps ).

Must have a look at the F4...
...it's a 'follower amp' ? isn't it ?
What are you going to drive it with ?

Cheers

Si.

[Einric]

I will be driving it with an all 6CG7 Glassware Aikido.

[Einric]

1/4W Wirewounds are pretty spendy.

[The Space Egg Corp]

Hey Einric...

N I C E !...

...She just went in my 'cool amp' folder !

Broskie has some cool designs...
...Your woodwork & caligraphy look great.

What output caps you got ?...
...is that 'Obligato Gold' ?

Cheers

Si.

[The Space Egg Corp]

Hi Einric

Sorry missed your last post.

Yeah...I see small ones at £3-4 UK each...
...but the Welwyns at £1/2 UK each.

I don't see the 'tolerance thing' as much of a deal...
...as long as the key ones are matched per-position, per-channel...
...at the Welwyn prices, as small 'wastage' is even OK.

Even at 5% tolerance...in a small batch...they come up 'good enough' on value...with a teeny bit of matching.
The series values & large ones are normaly less critical anyhow.

Only question is...will they fit the board...3W's are about 1/2" long.

Cheers

Si.

[PreSapian]

how about caddock thick films?

[Einric]

Si,
Thank you for your kind words.
Yes I did use Obbligato Golds.
The design on the front actually says Ai-Ki-Do in Japanese.
I did it with a my soldering iron w/ a 1/8" tip.
I took the writing from Google Images and scaled it down to the size I wanted.
Then I taped it to the front and traced it with an X-Acto knife.
Then removed the paper and filled it in with my "wood burning" tool.

The size of these wirewounds is my main concern.
I do not know if they will fit.
I will compare my F5 boards to the online pictures of the F4 and see if there is any way of judging.
Maybe I will take the online picture and scale it to life size.
Then I can measure for fitment.

Thanks,
Richard