L'Amp: A simple SIT Amp

[vdi_nenna]

I picked up 4 different input caps to test: ClarityCaps, Mundorf, Zen Audio, and Dayton Audio.
For the input resistors naked Vishays...I figure this circuit is worth it.

[juanitox]

for the 10uf the clarity cap ESA (250V) is cheap and you can use it on the output too. the quality of the 10000uf is not critical as you bypass them with a 10uf .
also carbon comp for the gate stopper, kiwame 2w is good and small and you can solder it directly on the 2SK82.
don't forget the PS if the CRC is good for the Job , i have found in my system that a CLC ( with the same value for the Caps) sounds faster and even more silent with my 102db speaker..

good building at all

[vdi_nenna]

10uf the clarity cap ESA (250V) is cheap

Cheap compared to other ClarityCaps maybe. $20 each is not cheap.

[KASUMI]

Originally Posted by juanitox

for the 10uf the clarity cap ESA (250V) is cheap and you can use it on the output too. the quality of the 10000uf is not critical as you bypass them with a 10uf .
also carbon comp for the gate stopper, kiwame 2w is good and small and you can solder it directly on the 2SK82.
don't forget the PS if the CRC is good for the Job , i have found in my system that a CLC ( with the same value for the Caps) sounds faster and even more silent with my 102db speaker..

good building at all

Hi juanitox
Why are you bypassing the 10k with a 10uF ? I'm learning
What size inductor were you using in the CLC ?
Cheers
Rob

[juanitox]

hi Kasumi, i'm learning too .. the 10uf bypass on the output cap is to get more open highs than with the electrolyte alone.
for the CLC power supply i use a 10mh hammond choke but Nelson Pass usually use 2mh ones

20$ for a good quality 10uf film Cap is correct when you compare with mundof S/O , VCAP , etc.. and i don't talk of the crazy duelund brand

[OlavHaal]

Hi Michael or the one knowing more than me...

Wondered if I should order 2 pcs of 100 kohm to use instead of the 47 kohm on the gate/earth input? I see NP`s SIT 1 has switchable input 10/100 kohm - to use with passive preamps. My B1-passive may not be able to fully utilize the bandwith of the LÀmp?

Anyone....

Still waiting for my few 1 ohms film-resistors(have some 10 ohms ohmite - but will be too many to paralell)


Regards

Olav

[Zen Mod]

SIT 1 have implemented buffer

switch is for pre-buffer/post-buffer

permutations in front of you are numerous

[vdi_nenna]

and i don't talk of the crazy duelund brand

I have heard them in a friend's system. They are crazy good, but at $800 and having to have them in a separate box outside the chassis, it's almost silly. I guess if you have it $$$$ spend it!

[Michael Rothacher]

B1 certainly won't have any trouble with 47k. However, it is important to remember that the B1 has no gain and that L'Amp has very little gain. So, if your source is an iPod or something with very little output, you may be disappointed. On the other hand if you have really efficeint speakers it may not be an issue. Ideally, an active preamp with low output impedance, capable of 5-6V out (or more) would be nice here.

[generg]

Originally Posted by OlavHaal

Hi Michael or the one knowing more than me...

Wondered if I should order 2 pcs of 100 kohm to use instead of the 47 kohm on the gate/earth input?
Regards

Olav

Hi Olav,

I think Nelson had reasons to skip the 47k from the prototype of SIT-2

the driving of the SITs capacities is better with 1ok, Nelson did the same with the F2J, first the input resistor was 47k too, a compromise between usability for many pres
and bandwidth, now you can see that he implemented even 8k2 in the F2J.

and as Zen Mod said, the 100k you can switch now in the SIT-1 are done with a B1 like (?) buffer.....

so do not buy 2x 100k.... look at your pre output impedance...your B1 can drive the 47k for sure and the 10k also I suppose....but as Mike said yo have not much gain!