B1 Buffer Preamp

[xecluded]

Cool. That's a big help. Many thanks.

 

[mhouston]

Has anyone built the B1 point to point. i am tempted to try it point to point but not sure how to connect the jfet by looking at the schematics - i meant which leg go to where (in layman term.)

I built mine on veroboard or strip brd. And three BoZs two.

 

[Kinnja]

Has anyone built the B1 point to point. i am tempted to try it point to point but not sure how to connect the jfet by looking at the schematics - i meant which leg go to where (in layman term.)

The schematic uses standard symbols. Using the jfet's data sheet, and searching the internet will provide you with the info you need. I put little stickers on mine to make sure I wouldn't mix them up.

 

[xecluded]

After some reading from the suggestion, I think this is how i suppose to connect the JFet chip.

the middle leg or GATE goes to the 1uf cap.
the DRAIN leg goes to 10k resistor, 18V supply, etc...
the SOURCE leg goes to the 10uf cap

Thanks again everyone for your help.

 

[studeb]

Did you check a datasheet for the jfets you have? i think some of the sk170 have different pinouts

 

[xecluded]

The Jfets that i have are the ones that I've ordered from Pass DIY that came with the board. I had mine working with the included board. Nice i was able to make it to work well, I now want to remove the JFets off the board and experience with making it point to point.

 

[AndrewT]

Did you check a datasheet for the jfets you have? i think some of the sk170 have different pinouts

according to the datasheets the pinout of the Tosh and Linear are identical. Linear describe their lsk as a replacement for the Tosh 2sk

It's the other jFETs that come in various pin outs.

 

[studeb]

thank you sir, i admit to being to slow this am to check

 

[mhouston]

I have been thinking about building a BoZ on the output cap which is a large poly about 1" long and 3/4" tall.

You could probably do the same with the B1. My BoZSE has no input caps and you would have to relocate the large storage caps or replace them with one 100uf cap or something.

 

[regiregi22]

according to the datasheets the pinout of the Tosh and Linear are identical. Linear describe their lsk as a replacement for the Tosh 2sk

It's the other jFETs that come in various pin outs.

I thought they were only made (lincensed by in any way) by Toshiba. We know that they are reaching their End Of Life but, what about the other manufacturers, are they still producing?

Are they really equivalent replacements or just have some thins in common and it's just a commercial approach?

Regards,
Regi

 

[Kinnja]

I thought they were only made (lincensed by in any way) by Toshiba. We know that they are reaching their End Of Life but, what about the other manufacturers, are they still producing?

Are they really equivalent replacements or just have some thins in common and it's just a commercial approach?

Regards,
Regi

I thought they were no longer being manufactured, but mouser.com lists the Toshiba 2sk170 as a new item.

 

[labjr]

I thought they were no longer being manufactured, but mouser.com lists the Toshiba 2sk170 as a new item.

Do they have any in stock?

 

[budwiser]

5466 in stock. .80 each

 

[regiregi22]

But nothing regarding the complementary 2sj74

 

[MechanicalAnimal]

Quick question guys,

in stead of metalfilm resistors, can i use carbonfilm-resistors?

(not sure if "carbonfilm" is the correct name, could it be "coal"? i have to translate from Dutch, sorry)

I rather not use digikey-BOM because of 30 dollars shipping on 8 dollar items.

thanks

Maarten

 

[6L6]

Carbon resistors will work well.

 

[MechanicalAnimal]

Carbon resistors will work well.

Cheers mate

 

[MechanicalAnimal]

hhmmm..here goes another pre-Xmax-B1-components-related Q?

Can i change the standard Digikey-BOM panasonic C1 and C2 elco

with this one form pana?

it's 10.000μF, which shouldnt be a problem (>1000μF should be okay in B1) but will it fit? Slightly confused about mounting, snap-in, throughhole etcetera.

Pin-diameter is the same @ 0.8mm (sorry, metric-dude here) and distance @ 10mm. Size wouldnt be a problem 25mm x 35mm (wxh) as Digikey-elco is 22x50 mm's.

i gladly welcome all advices and alternatives

Merry Xmas* from the Netherlands

*i know....almost...almost...just practising already

 

[6L6]

It's 1/3 smaller than the value specified. Try to find a 15000uf. You may use a bigger voltage rating - 35v.

 

[UrSv]

That Panasonic cap would work just fine. Try to feed the B1 with at least a half-decent supply and you're OK.