Wayne's BA 2018 linestage

[damuffin]

http://www.linearsystems.com/lsdata/files/BA2018-R1_Wayne.ppt
Here’s the PowerPoint with all the device details.

 

[mpmarino]

No in the 2018 line stage. Can't LSK parts be used alternatively?

At ~4:08 in the video, Wayne certainly indicates that it's fine. The SMT part is in the big houses, so I think it's why he drew it around them.

 

[labjr]

At ~4:08 in the video, Wayne certainly indicates that it's fine. The SMT part is in the big houses, so I think it's why he drew it around them.

Thanks! Back to my question. Has anyone tried and compared? I'm wondering if there's a noticable difference in this application?

 

[chat72]

No in the 2018 line stage. Can't LSK parts be used alternatively?

I use what Jim gave me, 2sk209.

 

[6L6]

Yes, the LSK170 can be used in place of the Toshiba 2SK209.

 

[Russellc]

I don't suppose that there is a SMT version of J74? That would be too easy.

Russellc

 

[6L6]

You need the K170s, and yes, there is.

 

[labjr]

Do the JFEts need to be matched?

 

[wayne]

I didn’t match any of them but it wouldn’t hurt. They came pretty close just random on some.

 

[6L6]

No.


EDIT: I see Wayne answered at the same time. Both of mine have had random K209 off the reel, they work beautifully.

 

[BDP]

Do the JFEts need to be matched?

See post #132. You can easily check them yourself.

BDP

 

[Russellc]

You need the K170s, and yes, there is.

Hmm. Seems like we should make use of them. Other than being SMT, why aren't people using these given shortages of regular k170/j74 pieces?

Forgive the off topic, but I'm surprised!

Russellc

 

[mpmarino]

If one were to stack two circuits for balanced operation.....

Could it effectively convert Bal to SE, or visa versa?

If so, would you have to ground the balanced negative on the SE side?

 

[DougL]

I watched the Utube presentation of the BA 2018 Line stage.
I learned a lot going through the presentation and schematic.
My question is application related. What was the BA 2018 designed to drive?
I am guessing F4 / MOFO type circuits.

 

[wayne]

It wasn't really designed to drive anything in particular more of just a experiment. It will drive quite a few things though especially with the bigger outputs.

 

[gary s]

Wayne, if one were to use the bigger output transistors, what other components would need to be changed and what would be their new values?

Thanks in advance.

 

[wayne]

Change the 27 Ohm emitter resistors to 15 Ohms and double the output current.

 

[gary s]

Thanks for the very quick reply Wayne.

 

[Dennis Hui]

I worked on mine over the weekend using the kit kindly supplied by 6L6.
It's not quite done yet since I have yet to test it. I hope to be able to
do that this coming weekend.

 

[6L6]

Looks good! Test, listen, enjoy, and report back. 🙂 🙂 🙂