Wayne's BA 2018 linestage

[ra7]

Biggest problem is that I have to finish the front (more or less according to the attachment), but need a cool output-selector (or balance-pot of sort,or something to use that 4th knob, hahaha)

Cool front panel! What does the here/there knob do?

 

[mhenschel]

It might be waiting on two more words -- "and everywhere"

 

[myleftear]

It’s for headphones (here) or speaker (there) but the ambiguity could also mean it’s a balance knob...[emoji854]

 

[andynor]

Hello Andreas,


all is looking very good so far. I hope you can enjoy your WLS soon.
It is a very good preamp!


Dirk

Thanks for that, Dirk!

And thanks, David, for the review of it.

I am really looking forward to this. We’ll see how fast the last bits and pieces arrive, and hopefully it might sing within the next week.

Have a good one!

Andy

 

[myleftear]

They said it should be delivered this week...
Have fun, enjoy and keep us posted [emoji846]

 

[andynor]

That’s fabulous! Thank you, Myleftear!

I am so looking forward to getting her ready for listening.

 

[myleftear]

Her?
[emoji6][emoji4]

 

[mhenschel]

How a preamp is like a ship...

 

[myleftear]

Looks like you’re after the vfet-lottery too...

 

[mhenschel]

Actually, I had to look that up.

 

[myleftear]

Class X / Y line-capacitor?

I have little questions:

• The implementation of a line-capacitor across the mains, as in other Pass-gear (Pearl2, F-n etc.) is recommended/mandatory? (Same value (0.0033uF?)
• Ground loop breaker: a bit an obsolete question—Thermistor, Bridge à la Pearl2 or Elliott's loop breaker?
• What would be the easiest/smallest way to implement a relay-network for 3-way output-selector? (doing it by relay would allow me to have the knob placed independently and still have minimally short lines)

Many thanks!
david

 

[andynor]

I second the loop breaker question! Planning on doing the grounding in chassis tomorrow, ao it is ready for the WLS.

I have a 35/200 bridge and an NTC. How do I wire this up correctly? Wich wire goes where, and where does the thermistor go?

David I’ll check the Pearl 2 manual right away, see if I can grasp it.

Stupid question maybe, but I am no expert schem reader as you will know from the question...

Andy

 

[mhenschel]

@andynor -- check out:

Building a Pearl 2

Wiring Up Dual Mono Amplifier

 

[andynor]

That’s just what I need. Am also about to embark on a dual mono version of my BA-3. that stuff was needed. Thanks!

 

[myleftear]

With the thermistor, you'd connect the psi-ground to chassis. (PSU-GND — CL60 — Chassis)
Many say that's absolutely sufficient, 6L6 says Pearl2...

 

[andynor]

I have the thermistor solution on my BA-3. and while it is good enough for function, I find it not such a flexible solution, if not on a PCB of some sorts. So I wanna do the bridge/NTC solution for mainly that reason.

 

[andynor]

The bridge pics in 6L6s Pearl 2 build are excellent. If using an NTC too, does that replqce the black wire between audio gnd and the bridge positive post? Anyone?

 

[cubicincher]

to andynor #2297

Good morning Andy,


you connect your ground (audioground) of your PSU to the groundloopbreaker -
and
from the groundloopbreaker to the earthground.
You can find many , many recipes for groundloopbreakers....



Greets
Dirk

 

[andynor]

Thanks so much, Dirk, and for the e-mail about the subject this morning! I guess the different ways of doing this is one of the reasons for my confusion.

I have worked the front panel and back panel today, and am now ready to start with the gnd scheme. I think I’ll go for the Pearl 2 variant, meaning bridge without NTC. Thoughts appreciated.

Wish you all a good day!

Andy

 

[Russellc]

Hello Andreas,


all is looking very good so far. I hope you can enjoy your WLS soon.
It is a very good preamp!


Dirk

Yes, and it will match beautifully with his BA3, a wonderful combo!

Russellc