Surely I can't be the only one contemplating doing a clone layout of this design, but I might be the first one to actually finish it? 
It's going to be a month or so before the boards are here and tested (just ordered yesterday), so let's hope it works - normally publishing anything before testing risks jinx'ing the design but I'll take my chances
It's going to be a month or so before the boards are here and tested (just ordered yesterday), so let's hope it works - normally publishing anything before testing risks jinx'ing the design but I'll take my chances
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What is special about this line stage / Preamp compared to the other DIY projects like BA3-pre, Korg Pre and Whammy?
The line stage is quite complex with 14 transistors pr. channel. I build BA3-pre because of the large voltage swing to be used for MoFo and the interesting P3 adjustment and also because it is a class A non-feed back amp. I build Korg Pre because it is very special with a 2nd harmonic / triode SE signature and I build Whammy because it can be used as a good head phone amp and also as just a preamp and also because it seems to be an easy build with on board PSU. Where does this line stage fit in? …...why do I want to build one?
The line stage is quite complex with 14 transistors pr. channel. I build BA3-pre because of the large voltage swing to be used for MoFo and the interesting P3 adjustment and also because it is a class A non-feed back amp. I build Korg Pre because it is very special with a 2nd harmonic / triode SE signature and I build Whammy because it can be used as a good head phone amp and also as just a preamp and also because it seems to be an easy build with on board PSU. Where does this line stage fit in? …...why do I want to build one?
Yes, I am probably addicted as I initially thought that I would only build the ACA but now I am close to finish the BA3-pre and I have built the MoFo and also have M2X PCBs and Whammy kit and Korg pre as Christmas present will be here soon……...I hope. Then I was trying to figure out what kind of "signature" this line stage has.
I was not at BA18, but being a Wayne Colbourn design from the Pass stable - you can bet it will be anything but ordinary! Maybe Wayne can answer your question when he sees it, and put your mind at ease, besides what is another preamp between friends - soon you will have enough to listen to a different one each month.
We are all addicted when it comes to a Pass design.
We are all addicted when it comes to a Pass design.
I’m just sorta a newbie, but when I asked Wayne he said “it would drive the cables better”. I mean hey... it’s designed by Wayne, that’s reason unto itself.
Everything else you mentioned has signature, and it 'looks' like this is geared toward accuracy - maybe that's a reason? I guess we'll find out.
Of all the pre's I've done, I've lived with the NS10 clone the longest. The amps have plenty of character for me. I'm wondering if this might be an 'update'.
Nisbeth, I'm with you. Out on my own - I'll likely etch one. No time now tho
This is a pretty accurate gain stage it was done just for BA 2018 as a quick project after Paul Norton brought us a batch of LSK170 SMT parts. I had just purchased the KSA992 KSC1845 bipolars and just combined the parts. The JFET input I borrowed from Scott Wurcer with permission. A little simulation and a layout was done in time for BA. The alternate outputs can be biased up and have quite good drive capability. Just a monkey with a Audio precision and people that can hear.
Mark Johnson or Scott Wurcer are some of the experts here on circuits to name a few.
Mark Johnson or Scott Wurcer are some of the experts here on circuits to name a few.
Dont engage in denial....just admit your affliction and get in line to buy one. Reason indeed, we need no reason, build because you cant help yourself.
An extra pre amp or 10 will come in handy at some point I'm sure.Russellc
Don't forget that one of Wayne's design goals was to use current production, LOW COST, components exclusively. And he succeeded!
Look back at the powerpoint slides of his presentation, where prices are discussed. You'll see that he wasn't exaggerating when he described the talk as
That's not easy to do, and get measured performance as good as Wayne got.
High performance + low cost + lots of fun. What's not to like???
Look back at the powerpoint slides of his presentation, where prices are discussed. You'll see that he wasn't exaggerating when he described the talk as
A discrete opamp made from 3 cent bipolar transistors and 15 cent JFETs
That's not easy to do, and get measured performance as good as Wayne got.
High performance + low cost + lots of fun. What's not to like???
Ok...….I have sent a PM also to get a set of these line stages. High drive capability and stability is a good thing and I also realized the very small form factor of the boards. Then I have to learn to solder smd components. I have only done that once. For that I used a hot air attachment I have for my Weller gas solder iron.
Why build this pre? Price the Passlabs linestages. This linestage is from a designer that works there and you will find your answer. I have built a couple of BA-3 pre's, not my cup of tea. Great with my BA-1 and BA-2 but not as a standalone. Nothing wrong with it just not my favorite. When possible I usually use my B1 buffer because of it being so simple and neutral sounding. When using a pre with gain I reach for my LSK pre Nelson presented at the BAF a few years back. Excellent sounding to my ears. I am sure with some tweaking both the LSK and this design can be improved to a real high standard of audio perfection. The LSK linestage with no feedback appeals to my brain but in reality feedback is not that awful a thing if used correctly sonically. With both the LSK and this linestage I feel like Nelson and Wayne are giving a peak into what is in the retail linestages they sell.