Q2
I decided for the J113's, they can always be changed later should you want to, the PCB's are in good quality and especially with a desoldering iron it's not much of a hassle.
Getting the filter adjustments right for the entire system is likely to be much more important - the last THD-N adjustments/improvements really just is (potential) icing on the cake.
You could add the std. value 1.5nF in parallel to the 22nF but using the calc/sim webpage it might turn out to work perfectly well with 22nF and 47nF
That would be q2.
Also worthy of note, those looking to use 2sk170 fets instead can settle for using them in q1 position and get the performance they are looking for.
That s my plan, I noticed in the article that the ccs was set for 8mA. I bought 6 matched pairs 7 -9 mA. So as long as I solder them correctly pin wise, the J113's should be a match. I'll use them between channels like Dirk suggested.
I want this build to compliment the VFET amp, having the crossover in the same enclosure as the BA2018, the money I save on a separate enclosure and cables, the k170's are affordable. Rather pay for the JFETs than an alloy box.
I'm going to use the smps for the crossover, I have a spare smps filter from the store, would that be overkill to add?
I want this build to compliment the VFET amp, having the crossover in the same enclosure as the BA2018, the money I save on a separate enclosure and cables, the k170's are affordable. Rather pay for the JFETs than an alloy box.
I'm going to use the smps for the crossover, I have a spare smps filter from the store, would that be overkill to add?
My listening impressions: I built this crossover to replace an existing op-amp crossover. It’s set at LR24 at 400hz. Measured transfer function duplicates the op-amp crossover. Curves are identical. I did not expect it to sound much different.
Wow, was I wrong about that! The first thing that hit me was an increase in space almost to the point of reverberation. Imaging is improved and the bass is more powerful. Two items my system did not do well. Sibilance is a bit softer. On the whole I like it. Thanks so much to Mr. Pass for making this available.
Wow, was I wrong about that! The first thing that hit me was an increase in space almost to the point of reverberation. Imaging is improved and the bass is more powerful. Two items my system did not do well. Sibilance is a bit softer. On the whole I like it. Thanks so much to Mr. Pass for making this available.
Looking good!
I (dare I say it) also have the BA2018 in the pipeline and a Muses volume just waiting for the next pre-amp to get finalized, likely to be the BA3 and BA3B for the F4's though.
While as kindly mentioned by Dirk, the ASP's are an option for the LX521.4's I'd rather have the JFET's in the signal chain.
When (if?) I get the LX-minis back to test them out with the now assembled LX-Mini crossover - that might be the final push towards looking deeper into using the 6-24 xover instead of the 4x10HD
I of course hope that the one an only Mr. Pass
beats me 
to it
I (dare I say it) also have the BA2018 in the pipeline and a Muses volume just waiting for the next pre-amp to get finalized, likely to be the BA3 and BA3B for the F4's though.
While as kindly mentioned by Dirk, the ASP's are an option for the LX521.4's I'd rather have the JFET's in the signal chain.
When (if?) I get the LX-minis back to test them out with the now assembled LX-Mini crossover - that might be the final push towards looking deeper into using the 6-24 xover instead of the 4x10HD
I of course hope that the one an only Mr. Pass
beats me to it
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It would be nice to have the boards accept both types, I had to twist two pins to fit. Took extra time with verifying no shorts between pins. Otherwise I think very worth the effort. I also found a misprint on the board, printed 221k, schematic show's 1M, no big deal but if your going to change the PCB.
I think the time is here for preamp/active crossover integrated line stages.
I think the time is here for preamp/active crossover integrated line stages.
How about with Toshiba 2SK209 SMD parts? They are more widely available than the Linear Systems parts. They are cheap, plentiful and very high performance. Wayne uses them unmatched in the BA2018. For matching, just be sure you have good eyesight and steady hands to do the sorting. This can be done using a Peak Atlas PCA23 SOT-23 test fixture.
SOT23 Peak Component Adapter | Peak Electronic Design Limited
SOT23 Peak Component Adapter | Peak Electronic Design Limited