Changes to Speedball layout and components...

[StivVid]

I've just completed building the Speedball upgrade for my Crack.  This isn't my first build, so when I opened up the package for the Speedball upgrade I immediately noticed that the parts included with this kit were different than the parts included with Speedball kits in the past.  I've been searching for some info on the changes made to Speedball here in the forum, but I haven't found any yet.  If this is a topic already being discussed, could someone point me to the relevant thread?

I'm just curious as to why the changes were made and whether there are any noticeable improvements to sound and performance?  It's certainly easier to build, in my opinion.  That's a big plus.

 

[Paul Birkeland]

It's certainly easier to build, in my opinion.  That's a big plus.

That was the focus of the revision.  The two small boards were leftovers from the Extended Foreplay III upgrade, and we decided to abandon them and create a dedicated board for the purpose that is immensely easier to wire. 

We abandoned the 2N2907 and replaced it with the physically different but electrically identical PN2907 to eliminate the possibility of swapping those transistors.

We changed the R1 on the larger PC board to a Dale part so that it looks visually different than the R1 on the small board, as swapping these resistors was a very common error.  We also combined the series string R2 resistors on the big board to a single resistor per side.

There is now a heavy emphasis on properly mounting the TIP50 transistors, as this was rapidly becoming the most common build mistake with the Speedball.  It was also the mistake that was the most difficult to get builders to look for.

We also split the build out into two parts, so that the front board can be built, installed, and evaluated before the big board goes in.  In may help threads, I end up recommending that the 6080 be removed to test the boards on the 12AU7, so we are just doing this up front. 

We have not noticed a sonic difference from these changes.
-PB

 

[StivVid]

Thanks, PB.  That's exactly the info I was looking for.  I'm really liking the new layout and you're right--it was easy to mix up some of those parts in the old kit.  I've been listening more this afternoon and really like what I hear.  Thanks again for the info.