Help With a BD-2 Mod?

TopBoost · Post by **TopBoost** » 30 May 2016, 02:00

I've searched high and low on here and I can't find an answer to my question... so here goes:

I decided to mod an BD-2 using Brian Wampler's old book on modding pedals. For the Brent Mason mod and others C10 is listed TWICE.

As far as I can tell it's not C100 or C101, which are the HP/LP filters.

Any ideas?

indyguitarist · Post by **indyguitarist** » 30 May 2016, 14:50

TopBoost wrote:I've searched high and low on here and I can't find an answer to my question... so here goes:

I decided to mod an BD-2 using Brian Wampler's old book on modding pedals. For the Brent Mason mod and others C10 is listed TWICE.

As far as I can tell it's not C100 or C101, which are the HP/LP filters.

Any ideas?

It's been so long ago that I wrote those mods that I had to google for them

That should be the correct mod. I think.

TopBoost · Post by **TopBoost** » 30 May 2016, 21:06

Wow, what's better than to have the creator answer a post, haha? Thanks for the reply!!

The one I was looking at in the book was not the same as the one you posted, so I'm gonna assume it is the most recent. I'll go with the you showed me, here.

Just for fun, what were the two C10s referring to in the book, Mr Brian? Those caps were changed in just about every BD-2 mod.

MoonWatcher · Post by **MoonWatcher** » 31 May 2016, 21:05

TopBoost wrote:(What is the)...C10...cap changed (to) in just about every BD-2 mod?

It's kind of like the actual input cap of the actual effected part of the circuit, because it falls just after the input buffer (circuit), after the switching jfet (Q6).

Very generally speaking, you'll sometimes see this cap's original value reduced with some Boss pedal mods, such as for the BD2. I've seen it done with the DS1 also.

In the case of the BD2, I usually see C10 changed to 10nf, which raises the highpass filter corner frequency up to 72 hz (in conjunction with R23, which is 220k). Since the low E string unfretted has a frequency of about 80 hz, raising that filter's corner frequency close to the lowest frequency note that a guitar is capable of producing, will generally help to tighten things up a bit. It's one of those things that I personally consider to be "generally good sounding."

With the DS-1, the equivalent cap is C3. Switching it from the stock value of 47nf to 22nf (in conjunction with R6, which is 100k) will have a similar effect to changing C10 to 10nf in the BD-2 (you end up with the same highpass filter corner frequency of 72 hz).

What is interesting is the equivalent stock cap, C2 (stock value is 18nf), in the SD1, has a highpass filter corner frequency of 88 hz (with R4, which is 100k) - probably about as spot-on as you can get, if using standard tuning with six strings.

TopBoost · Post by **TopBoost** » 01 Jun 2016, 01:29

Thanks for the replies, guys.

I ended up with a .047uf cap at C101 and a .1uf cap in C100, along with rest of the Wampler mods

. Suits my needs.

MoonWatcher · Post by **MoonWatcher** » 01 Jun 2016, 20:52

TopBoost wrote:Thanks for the replies, guys.

I ended up with a .047uf cap at C101 and a .1uf cap in C100, along with rest of the Wampler mods . Suits my needs.

Good to hear!

Just wanted to say that if you ever crack your BD2 open again to mess with those tone circuit caps some more, try the values used in the OD3 (33n and 22n). Boss got it spot-on with those.