Project this summer: (modded) Bluesbreaker

[Steben]

Just ordered a breaker kit and some stuff from Musikding.
Planning to stuff it into an amp switch pedal I painted Daphne Blue.
Drilled the pot holes.



What I plan to do is the following:

- standard V1 circuit
- "boost" switch which engages V2 style arrangement in first stage for more gain.
- additionally add a soft clipper loop in first stage. This will be experimenting. Perhaps LED which means with strat almost no clipping in V1 arrangement unless boosted by pedal in front.

[ElectricDruid]

That enclosure is beautiful! Looking forward to this one.

[Steben]

That enclosure is beautiful! Looking forward to this one.

Thx! I do too 

[phasetrans]

...What I plan to do is the following:

- standard V1 circuit
- "boost" switch which engages V2 style arrangement in first stage for more gain.
- additionally add a soft clipper loop in first stage. This will be experimenting. Perhaps LED which means with strat almost no clipping in V1 arrangement unless boosted by pedal in front.

Interesting. I have a friend with an intermittent blues breaker, so I wanted to try to see if I could do him one better. Haven't built it yet, but hope to try it this summer. I might move the gain to stage 1.

[Steben]

Stage 1 gain
blue to cyan lines are V1 with pot from 10 to 100k
red to yellow lines are V2 with pot from 10 to 100k

Drawing of what I intend to achieve:

[Mark Hammer]

Try this:  https://www.diystompboxes.com/smfforum/index.php?topic=126135.0
A little more "muscular" than a Bluesbreaker, but the same basic engine.

[Steben]

"Dry fit"

On to drilling jack holes.

[Mark Hammer]

I have a bunch of those knobs, but never find an enclosure or application to use them, because of their size.  Maybe it's the detail on the vernier around their perimeter, or maybe it's just an association I have with previous lab equipment, but they do look really "scientific", don't they? 

[Steben]

I have a bunch of those knobs, but never find an enclosure or application to use them, because of their size.  Maybe it's the detail on the vernier around their perimeter, or maybe it's just an association I have with previous lab equipment, but they do look really "scientific", don't they?

Yes, yet the "scale" numbers remind me most of all of Fender amps and classic guitar knobs. And early fuzzes. I adore them. They need space and big angled boxes are a fit. Flat Hammond enclosures are not a home for these guys.

[antonis]

They need space and big angled boxes are a fit.

And an arrow mark for vernier number setting indicator..

[Steben]

so far so good

[Steben]

Done.
Sounds great.
Adding diodes in the first loop doesn't add too much in V1 circuit in (lower) drive since the lower to mid frequencies aren't that much amplified.

The "boost" functions works .... but there is a caveat... I used a 3PDT to engage a LED and the two resistor positions.
This means at boost, the high frequencies shine too much through. I might redo this with a complete new leg circuit for one lug in the switch and engage a larger cap in the feedback loop.

And I do not have a name yet 

[Steben]

Still is a very bright pedal by nature. The 100pf might be higher value.
(Now permanent) Schematic:

[Mark Hammer]

The "problem" lies in the ground leg caps in the first stage.  Make those larger values and you might be happier. 

Remember that the bass rolloff will be set by the value of the ground-leg cap in conjunction with the ground-leg resistance.  In your "boost" setting, you have the 4k7 resistor going to a 10nf cap.  Keep in mind that a Tube Screamer has a 4k7 resistor going to a 47nf cap and that rolls off bass around 720hz.  A 10nf cap will move that rolloff up by almost a factor of 5x!!!   I think you'd be happier if you made that 10nf cap 100nf.  You might also want to raise the value of the 10nf cap connecting the 3k3 resistor as well.

Essentially what you've done is kept the cap values the same as the Bluesbreaker (or KoT), but added an alternate set of gain-setting resistors for your "boost" function.  It's the maintaining the cap values that gets you the searing brightness.  Maybe what you could do is use your 3PDT to connect the 4k7/3k3 pair to their caps, OR the 27k/33k pair to their caps.  You'd still have the 3rd set of contacts to indicate boost status.

The drawback with this suggestion is that you'll get pretty loud switch-popping.  The "cure" would seem to be connecting the caps to their relevant resistors via 1meg resistors.  The 3PDT would then be used to bridge/bypass whichever pair of 1meg resistors you select.  When unbridged, the corresponding subcircuit -whether boost or normal - is effectively out of circuit, and the gain and EQ curve set by whichever pair of resistors/caps you have bridged/selected.

Make sense?

[GGBB]

I've been using the same kind of mod plus a few extras in my bluesbreaker copy for a few years now - I've called it the "Notorious OD". Yes - the V2/Morning Glory mode especially is quite bright - which is why I added a fat switch to mine. The 33n setting is what I use almost always in V1/King of Tone mode. The combination of the dark (tone) and bright (presence) controls along with the fat switch make for a wide range of flexibility with controlling upper mids/warmth/sparkle/fullness. It goes a lot of places tonally that the standard Bluesbreaker/King of Tone/Morning Glory don't. Just finishing off a new build right now going into a triple drive pedal (Timmy/custom clean boost/Notorious) to which I've added a clipping/clean boost switch.



No switch pops done this way.

[Mark Hammer]

I stuck a Wattbreaker and a Crank booster in a 1590BB, with an order-flipper toggle, so you can have boost-before-drive or drive-before-boost.  NOT gentle.

[GGBB]

I stuck a Wattbreaker and a Crank booster in a 1590BB, with an order-flipper toggle, so you can have boost-before-drive or drive-before-boost.  NOT gentle.

I'm putting a direction toggle in mine as well - clean boost will always be in the middle. I had SUCH a hard time deciding on the "default" order (physical right-to-left).

[Shoeman]

Not to get us too far off topic, but how do you guys add those order select switches? 

[Steben]

I stuck a Wattbreaker and a Crank booster in a 1590BB, with an order-flipper toggle, so you can have boost-before-drive or drive-before-boost.  NOT gentle.

Is the drive before boost often in play? 

[Mark Hammer]

I stuck a Wattbreaker and a Crank booster in a 1590BB, with an order-flipper toggle, so you can have boost-before-drive or drive-before-boost.  NOT gentle.

Is the drive before boost often in play? 

It can be.  Sometimes you want to use the "boost" as a simple level changer.