The Brassmaster Mysteries

[lowstar]

hi people,

there have been some rumours about the brassmaster lately, see this thread for instance: http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=b42a513333f2785ed4ecd0558b791fb8&topic=56690.0

i am the guy who was mentioned in this thread that found out about the mislabelled resistor, here is a link to a pic that has the info (also missing cap and resistor labels written in there):
http://forum.musikding.de/gallery/displayimage.php?album=random&cat=10491&pos=-2236
i built my brassmaster according to the pic i posted (long ago). my harmonics hi/lo switch works in the brass hi position and makes a significant change to the sound, it get´s a bit brighter. generally, the brass lo setting yields a lot more volume in my build, but then again, i never heard an original.

today i tried to implement the changes that mountainking suggested in the linked thread above, and it did not work. the harmonics hi/lo switch stops working when the changes are done.

i reverted my build to working condition.

anybody else that has tried that and can confirm ?

the whole thing got me interested again because there´s a lot of brassmaster talk over at the talkbass.com forum, a company is building brassmaster clones, they say that the schematics on the net are wrong (including the one over at geo) and that they traced an original. in their build (from what i can tell from the soundsamples), the harmonics switch also seems to work in the brass lo position ...?...

comparing the factory schematic and r.g.´s version, can somebody tell me why the twin t filter section is different in the geo version ??

cheers,
lowstar

[Meanderthal]

 Hmmm I didn't know anyone had suggested a solution... Yeah, that switch is pretty useless as is. Would be nice if it did something noticable... all that trouble getting a 3pdt toggle...

[lowstar]

the switch IS WORKING in my build, because of the changes/mistakes i found (check the link).

cheers,
lowstar

[R.G.]

Well I can tell you why it's different in my version - I worked from the factory schemo which may or may not be what they actually built. I did not trace one out. I modified how the switches were used to simplify the switching. There is always the possibility that I made a mistake, as I do that from time to time.

I'd be interested in seeing what the actual manufactured version looks like. Never seen one in real life.

[Meanderthal]

the switch IS WORKING in my build, because of the changes/mistakes i found (check the link).

cheers,
lowstar

OOOHHH!(the other link!) Wow, thanks...  

[lowstar]

is there anybody on this board with a real maestro brassmaster ? with some good pics, we could solve the mystery once and for all...

cheers,
lowstar

[mountainking]

today i tried to implement the changes that mountainking suggested in the linked thread above, and it did not work. the harmonics hi/lo switch stops working when the changes are done.

Did the changes fix the problem with the brass switch? Also, how does changing the way the components are labeled/numbered change the way the circuit work? I'm not trying to be a smart ass, I'm just alittle confused by what you wrote.

Alan

[lowstar]

yeah, my post is quite long...

if you look at my post, you see in the link to the pic that what is called r22 is actually r27...so if you put a 22k resistor in the place where the 6.8k should have gone, it might make a difference...(plus, vice versa, whatcha gonna put in where the 6k8 should be ? maybe the 22k)

Also, how does changing the way the components are labeled/numbered change the way the circuit work?

if a component on the schem is labelled differently than on the layout (e.g. the layout has only numbers and no values), and the numbers don´t correspond, it will change the way a circuit works.
to answer your first question: when i implied your suggested changes, the switch stopped working. after i put the board back to the original state, the switch worked again.

cheers,
lowstar

[mountainking]

Hey I just looked at this thread again http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=b42a513333f2785ed4ecd0558b791fb8&topic=56690.0 and I looked the changes Moosapotamus made to the filter section again and I think what he drew was more likely correct, then the changes I suggested. Both changes will give similar results but Charlie's will probably yeld better ones. I thought he was trying to show the changes that I was suggesting and since it wasn't exactlly what I was trying to describe I guess I didn't take a good look at what he had draw. I should have taken a closer look.

[mountainking]

yeah, my post is quite long...

if you look at my post, you see in the link to the pic that what is called r22 is actually r27...so if you put a 22k resistor in the place where the 6.8k should have gone, it might make a difference...(plus, vice versa, whatcha gonna put in where the 6k8 should be ? maybe the 22k)

Also, how does changing the way the components are labeled/numbered change the way the circuit work?

if a component on the schem is labelled differently than on the layout (e.g. the layout has only numbers and no values), and the numbers don´t correspond, it will change the way a circuit works.
to answer your first question: when i implied your suggested changes, the switch stopped working. after i put the board back to the original state, the switch worked again.

cheers,
lowstar

Ok, I understand now. Thats makes things much clearer. Sorry I'm abit of a scatterbrain sometimes.

Alan

[moosapotamus]

i built my brassmaster according to the pic i posted (long ago). my harmonics hi/lo switch works in the brass hi position and makes a significant change to the sound, it get´s a bit brighter. generally, the brass lo setting yields a lot more volume in my build, but then again, i never heard an original.

So, you built yours based on the pic at Musikding? What layout did you use?

...so if you put a 22k resistor in the place where the 6.8k should have gone, it might make a difference...

"...might make a difference..."? I thought you just wrote that it DID make a difference.

I'm sorry... I'm still a bit confused about what you actually did to get yours to work. RG's layout at GGG, for example, is based on the scheme that the pic at Musikding was taken from. So, I still don't see how switching around the component labels would make any difference. What am I missing?

BTW - mountainking... In the drawing I posted in that other thread, I actually was trying to interpret the fix that you were describing.

~ Charlie

[mountainking]

BTW - mountainking... In the drawing I posted in that other thread, I actually was trying to interpret the fix that you were describing.

~ Charlie

Thats what I was trying to say. You drew what you thought I was trying to describe, but you ended up drawing something alittle different and I think what you drew might actually work better then what I suggested. Make sense?

[R.G.]

You drew what you thought I was trying to describe, but you ended up drawing something alittle different and I think what you drew might actually work better then what I suggested. Make sense?

Ah... I know that you think you understand what you think I meant, but I think that what you understood means that I said it wrong...

In other words - gentlemen, which schematic is correct with the component values in the right places? I can correct nomenclature and labeling easily enough once we know which component value connects where.

[moosapotamus]

Yup
~ Charlie

[MikeH]

I've had mine in pieces ever since I started that thread.  I also couldn't get the changes suggested in there to work.  I'll try this one, hopefully that will get it up and going.  I actually know a guy who has a brassmaster, I should see if I can get some gut pics of it.

[lowstar]

So, you built yours based on the pic at Musikding? What layout did you use?

who said i built the thing according to a layout at musikding ? the pic shows the r22/r27 switch, i used RG´s layout.

RG's layout at GGG, for example, is based on the scheme that the pic at Musikding was taken from.

of course it is the same scheme of RG´s project file, i used a section of the scheme to show which resistors you have to switch, just like you did in the thread of mountainking.

"...might make a difference..."? I thought you just wrote that it DID make a difference.

of course it DOES make a difference, i used the word "might" as a more general way of describing that using 22k instead of 6k8 will make a difference, like saying "crashing a car with 220mph instead of 68mph might make a difference in terms of how badly you´re gonna be injured".

So, I still don't see how switching around the component labels would make any difference. What am I missing?

all that you are missing you can actually read in my post before, but i´ll care to elaborate some more. RG´s project file has a schematic with numbers and values, and a layout with just numbers. so, it happens that r27 and r22 are switched...the resistor that you will solder in as r22 should actually be 6k8 and not 22k, because the 22k resistor is numbered r27 on the layout, the schem says r22...so i posted the corrected labeling...and, chances are when somebody uses the 22k for r22, he might use the 6k8 for r27...oh god, i used the word "might" again...

In other words - gentlemen, which schematic is correct with the component values in the right places? I can correct nomenclature and labeling easily enough once we know which component value connects where.

I'll try this one, hopefully that will get it up and going.

thanks, that´s my intention and the reason for this whole thread. try out the values that i posted in the little pic, see if it works...i´m eager to find out.

I actually know a guy who has a brassmaster, I should see if I can get some gut pics of it.

that would be fabulous ! 

cheers,
lowstar

[Dan N]

Just throwing this out there...

I looked at the geofex.com pdf and if I were to build as-is, I'd be in a little trouble. Q7 is flipped on the parts layout. E should going to R18 R22/27/whatever C11. Also, the trace from C12 should stop at R28. The schematic does not show C12 connecting to R28/R25/C10/switch.

I'd love to build one of these some day.

[Dan N]

I think mountainking may have nailed it. With his solution you get this:

http://users.rio.com/senorris/junk/brasstwint.gif

The other way you got me and a bunch of poor electrons scratching our heads...

[RickL]

[quoteis there anybody on this board with a real maestro brassmaster ? with some good pics, we could solve the mystery once and for all... ][/quote]

I've got one. It'll be at least a week until I can get a chance to look into it, if I can even remember where it is. I finally got a digital camera so I should be able to post pictures or at least read component values.

I frankly don't see what the big deal is about this pedal. It sounds like about a million other fuzz pedals to me. I bought it for $40 after it sat in a music store for about a year (mind you this was 10 or 15 years ago, but even then Big Muffs and Tube Screamers were selling for more than that).

[Meanderthal]

I frankly don't see what the big deal is about this pedal.

On guitar, it just sounds like a bad fuzz, but on bass the thing is incredible. It lets thru a whole lot of bottom end, and will do a decent octave/fuzz even when driven by a Hog's Foot. It likes to be driven by other pedals in general! Also, I've found the gating to be very practical... when ya stop playin this thing shuts up right away!
What it lacks in sustain can be made up for by driving it with a compressor- instant transformation into a distortion.
In fact, the more I use it, the more I like it. It has bumped off my pedalboard both my ds-1 and BMP.

Oh, BTW, ya know that tuba sound Jack Bruce got in early Cream? Drive the Brassmaster with a Hog's Foot, then cut the highs after the Brassmaster yet again, and it NAILS that sick sound.

I've found that just adding an ordinary volume and tone(lpf, it already has a hpf) to the tail end of it both makes it more practical and more versatile.

All this without the switch being functional! So, yeah, I believe this is a worthy investigation!