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Maestro - Brass Master : the corrections

PostPosted: 22 Dec 2008, 00:27
by chicago_mike
I have the r g keen layout and a gut shot of an origional.

But I would like a shot of the trace side, if anybody has one.

Thanks kindly. :)

Re: Maestro Brass Master request

PostPosted: 22 Dec 2008, 02:04
by modman
I found this:

Re: Maestro Brass Master request

PostPosted: 22 Dec 2008, 03:00
by analogguru
modman wrote:I found this:

exactly that´s the reason why he needs the trackside.... because the schematic is wrong.... :wink:

analogguru

Re: Maestro Brass Master request

PostPosted: 22 Dec 2008, 05:14
by toneman
how can a factory schematic be wrong?? :hmmm:

Re: Maestro Brass Master request

PostPosted: 22 Dec 2008, 07:56
by chicago_mike
Factory schematics are wrong many many times. On purpose.

If anybody out there has a trace side of this thing. Unless one of us is good enough to take the component side and make a trace of that. I know Im not that good. :oops:

Maestro Bass Brassmaster work

PostPosted: 23 Dec 2008, 15:55
by R.G.
Not sure why the other topic is locked, but I thought I'd toss in that I have some new info on the Brassmaster, and the prospect of more yet.

The factory schemo is incorrect - in digging through it and simulating stages, it can't work the way it's shown. I've correct a couple of issues. There will be more on this as I dig it out.

Re: Maestro Bass Brassmaster work

PostPosted: 23 Dec 2008, 16:53
by Bernardduur
Awesome!

Someone knows if the B:ASSMASTER by Malekko (I thought) is based upon this schematic? I still need to review some pedal for my job and that one is high on my list!

Re: Maestro Bass Brassmaster work

PostPosted: 23 Dec 2008, 18:04
by chicago_mike
Im not sure my thread got the locky-wocky, but im not going to fuzz about it. :)

But R.G., thanks for investigating this further. :)

Re: Maestro Brass Master request

PostPosted: 24 Dec 2008, 06:35
by gtrgeek1
Hi guys, first post here. I have completed a few projects from here and wanted to give back. Last year I took on the brassmaster project. I started with the schematic posted earlier in this thread and used RG's board layout. It never sounded that great, but I have played originals, so I knew what it was capable of. There are two resistors swapped on RG's layout. I need to check my notes as to which ones, but after changing these it did sound much better.

A very close friend of mine was then kind enough to lend me an original to reverse engineer. A week later another friend shows up at my place with 2 more. So now with three of these things I knew I would get to the bottom of it. I took the "incorrect" schematic and redrew it into Circuitmaker, I then took pictures of both sides of the pcb and did an exact pcb layout in Traxmaker. Using the check function I was able to verify that the schematic is in fact correct, and matches the pcb. The only inaccuracy is that the Q1 supply is not marked, but it should be fed from the 8 volt supply. I checked parts values and connections on the other two and they were all the same.

I'd like to offer the layout here, but I only have it in Traxmaker or Protel. If you give me till after the holidays I can probably post pdfs of the layout. I copied the original exactly, so in order to build one there are a lot of wires to connect. If someone can convert the files, just pm me and I'll email them to you to post for all.

The B:assmaster is also the same basic pcb. The actual pcb looks almost EXACTLY like RGs with a few changes. The main difference is entire circuit runs off of the 9v supply, and the 8v supply is missing. I also checked all the connections on this pcb and verified that it matches the original schematic.

All the units I have seen use 1N456 diodes. When I measured them with the diode check function of my meter, they all seemed matched. The diodes in the originals also read on the high side (.700). So I bought a bunch from Mouser, found some matching, high reading ones and viola. The matched diodes made the octave up much more pronounced.

I have more notes, but they need to be dug out.

Regards, John

Re: Maestro Brass Master request

PostPosted: 24 Dec 2008, 18:41
by unbeliever
Very cool. I have Protel also, and am more than happy to do the manipulation to get the info available to people here if you send me the file. I'll PM you.

Re: Maestro Brass Master request

PostPosted: 24 Dec 2008, 22:56
by borislavgajic
I can probably post pdfs of the layout. I copied the original exactly


I can hardly wait to see!!! :thumbsup

You can use ...PDF Factory...free software,and then when you use PRINT function ( in protel or other software) instead of your printer you choose virtual print with pdfFactory......and there it is..............it is very easy and nice D.Hendrik pointed me to it :thumbsup

boris

Re: Maestro Brass Master request

PostPosted: 25 Dec 2008, 00:09
by toneman
imo, all the schemos looked like they would function.
after all, RG's info has been up since 2002; and GGG is/has been selling pcbs with same schemo.

looking forward to the new pdfs! :D
especially a orig pcb bottom :wink:

was wondering,.................... do U have an o-scope?

i'd like to see a sine or triangle wave fed in, with probe points at:
collector of Q1 (is it clean or clipped?)
collector of Q2 (ditto; does the directly coupled base of Q3 affect the waveform? how?)
what does the output of C4 & C5 look like before the diode ring?

inquiring minds and all that.........

btw, the diode ring reminds me of the ringstinger 8)

Re: Maestro Brass Master request

PostPosted: 25 Dec 2008, 19:47
by gtrgeek1
I did scope out the clone against the original stage by stage. I did not take any notes, but I do remember that no clipping or real distortion happened until the diodes.

Re: Maestro Brass Master request

PostPosted: 26 Dec 2008, 19:45
by unbeliever
Here are some pdfs produced from the file gtrgeek1 sent me. Do I need to do a PCB at the right size also? Let me know. And good work!

http://prophecysound.com/freestompbox/BrassMasterOverlay.pdf
http://prophecysound.com/freestompbox/BrassMasterPCB.pdf

Re: Maestro Brass Master request

PostPosted: 26 Dec 2008, 22:59
by chicago_mike
:hug:

Awesome!! :D

Re: Maestro Brass Master request

PostPosted: 27 Dec 2008, 11:16
by borislavgajic
some guts please? :hmmm:

boris

Re: Maestro Brass Master request

PostPosted: 27 Dec 2008, 11:22
by bajaman
great work guys and thanks for sharing / co-operating :)
bajaman

Re: Maestro Brass Master request

PostPosted: 27 Dec 2008, 11:52
by analogguru
gtrgeek1 wrote:I then took pictures of both sides of the pcb.....

Do you still have this pictures ? for sharing ?

analogguru

Re: Maestro Brass Master request

PostPosted: 27 Dec 2008, 15:28
by chicago_mike
Hey Baja,

Now its time for you to make some "baja approved" improvemets to the circuit. :mrgreen:

Re: Maestro Brass Master request

PostPosted: 27 Dec 2008, 20:22
by borislavgajic
analogguru wrote:
gtrgeek1 wrote:I then took pictures of both sides of the pcb.....

Do you still have this pictures ? for sharing ?

analogguru


yes/no?????
please post pictures of original pcb
thanks

boris