Maestro - Brass Master : the corrections  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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9 volt
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Post by 9 volt »

'From Jaycar'....yep. Cool I'm in! Thanks

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sonicvi
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Post by sonicvi »

unbeliever wrote: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/B ... verlay.pdf
http://prophecysound.com/freestompbox/B ... terPCB.pdf

I took the liberty of making all the traces on this layout black and adding holes on the pads. It's also resized to print at 134x63mm (at least from Photoshop) which I measured the original to be from the gutshot using the the 9V battery (49mm long) as a reference.
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vanessa
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Post by vanessa »

Does anyone know what year these first came out?

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Post by DavidRavenMoon »

vanessa wrote:Does anyone know what year these first came out?
I believe it was '72, since Squire uses one on Close to the Edge. I bought mine in '73 I think, just shortly before I got my first 4001.
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controller700
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Post by controller700 »

unbeliever wrote: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/B ... verlay.pdf
http://prophecysound.com/freestompbox/B ... terPCB.pdf
Hi!

Has anyone confirmed this Layout? Can someone please give me a clear wiring diagram for this? It´s quite confusing at the moment... :oops:

I would prefer to use R.G.´s updated layout, but cannot find the PCB files for it! The PCB at GGG looks not the same as in R.G.´s new layout... any suggestions?


Thanks!

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Post by R.G. »

controller700 wrote:I would prefer to use R.G.´s updated layout, but cannot find the PCB files for it! The PCB at GGG looks not the same as in R.G.´s new layout... any suggestions?
Same suggestion as by email. The board from GGG has been confirmed to produce correct sounding units when corrected with the two or three steps noted at GEOFEX. Those consist of
1. turn around the darlington 180 degrees. The factory schematic shows the incorrect pinout, and I correctly used the incorrect pinout. :lol:
2. two resistors are swapped.
3. I deliberately made the switching easier by changing switching between two resistors into paralleling two resistors. By actual builders comments, this produces little change, but by recalculating the resistors you can get *exactly* the same values as in the original.

No one has licensed the new layout, and I don't make PCBs to sell. If one of you wants to buy a license for making the new layout, cool. Contact me.

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Post by controller700 »

Thanks a lot R.G.!

Your email solved all problems! :thumbsup

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chicago_mike
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Post by chicago_mike »

Reviving an old thread:

Okay so a limited edition malekko assmaster has germanium trannies...

what would an older germanium equivalent be for the 2n3392's?

TY :)
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Post by xaxxop »

busterbassballs wrote:
Could you use a 3k to 3k transformer? (1:1) Thanks
Yes, That's what I used on my first one (from Jaycar?) and it works fine!
please where can I buy the transformer? :roll:
Leandro

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Mike31
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Post by Mike31 »

The limited edition assmaster uses, (I believe), 2 germanium trannys along with 4 germanium diodes. I have some 1n34a's and a couple of Ac127's.
I'm guessing the trannys go in Q4 and Q5 of the ggg schematic. Anyone know for sure? :hmmm:

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Post by xaxxop »

friends! good day.
This is the transformer I need for the Brassmaster?
http://www.jaycar.com.au/productView.asp?ID=MM2534
Has any other ideas where I can buy?
thank you very much :P
Leandro

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Post by busterbassballs »

Mouser #42TM018 available from

http://www.smallbearelec.com/Detail.bok?no=342

or any 1:1 ratio small audio trans should be fine

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Post by Crumbchildz »

I just built the GGG version of this box. It's slays all my other dirt boxes. I've always run two amps for my bass rig, one "clean" and the other one effected, so I've never really had a need for a clean blend. This box has changed my opinion on that! I'm going to build little clean blend circuits into all of my dirty boxes now. It makes such a huge difference.
Loud's a tone, right?

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Post by chicago_mike »

Mike31 wrote:The limited edition assmaster uses, (I believe), 2 germanium trannys along with 4 germanium diodes. I have some 1n34a's and a couple of Ac127's.
I'm guessing the trannys go in Q4 and Q5 of the ggg schematic. Anyone know for sure? :hmmm:
Im waiting the trannies for mine but I do have some germaniums I can fake it with to see :)
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Post by Kollaps »

Anyone ever come to a final verdict on the GE Malekko version? I recently joined a band as their bass player, but, as you can imagine, things don't sound the same on the bass as guitar, and I've always wanted to give that box a shot.

In a related question, if Malekko still browses this board, I was wondering if he would be so kind as to share how he got the silverburst finish on some of those boxes. Matches my Les Paul perfectly, if the pics look like they do in person!

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Post by speyflyfisher »

Mike31 wrote:The limited edition assmaster uses, (I believe), 2 germanium trannys along with 4 germanium diodes. I have some 1n34a's and a couple of Ac127's.
I'm guessing the trannys go in Q4 and Q5 of the ggg schematic. Anyone know for sure? :hmmm:
Has anyone confirmed that Q4 and Q5 on the GGG schematic is where the germanium transistors are placed?

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Post by theehman »

Maybe I overlooked the schematic somewhere.

On RG's layout, should the resistor in the R22 spot be 22k or 6.8K? I just picked up a clone from another builder and it's using the older Brass Blaster board. I want to make sure it's been corrected.
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Post by Dan N »

I don't know which is R22. Even have a kind of vague recollection there might have been two R22's? R. G.'s layout was always good except for the pinout of the darlington. Funny how long it took for that to be discovered. :)

Anyway, this was in my files. It could be right.
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Post by theehman »

Dan N wrote:I don't know which is R22. Even have a kind of vague recollection there might have been two R22's? R. G.'s layout was always good except for the pinout of the darlington. Funny how long it took for that to be discovered. :)

Anyway, this was in my files. It could be right.
Thanks, Dan. That looks to be the incorrect original layout. My clone has Q6 inserted correctly but it looks like R22 and R27 weren't swapped around yet.
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Post by R.G. »

theehman wrote:Thanks, Dan. That looks to be the incorrect original layout. My clone has Q6 inserted correctly but it looks like R22 and R27 weren't swapped around yet.
It's worth noting that the layout was always correct - the pinout for the darlington was incorrect on the factory schemo, so the body diagram on the parts diagram matched the factory schemo, which was incorrect. There was a typo reversal of two resistor numbers. I believe the history is here.

If it's a problem, I can dig out the archives for you.

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