EWS Little Brute Drive  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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zedsnotdead
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Post by zedsnotdead »

Ok, so I have a friend of mine that wants to make the trimpots on this available outside the enclosure.
Since I never had a chance to contribute, here are some gut shots (click to enlarge).

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What do you think? What is it based of?

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allesz
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Post by allesz »

Wow, I always found this little pedal incredible construction wise; making place for the 9V battery in a 1590a enclosure is not easy.
Post the values for the caps if you have the pedal still open.
How does it sounds, and what the internal pots do? maybe you just can drill two small holes on the back in order to use a little screw driver.... otherwise, even with 9mm pots, it seems hard to save the battery.
Thank you.

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alexradium
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Post by alexradium »

i guess its similar to the Brute drive without the EQ/boost section,dual opamp with leds to ground,please explain the pots functions.

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Post by alexradium »

i guess its similar to the Brute drive without the EQ/boost section,dual opamp with leds to ground,please explain the pots functions.
Also take note of all the resistor and caps values,i could try a tracing

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alexradium
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Post by alexradium »

If you bring out the trimpots it will look a lot like a crunch box,only difference being the gain pot which is doubled,i guess one on each stage feedback.

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zedsnotdead
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Post by zedsnotdead »

Well, I am going to put the circuit into a 1590B, drill 3 holes for the gain, level and tone (those last two are the trimpots).
Need to get the value of the caps and resistors also.
It has a IC which is sanded on top to hide the brand/model/type.

I will keep you posted.

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bigorangefan79
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Post by bigorangefan79 »

littleBrute.png
littleBrute.png (8.7 KiB) Viewed 2392 times

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zedsnotdead
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Post by zedsnotdead »

@bigorangefan

you already have this one? :D
Should I re-check the values?

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bigorangefan79
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Post by bigorangefan79 »

Yeah, just realized I'd never shared it. Great mean little pedal.

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zedsnotdead
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Post by zedsnotdead »

Do you have a PCB layout for it also?

i am asking because I don't know how to work with software (e.g. eagle), but I am making efforts to understand how it works... to date I am a bit frustrated though.... :oops:

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alexradium
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Post by alexradium »

bigorangefan79 wrote:
littleBrute.png
i'm on my way to try this circuit,i noticed the 400k bias resistor is tied to the collector ,not Va which is typical.
Is it correct this way?
thank you

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Nocentelli
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Post by Nocentelli »

alexradium wrote:
bigorangefan79 wrote:
littleBrute.png
i'm on my way to try this circuit,i noticed the 400k bias resistor is tied to the collector ,not Va which is typical.
Is it correct this way?
thank you
Big muff Q1 is similar.
Steven_M wrote: 21 Jan 2011, 17:52
biffa wrote:Sorry,but u r not the only member here
I'm not? Well fuck this site then. I only want meaningful conversations with myself.

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mmolteratx
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Post by mmolteratx »

alexradium wrote:
bigorangefan79 wrote:
littleBrute.png
i'm on my way to try this circuit,i noticed the 400k bias resistor is tied to the collector ,not Va which is typical.
Is it correct this way?
thank you
Self bias. I think it was actually the first way we were taught to bias transistors in my intro to circuits class. Then the resistor divider.

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marcao_cfh
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Post by marcao_cfh »

Sorry for ressurrect this thread, but I'm confused about the gain pot. Is it linear or log? GainA is log and gainB is lin at the schematic. Also, does anybody still have the pictures of the original board?

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