brassmaster build report and questions...

Started by caress, August 16, 2007, 03:57:52 PM

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caress

i just perfed up and boxed my dual bass destroyer... ;D

i used the brassmaster's clean blend over two different fuzzes in the "fuzz" portion of the brassmaster and i omitted the "brass" switch from the brassmaster...
the signal path goes as follows:  in>brassmaster input/splitter>(one side to clean blend) / the other side to a switch.  the switch goes to either the brassmaster or a crashsync, each of which have a big muff tone & recovery stage>brassmaster mixing/output preamps>[switch]>nyquist aliaser>out

it sounds really amazing.  really huge and gnarly.  one problem though  :(  -- when the "harmonic" switch connects the 82k to the volume pot, i get a HUGE boost in gain...not a good huge, though.
*the output of the clean signal is clean and well boosted.
*the output of the brassmaster fuzz is about unity when the "harmonic" switch is open.
*the output of the brassmaster fuzz is way louder than the clean boosted signal when the "harmonic" switch is closed.

i'd like to slightly lower the gain of the closed position and slightly raise the gain of the open position.  i considered lowering R28 (150k) and raising R29 (82k) -- (from RG's schem) -- but i audio probed at the point where R28 and C12 (.05uf) meet and it was only a bit louder, nowhere near the gain of the "harmonic" closed position...  any ideas?

ambulancevoice

Open Your Mouth, Heres Your Money

caress

Quote from: ambulancevoice on August 16, 2007, 04:36:00 PM
pics!!!!!
as soon as i figure this out and finish it up!!!  that is my priority...

moosapotamus

That harmonic switch has been discussed a bit.
Try searching "brassmaster".
IIRC, there were a few different ways that folks were wiring it up to get it to work.

~ Charlie
moosapotamus.net
"I tend to like anything that I think sounds good."

caress

Quote from: moosapotamus on August 16, 2007, 05:34:49 PM
That harmonic switch has been discussed a bit.
Try searching "brassmaster".
IIRC, there were a few different ways that folks were wiring it up to get it to work.

~ Charlie

i did some previous searching and i searched a bit more...i've been searching for a while...haha  anyways, it still seems like most people were having trouble with the "brass" 3pdt switch.  i simply omitted this and left the twin-t with the 47k's (R25/R23) and the 22k (R22).

caress

well, still having difficulties with the volume issues...i'm pretty sure i can lower the gain of the closed position by using a higher resistance than the 82k.  raising the gain of the open position is still a little over my head, though.  probing showed that right before the signal enters the base of Q6 (the filter amp) it is pretty hot.  coming out of the collector it is attenuated by a huge amount...hmm.  i'm guessing i can mess with R21 or R19 to get more gain, but which direction should i take?  i only ask because i foolishly boxed and wired everything up already... :P  it's pretty difficult to do any heavy experimenting on the circuit now...

also, for the crashsync side i'm pretty sure my signals are out of phase with each other.  when i blend in the clean signal, the bass gets more or less cancelled out.  is there a simple way to flip the phase?  i'm aware that the crash sync has a non-inverting amplifier fed into an inverting amplifier, so would i need to use another inverting amplifier after the output?  confusion...

caress