Hi
I'm building a signal Mixer + Splitter for my guitar pedal board; the idea is it will receive two guitar signals, mix/blend them together and then send the mixed signal to two amps.
I have one already using two devices, a separate mixer and a separate splitter that I built years ago based on Runoffgroove's Splitter Blend, but I want to make a more compact version in a single small box.
So, I want to use the same circuits, I know they work well for me but I think the way the Mixer is coupled to the Splitter internally could possibly be rationalised a little bit.
The dotted line marks the point where the two devices meet, they will be permanently connected in this one device; but the intention of the original design would be that there would be other Guitar FX etc. connected in-between these two sections at the dotted line, so I think the two 10uF caps in Yellow are there to allow for a low impedance device like a Fuzz to be connected in the middle without creating a High Pass filter, but in this circuit I think they could be much smaller???
Also, I'm not sure the 1M resistor in red is strictly necessary in this configuration??
Any help would be appreciated, I'm sure I could build it as is and it will work fine, but it would be good to learn a better way of doing it.
I'm building a signal Mixer + Splitter for my guitar pedal board; the idea is it will receive two guitar signals, mix/blend them together and then send the mixed signal to two amps.
I have one already using two devices, a separate mixer and a separate splitter that I built years ago based on Runoffgroove's Splitter Blend, but I want to make a more compact version in a single small box.
So, I want to use the same circuits, I know they work well for me but I think the way the Mixer is coupled to the Splitter internally could possibly be rationalised a little bit.
The dotted line marks the point where the two devices meet, they will be permanently connected in this one device; but the intention of the original design would be that there would be other Guitar FX etc. connected in-between these two sections at the dotted line, so I think the two 10uF caps in Yellow are there to allow for a low impedance device like a Fuzz to be connected in the middle without creating a High Pass filter, but in this circuit I think they could be much smaller???
Also, I'm not sure the 1M resistor in red is strictly necessary in this configuration??
Any help would be appreciated, I'm sure I could build it as is and it will work fine, but it would be good to learn a better way of doing it.
The idea may be good. In true you will fade one input while increasing the other with the pot. It usually is called cross fading. 10uF caps and 1M can be ommited.
Thanks @Osvaldo de Banfield
I use it to lay OD, Distortion etc over clean reverb and delay, I find it gives a studio recorded sound to a live settup. There's also a neat feature for inverting one of the input signals which I didnt draw so if you get an inverting FX in the chain you can flip it to avoid cancelation.
I use it to lay OD, Distortion etc over clean reverb and delay, I find it gives a studio recorded sound to a live settup. There's also a neat feature for inverting one of the input signals which I didnt draw so if you get an inverting FX in the chain you can flip it to avoid cancelation.
All what I say is from an engineering point of view. I am not musician nor I know anything about music, musicians and their habits. So I don't oppine about it.
@bucks bunny
The output buffers could potentiall be connected to amps, effects, etc of different input impedance, so the buffers are to iscolate the next two devices from each other.
The output buffers could potentiall be connected to amps, effects, etc of different input impedance, so the buffers are to iscolate the next two devices from each other.
You are not going to save a dollar's worth of parts.
The two output buffers ARE redundant-- that is the point of a buffer, you can hang crap and multiple crap on the end and no harm is done. (Up to a point, but it is hard to find enough load in stage-gear to strain a 19-cent chip. The guys who design inputs look bad if their inputs load stuff down.)
You can actually take out all three middle-caps and two 12-cent resistors, let that cross-fade network float at Vref. Or you may want one resistor to Vref for when the pot wiper gets dirty, it will scritch instead of CRACK!!
The two output buffers ARE redundant-- that is the point of a buffer, you can hang crap and multiple crap on the end and no harm is done. (Up to a point, but it is hard to find enough load in stage-gear to strain a 19-cent chip. The guys who design inputs look bad if their inputs load stuff down.)
You can actually take out all three middle-caps and two 12-cent resistors, let that cross-fade network float at Vref. Or you may want one resistor to Vref for when the pot wiper gets dirty, it will scritch instead of CRACK!!
There is not only one problem. Tbh I am too lazy to teach these basics. There are loads of working circuits around to learn from.
Hmm, U2A looks like a straight copy from the runoffgroove design and there from the original polarity reverser circuit by R.G. Keen (2001)
Certainly one could drop the R values to remove some noise ( at the cost of batttery life) but I can't see any particular problem. While I've not built the original circuit I've no reason to believe it doesn't work. I'll have to dig out Horowitz and Hill to see what they recommend for this problem
Certainly one could drop the R values to remove some noise ( at the cost of batttery life) but I can't see any particular problem. While I've not built the original circuit I've no reason to believe it doesn't work. I'll have to dig out Horowitz and Hill to see what they recommend for this problem
I am not a fan of unity gain opamp buffers. First off I would make the supplies dual, easy LTC1044 regulate to -6V and the 9V to 6V. Then use a pair of LSK389 in IDSS as direct coupled buffers in totem pole. Sounds great use the A version as the current gets too high in B, C or D.
Buffer each input to a volume control into a discrete JFET stage.
You can also do summing with a discrete JFETS and just combine the drains into like a 10K:10K transformer or two in parallel and then you can change the polarity of either of the outputs.
I made a buffer that way recently and one of the outputs polarity can be changed by foot switch or DC input. So gigrig G3 or something like that can switch the polarity depending on your pedal string.
Gordon
Buffer each input to a volume control into a discrete JFET stage.
You can also do summing with a discrete JFETS and just combine the drains into like a 10K:10K transformer or two in parallel and then you can change the polarity of either of the outputs.
I made a buffer that way recently and one of the outputs polarity can be changed by foot switch or DC input. So gigrig G3 or something like that can switch the polarity depending on your pedal string.
Gordon
Just a suggestion, but if you want a more useful output splitter, you could use one of the output opamps to drive an audio transformer, for a isolated output. Use it to feed the second guitar amp or stage mixer and avoid ground loops and hum with the equipment connected to the other non isolated buffer.