Summing amp Questions

[lukatosh]

Hello everyone, best regards from Chile.

i've been looking at those summing pedals available in the market; Stereo Module from Mathew effects, Summing amp from JHS and others...

Since in the theory it's not hard to understand how this works i would like to build one of these but also instroduce the "polarity reverse" option introduced by R.G.Keen

This weekend i'm plannig to start drawing the schem and i'll post it for general discuss.



From the picture above, it looks like JHS consider a buffering stage for channel left and right followed by the inverting summing stage (NE5534).

Now, take a look at the LT1054... What's the pourpose of the transistor? Looks like the circuit works with -+9v

Finally... since the NE5534 it's hard to find. Is there any special consideration for using it? Could i replace it for a TL072 or other NE5532?  it looks like nothing is connected to the 5534 compensation pins.

Thanks so much!! Please excuse my English i'm thinking in "spanish"...

[PRR]

'5534 should be easy to find. A '5532 is a dual '5534. In most guitar work a TL072 will be fine.