DIY attenuator

I can’t see the 3rd and 4th attachments.


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I can’t see the 3rd and 4th attachments.


Sent from my iPhone using Tapatalk

 

It's effectively a treble bypass switch. As long as you used an on/off/on switch it looks like it's wired fine.
Depending on the wattage of the amp and the amount you are attenuating the switch might not make a difference.

 

I dont know if any of this will help these are pics of a weber unit that a friend of mine asked me to mod ( this was one of weber's proto type units) it uses an 8 ohm Mas unit instead of the 8 ohm resister

this schematic looks close to what you are building




if you have the full schematic I would like to post it in the DIY post I have incase some one else wants to build one

 

you may be able to adapt you design to the schematic , hope this helps!

 

weber used an 8ohm mass driver instead of the 8ohm resistor , but the design for the tone is just a little more elaborate than your design , basically the same circuit.

 

I dulled down this photo so you could see the controls

 

Whether you use your unit or the weber (which uses the speaker's voice coil to simulate some speaker reactance) the fact remain that they are both passive. Neither unit can add treble, they both use bypass caps to pass the existing high frequencies to the output. The rheostat will roll off some treble as you attenuate the signal. It's most noticeable with high wattage amps at full attenuation. With lower wattage amps and lower attenuation levels the roll off is very slight. The higher rated the rheostat the better.
If anyone else wants to build this here's the link
https://guitar.com/guides/diy-workshop/diy-workshop-build-your-own-attenuator/

 

I’ve made a couple of those...my hearing is such that I couldn’t tell any difference with the different bypass caps...I still have them in the circuit but I can’t hear it...the attenuator works fine if you keep it rated for your wattage and don’t try to squeeze it down to bedroom level...it does quiet things down though...

 

thanks Ill add it to my DIY thread!

 

In the circuit description the L pad is wired one way:

but in the basic diagram its wired the same as the build.

 

This is what I built to use with my Marshall - it does the job OK.

 

Warrent is correct about how the bright switches work. The caps allows higher frequencies to pass without attenuation, thereby making the amp seem brighter. I haven't done this in a while, but I think the higher value the cap is, the lower frequency threshold is extended.

With different amps you may have to experiment until you find something you like. Use alligator clips to test until you find the right one. I've never used more than one, but that's personal preference.

I've built a number of attenuators using that variable L-pad. It was originally designed for audio system use. For guitar use, I wouldn't use it with an amp over 30-35 watts rms, maybe a little more but only if you put a cooling fan in the enclosure. I've used it with my BF bandmaster but only dialed down a bit.