RM80 Boost Function

[davec629]

I'm looking for information on adjusting the volume boost function on my RM80.
Thanks, David

 

[Scooter]

If it's like the RM50 (and I think it is), you can hook up a regular single-button footswitch to boost the volume to max. Just keep the master volume at 75% and hit the switch to boost it to 100%

 

[davec629]

Thats what I was doing wrong. I had the master set low with the channels set high. When I hit the boost it would get too loud. Thanks for the info.

 

[bruce egnater]

Please email me at [email protected]
I can send you a schematic for the boost pedal (second master). Can someone tell me how to post the PDF schematic here?

Bruce Egnater

 

[Chad]

Bruce: Thanks for helping out here on the forum!!

Regarding the PDF, you'll probably have to host it somewhere, then place a link to it within a post.

 

[burner]

Boost level.... why didn't they put that in the RM100?

 

[randallweb]

You can now get the schematic for the boost switch here:

http://www.randallamplifiers.com/about/pdf/RANDALL RM BOOST.pdf

It's a pdf and 42k file size.

 

[okstrat]

Bump, I had no idea this even existed. Saw someone's thread about building a pedal, but he didn't link to this. GOOD info in this thread for RM50/80 owners!

Pete
(just bought an RM50)

 

[DaveS]

Guys, I built a pedal similar to the schematic posted and it works great. The only thing I did differently was to use an audio taper 250K pot. I found that I could have better control over the level of boost. With the linear taper it gets loud quickly. The other thing I did was to incorporate this in a two-button footswitch so that I could have channel selection and boost control for the RM50 in the same footswitch! I'm happy to send photos to anyone interested. Just PM me with an email addr - I'm not sure how to post the pics here. Dave

 

[johnmfer]

The PDF posted was extremely helpful, as have several of the threads talking more about the MVB.

My RM50 has always been a little kooky with the Master Volume Boost. Occasionally while playing, with nothing plugged into the MVB jack, the amp would suddenly go to max volume and scare the living crap out of me considering it's the amp I use at home at bedroom levels. I rectified this by taking an old 1/4" plug and soldering the lead to the ground. It only sticks out of the back of the amp a little. Recently the solder must have broken or something because the amp did it again, causing me to research this.

So, if anyone has built the pedal in the above schematic, why do they use a 4K7 resistor? My research tells me with a 3.8 V LED it should have a 520 ohm resistor. I know virtually nothing about electronics.

I was researching for a different project and saw this recently, thought I'd ask? I tried a 1k resistor between a 9V source and a 3.8V LED and got no light, so it seems like 4K7 would be even more overkill.

 

[okstrat]

I was researching for a different project and saw this recently, thought I'd ask? I tried a 1k resistor between a 9V source and a 3.8V LED and got no light, so it seems like 4K7 would be even more overkill.

I might be wrong, but who says it was a 3.8v LED in the schematic?

Pete