The Electric Piano Forum

Repairs, Maintenance & Upgrades => Parts, Service, Maintenance & Repairs => Topic started by: JordanShadle on March 01, 2019, 12:49:42 AM

Title: Bass boost on Rhodes not working
Post by: JordanShadle on March 01, 2019, 12:49:42 AM
The bass boost knob doesn't do anything and I popped the cover to see some wires taped together as if a previous owner had tried to mess with it in some way. I have no idea what I'm looking at so can anybody out there check it out and maybe point to where I can find out how to fix it? https://imgur.com/a/1hGYEHP
Title: Re: Bass boost on Rhodes not working
Post by: Tim Hodges on March 01, 2019, 07:03:23 AM
Definitely looks a bit funny, any chance you can remove the namerail to provide a photo from behind?
Title: Re: Bass boost on Rhodes not working
Post by: JordanShadle on March 01, 2019, 08:53:39 PM
I tried to pull back the taped wires to show which ones were connected to each other. Hopefully you can see what's going on from this, if not just let me know and I can try again haha https://imgur.com/a/G6yMUUD
Title: Re: Bass boost on Rhodes not working
Post by: sookwinder on March 02, 2019, 04:37:01 AM
BTW, not withstanding what Fender/Rhodes called it, it isn't actually a bass boost ... it is a bass cut.
Just the same principle as the bass control on an amp... a high pass filter.
One extreme allows all the signal through, the other extreme cut the bass signal.
Title: Re: Bass boost on Rhodes not working
Post by: JordanShadle on March 02, 2019, 09:21:00 AM
Good to know! I hope to hear it first hand sometime soon lol
Title: Re: Bass boost on Rhodes not working
Post by: pnoboy on March 02, 2019, 02:43:38 PM
The schematic for what should be in your stage schematic is super simple.  You can find a diagram here http://www.fenderrhodes.com/img/service/manual/stgschem.gif (http://www.fenderrhodes.com/img/service/manual/stgschem.gif).  For more sparkle in the sound, I recommend scaling the values.   For example, you could use a 50k pot for the volume control, a 250k pot for the bass control and a 10nF capacitor.  To raise the impedance even more, you could use a 100k volume pot, a 500k bass pot, and a 4.7 nF capacitor.
Title: Re: Bass boost on Rhodes not working
Post by: sean on March 03, 2019, 09:09:04 PM

Compare your circuitry to the diagrams and photos at https://ep-forum.com/smf/index.php?topic=4650.msg22605#msg22605

Sean
Title: Re: Bass boost on Rhodes not working
Post by: JordanShadle on March 03, 2019, 11:55:48 PM
I was having trouble figuring out the schematic but that wiring diagram helps me out a lot. Thank you very much!