Title: The mystery of the 'pedal' and 'manual' switches Post by: Franc on December 13, 2009, 05:01:56 PM Hi, I have built a couple of HRMs already but this amp still has a lot of mysteries to me.
For starters the 2 switches on the back. From a user's point of view: what's the use of these switches? Why would anyone ever set them to manual as there's no way to manually switch the channels or the boost? What's the point? Technically: I see a difference between the pics on Ceriatone's website (pics of completed amp) and the layout there. I am not sure if it is important as I don't know the reason for the caps that are mounted (differently) to the switches. What do they do? I have more questions about this amp, but let's focus on these for now :) Thanks in advance. Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: bluesfendermanblues on December 13, 2009, 06:02:11 PM For starters the 2 switches on the back. From a user's point of view: what's the use of these switches? Why would anyone ever set them to manual as there's no way to manually switch the channels or the boost? What's the point? If the pedal is not connected, you can turn on the od by switching to 'manual' same with PAB. However, I don't use the switches at all. Guess they are on the back because thats what Dumble did.. Technically: I see a difference between the pics on Ceriatone's website (pics of completed amp) and the layout there. I am not sure if it is important as I don't know the reason for the caps that are mounted (differently) to the switches. What do they do? Que? Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: Franc on December 13, 2009, 06:15:12 PM If the pedal is not connected, you can turn on the od by switching to 'manual' same with PAB. However, I don't use the switches at all. Guess they are on the back because thats what Dumble did.. Really? I never noticed that. I will try right now :) In any case, whether the pedal is connected or not should not make a difference as in the manual position the wires coming from the pedal are disconnected, but I get your point. (http://i256.photobucket.com/albums/hh198/Franc1974/manualorpedal.jpg) Look at the pic: the black wire from the pedal connector is wired differently. (http://www.ceriatone.com/images/completeAmpsPic/Overtone_HRM50/b23B.jpg) Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: Franc on December 13, 2009, 07:34:02 PM Okay, I just tried and without pedal attached, putting the PAB switch to manual engages the PAB :) and putting it to pedal disengages.
However, the switch for the OD works the other way around and I am not sure I understand? Switching to manual without pedal disengages the OD channel and switching to pedal engages. Did I miswire anything or is this the way it should be? Just trying to understand what's going on with those 2 switches :) Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: Franc on December 13, 2009, 07:47:26 PM (http://i256.photobucket.com/albums/hh198/Franc1974/manualorpedal.jpg)
Looking at the OD switch, the 0.1u cap doesn't appear to do anything, because the top left lug of the switch where one end of the cap is connected to, doesn't go anywhere. When switched to manual, S is connected to ground and the cap (which does nothing as it is floating). When switched to pedal, S is connected to the pedal and the cap is shorted out (but still floating). So this must be a mistake in the layout? When you look at the picture of the finished amp, you see the wire from the pedal is going to the left upper lug, always connected to the cap. I wonder if both switches shouldn't be wired the same.... Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: erwin_ve on December 13, 2009, 07:54:10 PM Hi Franc, does this help?
Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: Franc on December 13, 2009, 07:58:56 PM Well, partly, thanks :)
The top half of your picture shows what you expect and I know it is working this way, but the layout obviously is wrong here. What are the caops for, to avoid switching noise? Can you explain why in manual position without pedal, the amp is on the clean channel? I know it doesn't REALLY matter but I wonder if I made a mistake somewhere... Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: erwin_ve on December 13, 2009, 08:28:44 PM Well, partly, thanks :) The caps I assume that's minimize popping/clicking when the relays are energized.The top half of your picture shows what you expect and I know it is working this way, but the layout obviously is wrong here. What are the caops for, to avoid switching noise? Can you explain why in manual position without pedal, the amp is on the clean channel? I know it doesn't REALLY matter but I wonder if I made a mistake somewhere... In original dumble's the relay coil is energized when engaging OD mode. The Ceriatone Od mode is not energizing the relay coil. Only when the Od mode is off the relay is energized. That's why it's reversed on the diagram. Problably due to hum issues when energizing the coil in Od mode. Title: Re: The mystery of the 'pedal' and 'manual' switches Post by: bluesfendermanblues on December 13, 2009, 11:21:07 PM Okay, I just tried and without pedal attached, putting the PAB switch to manual engages the PAB :) and putting it to pedal disengages. However, the switch for the OD works the other way around and I am not sure I understand? Switching to manual without pedal disengages the OD channel and switching to pedal engages. Did I miswire anything or is this the way it should be? Just trying to understand what's going on with those 2 switches :) You are absolutely right. The OD relay is wired 'wrong' in the Ceriatone. It's not a big deal...but the relay should be on when its off, in order to get the switch on the back to function like the PAB ditto. However, it abviously has no impact on sound. So just forget about it. |