Page 1 of 1

Peavy Ultra Plus switch Latency

Posted: Sat Jun 18, 2022 8:36 am
by Jay_Jarod
Hi everyone,
I do own a Peavey Ultra Plus for years now.
This is my first post and i didnt find a topic treating the problem i encounter.

Here is the problem, when i switch channel with the footswitch there is a small latency (i would say about 0.2/0.3s). You can ear it if you pay attention and you can also clearly see it on a record track.
I did find a solution a few years ago. Some forums were talking about removing an electrical relay as a solution gave by PV but as i'm not a tech i didn't want to try it by myself.
Now that i found someone capable of reparing electronics i can't find the solution on the internet...

Thank you for your help and please excuse my poor i bet you guessed this is not my native langage :)
Jay

Re: Peavy Ultra Plus switch Latency

Posted: Mon Jun 20, 2022 3:59 pm
by Enzo
OK, let us define the condition. Does it actually delay SWITCHING? Or does it switch right away, but the sound drops out for a brief moment? Very different things. In those high gain amps, they have a mute. Whenever you change channels, all sorts of things have to change. And it can make noises. SO they have this little pulse of mute to cover any noise. Peavey calls that a clamp circuit. A triac controls a JFET which shunts the signal path for a moment. There is a cap in the circuit that serves as timing. If you remove the cap it acts faster. Any competent technician can figure out how to speed up the clamp.

Re: Peavy Ultra Plus switch Latency

Posted: Mon Jun 20, 2022 5:40 pm
by dak
Enzo wrote:
Mon Jun 20, 2022 3:59 pm
A triac controls a JFET which shunts the signal path for a moment. There is a cap in the circuit that serves as timing. If you remove the cap it acts faster. Any competent technician can figure out how to speed up the clamp.
Competent technicians are an endangered species due to habitat loss. Fewer and fewer devices are built from general-purpose components and thus can be repaired by general-purpose technicians.

Re: Peavy Ultra Plus switch Latency

Posted: Mon Jun 27, 2022 3:59 am
by Jay_Jarod
Hello, in my case this is what you described as : "it switches right away, but the sound drops out for a brief moment".
Thank for your answers, I will share them to my technician.

Re: Peavy Ultra Plus switch Latency

Posted: Mon Jun 27, 2022 7:34 pm
by Enzo
For your tech, the small circuit is called CLAMP and involves a tiny triac and two JFETs, plus timing cap C200