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Yamaha P2201 Power Switch Snubber Wiring

spark1

spark1

Lunatic Member
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I'm doing a bit of work on my P2201 (updating fuse resistors and maybe the filter caps).

This amp has always had a quick, sharp pop thru the speakers at power on, so I am thinking about replacing the snubbers on the power switch while I'm at it. The current snubbers are an integrated capacitor and resistor package (.033uf and 120ohm, 250V).

I have some 330V .033 X-rated caps and 120ohm resistors on hand, but wanted to confirm how they would be wired. I've seen differing diagrams for how a snubber is constructed. Also, this switch is a bit different from the few others I've worked on.

It might be prudent at this point to ask if replacing the snubbers has a decent potential for eliminating or reducing the pop?

Assuming there is, I'll go ahead and replace them once I'm sure about wiring them.

20251215_213512.jpg

Here is a pic of the switch as is. The purple wire comes from mains power, and is jumped across the switch. The brown wires go to the transformer. The snubbers are attached on each side of the switch.

My working assumption is that I would simply remove them, wire the new caps in their place, and then wire the resistors in parallel with the caps. If this is correct, I'll probably just solder the resistors across the caps, and then solder the caps to the switch, same as the integrated snubber packages.

I sure would appreciate a yay or nay, and any other guidance you might share. Thanks in advance.
 
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Thanks. Unfortunately I'm not sure how to apply that information to the physical wiring of the switch.
 
spark1 said:
This amp has always had a quick, sharp pop thru the speakers at power on, so I am thinking about replacing the snubbers on the power switch while I'm at it. The current snubbers are an integrated capacitor and resistor package (.033uf and 120ohm, 250V).
Click to expand...
New snubbers probably won't reduce the " pop". I don't think the P-2201 has a protect relay. Your best bet is to disconnect speakers before power-up.
 
Best not to kluge together individual parts for this anyway … snubbers don’t usually go bad in my experience. I’d do what was suggested above.
 
avionic said:
New snubbers probably won't reduce the " pop". I don't think the P-2201 has a protect relay. Your best bet is to disconnect speakers before power-up.
Click to expand...

Thanks.

I assume you mean by adding a switch between the speaker terminals of the amplifier and the speakers themselves?

Or did you have something else in mind?

I've seen examples of adding a protection relay to the amp, but that would be pushing the envelope of my capabilities.
 
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Sparkplug said:
Best not to kluge together individual parts for this anyway … snubbers don’t usually go bad in my experience. I’d do what was suggested above.
Click to expand...

Thanks. I was hoping to avoid a kluge by correctly replicating the existing snubbers with individual components, since I was unable to find an integrated snubber. But it sounds as if it will have no effect on the pop, so I will leave them as is.
 
In searching the web, I found a stand-alone external speaker protection unit. Can't post ebay links, but can be found by searching for:

External Speaker Protector For Stereo Amplifier / Speaker Protection​

Conceptually, seems like a great solution for someone with limited electronic skills/knowledge. But of course there is always the question of quality and suitability when dealing with a small Chinese manufacturer.

If I thought it was trustworthy, I could simply power it by plugging it into the auxiliary AC outlet on the rear of the amp, connect speaker outputs to its inputs and connect speakers to its outputs.
 
I'm wondering if it's the switch itself failing or dirty? We can prove that switch good or bad with 2 alligator clips across the snubbers in place. If ya wanna prove the switch:

Regarding the nice photo in post #1. I'd Alligator jumper from the brown wire on the LEFT side of the switch to the purple wire. Then with a 2nd jumper, clip from brown on the RIGHT side of the switch to the #3 contact.
Now that the switch is bypassed, make sure the power button is physically off. Then plug the power cord in the wall outlet or some switched source of your choosing. If the speakers don't pop anymore, the switch is the issue.

Edit & disclaimer: the alligator clips should be a heavy enough gauge to handle power supply energy! Suggest 18 AWG minimum.
 
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Thanks very much for this excellent suggestion. I won't be able to get to it until tomorrow evening, but will report back.

It will be good to eliminate the switch/snubbers. After reading more, the turn-on pop seems to be very common with this amp; perhaps even normal.

As @avionic suggested, the issue seems more likely to be a function of not having a traditional protection relay.

So it looks like I may have to get educated about the variables involved with choosing one, and installing it!

BTW, I've got a perfect set of jumpers for the switch test. Thanks again.
 
Right on...I also wanted to back up/ agree with @Sparkplug regarding the snubber caps. I haven't seen one go bad yet.
Another concern I have is flux on the switch contact area. It should be dry, hard, or non existent on a piece that old. Since it looks damp, I'd dip your toothbrush in IPA and clean the contact area. Good luck
 
spark1 said:
As @avionic suggested, the issue seems more likely to be a function of not having a traditional protection relay
Click to expand...
And it probably is at the end of the day as our Sensei knows best. Just wanted to chime in best I can a little before ya go the Chinese work around route.
 
As everyone predicted, the switch is fine. Bypassed it and still got the pop. And it ohms out pretty much perfectly.

Trying to get more info from the seller as regards the speaker protector mentioned above, but language is a proving a barrier. My primary concern is whether or not it can survive a full rail voltage incident. Or at least go open, giving its life to save the speakers.

But of course, these may not be the right questions. Bottom line, I want to implement something that will allow me to use this amp with some of my better speakers without worrying about the potential for killing them.

I've owned it for quite a while, and never had any issues with it, but I've always just used it in my workshop system with an old set of AR2a's (restored) or Snell J's. Nice speakers, but I need some insurance before I use it with my better stuff.
 
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