Making of an amp switch (audiophile quality)

[sann]

At a certain juncture during my acquisition / upgrade path, It became an absolute necessity to have a amp switch, so that I could use my front speakers for both AVR and stereo amp.

I started acquiring components needed and ordered Nakamichi banana plugs and posts from ebay. Now most important thing was the switch, and I did not want using four / two switches, I wanted to have a single switch which should switch the amps in one go.

Some searching yeilded the result in the form of 4PDT switch (Four Pole Dual Throw) and I ordered the same form eBay, however the first shipment did not reach me, the seller was kind enough to ship it again, but in the mean time, I found a very good quality 4PDT switch in the local market. I purchased a cabinet, washers, heat shrink and was all set to go.

I will let the pics (low res mobile cam) do the talking.

The Cabinet (I would have preferred a black box :sad

Holes Drilled

Audioquest cable with connectors soldered

With heat shrink sleeve

Plastic insulator inside

The switch side view

Ready to use

The back view

Operational switch

Now, why I call it audiophile quality - as you can see in the pics that the posts and the connecters are gold plated, and hence electrons feel good that they are passing through gold and sound better.

Finally, a special thanks to FM Omishra, for his valuable suggestions throughout the build process.
I am yet to implement one of his suggestion to keep the cable run minimal inside the switch.

Thanks for reading
-Sann'

 

[Flash]

Great work .......... Congrats :clapping::clapping::clapping:

And Omishra is someone I really want to catch up with and share some notes ....

 

[krishnenduk]

Bro..

Can u post the components needed, from where u've acquired them and approximate cost of each item???

Thanks and regards...

 

[doors666]

Can you switch while the amps are on or do you switch when they are all off. Is there a switchover thump or something like that.

 

[tirthankar]

The electrons feel good while passing through the connectors, but are you sure they are not getting depressed while going through the switch contacts?

To be sure that they are happy all the way and arrive at the speakers joyful and spirited, ready to pump the drivers with gutso - you should make sure that all the contact points are gold plated, and that solid gold bars instead of measly audioquest is used hyeah:

Seriously, good job there... :thumbsup: which audioquest cables are those?

 

[sann]

Bro..

Can u post the components needed, from where u've acquired them and approximate cost of each item???

Thanks and regards...

Approximate cost breakup:

1. Banana Plug - $12 (eBay)
2. Binding post - $12 (eBay)
3. Cabinet - 55 INR (Local market)
4. 4PDT switch - 123 INR (Local market)
5. Cabinet screws + Heat shrink + washers + lugs + Y connector (~50 INR) (Local market)
6. ~1 mtr speaker cable (depends which one you use) I used the the same cable which I am using for my fronts.

Regards,
Sann

 

[venkatcr]

Can you switch while the amps are on or do you switch when they are all off. Is there a switchover thump or something like that.

Doors, it is not advisable to use the switch when the amps are on. It is safer to always switch off the amps, and then use the use the switch.

Cheers

 

[sann]

Can you switch while the amps are on or do you switch when they are all off. Is there a switchover thump or something like that.

Yes, I can switch with both the amps ON, without any thump or mixed input. The switch used is ON-OFF-ON, and it disconnects the first set of inputs completely before connecting to the other set.

I can also avoid the speaker pop, while powering off my power amp, as it does not have the protection circuit yet, so if I switch the output to the other amp/keep it in off position before powering off my power amp, the capacitor discharge is blocked from going to the speakers.

Regards,
Sann'

 

[doors666]

Doors, it is not advisable to use the switch when the amps are on. It is safer to always switch off the amps, and then use the use the switch.

Cheers

I agree and thats why the question. while the equipment is in use and a kid goes and flicks the switch, it shouldnt harm the equipment.
I guess using an on-off-on switch is a good idea.

 

[sann]

Doors, it is not advisable to use the switch when the amps are on. It is safer to always switch off the amps, and then use the use the switch.

Cheers

My post crossed with Venkat's.
Hi Venkat,
Yes, I could see a possibility of ON-OFF-ON malfunctioning. Apart from that do you see other impacts of keeping both the amps on and switching?
Regards,
Sann

 

[Kannan]

excellent work. looks really good.

I had made a very cheap version of the same (cost less than 100 rupees) from a earlier post here.
Just used 4 simple 2 way anchor switches and directly wired the amps. No binding posts or banana plugs....

 

[omishra]

sann, great work, Thanks

And Omishra is someone I really want to catch up with and share some notes ....

I think after knowing that I am the culprit who is spoiling guys by encouraging DIY bug, their respected better half will give me special hate treatment.
so far not confronted to anyone.

 

[BLASTO]

Is it similar to "HT bypass" in musical fidelity?
I hope other amps have them?

Never understood the concept of HT bypass though.

 

[TheCoolestOne]

Great job Sann. Looks nice. I too was looking at making something similar but time is a constraint at the moment, atleast for the next one month. I would get in touch with you for inputs on the build.

 

[venkatcr]

Apart from that do you see other impacts of keeping both the amps on and switching?Sann

It is just not worth taking the risk of both amps supplying juice at the same time and burning your speakers or the crossovers. It just takes a few seconds to follow a safe path. Switch off (or at least put on standby) the amps, toggle the amp switch, and power on the needed amp again. I have supplied these switches to a large number of people, and I have always insisted on a safe path.

There is the vague possibility of a feedback - power from one amp going to the other, and blowing some fuse somewhere. Even when I insert a power cord, I always play safe, power of the switch, insert the power cord, and then power on the switch.

Cheers

 

[Thad E Ginathom]

long time back, I was told never to run an amp without speakers connected. I accepted it, but have never known if it is actually right or not.

Enlightenment, please?

 

[sann]

The electrons feel good while passing through the connectors, but are you sure they are not getting depressed while going through the switch contacts?

To be sure that they are happy all the way and arrive at the speakers joyful and spirited, ready to pump the drivers with gutso - you should make sure that all the contact points are gold plated, and that solid gold bars instead of measly audioquest is used hyeah:

Seriously, good job there... :thumbsup: which audioquest cables are those?

:lol: Somehow I prefer the sound which comes from the combination of gold and nickel plated copper
I am using this cable.

 

[pupupuchi28]

Very well finished product brother!

 

[Moviela]

Nice work inside the box. Very well done terminations and dressing. The toggle switch handle does look a bit "industrial" for home use, but it is a quality "break-before-make" four pole, double throw switch. This is fine for a bi-amped stereo set up, but how would you switch a 7.1 installation?

You would use a relay or two. The coil of the relay could be connected to one amp. When that amp was turned on the relay would steer the speakers to its output. When the amp is turned off the speakers revert to the other source. No buttons to push. Automation is wonderful.

 

[Moviela]

The electrons feel good while passing through the connectors, but are you sure they are not getting depressed while going through the switch contacts?

That is a common misconception that the electrons actually pass through a circuit like water in a pipe. In a CRT or vacuum tube electrons emitted from a cathode actually do fly through space to the screen or plate. When the electrons in the the cathode are depleted the tube (valve for our British friends) stops working.

In a wired circuit the electrons are like a line of chaps in a queue. One nudges the neighbor, and he nudges the guy on the other side. At almost the speed of light the nudge arrives at the end of the queue, but nobody moved.

Unfortunately, none of the switch contact copper electrons ever find themselves living on the golden thrones of the Nakamichi Palace connectors. Just like real life.hyeah: