Making of an amp switch (audiophile quality)

[sann]

Very well finished product brother!

Thanks!

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?

Thanks! As of now I just switch the front channels of the AVR and the L-R out of the st.amp, rest of the channels of the AVR are not controlled.

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.

Thats a nice idea, as soon as the stereo amp is on, it will kick away the AVR, fronts as well as other channels. Will think about it.
Regards,
Sann

 

[venkatcr]

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.

Does not make any sense to me. If you have no connections, what harm can you cause? Must have been started my speaker manufacturers to sell their products.

Cheers

 

[anm]

Thad - what he could have meant is that do not run an amp with cable going out of it, and the other end not connected to speakers. this can certainly blow up the amp if terminals touch each other by mistake.

 

[Thad E Ginathom]

Yes, the short-circuit risk makes sense, but it was the no-load aspect I was against. It was really all a myth?

 

[ajinkya]

Yes, the short-circuit risk makes sense, but it was the no-load aspect I was against. It was really all a myth?

Thad,

One more aspect could be that long runs of unterminated speaker wire could pick up electrical interference by acting as an antenna. If the amplifier inputs are buffered and well-designed, this should not be a problem. For cheaply-made amplifiers, the possibility exists.

 

[Thad E Ginathom]

OK, so I was told wrong, and have thought wrong for approx 40 years on this one!

There is nothing wrong with having an amp powered on with no speakers attached, and nothing dangerous in a switch which might have the same result.

I suppose, if it had been true, I might have found a warning about it in equipment manuals.

Right.

Now, about that green ink on CDs thing...

:lol:

 

[omishra]

OK, so I was told wrong, and have thought wrong for approx 40 years on this one!

There is nothing wrong with having an amp powered on with no speakers attached, and nothing dangerous in a switch which might have the same result.

I suppose, if it had been true, I might have found a warning about it in equipment manuals.

Right.

Now, about that green ink on CDs thing...

:lol:

Actually, now a days speaker protection and delayed connection feature in good amp has relays in speaker lines inside amp chassis. Which makes and breaks connection while amp is working. Also there is some zobal network and other protection to protect output devices in case of noload/impedance mismatch conditions.

BTW my all DIY amps are working same way as defined above which I got references after lot of reading. So it seems no problem till the time switch is working in fashion - break before make.

 

[dineshvarma2k]

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?

This holds good for Tube Amplifier, I guess but not for SS.

Regards

 

[Thad E Ginathom]

Ahh... so there was some basis in the idea after all? Thanks.

 

[krishnenduk]

Just saw a website which has good collection of some stuffs for DIY...

:: YOUR PRICE ::

Its like indian version of monoprice...

 

[sann]

Just saw a website which has good collection of some stuffs for DIY...

:: YOUR PRICE ::

Its like indian version of monoprice...

Thanks! Some of the items look like mx.

 

[hemantwaghe]

@sann ,@omishra and others
please here is backside of 4PDT swich I bought for Rs 145 from Lamington road)

Please confirm the wiring configuration is right

also 4 pole triple throw sich available , 4 pole 4 throw??? Or am I asking too much??

 

[sann]

Hemant, please make sure you are using on-off-on 4PDT. So that it completely breaks the connection before connecting to the other input.
Your connection looks to be OK, but please make sure to check for continuity using a MM.
Will let you know about 3&4 throw.

 

[reubensm]

I am not an expert in this particular area but I have been always advised that electronic switching or relay-based switching is always more reliable. Mechanical switching may have long term challenges, I assume. Any thoughts?

 

[venkatcr]

I am not an expert in this particular area but I have been always advised that electronic switching or relay-based switching is always more reliable. Mechanical switching may have long term challenges, I assume. Any thoughts?

These are DIYs switches. Making them electronic or relay based will be expensive. I have supplied quite a number if switches to members over the last 3 or 4 years, and I have never heard a complaint. At the cost, even if they give trouble, throw them and install a new one.

As I had mentioned many times, as long as you power off, switch and power on, you should have not issues.

Cheers

 

[omishra]

@sann ,@omishra and others
please here is backside of 4PDT swich I bought for Rs 145 from Lamington road)

Please confirm the wiring configuration is right

also 4 pole triple throw sich available , 4 pole 4 throw??? Or am I asking too much??

Sann explained it all! Your understanding is correct, make sure switch is ON-OFF-ON type.

 

[parthabhatta]

Made one for me. 2 AMPS 2 SPEAKERS with relays. Unknowingly, opened a new thread.
http://www.hifivision.com/diy/65168-2-amp-2-speaker-switcher.html

MODs, requesting a merge of my thread with this, if possible.