idiots guide to amp building

[a.palfreyman]

Trouble is I bet the higher volts are NOT in winter when most needed!

 

[muchtoofast]

.... just play endless loads of good music when it gets cold... and solder at the same time

 

[muchtoofast]

As for soft start I prefer a speaker protection module that also has a switch on delay
A soft start does not stop switch on thump in my experience
Alan

https://cpc.farnell.com/velleman-kit/k4700/k4700-2channel-loudspeaker-protector/dp/HK00743 any good for speaker protection please Alan? Do you have better options?

Thanks in advance

 

[say it as it is]

I have the Avondale soft start I thought that offered a level of protection by avoiding the inrush of current?

 

[muchtoofast]

Be wary that purchasing from Europe now incurs Tax and fees. Just got stung for £57 extra from Fedex for a £210 order from modushop.

 

[say it as it is]

Ouch

 

[muchtoofast]

I have the Avondale soft start I thought that offered a level of protection by avoiding the inrush of current?

Think that bit stops the fuses blowing/ circuit breakers tripping when the inrush happens at switch on?

Doesnt the seperate speaker protection module stop excessive DC due to circuit failure or other things blowing the cones?

 

[say it as it is]

Ok will have a look into this then never fitted such items literally where do they go? As space tight?
Do factory amps have them then? Concern there is a potential to degrade the sound quality as not seen them on Les built amps for example?

 

[muchtoofast]

Ouch

Yeah, makes it all quite costly and our UK cottage industry more viable for things like transformers. Glad now I've asked Terry at Cantebury Windings to construct a transformer for me, the other option was Toroidy in Poland... which wouold have also been hit with tax.

 

[say it as it is]

I try to buy from UK now if possible as well

 

[muchtoofast]

Ok will have a look into this then never fitted such items literally where do they go? As space tight?
Do factory amps have them then? Concern there is a potential to degrade the sound quality as not seen them on Les built amps for example?

Valid question, maybe someone that has the experience can let us know if speaker protection necessary or just paranoia? What does it do to the sound?

 

[Arkless Electronics]

If the amp goes DC... and Avondale amps can do this (as can most DC coupled amps) then it is almost certain that a woofer will be destroyed. I built and fitted a Velleman module to a customers Avondale amp about 6 months ago in which an NCC200 had gone DC and taken out the woofer in one of his Rega speakers. The NCC200 itself was beyond repair also so I fitted NCC220's as an upgrade along with the Velleman. There are loads of Chi fi protection modules available on epay also of course but as a generality these things are a "grudge purpose" so few if any are truly up to the job in every way and under all circumstances. Better than now't though!

 

[say it as it is]

ok so worth looking into then? excuse my ignorance but where and how should they be wired in and do they have an effect on sound?

 

[337alant]

https://cpc.farnell.com/velleman-kit/k4700/k4700-2channel-loudspeaker-protector/dp/HK00743 any good for speaker protection please Alan? Do you have better options?

Thanks in advance

Yes the Velleman kit works well only thing I don't like about it is the speaker wire connections are pants
The speaker protection modules based on the UPC-1237 are a very good alternative and offer a more robust speaker connection
There are loads of them on EBay
300W Digital Power Amplifier Protection Board Delay Relay Speaker Protection | eBay
Alan

 

[say it as it is]

ok where do you get the 12-16\v supply from on avondale boards?

 

[Arkless Electronics]

Yes the Velleman kit works well only thing I don't like about it is the speaker wire connections are pants
The speaker protection modules based on the UPC-1237 are a very good alternative and offer a more robust speaker connection
There are loads of them on EBay
300W Digital Power Amplifier Protection Board Delay Relay Speaker Protection | eBay
Alan

I have no problems with the Vellemans speaker terminals and vastly prefer them to the one's on the module you linked to. I wouldn't touch that with a bargepole TBH! A decent quality relay is more than that entire thing...

 

[Arkless Electronics]

ok where do you get the 12-16\v supply from on avondale boards?

Whilst the Velleman is also cheap and nasty it does have the big advantage of on board PSU.

 

[Mike Hanson]

ok where do you get the 12-16\v supply from on avondale boards?

I have an extra little transformer for the UPC-1237 module. It takes very little current, so a small one will do just fine.

BTW, I was discussing these with Les at Avondale, and he seemed to think they were not too bad, except that you couldn't trust the cheap electrolytic capacitors. He recommended that I replace them all.

 

[Mike Hanson]

There are also modules from XRK Audio: https://www.etsy.com/ca/listing/932...-protection-gen2?ref=shop_home_active_3&crt=1. These ones don't require a separate transformer, as you can just power them them from your main supply.

 

[Arkless Electronics]

The only way to get a good quality protection unit is to build it from scratch yourself IMHO. It's in the nature of them being grudge purchases that all the ones you can buy are cheap and nasty and in fact won't protect against all DC faults under all circumstances... then there's the reliability of those el cheapo Chinese relays and possible effect on sound quality, especially as they age and contacts wear or become pitted.