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NCC200 V1.4/Cap6 GB

I suppose what I was thinking was there something about the Voyager setup that makes the amp more prone to frying speakers or was it the time delay that was the main reason for this device. That is, is it important when the VBE power is switched on - before or after the main amp psu or is it OK for them both to come on together. I think I would prefer to do without this device if I can.
 
The main p/s and VBE switch on together. Other than I cannot say but I'm sure someone with more knowledge will step in.

The speaker protector can save having to buy new speakers should something untoward happen.
 
I think a few of us have fried a woofer or two when fiddling.
I would say these circuits are far more reliable than we are. A bit too high front end voltage had a couple of mine and, of course failure to discharge power supply caps before connecting up power supplies are good ways of blowing amps and thus speakers.
With the extra power supplies, a slip in these areas gives more opportunity for damage.
I have speaker protection and they have saved a board.
Sound quality wise there must be some effect but not enough for me to notice. And the time and loot you spend fixing things when the smoke has cleared ( well not literally, usually ) makes these things a sound precaution ( gosh that was unintended!! ).
I also have put inline fuses between the back end supplies and the back end. Not sure that there is a big deterioration in handling of transients and I may remove this added level of protection when I am feeling brave. I guess this an area where additional impedance might be undesirable. Good luck!
Cheers Andy.
 
I'm no expert but my take on things is that the Velleman boards that everyone seems to be using are kind of 'mechanical' in that they control a relay which breaks the circuit if they detect any problems. In this way they're not like other SOA circuits which are more in the way of the signal circuit. Of course there may be some degradation through the physical relay connection but if you took that to its logical conclusion you wouldn't use speaker plugs and sockets
 
econorm said:
I suppose what I was thinking was there something about the Voyager setup that makes the amp more prone to frying speakers or was it the time delay that was the main reason for this device. That is, is it important when the VBE power is switched on - before or after the main amp psu or is it OK for them both to come on together. I think I would prefer to do without this device if I can.
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Thanks guys. I always like to benefit from others experience so looks like I will have to make room for the velleman board in my system also. Now I have to start buying the bits.
 
I'm of the opinion that loudspeaker protection boards are used because so many NCCs are diy built. It's less hassle to sort out an incorrect or poorly built NCC or VBE rather than having to repair your loudspeakers. I would never advocate using your main speakers for first time listening tests either. Get hold of a pair of cheap but properly working loudspeakers for initial listening tests. I bought some Gale Silver Monitors years ago for a tenner and they're small enough to be put out of the way when not in use.
 
Ive used NCC200 for years without speaker protection and had no problems, check the DC offset if its in spec don't worry.

However in my Voyager build I decided to fit the velleman units and I am happy with what they do
At a recent bake off we were using my amps and another user tried his croft amp with his interconnect, one of my amps refused to switch on showing a red DC light on the front panel, turns out the lead has a dropped ground so it would have produced the tweeter destructing oscillation squeal if not for the speaker protection

Alan
 
Chops54 said:
I'm of the opinion that loudspeaker protection boards are used because so many NCCs are diy built. It's less hassle to sort out an incorrect or poorly built NCC or VBE rather than having to repair your loudspeakers. I would never advocate using your main speakers for first time listening tests either. Get hold of a pair of cheap but properly working loudspeakers for initial listening tests. I bought some Gale Silver Monitors years ago for a tenner and they're small enough to be put out of the way when not in use.
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Really good point.

I always use the stunt speakers on first switch on. My cheap and cheerful’s are maybe my most important speakers.

Charity shops and such like are a good place to look.

Yes used often with DIY amps but plenty of commercial designs use them as well. In fact I believe that Les uses them in his builds.

The little bit of switch on delay can be useful also for a less bumpy switch on ride.

Nothing wrong with a little extra piece of mind IMHO and if you do think that they screw the sound then just take them out again once you are happy that your amps are working well.

My voyager clones have been working flawlessly now for quite some time and sound superb so the speaker pro’s have stayed in.

I like the little extra protection they provide for very little cost.
 
Alan, my Alpha 8s which predate the NCCs have never had any LS protection but like you and Shaun I decided to go with the flow and include it in my last Voyager build. Like you I also know that it works ;) No LS protection or SOA on my MisterC6 Naim 120 boards either :eek: so I'm always careful what I partner them with and how they're connected up.
 
Chops54 said:
Alan, my Alpha 8s which predate the NCCs have never had any LS protection but like you and Shaun I decided to go with the flow and include it in my last Voyager build. Like you I also know that it works ;) No LS protection or SOA on my MisterC6 Naim 120 boards either :eek: so I'm always careful what I partner them with and how they're connected up.
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Simon +1
I am still not 100% convinced that these veleman relays don't detract from the sound quality of the amplifier
My Hackernap amp still has no protection and sounds superb, i have lent it out a few times and just have to remind the borrower to switch off whenever changing speaker connections or hot swapping pre to power signal leads
Touching speaker connections together HOT will without doubt will reveal the magic blue smoke from the output transistors :(

Alan
 
Hi Shaun,

Is it too late now to add to my order please?
If possible could I add -
2x Large U shaped heat sinks with fixing kits for the OP transistors.​
No Worries if you can't.
Thanks.

Kind Regards
Roy.
 
Hi All

I’ve just had word from Les that he now has all of the parts needed.

The GB can now go ahead.

So just to recap:

I’ll be starting to send out invoices by PM starting Monday. These will be minus shipping charges as that’s a bit of an unknown until I post so postage charges will follow.

I’ll start with those outside of the EU.

Then EU excluding the UK.

UK members will be last as the post will be quicker.

Payment by PayPal as a GIFT please as I’m reluctant to pay the extra charges.

Once I have received all payments I’ll contact Les and arrange to collect the parts.

Then I’ll start shipping.

Hope that’s clear.

Please keep an eye on your PM boxes as of Monday.

Getting closer to the fun.:)
 
337alant said:
Simon +1
I am still not 100% convinced that these veleman relays don't detract from the sound quality of the amplifier
My Hackernap amp still has no protection and sounds superb, i have lent it out a few times and just have to remind the borrower to switch off whenever changing speaker connections or hot swapping pre to power signal leads
Touching speaker connections together HOT will without doubt will reveal the magic blue smoke from the output transistors :(

Alan
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Hi Alan you may be correct but if Les fitted them i assumed he had compared quality and found them ok, and at about £15 i was convinced. I would be interested if anyone has compared voyagers with and without.
 
Hi,

The only problem with relays is that after a while the contacts can become dirty/tarnished/burned etc, and you can end up with increased resistance.
A few years back (quite a few now), I worked for an International Computer firm in the Calibration/Maintenance department, and one of the more common faults in various 'Test Rigs' was bad relay contacts - high resistance. Indeed some machines had a program you could run for a few seconds to clean the relay contacts as part of their maintenance.

Just my two pennies worth.

Kind Regards
Roy.
 
BarryM said:
Excellent news.

Many thanks to yourself and Les again for all the hard work.

Cheers,
Barry.
Click to expand...

No worries.

The next best thing to my own DIY is facilitating other peoples.

On relays.

One of the really great things about DIY is choice.

Each person decides on their own priorities and these threads can help the individual decide with eyes open.

I use OP relays but it’s not proscribed.

I’m sure that people know the pros and cons.

It’s all part of the process IMHO.:cool:
 
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