Aleph 2 speaker protector?

[tomchaoda]

In the original NP design, Aleph 2 only used Inrush Current Thermistor. That's why I saw many DIYers adding either Speaker Protector circuit or Delay-relay mechanism to protect their speakers. Is this really necessary or NP's original design is good enogh!

Can any one share your thought?

Example are here:

http://myweb.hinet.net/home4/chihc/a.../control-2.jpg

He has both delay-relay and speaker protector boards.

Thomas

[roddyama]

There were a few that I've seen that have tried, or have implemented a relay disconnect of the speakers. Most however were talking about implementing a delayed power-up with a soft-start circuit to limit the high current inrush during power-up.

[Yonnat]

Hi,

I ask for the same question a few month ago, Mr Pass himself said that he never heard any problem with Aleph amps who destroyed speakers, so I used the original scheme and it works perfect, it is sure that your work must be perfect soldering, isolating and so on.

Yonnat.

[jewilson]

Just finished an Aleph 1.2 and there no turn on thump on pops wit these amps.

[GRollins]

Don't fuse the rails. You'll regret it.

Grey

[nbaula]

Hi! Grey how about fuse in between transformer and the brigde rectifier? Is this O.K.

[jewilson]

You don't want to put a fuse their. The Fuse goes on the AC line so when it goes everthing goes off. By fusing the the bridge you would still leave the tranformer running and part of the supply that was not fused. That could cause a cascading failure. Put the fuse on the AC side before the transformer.

[tomchaoda]

This is another case used by one DIYer in Taiwan in his Aleph 1.2. The circuit use one switch to protect the power, bypass the thermistor after 7 sec. and switch on the speaker after that. The good thing is if the power is off, the relay shuts off right away. The original design also comes from diyaudio here:

Pulse Power Switch

How about sharing your idea regarding this design?

[zygibajt]

I don't think any of this circuits is needed.
There sure is some turn on pop in the speakers,but even when used with very sensitive drivers like Lowther or Fostex it doesn't hurt.

bARTEK

[jewilson]

Totally unnecessary and over complex

The circuit use one switch to protect the power, bypass the thermistor after 7 sec. and switch on the speaker after that. The good thing is if the power is off, the relay shuts off right away. The original design also comes from diyaudio here:

I don't know of any standard transformers that offer 16VAC with the 50 or 40 VAC needed for an Aleph. That’s a custom transformer

Why would some on build this circuit with all the relays, this is a poor design........