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Avondale Power Amplifiers

Discussion in 'audio' started by Bruv Sawney, Jun 18, 2022.

  1. Mike Hanson

    Mike Hanson Lovely!

    I don't recall that thread, so I'll take look to see if I can find it.
  2. S-Man

    S-Man Kinkless Tetrode Admirer

    Not quite. Naim has SOA protection and reasonable supply voltages. Many Avondale builds push the rails up which could cause thermal stability issues as well as SOA issues.
  3. Bruv Sawney

    Bruv Sawney Member

    Again, thanks for the input!

    I’ve done a forum search on “speaker protection” and read through what appear to be the relevant threads. I don’t understand all the technical stuff but, from what I can understand, it seems that a) the failures are very rare and ‘speaker protection” is a “nice to have” but not an absolute requirement and b) most of the failures occur with home builds where a voltage is set too high.

    Would that be a fair summation?

    Notwithstanding the above, if I did decide to add speaker protection, would it fit in the NAP 250 case? I’m assuming soldering is required so it’s not something I could do myself. Is it something that Avondale, Witch hat, CHC, etc. would take on and would it be expensive?
  4. Vinny

    Vinny pfm Member

    No. On either count.

    Car seat-belts are more than "nice to haves".

    I would refer you to comments in the post by @S-Man above, which is/are precisely what I was alluding to.

    Speaker protection boards, complete, ready-built, are freely available and generally need no more than some screw terminals tightening onto the appropriate stripped wires. They are around 10 x 8 x 3cm high. All the ones that I have seen have been stereo, so in mono-blocks, just half the board is used. Input voltage, to actually power the protection circuit, is generally a huge range, AC or DC.
  5. Bruv Sawney

    Bruv Sawney Member

    It would appear (see photo above) that there is no room for a 10 x 8 x 3cm module even if I knew how to wire it.

    I guess I’ll just have to take the risk!
  6. Vinny

    Vinny pfm Member

    There is room - probably attached vertically somewhere. Then fit a small power supply TX, to power it.

    Fiddly, but far from impossible.
  7. chiily

    chiily PFM Special Builder

    I've often taken to mounting the speaker protection PCB on the back panel.

    [​IMG]2021-11-28_11-19-09 by Garf Arf, on Flickr
    [​IMG]PXL_20210328_184435583 by Garf Arf, on Flickr
    [​IMG]IMG_20201108_093817 by Garf Arf, on Flickr

    I know these are DIY builds and you would have mess up the wires in the 250 wiring harness, but expensive are your speakers?
    Vinny likes this.
  8. Vinny

    Vinny pfm Member

  9. Bruv Sawney

    Bruv Sawney Member

    For me….impossible!!!
  10. Bruv Sawney

    Bruv Sawney Member

    I’ve got SBL’s with Avondale passive crossovers……I’m assuming any potential damage would be to the speakers not the crossovers?
  11. Vinny

    Vinny pfm Member

    Any malfunction that affects the speaker (it would only ever be one at any one time, unless you are the unluckiest person on earth), would take out the woofer. The circuit/board would obviously have predeceased the driver by a very short period.

    Time to fit speaker protection for someone set up for the job? A couple of hours? Just to give you some idea of what anyone might charge to do the deed.

    Prices for the circuit can be found on EPay, but pretty cheap.

    Les might well offer to do the job, but if his schedule is as normal, there'd be quite a wait.

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