Still building and fixing?

[ian917]

Not me building them but I'm hoping (fingers' crossed) that I will have one or both of Onix OA21 Icon and Onix DNA50 amplifiers ready for the Show.

 

[Lurch]

Whilst I'm not a DIYer, I still have my own problem to resolve. One of my 989s has developed an intermitant fault in that the right channel briefly cuts out. Sometime for half a second sometimes for upto 3 seconds, it may do it just the once or 5 - 6 times on the trot. I between times there is no sound degradation and the whole system sound great. Will nurse them through my next BO on 09/02 then it's yot another 320 round trip to OTA, so will leave it with them and pick up on the way to Keggy on the 14th. Hopefully not to expensive as Steve reckons it could be a dry joint making the protection circuit kick in..... Or it could be another panel, Arrgh! 

Just had a partial update from OTA, apparently, pcb component problems are very very rare and the only thing to make the spark arrestor kick in and shut things down is a panel problem. >   :nerves:  

Having taken both speakers up this time they have removed All 12 panels, and then using the best 6 reassembled 1 fully working speaker. The remaining 6 panels are going to be  checked over the next couple of days to see which one/ones need fettling. I should hopecully have a final, cost of repair for Monday or Tuesday (if its a bass panel gone then my arse is covered as it will be an FOC warranty job) but I get the feeling caviar and wagu beef is off the menu for a while, but at least I know they will be fit for duty intime for Keggy. 

 

[Tony_J]

Just had a partial update from OTA, apparently, pcb component problems are very very rare and the only thing to make the spark arrestor kick in and shut things down is a panel problem. >   :nerves:  

Having taken both speakers up this time they have removed All 12 panels, and then using the best 6 reassembled 1 fully working speaker. The remaining 6 panels are going to be  checked over the next couple of days to see which one/ones need fettling. I should hopecully have a final, cost of repair for Monday or Tuesday (if its a bass panel gone then my arse is covered as it will be an FOC warranty job) but I get the feeling caviar and wagu beef is off the menu for a while, but at least I know they will be fit for duty intime for Keggy. 

That's a pain in the arse wallet. Fingers crossed.

 

[bencat]

John so unlucky for this to happen so close to the Wam Show . Will hope that it is one of the panels that OTA fitted and you can minimise the costs but knowing the way things work it will almost certainly not be the case . With a following wind at least they should be up and running for the show and hopefully I can get a listen on Saturday Night .

 

[rabski]

Got bored trying to sort the new phono, so I'm halfway through putting together a shunt-regulated all-valve power supply for it based on a chassis from an old valve DAC build. The box count for Kegworth is getting insane, so I may have to cut back on some of the options.

 

[Lurch]

Nah. 

Just hire an artic and bring the lot. 

 

[rabski]

Nice thought John, but if it won't fit in the car, it ain't coming. It'll be mad enough as it is, and there's only so many phono stages you can listen to one after the other. If it's all working and complete, it'll probably end up as two each of phono stages, preamps and DACs. I'm definitely not aiming for two 845s, because the new one won't be in one piece and I want to spend the time I've got sorting out what can (probably) be finished. Anyway, there'll be enough valves to warm the room up nicely.

 

[bencat]

Ah well got brave and after finding the issue with the MiniDSP DDRC 24 decided I should try and get the full KEF Stacked pair working , well it did for about thirty seconds then a nice big pop and both Quad 405,s are blown . Change of fuse has made no difference this time and I will need to see if I can get a repair done on them both in time for Kegworth .

Even if I do get that done in time there is the shaky decision do I just go for a single pair or persist with the stacked pair and risk another blow up ?

Cause of this one was one of the bass connectors on the bass speaker being broken and this allowed the bass cable to touch the speaker frame .  No idea how the fibre/cardboard attachment broke it was not showing any issues when I soldered it .

Ah well what will be will be may need to get a bit creative for a system for the show .

 

[greybeard]

Oh no Andrew, didn't you have problems with the 405's at Kegworth last year?  Let's hope you can get them fixed in time for Kegworth.

 

[Tony_J]

That's very sad Andrew. Hope you can get it up and running in time!

 

[Lurch]

@bencat

Andrew would you like me to bring my pair of Cambridge A50s (Stan Curtis era) power amps, they can be run as stereo or bridged mono, just incase you have a problem on the day? I have plenty of room as am borrowing the works van for the weekend. 

 

[rabski]

@bencat

Andrew would you like me to bring my pair of Cambridge A50s (Stan Curtis era) power amps, they can be run as stereo or bridged mono, just incase you have a problem on the day? I have plenty of room as am borrowing the works van for the weekend. 

Proper 'wam at its best' :notworthy:

 

[bencat]

@bencat

Andrew would you like me to bring my pair of Cambridge A50s (Stan Curtis era) power amps, they can be run as stereo or bridged mono, just incase you have a problem on the day? I have plenty of room as am borrowing the works van for the weekend. 

John a very kind thought but I would not use anyone elses equipment with my propensity to have things go boom . I can get annoyed and swear when it is my own kit but would be mortified if i destroyed anyone elses .

If I am not able to get the Quad 405.s repaired in time then I will switch and bring a fairly conventional system with a passive set of speakers . If I do this then I have a Croft OTL that I will be collecting from Colin and I am sure this will do very well as the power for the system . I can easily bring a couple of pre-amps if needed and it is not real issue to put a system together . Not really what I want to do but if needs must then that is the route I will go down .

 

[dave]

We could start a short circuit proof amps thread, there must be some

 

[bencat]

We could start a short circuit proof amps thread, there must be some

Bet I could still find a way.

 

[lostwin]

We could start a short circuit proof amps thread, there must be some

Octave valve amps have built in protection, they demo at shows by shorting the speaker cables.

Here you go

 

[rabski]

Success 'ere (sorry Andrew).

Valve rectified and regulated supply seems to have cured the lack of volts and bass distortion, so valve phono Mk II is now running in. It uses a pair of ECC82s and a pair of ECC83s, so some tube rolling fun to try and get the best from it. I also want to try and squeeze some Russian teflons in, but they're a bit on the large side.

PSU with apologies for rubbish phone pic.

 

[Tony_J]

4th IcePower amp now constructed so I now have a separate amp channel per driver. Hopefully the last of the modifications before the show!

 

[rabski]

4th IcePower amp now constructed so I now have a separate amp channel per driver. Hopefully the last of the modifications before the show!

Ah, 'hopefully'. One relatively short word that is asking for trouble

By comparison, all I need to do now is build the valve DAC, change the capacitors (and run them in a bit) in the phono and preamp, redo the plate resistors in the pre and probably remake the contacts for the battery bias. And probably a thousand other bits. Anyway, the system will probably all be in one piece, so it really depends on how much I can finish. There is always phono Mk I and preamp Mk I...

 

[bencat]

Well Peter at Fidele Audio was very good to me and agreed to look and try and repair the Quads the same day while I waited. The right channel on each amp was kapoot (bass) one just the transistors the other more serious . Peter was as good as his word and worked for over two hours removing and replacing all faulty items and then played both amps running perfectly .

Issue seems to be that the quick blow fuses just do not blow quickly enough and the only suggestion Peter could come up with was to fit pico fuses which are many times faster and so should protect the drivers , transistors etc from any harm . These though are soldered in . Just a question as i came up with in idea while I was trying to sleep . If the pico fuse was soldered to a blown fuse case and then inserted in the fuse holder would that work ?

So now have two working amps again and have to think abotu how to approach this to ensure I end up with a working sytem . Have left my thoghts on the DIY thread as i am messing this thread up a little too much .

Will post final details here .