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Courtiestown - Naim Amplifier (Avondale) Upgrade Project

laverda said:
I wasn't sure if I was going to share my ETC 'issues' but Ive decided It may be in the best interests to others and all that follow these pages.

In short I had the Hum and Buzzing issue as previously mentioned by Richard and James back in this tread.

One of the two ETC 500va transformers I purchased blew up, filling the house with acrid smoke. Luckily the house smoke and fire detection system kicked in and saved the day.

After lengthy discussions and an investigation by ETC they could not find anything wrong or a reason why this could happen and deemed that the transformer must have been overloaded.

This blow up took out the PSU and amp board down stream.

ETC sited that I read the purchase contract which clearly states in clause 6. No claim for loss or damage as a result of consequential damage of any form. (Or word to that effect.) I did get a refund for the cost of the transformers and shipping though.


53532524723_7252ba058f_k_d.jpg
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I have had that a couple of times caused by a blown bridge on a unfused secondary.
Loads of smoke.

Pete
 
James Evans said:
If you take out that predrilled base plate would you gain enough internal height? Or is that sat pretty much as low as it will go anyway?
Click to expand...
Unfortunately there wouldn't be quite enough by some 2 - 3mm...........

This pair of transformers are also whisper quiet and there is no hum pick-up despite their being quite close to the SE boards.

That's six channels on EI pattern transformers now - next challenge will be finding an organisation that can make some none-buzzy EI pattern transformers............

Currently listening to John Martyn 'Grace and Danger'.............

Regards

Richard
 
laverda said:
This blow up took out the PSU and amp board down stream.
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It’s very unlikely that the transformer took out the PSU and amp. Much more likely that the amp failed and took out the transformer.

Fuses and/or SOA protection could have avoided this.
 
S-Man said:
It’s very unlikely that the transformer took out the PSU and amp. Much more likely that the amp failed and took out the transformer.

Fuses and/or SOA protection could have avoided this.
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Not in this case, the amp was working, playing music while the transformer was crackling away with smoke pouring out the top and sides.

The amp (duel mono, only one channel affected) was playing music while smoke was poring out of the amp case. No fuse blew and the speaker protection didn't cut in. It wasn't until after and the Tx cooled down I could ascertain the damage. I was expecting some chard remains of the PSU and amp board but nothing like that.

I reinstated the toroidal's and it powered up..!!.. but the affected channel it didn't sound well at all....on investigation one of the caps in the CAP6 was way down to 10uF from 10000uF......

There was a protracted investigation by ETC on the returned transformers and they could not and would not apportion blame on any of the down stream equipment.

I was amazed that during my many conversations they didn't even know the 1.414% AC - DC equation.
 
Good evening all,

I've been listening to my system yesterday evening after the first transformer changeout and again this evening.

There is definitely more detail in the upper registers - the only change was 2 x 500VA conventional laminate transformers being replaced by two 'C' core 350VA ones.

I had thought the bass was pretty well controlled previously but replacing the 2 x 300VA (the 40V windings not being used) toroids with the 2 x 500VA 'C' core devices appears to have improved the bass handling capability (try Faithless's Reckless - I'm not a fan but it is a good test).

I must get on with selling some stuff.........

Regards

Richard
 
Good afternoon all,

DOES THE AMPLIFIER MAKE A DIFFERENCE?

I guess the title of this post could be seen as contentious as I know I have read that some, even on this forum, do not believe amplifiers impact on the sound.

Given I had a multi-channel Naim system driving my Isobariks i.e. SNAXO 3-6/ Supercap, 3 x NAP250 and 2 x NAP135 there are those out there who would assume some kind of musical nirvana would have been achieved. I'd probably be amongst that number but reading on this forum suggested maybe Naim wasn't the be all and end all of amplification.

My experience in the last 12 months has me wondering at how amplifiers can 'sound' so very different.

I posted on the what are you listening to now thread yesterday evening - the choice of tracks were brilliant examples of the audio engineers 'art' and very good at showing a 'soundstage' and convincing me I'm still heading in the right direction.

My system sounds massively different under the current amplification and I would love to understand why this is, it leaves the Naim system a long way behind.

There is the old Quad advert about a perfect amplifier being a wire with gain?

In basic terms an amplifier 'simply' amplifies the signal fed to it so all amplifiers should sound the same - but this simply isn't true.

I have heard changes to what an amplifier does by changing the power supply transformer - 'all' a transformer does is change an AC voltage by conventional theory.

By changing the amplifier driving the tweeters or the ones on the base from toroid to 'C' core most definitely brings about an audible difference.

Graham is convinced that the SMD rectifiers in an Avondale CAP6 make a sonic difference - I don't doubt him and have bought some AA FWBR to carry out changes to a pair of my CAP6's and try this out for myself.

I'm currently investigating getting a pair of 'R' transformers from James Transformers - anybody on here any direct experience?

Regards

Richard
 
Good afternoon all,

I placed an order with James Transformers this morning. $386 all in for 2off 650VA 'R' core devices. 10 day lead time and some 20 days postage - it will be interesting to see what happens when they arrive in the UK by way of charges.

Regards

Richard
 
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I'm very tempted to follow you on this path Richard. The Avondale amps have long intrigued me and your transformer swapping seems great fun. I need to get the Isobariks back working first and then I want to go for Les' latest and best amplifier boards and build a couple of units to put on tweeter duties. As a complete novice on anything like this, I'm expecting to enjoy the challenge. I'm getting excited just thinking about it. I need to find a really nice 'big enough' chassis first I think.
 
Anyone interested in EI transformers I can recommend Magestic, used them a few times over the years.Just got a couple of
460VA units for some valve amps, not tested them under load yet but not a peep
Out of them unloaded.
As their a UK supplier not cheap though but their experienced in supplying audio
grade units.
 
GWM said:
Anyone interested in EI transformers I can recommend Magestic, used them a few times over the years.Just got a couple of
460VA units for some valve amps, not tested them under load yet but not a peep
Out of them unloaded.
As their a UK supplier not cheap though but their experienced in supplying audio
grade units.
Click to expand...

Ah Ha, I was speaking to some one only the other day about Majestic and I will be getting a quote for some C cores which I believe they do. Looking at their web site they'll do anything you want.
 
Good evening all,

I'm in the middle of modifying (bodging if you will) some older PCB CAP6's to take the new SMD Schottky FWBR:-

E1goJdm.jpg


These acquired off one MJS and AA very kindly had the heatsinks re-made for me.

UQzIYPe.jpg


First up is removing the existing heatsink, rectifiers and one AC inlet tab:-

X1nZSpf.jpg


Then removing the existing SMD chokes and replacing with wire links:-

JQGwSJ0.jpg


Then mark the PCB's and taken them out to the shed to drill a mounting hole for the FWBR (AA do provide plastic mounting pillars along with assorted fixings to be clear - I used M4 x 30mm brass bolts, washers and nuts):-

tisoSOl.jpg


Then wire them up:-

nEyc2id.jpg


That's one done and I'll get the other done shortly. Tomorrow I'll look to test these and then install them in one of the two 'C' cored amplifiers to allow a test between the two driving the Kan2's.

Regards

Richard
 
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Good morning all,

Just bought another 12off 10,000uF/ 80V capacitors - would love to buy in the UK but RS (one type available only) too expensive compared to Mouser/ DigiKey and Farnell don't even have any in stock.

How can it be cheaper to airfreight them from Texas................?

Regards

Richard
 
Richard,

I asked the question some years a go to a Mouser Rep, his reply was they have their own plane/s that 'taxi' freight from one country to the next. Its just a matter of 'picking it up here and dropping it of there'. I believe DigiKey RS and Farnell have a similar type of service. £12 and they sort all the duties and taxes. Amazing realy.
 
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