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Courtiestown - Naim Amplifier (Avondale) Upgrade Project

Good evening all,

I've just completed a listening session and went to power the amplifiers down and thought "Hang on a moment those noisy ETC transformers don't sound quite so noisy".

Resorting to the same NIOSH app. the noise level was back down to circa 32dB(A) rather than the 35dB(A) they had been at.

A check on the myenergi app showed we were on mains electricity rather than supplied from the Tesla PW2.......... I've left this one amplifier powered up and will run a further check this time tomorrow night after it has had 24hrs to 'come up to temperature'.

Regards

Richard
 
Good evening all,

Somewhat sadly I'm having to give up on my ETC transformer project as the 'buzzing' issues are clearly not going to go away.

Two other purchasers of ETC transformers are also in the same boat.

LesW is aware of the 'challenges' the three of us have experienced.

Need to give some thought to alternatives............

Regards

Richard
 
Richard Lines said:
Good evening all,

Somewhat sadly I'm having to give up on my ETC transformer project as the 'buzzing' issues are clearly not going to go away.

Two other purchasers of ETC transformers are also in the same boat.

LesW is aware of the 'challenges' the three of us have experienced.

Need to give some thought to alternatives............

Regards

Richard
Click to expand...
Is it loose laminations? havent they had a varnish bath?

Pete
 
Richard Lines said:
??????????
Click to expand...
I think he's suggesting that we stop trying to use build linear power supplies, and move to the dark side. ;)

I do have one stereo NCC200 amp in the bedroom using stacked Meanwell supplies. The bass from it is a bit too thin, but everything else sounds very impressive. With that regulated supply, I would say that it sounds more detailed and organized than an unregulated linear supply. If only it could supply enough current when the bass says NOW!
 
Pete MB&D said:
Is it loose laminations? havent they had a varnish bath?
Click to expand...
I believe both Graham and James' Have been back to ETC and been re-torqued and re-dipped to no avail.

It appears they (ETC) have no experience of building transformers for the audio market.

I could follow David's advice above and buy some of the new Linn monoblocks..........

I am in the process of acquiring some 'C' core devices...........

Regards

Richard
 
Last edited:
wd40addict said:
Big capacitors on the Meanwell's output?
Click to expand...
I recall a conversation back when we were playing with them more, with the poster commenting that the SMPS' regulation could very likely struggle with a bank of capacitors.

Also, you wouldn't get the same regulation benefits.

It might be interesting to try bi-amping: using an unrelgulated LPS on the LF, and the regulated SMPS on HF.

It would be relatively easy for me to drop my SE200 boards into that amp with the stacked MeanWell supplies, then use NCC300 dual- mono on the bass. Hmmm...
 
There are linear regulated supplies too for power amps, one being the Naim approach. If you are biamping, it's tempting to do as Mike stated, use the regulated one for HF.
The only downside with linear one is that you need a bigger heatsink if you are providing power to the whole amp and not just the front-end. Some companies have done it with great results.
 
.. and there are much-more nuanced approaches, possible too:

Front -end regulation, for most conventiaonal power amp archtectures, is >99+% of the issue solved.
Emitter-follower output stages have huge intrinsic PSRR, so trying to supply them with regulated supplies ..is more than a bit inefficient /fools errand.

however - Cascodes, if you must .. ;)
 
Good afternoon all,

I now have a pair of 'C' core transformers to replace the ETC devices (the latter soon heading back to ETC for a refund):-

0h5NmKn.jpeg


I have no idea as to the history of these..........

Will be applying power shortly and confirming the 2 x 35 - 0 - 35V outputs.

Regards

Richard
 
Good morning all,

OK so I had a 90 minute listening session last night and I was, again, surprised, very pleasantly, at what I was hearing.

As any followers of this, or the Isobarik, thread will be aware it is extremely difficult for me to listen to any one amplifier in a set-up consisting of five of the damn things.

The 'C' core transformer'd amplifier is driving the tweeters (in series) and there was clearly detail there I didn't recognise from my listening sessions in 'known' tracks. This is over and above what I knew the ETC devices were doing. The devices shown above are 350VA.

This is, of course, very subjective and I'm well aware of expectation bias creeping in.

I am now convinced that 'conventional' laminate transformers are delivering something sonically which toroid devices don't appear to be. Does anybody have a sound (no pun intended) scientific explanation for this?

I also have this pair of transformers to install:-

1pXGmZZ.jpeg


These are 500VA devices.

Regards

Richard
 
I'm guessing these C cores are mechanically quiet then Richard, no buzzing? Obvious next question... where are you sourcing them from?
 
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
 
Good afternoon all,

Currently on with fitting the 500VA 'C' core transformers in to an amplifier having removed some Canterbury Winding 340VA toroids (two out of four bought off one S.Brogden of this parish two years ago).

There's no way the lid will go back on this case so I'll need to fit some spacers......

xa8vVCM.jpeg


Should be up and running within an hour. These will be driving the front bass units on the Isobariks, the rears are driven by an amplifier fitted with Tiger Toroid 500VA units.

Regards

Richard
 
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?
 
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