Cheers Mike, and what about the 4x rods that pass through the transformer corners, should they be removed or left in place
THAT ^^^^^ (meaning Old School)
If in doubt, ask a seasoned shop employee, a fresh one may only know or even prefer the modern, ecological, Rita Thunberg approved type.
You do NOT want water inside, so no "green/ecological" water based type but old style oil/stinking/solvents type.
QUOTE=RandomAudioGuy;6808741]Do you need to heat the transformer or vanish before you dunk it? Or can you just do it room temp?
You say let it submerse overnight, then hang it so the excess drops. Will it not be too dried overnight? Or does 'transformer' vanish take really long to dry?
[/QUOTE]
No need to *heat* it up, just leave trnsformr in the Sun or near a stove or lamp so it warms up somewhat(you can still hold it in your hand) so as to remove moisture/ condensation from inside.
Or warm it up a little with a heat gun or hair dryer.
I mentioned two different types varnish, don´t mix them as one: household varnish will surface dry overnight, deep inside it will take longer, main reason for waiting overnight is to avoid you cussing me because it still leaks a little and makes a sticky mess inside your amplifier :
Dedicated/Industrial type has an additive which makes it gelify (so no more dripping) within the hour
You may try to get some if you wish, but home type works as well, only longer.
Is this the same procedure with EI and toroidal transformers?
It´s a pity to junk a heavy expensive full of strategic components (copper and silicon steel) piece of Technolgy only because of buzzing.
As of "Cabothane", avoid the words "water - Green - Ecological - Solvent Free - No smell" on the label.
Tried to suggest a specific type but that shop you linked is way too well supplied,offered >600 options. 😱
Serious, visit a local established or Mom&Pop type shop and ask owners, tell them you want an old style/classic wood varnish, which is NOT water based, Ecological, etc. , just "what my Dad would have used in his time".
Serious 🙂
If in doubt, ask a seasoned shop employee, a fresh one may only know or even prefer the modern, ecological, Rita Thunberg approved type.
You do NOT want water inside, so no "green/ecological" water based type but old style oil/stinking/solvents type.
QUOTE=RandomAudioGuy;6808741]Do you need to heat the transformer or vanish before you dunk it? Or can you just do it room temp?
You say let it submerse overnight, then hang it so the excess drops. Will it not be too dried overnight? Or does 'transformer' vanish take really long to dry?
[/QUOTE]
No need to *heat* it up, just leave trnsformr in the Sun or near a stove or lamp so it warms up somewhat(you can still hold it in your hand) so as to remove moisture/ condensation from inside.
Or warm it up a little with a heat gun or hair dryer.
I mentioned two different types varnish, don´t mix them as one: household varnish will surface dry overnight, deep inside it will take longer, main reason for waiting overnight is to avoid you cussing me because it still leaks a little and makes a sticky mess inside your amplifier :
Dedicated/Industrial type has an additive which makes it gelify (so no more dripping) within the hour
You may try to get some if you wish, but home type works as well, only longer.
Is this the same procedure with EI and toroidal transformers?
It´s a pity to junk a heavy expensive full of strategic components (copper and silicon steel) piece of Technolgy only because of buzzing.
As of "Cabothane", avoid the words "water - Green - Ecological - Solvent Free - No smell" on the label.
Tried to suggest a specific type but that shop you linked is way too well supplied,offered >600 options. 😱
Serious, visit a local established or Mom&Pop type shop and ask owners, tell them you want an old style/classic wood varnish, which is NOT water based, Ecological, etc. , just "what my Dad would have used in his time".
Serious 🙂
I would leave tube light chokes on load when varnishing them, the vibration actually helped it penetrate, and the higher temperature caused better flow.
I would take them off power when the buzzing died, and close up next day.
I use air dry insulating varnish, very cheap, $3 per liter here.
I would take them off power when the buzzing died, and close up next day.
I use air dry insulating varnish, very cheap, $3 per liter here.
I saw a good product in NZ last night when browsing ,. but it was only in 55mL bottles, whilst you might only use that or twice that eventually.. you wouldn't be able to submerge it in that little.
It's a little overkill anyway .... and too expensive in 55mL bottles MG Chemicals 4228 Red Insulating Varnish 55ml
It's a little overkill anyway .... and too expensive in 55mL bottles MG Chemicals 4228 Red Insulating Varnish 55ml
Yeah I definitely couldn’t find any insulating varnish even though if I tried really hard I could possibly get some from the tx manufacturers we deal with. Anyway I’ve got it soaking in old school cheap stinky varnish right now, will dry it overnight and see if any luck.
mainframe said:
You'll need longer than 'overnight'
As mentioned, the outer surfaces might dry, but the internals will still be liquid.
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Polyurethane is OK at ambient environmental temperatures but a warm to hot running power transformer will break down almost any water-dispersed polymer paint. Another reason is the water that the resin is dispersed in, doesn't wet or penetrate deep enough in the windings to leave sufficient resin there.
At those varnish prices (NZ$70 plus for a lousy 1litre tin of solvent varnish) I'd be thinking that it's time for new transformer. Since your amp is an iconic Perraux model, I wouldn't fiddle about with a good chance of a bodged repair attempt unless you can be certain of your procedure and outcome before you start and btw - that means using a vacuum pump and chamber to remove air before submerging it in varnish. I know lots of people suggest half-hearted soaking alone and multiple (as in dozens of) treatments) to get sufficient penetration but some have kept the efforts up for months, still unsuccessfully. Why waste your time and money?
At those varnish prices (NZ$70 plus for a lousy 1litre tin of solvent varnish) I'd be thinking that it's time for new transformer. Since your amp is an iconic Perraux model, I wouldn't fiddle about with a good chance of a bodged repair attempt unless you can be certain of your procedure and outcome before you start and btw - that means using a vacuum pump and chamber to remove air before submerging it in varnish. I know lots of people suggest half-hearted soaking alone and multiple (as in dozens of) treatments) to get sufficient penetration but some have kept the efforts up for months, still unsuccessfully. Why waste your time and money?
It seems phenolic is the chemistry to look for.
There is a company called elantas beck, quite famous, you can see their product list.
Amazon is selling 4 liters for US $45 or so here.
PLAZA Insulating Resin for Motor, Alternators, Transformer winding - (4 x 1 Litre bottle) Pack : Amazon.in: Industrial & Scientific
There is a company called elantas beck, quite famous, you can see their product list.
Amazon is selling 4 liters for US $45 or so here.
PLAZA Insulating Resin for Motor, Alternators, Transformer winding - (4 x 1 Litre bottle) Pack : Amazon.in: Industrial & Scientific
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I'll leave it for a couple days to dry, if it doesn't solve the problem I'll go down the toroidal path. And the EI can be kept for purity if need ever be. If the toroid hums ill sell it and go SMPS. I think I can make that 1000VA toroid fit, will just need to suck up the freight. As mentioned, the varnish wasn't that cheap..
"Elantas Beck" is the company which makes High grade insulating varnish for Transformers / Motors in India. In some countries it is sold as "Dr Beck"
Weird.
Here World Class Akzo Nobel (Holland) Cetol brand costs all of U$10 a liter 😉
Brands | AkzoNobel
Price: 1067$ (Argentine Pesos) divided by 103.75 USD/$Arg exchange rate=10.28 USD
Same with other world class brands from Sherwin Williams, ICI (Imperial Chemical Industries), etc. 😕
Local only brands? (which are still very good): about $7 USD.
Mysteries of Globalization.
New Zealand (NZ) CT Cheah (ChuanTeong.Cheah@altana.com)
He is in charge of NZ for Altana, parent of Elantas Beck.
He may help you find what you need.
He is in charge of NZ for Altana, parent of Elantas Beck.
He may help you find what you need.
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No change after varnish job. No success. Same amount of noise from the core. If I were to guess, it'd be maybe the varnish was too thick to get into the trouble spots or the transformer is just at end of life.
So that leaves me with
1a. DC blocker circuit - but I'm still to be convinced as I have two dead silent amps here with EI transformers.
2. 1000VA Toroidal replacement (unless someone knows of a EI replacement @800VA?)
3. SMPS , remove rectifier and filter caps. Anyone have any objections to this?
So that leaves me with
1a. DC blocker circuit - but I'm still to be convinced as I have two dead silent amps here with EI transformers.
2. 1000VA Toroidal replacement (unless someone knows of a EI replacement @800VA?)
3. SMPS , remove rectifier and filter caps. Anyone have any objections to this?
I've had many amps with transformer hum. At one stage I thought it was my power, so tried plugging everything I had into 1 power board. Tried surge protectors, power conditioners (which ironically hummed a lot). Tried removing earth as well. All had the same results.
I am almost certain it's not my power but the transformers (guess I've just been very unlucky).
So I'm very curious as to the solution
I am with you, I don't think DC blocker is the way to go.
I don't know which is better between 1 and 2, but my question would be with SMPS.
Would that be able to generate the amount of currents you need to drive a big amp? If it does, is there a reason not to use it?
I am almost certain it's not my power but the transformers (guess I've just been very unlucky).
So I'm very curious as to the solution
I am with you, I don't think DC blocker is the way to go.
I don't know which is better between 1 and 2, but my question would be with SMPS.
Would that be able to generate the amount of currents you need to drive a big amp? If it does, is there a reason not to use it?
Looking at my transformer very closely, I actually suspect someone has had a go at this before. There was a varnish over the transformer that I've not seen on all the transformer windings we usually deal with. I could be wrong, of course. But anyway, it doesn't change the result, I haven't had any success.