one transformer ok?

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kenk

one transformer ok?
« on: 24 Feb 2004, 07:33 pm »
Hi all,

It is ok to use one 300va transformer with 2 secondaries instead of two 160va transformers?  

It is cheaper that way.

Please advice.

Thanks,

Ken

Maerten

  • Jr. Member
  • Posts: 10
one transformer ok?
« Reply #1 on: 24 Feb 2004, 10:14 pm »
If im correct you want to use one transformer for 2 channels?

Its possible, but i read somewhere in a post, made by hugh, or maybe his site, that it seriously affects the performance of your amplifier.

It was not adviced, the detail and staging would be considerably worse with only one transformer

Just my two cents, if i were you i'd wait for someone to post who actually knows things  :roll:

Maarten

EDIT---------------

I found this in the FAQ on the aspen amplifiers site !

Quote
We don't recommend a single power supply for both channels;  we strongly recommend a pair of separate, 160VA transformers, and the regulation of these transformers is not really the big issue.


You might want to look at it yourself here:

Power FAQ

Good luck,

Maarten

kenk

one transformer
« Reply #2 on: 24 Feb 2004, 10:19 pm »
"If im correct you want to use one transformer for 2 channels? "

Yes, you are correct.  Just trying to save some bucks.

Thanks for advice.

Ken

AKSA

one transformer ok?
« Reply #3 on: 25 Feb 2004, 12:02 am »
Kenk,

Don't do it.  One transformer gives the same dynamics, but increased crosstalk and very degraded soundstaging by comparison.

I've been over this ground a few times now, and in every single case, the dual supply was so much better it absolutely creamed the single supply in all listening tests.

Actually, two transformers is great.  If you can supply each transformer from different power fuses at the main switchboard, believe me, you can hear a slight improvement again.

Cheers,

Hugh

TG

Re: one transformer ok?
« Reply #4 on: 25 Feb 2004, 12:17 am »
Quote from: kenk
It is ok to use one 300va transformer with 2 secondaries instead of two 160va transformers?

It's not worth the loss in quality for the comparitively small cost saving.

The preamps & amps which I've built with a single power supply have all sounded greatly improved by modifying them to dedicated dual power supplies.  As Hugh said above, taking this back as far as possible (to the fuse, or even to separate mains inputs) will have benefits.

The power supply is not just a mass of power sitting in the background making the signal circuit work - it is as much a part of the sound as anything else.  I think of the signal circuit as actually being the modulator for the power supply - a transparent "shaping" conduit between the rectified power and the speakers. :idea:

Cheers

andyr

one transformer ok?
« Reply #5 on: 25 Feb 2004, 12:36 am »
Quote from: AKSA
Kenk,

Actually, two transformers is great.  If you can supply each transformer from different power fuses at the main switchboard, believe me, you can hear a slight improvement again.

Cheers,

Hugh
Hugh,

As you know I built my 3 x stereo AKSAs as 6 monoblocks - ie. each module's power supply has its own IEC cord, fuse & switch.

Are you saying that if I had a separate power circuit (with circuit-breaker) from the switchboard for EACH monoblock, it would sound better?

If so, then I would assume it would be a good idea to have an additional power circuit for all the (non-current-draw) source components??

Regards,

Andy

EchiDna

one transformer ok?
« Reply #6 on: 25 Feb 2004, 03:30 am »
yea gods!

this is taking mono power supplies to the extreme! lets see... 6 monoblock amps each with a dedicated line from the switchboard? then source lines as well... yikes...  I hope you can get mates rates from a sparky for the install!

 :o

SamL

one transformer ok?
« Reply #7 on: 25 Feb 2004, 03:51 am »
Hi Andy,

Did you manage to get the silver IEC connectors at the end?
You were talking about it some time ago.

Sam

andyr

one transformer ok?
« Reply #8 on: 25 Feb 2004, 04:28 am »
Hi, Sam,

Yes I did ... from Acme Audio Labs.  I bought 3 x IEC panel plugs & 3 mains fuse holders.

However, I am not retrofitting my existing AKSAs ... not at this point in time, anyway.  I will use one of each in the GK-1 which is under construction and keep the other two sets for some other project ... like the DAKSA!!

Regards,

Andy

andyr

one transformer ok?
« Reply #9 on: 25 Feb 2004, 04:35 am »
Quote from: EchiDna
yea gods!

this is taking mono power supplies to the extreme! lets see... 6 monoblock amps each with a dedicated line from the switchboard? then source lines as well... yikes...  I hope you can get mates rates from a sparky for the install!

 :o
Hi, EchiDna,

Just planning my next house and its music room!!

BTW, most sparkies would not have the faintest clue about the sort of thing we are talking about here bcoz they think in terms of the regulations concerning thickness of copper vs. amperage, to stop the wire getting hot enough to become a fire risk in the wall cavity.

Thick enough copper - and multiple separate powerline runs - is all about minimising voltage sag when a big base transient comes on.

Regards,

Andy

EchiDna

one transformer ok?
« Reply #10 on: 25 Feb 2004, 11:06 am »
Quote from: andyr
Hi, EchiDna,

Just planning my next house and its music room!!

BTW, most sparkies would not have the faintest clue about the sort of thing we are talking about here bcoz they think in terms of the regulations concerning thickness of copper vs. amperage, to stop the wire getting hot enough to become a fire risk in the wall cavity.

Thick enough copper - and multiple separate powerline runs - is all about minimising voltage sag when a big base transient comes on.

Regards,

Andy


Cheers Andy,
I understand the concept and the reasoning.... but still.... I fully intend to run dedidicated lines when I build or buy my first house with a dedicated HT/Listening room (living in 'apartmentised' Singapore for 7+ years now).

GL with the project, let us know how it pans out.

cmscott6

one transformer ok?
« Reply #11 on: 25 Feb 2004, 02:20 pm »
Sorry to continue off-topic, but I'm slowly rewiring my house and getting close to the (new) stereo circuit.  

So if I run two dedicated mains circuits from the box to the AKSA (one per channel), what about the phase of each line?  (Might as well take this to the manic audio absurdity level  :lol: )  Would it be better for each channel then to come off of separate legs of the AC (opposing phase) and share a neutral?  Or wire each circuit individually from the same leg, and therefore have the same AC phase?  (My first choice.)

DSK

one transformer ok?
« Reply #12 on: 25 Feb 2004, 09:03 pm »
Hi cmscott6,

Those that have researched this on Audio Asylum always suggest that all your hifi dedicated lines be on the same phase as each other, but on the opposite phase to your noisiest household appliances (refrigerator etc). They also recommend that the dedicated lines be the first ones out of your main panel if possible.

Cheers,
Darren.

andyr

one transformer ok?
« Reply #13 on: 26 Feb 2004, 10:28 am »
Quote from: DSK
Hi cmscott6,

Those that have researched this on Audio Asylum always suggest that all your hifi dedicated lines be on the same phase as each other, but on the opposite phase to your noisiest household appliances (refrigerator etc). They also recommend that the dedicated lines be the first ones out of your main panel if possible.

Cheers,
Darren.
Darren, hi.

As our friend cmscott6 is a resident of the good ol' USofA, I suspect what he means by phase is not what we (more advanced!) citizens of the world with our 3-pin-plug-systems mean by phase - ie. do you have 1-phase, 2-phase or 3-phase power coming into your house (which enables you to separate "noisy" things like fridges from "delicate" things like power amps) - but whether you have the 2-prong plugs inverted or not.

US people seem to worry about this all the time whereas I have never been able to hear the difference when I invert the active and the neutral (I made up a pair of very short "cheater" extension cords.

If I am wrong about what cmscott is thinking ... then I agree with you - if you can do it (almost impossible if there is already a powerline to the house!), have two "actives" coming into the house and put the hi-fi gear on one and everything else on the other.

Regards,

Andy

DSK

one transformer ok?
« Reply #14 on: 26 Feb 2004, 10:57 pm »
AndyR,
No, the phasing we are talking about here is nothing to do with what we call 3-phase etc  and my original answer is correct and stands. The USA have a 2 phase supply whereas in Australia we only have the one phase.

It is a simple and common exercise for a US electrician to do what I described. It is standard practice really.


Cheers,
Darren.