Changing A/V receiver Transformer. Can I?

[AdrianQ]

Hi everyone, hope this post is not in the wrong section.
I was reading the Audioholics post on "Amplifier and Power Supply Basics".
So my question is, if many mid tier A/V Receivers skimp on their transformers (cost and weight etc) . Can I simply buy a larger one with same output voltage but larger VA and put it in?
Dont really want to mess around with capacitors and rectifiers. I'm not trying to gain extra power ,just give more headroom to the power supply .
Any comments would be appreciated.

 

[everettT]

Hi everyone, hope this post is not in the wrong section.
I was reading the Audioholics post on "Amplifier and Power Supply Basics".
So my question is, if many mid tier A/V Receivers skimp on their transformers (cost and weight etc) . Can I simply buy a larger one with same output voltage but larger VA and put it in?
Dont really want to mess around with capacitors and rectifiers. I'm not trying to gain extra power ,just give more headroom to the power supply .
Any comments would be appreciated.

I'd just buy a better unit. Putting in a larger transformer isnt worth the trouble for the minamal gain.

 

[TLS Guy]

Hi everyone, hope this post is not in the wrong section.
I was reading the Audioholics post on "Amplifier and Power Supply Basics".
So my question is, if many mid tier A/V Receivers skimp on their transformers (cost and weight etc) . Can I simply buy a larger one with same output voltage but larger VA and put it in?
Dont really want to mess around with capacitors and rectifiers. I'm not trying to gain extra power ,just give more headroom to the power supply .
Any comments would be appreciated.

Well there are lots of voltages, out from the transformer. Next you would need to redesign the WHOLE power supply, the rectifier, smoothing and regulation. Just changing the transformer, which you can't, would buy you nothing except trouble and a pile of it.

If you are not happy with receivers, then get a pre/pro and external amps, or at least only use receiver preouts and not the power amps. The pre/pro route is the high road, and the preferred solution for a top end AV system.

 

[AdrianQ]

I'd just buy a better unit. Putting in a larger transformer isnt worth the trouble for the minamal gain.

I actually just bought a Marantz SR6012 purely for preouts because my Yamaha didnt have any. Going to use a crown Xli2500 for my two front towers. I dont live in the U.S so my Marantz will cost me about double after shipping and Glorious taxes.

 

[AdrianQ]

Well there are lots of voltages, out from the transformer. Next you would need to redesign the WHOLE power supply, the rectifier, smoothing and regulation. Just changing the transformer, which you can't, would buy you nothing except trouble and a pile of it.

If you are not happy with receivers, then get a pre/pro and external amps, or at least only use receiver preouts and not the power amps. The pre/pro route is the high road, and the preferred solution for a top end AV system.

Ah thats what I was afraid of. Dont have the expertise to delve into the actual power supply circuit. I just thought that if a Manufacturer had a choice between using a 250 va or 350va or 450va etc . They would choose the cheapest one that would give them acceptable results. Whereas I could put in something better WITHOUT having to redesign the circuit. Well that sucks .
My New A/V receiver does has pre-out ,so will be running a separate amp to my fronts

 

[PENG]

My New A/V receiver does has pre-out ,so will be running a separate amp to my fronts

That's the way to go, as larger VA transformer most likely won't fit anyway even if it has the exact same taps/outputs. You do have to make sure you get an amp that can be driven to it's full rated power by your AVR. We know D&M AVRs have high enough pre out voltages, and the lower end Yamaha AVRs may be marginal at best.

 

[slipperybidness]

Ah thats what I was afraid of. Dont have the expertise to delve into the actual power supply circuit. I just thought that if a Manufacturer had a choice between using a 250 va or 350va or 450va etc . They would choose the cheapest one that would give them acceptable results. Whereas I could put in something better WITHOUT having to redesign the circuit. Well that sucks .
My New A/V receiver does has pre-out ,so will be running a separate amp to my fronts

Also, realize that the transformer is one of the most expensive parts of the entire electronic device! Especially for class A or AB amps.

The next highest cost tends to be the chassis and the heat sinks.

Do you see the trend here? Big hunks of metal are not cheap!

So, swapping to a larger transformer, when you buy a single transformer, could cost you easily $100 (or more).

 

[KEW]

I actually just bought a Marantz SR6012 purely for preouts because my Yamaha didnt have any. Going to use a crown Xli2500 for my two front towers. I dont live in the U.S so my Marantz will cost me about double after shipping and Glorious taxes.

The Marantz 60XX series used the same amp section as the 70XX in the past. They just say the spec is 5 or 10 watts lower on the 60XX to convince people to buy the 70XX. That may have changed in the last couple of years, but my point is that the Marantz SR60XX is not a bad amp section (as AVR's at this price-point go)! Does teh 70XX have two more channels these days? Obviously, that would cause the amp sections to now be different.
Using the Xli2500 for your mains should do a lot to off-load demand, so I expect that is a good approach. Without knowing how many other speakers and what models you will be using the Marantz for (and how loud you like to get it) there are no guarantees, but under typical conditions, you should be good.

 

[AdrianQ]

The Marantz 60XX series used the same amp section as the 70XX in the past. They just say the spec is 5 or 10 watts lower on the 60XX to convince people to buy the 70XX. That may have changed in the last couple of years, but my point is that the Marantz SR60XX is not a bad amp section (as AVR's at this price-point go)! Does teh 70XX have two more channels these days? Obviously, that would cause the amp sections to now be different.
Using the Xli2500 for your mains should do a lot to off-load demand, so I expect that is a good approach. Without knowing how many other speakers and what models you will be using the Marantz for (and how loud you like to get it) there are no guarantees, but under typical conditions, you should be good.

I always wished to use a secondary power amp for my front speakers and had actually already ordered my Marantz and Xli2500 (last week) . Then after reading the article "Amplifier and Power Supply Basics " I kinda got a bit pissed off with the whole (whimpy power supply" thing and thought. Well i can fix that! Sometimes you just want something to work as well as it can. That lead to a youtube video where a gentlemen showed the same amp circuit with two different transformer va ratings and how that affected multiple things . Hence my quest to see if i could improve something simply by the addition of a transformer. I mean a 500va Toroid is about $90. It was just a thought as I like to Tinker

 

[AdrianQ]

Also, realize that the transformer is one of the most expensive parts of the entire electronic device! Especially for class A or AB amps.

The next highest cost tends to be the chassis and the heat sinks.

Do you see the trend here? Big hunks of metal are not cheap!

So, swapping to a larger transformer, when you buy a single transformer, could cost you easily $100 (or more).

Funnily enough the Marantz 8012 (mine is the 6012) uses a toroid transformer but is significantly higher in price. But a 500 va toroid is relatively cheap . Not that I think changing A transformer makes the whole receiver somehow different . Just thought it might add some headroom to the power supply circuit and maybe make things a little cooler.