Use of stepdown transformer?

Jay S · « **on:** 5 Feb 2004, 11:25 pm »

I'm thinking of getting a region-free Pioneer 563A universal player and having it modded. I can either buy a 220v version in HK or a 110v version in the U.S. Cost with shipping will be approximately the same. If I get a 110v version I'll have to use a step-down transformer here in HK.

Any views on whether using a step down transformer on a source will:

a) Improve sound quality by acting as an isolation transformer
b) Have no impact on sound quality
c) Will degrade sound quality (the step down transformer is an off the shelf consumer item)

As modded, the 563A will have an upgraded switchmode power supply for the transport and video circuits and a new transformer/linear power supply for the dac and analog audio circuitry. Whether or not a step-down transfomer is involved, I will plug it into a Blue Circle balanced power supply fitted with a Bybee Nitro power cord.

Thanks!

- Jay

bubba966 · « **Reply #1 on:** 5 Feb 2004, 11:53 pm »

Jay,

Am also interested in what the use of a step-down tranny does. I have to use one on my LD player as it's Japanese. And I currently have a cheap-ish one, though at some point I'll have BPT build me a better one.

And hey, you could always go with this http://www.audiocircle.com/index.php?topic=8016&highlight= and not have to worry about the step down tranny...

Jay S · « **Reply #2 on:** 6 Feb 2004, 12:48 am »

Hi Brian,

One modder told me that a step-down transformer would actually help sound quality (option A above) by helping to isolate the player from the power line. He would be concerned about using a power amp with a step up/down transformer but feels it helps with a source. I hope we can get other points of view on this.

Cheers,

- Jay

JohnR · « **Reply #3 on:** 6 Feb 2004, 01:00 am »

But you're already plugging it into the BC thingy. You're adding an extra transformer which *doesn't* have balanced output, another cord and plug (not removable, presumably), and... you're not saving any money!

Psychicanimal · « **Reply #4 on:** 6 Feb 2004, 09:07 pm »

My suggestion:

Check out Jon Risch's website and read his article on DIY balanced power. You can rig a smaller 220V/110V isolation transformer in balanced configuration and be very pleased...

PeteHK · « **Reply #5 on:** 10 Feb 2004, 02:37 am »

Hi Jay,

I remember reading on AVBuzz (HK audio newsgroup) a number of comments about the use of transformers. Many people were using them with the Pioneer 858i a while back. The general consensus seemed to be that the use of a transformer had a negative impact on the sound quality (if I remember correctly).

I'm at work at the moment, so I don't have the url. I'll try to post it later, and you can have a look.

Regards,

Peter

bubba966 · « **Reply #6 on:** 10 Feb 2004, 02:42 am »

The 858i is a Japanese model if I remember right. Which means it runs at 100v.

Were they using the right step down tranny (240>100)? Or were they using a 240>120 step down?

PeteHK · « **Reply #7 on:** 10 Feb 2004, 02:47 am »

Bubba,

Sorry, I should have made myself clearer. Yes, you're right, the 858i is the Japanese model running on 100V/50/60Hz. We're on 220V/60Hz here in Hong Kong, so they would have been using a step-down transformer from 220V to 100V.

Regards,

Peter

bubba966 · « **Reply #8 on:** 10 Feb 2004, 02:58 am »

So if they were using a 240v>110v step down, and you guys are on 220v, then they were probably running them at 90v intead of the 100v they should be getting.

I can't imagine that to work as well as if the right step down was used (220v>100v).

The other question I've got is were they using step down transformers that were built well?

The one I was offered with my LD player was a really cheap one. I searched for a higher quality one. And the best one I could find was still a bit disappointing.

So maybe if Jay bought or built a nice 220v>120v step down it wouldn't negatively effect the performance.

PeteHK · « **Reply #9 on:** 10 Feb 2004, 03:20 am »

Quote from: bubba966

So if they were using a 240v>110v step down, and you guys are on 220v, then they were probably running them at 90v intead of the 100v they should be getting.

I can't imagine that to work as well as if the right step down was used (220v>100v).

The other question I've got is were they using step down transformers that were built well?

The one I was offered with my LD player was a really cheap one. I searched for a higher quality one. And the best one I could find was still a bit disappointing. ...

Apologies again, I've edited my post to correct the error.

They were using the correct step-down transformer (220->100V). I cannot vouch for the quality, as specifics were not mentioned.

The negative reports I've read about using transformers may be related to the general power supply quality in Hong Kong. Many places do not have good power supplies, given that so many people live in high-density blocks of apartments. The problem is particularly acute in the summer time, when air-conditioners are on all the time, creating a huge current draw from buildings.

A friend of mine uses a Jon Risch power filter and he swears by it. He also says that the voltages he's seen in his building are "variable", to put it politely.

I bought a 220->100 step-down transformer for my Marantz SA-8260 (bought in Japan). The problem is that I can't compare it with/without the transformer. When I bought the transformer, I put a meter on the mains at the shop and got around 206V. With the transformer, we were getting around 96V. I've not checked it at home, but have not have any noticeable problems.

I also use a 1000W transformer for my projectors (also bought in Japan) and have had no issues. Visual degredation would be more obvious than sonic, so perhaps my building has a good supply to start with?

Based on my very limited experience, I don't believe that a transformer will have an impact on the quality of the sound - provided it is of good quality and does the step-down conversion accurately.

I remember reading about AC regenerators (PS?) a while back. If transformers do have a negative impact on sound quality, perhaps regenerators may provide the answer?

PeteHK · « **Reply #10 on:** 10 Feb 2004, 03:29 am »

Jay,

If you want to buy a transformer, try Ap Liu Street in Sham Shiu Po (Exit C on the MTR). You can get a 300W unit for about HK$250. There are lots of different manufacturers to chose from and they'll usually let you put a meter on them to check how well they do the voltage conversion. They're mostly made in China, but seem quite robust. I've been using a 300W unit (for my CD player) and a 1000W unit for the projectors for two years now. Let me know if you need any further details.

Regards,

Pete

Jay S · « **Reply #11 on:** 11 Feb 2004, 05:46 am »

Thanks a lot for the advice! I will likely just use a stepdown transformer. While I could buy a multivolt unit here in HK and ship it to the U.S. for mods, that would double the distance it would travel and increase the risk of damage during shipping...

What I wonder is whether I can plug this step-down transformer into my Blue Circle balanced power supply... it should be fine as the difference across the Live and Neutral would still be 220v.

bubba966 · « **Reply #12 on:** 11 Feb 2004, 05:59 am »

Jay, from what I recall reading about balanced power supplies, I don't think you'd have a problem running a step down off of it. But again I'm not an EE, so I don't know 100% on that one.

The step down I ended up with for my Pioneer HLD-X9 was a 1500w model. Not that I needed 1500w as I think the X9 only draws 50w or so, but because it was built a bit better than the lower wattage models.

So maybe you might want to give the higher output models a look as well. Unless the lower output models are built as good as the higher output models, then it wouldn't matter.

Jay S · « **Reply #13 on:** 20 Mar 2004, 01:41 am »

I checked with Gilbert of Blue Circle Audio and he confirmed that I could plug a step-down transformer into my Music Ring balanced power supply.

The only thing holding me up right now is deciding on which region-free mod to get... my current preferred provider has not replied to questions I sent by email, which makes me wonder....