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Audio Technica AT630 Step up transformer
- Thread starter arcorob
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arcorob
Addicted Member
Amazingly simple device
Dead dead quiet...no hum,no hiss...like adding a cable...but one that steps up 1:15 perfect loading (at least for 10 to 20 ohms carts)
The AT650 is another nice one and that one is adjustable..and more expensive...LOL
Dead dead quiet...no hum,no hiss...like adding a cable...but one that steps up 1:15 perfect loading (at least for 10 to 20 ohms carts)
The AT650 is another nice one and that one is adjustable..and more expensive...LOL
arcorob
Addicted Member
I am almost willing to bet
That if you open it up, it has those microphone Shure transformers inside (or equivalent)
Not sure on the loading but 20db gain is not a lot and look at the freq. response
10Hz to 30,000hz vs 15hz to 100000hz within .5db
Both are 1:15 step up...
The variable loading is cool but no way of knowing WHAT you are loading unless that dial has click stops for loading and he tells you how many ohms each
Send him an email :yes:
That if you open it up, it has those microphone Shure transformers inside (or equivalent)
Not sure on the loading but 20db gain is not a lot and look at the freq. response
10Hz to 30,000hz vs 15hz to 100000hz within .5db
Both are 1:15 step up...
The variable loading is cool but no way of knowing WHAT you are loading unless that dial has click stops for loading and he tells you how many ohms each
Send him an email :yes:
I recently bought a new (Bryston BP17 Cubed) pre-amp which, fortuitously, has a phono input, but only MM. So, to try it with my (vintage Mayware) MC cartridge, I needed a step-up transformer and discovered I still have my AT630 which I've not used in nearly 40 years! I'd forgotten all about it.
In conjunction with the Bryston pre-amp's outstandingly quiet and transparent MM stage, would it be better than my Dynavector P-75 outboard MC phono stage? To my great and pleasant surprise... YES! A real classic.
In conjunction with the Bryston pre-amp's outstandingly quiet and transparent MM stage, would it be better than my Dynavector P-75 outboard MC phono stage? To my great and pleasant surprise... YES! A real classic.
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lazycat
Well-Known Member
If you do open it, make sure it's on some newspaper. There's a lot of gooey, black sticky stuff in there - the foam deteriorates, well, mine had. lol
There was no written info on the transformer(s).
I re-flowed the solder joints and replaced the cables with some Mogami (2549 IIRC). This made quite an improvemnt to the sound, at least in my system.
The rotten foam/goo was replaced with small bubble-wrap - after taking ages to clean said goo with IPA.
For the price they go for on ebay they are a useful tool, if they have the correct impedance for your cartridge. I was using an AT.
The AT630 doesn't incorporate any sort of volume control or, indeed, any other adjustability. It either works with your cartridge as is or it doesn't.
You would have to be a complete lunatic to put a volume control on a step-up transformer. And a turns ratio of 1:1.5 would be completely useless.
The AT-650 has a rotary switch to select between three different turns ratios and has a "pass" position. Unfortunately, Audio Technica's spec sheet doesn't say what the turns ratios are, only that they're intended for cartridges with 3 ohm, 20 ohm and 40 ohm source impedances.
The AT-650 has a rotary switch to select between three different turns ratios and has a "pass" position. Unfortunately, Audio Technica's spec sheet doesn't say what the turns ratios are, only that they're intended for cartridges with 3 ohm, 20 ohm and 40 ohm source impedances.
scorpio333
Active Member
I recently re-wired one of mine using the same cable. The results are a bit strange. On one system using a NAD 7100, it sounds fine. On another using a Decware ZP3, it sounds horrendous. The whole entire soundstage is about 3’ tall and 3’ wide. When I try the other all stock 630, it’s spot on and sounds great. I’ve been trying to use the rewired 630 on the 7100 as much as possible, perhaps the cables need to break in.
lazycat
Well-Known Member
All I can suggest is that you open it up and check the wiring. Sounds like something has gone awry - wire touching the case? Poor solder joint? - No offence meant. I did reflow the solder on the remaining joints.
Mine was straightforward except for cleaning the goo. I'm not sure how cables 'break-in' TBH. Especially at such a low voltage - or any for that matter.
scorpio333
Active Member
Should have also mentioned, I stuffed the case with cotton wool. All the old spongey gooey stuff was a mess.
No offense taken on the soldering, I’m no pro! Sometime this week I plan to crack it back open.
No offense taken on the soldering, I’m no pro! Sometime this week I plan to crack it back open.
lazycat
Well-Known Member
Good luck with it. For the life of me I can't remember what it looks like inside, except for the transformer and the muck.
I think I've fettled too much kit and it's all blurred into one. rofl.
scorpio333
Active Member
All better now. Somehow, likely while sliding the cover back on, one of the solder pads lifted and the joint wasn’t very solid. I also left out the packing I had in there.
lazycat
Well-Known Member
Good news. It's usually something simple.