SY must be right, he has the PhD in physics. From now on, audio transformers are PERFECT, without any tradeoffs, (except cost and size) and everyone should use them, whether they need them or not.
Now, can we move on?
Now, can we move on?
John,
You missed the point and appear somewhat rattled and insecure.
Having a superior attitude is not an endearing quality that most well balanced people find attractive. Although it is not uncommon with technical people. I hope you don't speak to you clients like that. Its certainly not a measure of success.
Actually my standard of excellence is right up there John.
I own mostly recent model Pass Labs equipment and I am looking at acquiring an Ayre CX-7 player have having sold my Lavry DA-10 to a friend. What is just as important to me is the person behind the brand.
Parasound never really did a lot for me I am sorry.
Ian
You missed the point and appear somewhat rattled and insecure.
Having a superior attitude is not an endearing quality that most well balanced people find attractive. Although it is not uncommon with technical people. I hope you don't speak to you clients like that. Its certainly not a measure of success.
Actually my standard of excellence is right up there John.
I own mostly recent model Pass Labs equipment and I am looking at acquiring an Ayre CX-7 player have having sold my Lavry DA-10 to a friend. What is just as important to me is the person behind the brand.
Parasound never really did a lot for me I am sorry.
Ian
That's OK, Macka. I just get A reviews to help Parasound make a living. Of course, I kind of like my 'Blowtorch' but I doubt that you will ever see or hear one, and it doesn't have any audio transformers, so nobody else will be interested, in future.
I am just a semi-retired old engineer who has tried to help others with audio design.
It is true that I waste my time for the most part trying to do this. They can just read a book. Why don't you recommend something? Let's compare books!
I am just a semi-retired old engineer who has tried to help others with audio design.
It is true that I waste my time for the most part trying to do this. They can just read a book. Why don't you recommend something? Let's compare books!
macka said:
What has this got to do with anything
It's great enough that we have someone with John's calibre in our forums.
janneman said:
Exactly the same topology as in my ~1990 Amber 5500, with about -110dB residual (at 1KHz). The Amber 5500 uses a canadian Hammond transformer, shielded in a octal socket tube like enclosure, and 5534 opamps. Amber Electro Design was eventually purchased by AP, so guess who originally designed this circuit 🙂
I doubt that anyone here wants to use transformers in everything whether they need them or not- except maybe SE 😉 BUT it seems disengenuous (sp) to argue that their biggest failings are size and cost after emphasizing that the Blowtorch and similar are made with no regard to size and cost....
john curl said:
Well, John, that's not the case at all. I am a friendly and non-
judgmental sort of guy, but I don't get out much. And then there
was the occasion when somebody played "Let's you and him fight".
Ok, I just received the copy of John's old datasheet for the Jensen JE-16-A from SY.
Because the distortion curves in this datasheet weren't nearly as good as the same curves published in Jensen's current datasheets, John leaped to conclusions and accused Jensen of being less than honest with their measurements. That Deane Jensen was an honest man and that the company had since "buried" this sort of information over the years and I was a dupe, a fool, and a shill for them.
First, the test conditions for the old JE-16-A and the new JT-16-A are virtually identical. 150 ohm source impedance and 6.2k load impedance. The only difference is that the RC damping network for the JE was 3.6k in series with 820pF and 4.5k in series with 620pF for the JT.
The overall distortion for the JE is significantly higher and the hysteresis "bump" is far more pronounced compared to the JT.
At first I thought the JE had used 50% nickel cores instead of the 80% nickel core that the JT uses. But the JE had the same rated input level as the JT.
So I called Jensen this morning. Bill wasn't available so I spoke to David who has been there since 1980. He said that the JE had in fact used an 80% nickel core. The improvement in performance of the JT over the old JE was due to two things.
Primarily the availability of better core material, and secondarily their precision CNC winding machines which allow them to wind more efficiently and get more turns on the bobbin (which probably explains the slight change in the damping network).
So there you have it. Nothing has been "buried" and Jensen is just as honest in their measurement data as they have always been. All they've done is improve the quality of their product over the years.
Given the false accusations that John has made, I think he owes nothing less than an apology.
se
Because the distortion curves in this datasheet weren't nearly as good as the same curves published in Jensen's current datasheets, John leaped to conclusions and accused Jensen of being less than honest with their measurements. That Deane Jensen was an honest man and that the company had since "buried" this sort of information over the years and I was a dupe, a fool, and a shill for them.
First, the test conditions for the old JE-16-A and the new JT-16-A are virtually identical. 150 ohm source impedance and 6.2k load impedance. The only difference is that the RC damping network for the JE was 3.6k in series with 820pF and 4.5k in series with 620pF for the JT.
The overall distortion for the JE is significantly higher and the hysteresis "bump" is far more pronounced compared to the JT.
At first I thought the JE had used 50% nickel cores instead of the 80% nickel core that the JT uses. But the JE had the same rated input level as the JT.
So I called Jensen this morning. Bill wasn't available so I spoke to David who has been there since 1980. He said that the JE had in fact used an 80% nickel core. The improvement in performance of the JT over the old JE was due to two things.
Primarily the availability of better core material, and secondarily their precision CNC winding machines which allow them to wind more efficiently and get more turns on the bobbin (which probably explains the slight change in the damping network).
So there you have it. Nothing has been "buried" and Jensen is just as honest in their measurement data as they have always been. All they've done is improve the quality of their product over the years.
Given the false accusations that John has made, I think he owes nothing less than an apology.
se
Thank you Steve. It is interesting that Dick Sequerra told me this morning that they might have improved their core a little and perhaps added more windings. Then we went on to talk about metglas transformers that are more interesting to us, in particular.
And here are the scans for the old JE-16-A datasheet.
se
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
se
For that 'fat sound' get those 50/50 transformers from CineMag. This will be found in AN-104, 'Output Transformer Lamination Selection' at the CineMag website. Steve can give you the link I would hope. Go for it, perfect sound forever!
john curl said:
Ah, yes. The "freeze-dried" cores as my friend calls them.
Once you discover what the trade-offs are, let me know if you still find them as interesting. 😀
se
syn08 said:
Hofer's patent was granted in 1986. AP made the owner of the Amber outfit, Wayne Jones IIRC, a VP when they bought the store.
Jan Didden
dimitri said:
What is it? One of the Edcors?
0dB referenced to what?
Yes. I'd had some thoughts of using a little M6 Edcor or similar for a tube-less guitar distortion unit. It would use a level adjustment to gradually overload the transformer, as well as having an adjustable DC current that could be run through one of the windings to make the distortion more asymmetric.
Just another of the things I've been meaning to do but haven't got 'round to. 😀
se
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