Matching transformer for Mac headphones output

[Klaus]

Hi all
maybe someone knows if such transformers exist :
From Mac Headphone output to XLR mic input balanced, 12dB upwards ( headphones unbal ca. 50 ohms output imp ? - to XLR bal line > 1kohms input imp )
Thanks a lot for hints
and best regards
Klaus

[mikehalloran]

Ok... that's how you want to do it. Easy if you don't mind the result being mono.

What are you trying to accomplish?

[HCMarkus]

A little stereo mixer with balanced outs?

[musicman691]

From Radial Engineering:
Radial Trim http://www.radialeng.com/trimtwo.php passive di
Radial JPC http://www.radialeng.com/jpc.php active di

[Klaus]

Ok... that's how you want to do it. Easy if you don't mind the result being mono.

What are you trying to accomplish?

Thanks for replies !
not mono, 2 transformers...

I need :
- passive transformer
- +12db voltage gain upwards ( 1:4 transformer ratio ) to drive i.e. power amps, processors etc.
- using the full source power of a headphones output @ about 50 ohms primary impedance
- should deliver this power @ about 900 ohms secondary load ( imp = quadratic ratio )
Maybe I should start to wind my own...
Thanks
Klaus

[musicman691]

Ok... that's how you want to do it. Easy if you don't mind the result being mono.

What are you trying to accomplish?

Thanks for replies !
not mono, 2 transformers...

I need :
- passive transformer
- +12db voltage gain upwards ( 1:4 transformer ratio ) to drive i.e. power amps, processors etc.
- using the full source power of a headphones output @ about 50 ohms primary impedance
- should deliver this power @ about 900 ohms secondary load ( imp = quadratic ratio )
Maybe I should start to wind my own...
Thanks
Klaus

Did you look at the two Radial products I listed? It seems like maybe the passive one is what you need. I have to ask - do you even have the specs on what the headphone output on a Mac delivers?

[mikehalloran]

Again, what are you trying to accomplish? In other words, what are you going out of and into?

[musicman691]

Again, what are you trying to accomplish? In other words, what are you going out of and into?

Like he said a couple of posts back he wants to come directly out of his Mac and into a power amp or some kind of outboard gear. Looks like he's trying to skip out of going through a real audio interface and into outboard gear. Trying to be cheap and it may not work with any semblance of good audio. I know the Radial stuff I mentioned might do the job but without knowing his exact situation (which he's apparently reluctant to say) it's hard to say if he has a real concept of what needs to be done.

Radial gear can do a lot of things but miracles -

[mikehalloran]

nto a power amp or some kind of outboard gear.

No, he actually did not say that or anything of the kind. Yes, you made a reasonable guess—but that's all it is.

I have extensive experience in matching and mismatching gear. I've been hooking up the impossible to the ridiculous since the late 1960s when my dad worked at AMPEX.

Nowadays, since I often use an iPad/iPhone/iPod as a sound source in ways that Apple and pro gear mfrs never designed, I may know of a simpler solution—once I know what he is trying to accomplish instead of how.

[Klaus]

Ok... that's how you want to do it. Easy if you don't mind the result being mono.

What are you trying to accomplish?

Thanks for replies !
not mono, 2 transformers...

I need :
- passive transformer
- +12db voltage gain upwards ( 1:4 transformer ratio ) to drive i.e. power amps, processors etc.
- using the full source power of a headphones output @ about 50 ohms primary impedance
- should deliver this power @ about 900 ohms secondary load ( imp = quadratic ratio )
Maybe I should start to wind my own...
Thanks
Klaus

Hmmhh....
I thought to be 'technically' clear what I need...
Hardware wise , I need a transformer that 'converts' the headphone output power to a line level input - i.e. power amp input. I think the Mac headphone output is @ -12dB line level, while the power amp input levels are @ + 4dB level. ( Crest pro 7200 )
If my calculation is right, an upward ratio of about 6.3 ( + 16dB ) will transform a headphone output impedance of 75 ohms to about 3kohms - if the transformer can handle it 'power - wise'.
+12db voltage gain upwards ( 1:4 transformer ratio ) would be ok too...as a starting point

I know this is 'old sclool' and am trying to find transformer manufacturers that may have exactly such a thing in their product line.
I didn't find any until now...but maybe you guys know how could make them...
BTW
The Mac mini 1,1 / 2,1 has 24b convertors, and compared to what some DJs play nowadays, is ages ahead in quality against these MP3s...and sufficient to use a Mac mini as 'insert' for leveling and sound enhancement.
Unfortunately it works @ consumer level of -12dB, thus my needs.
OK now you got it, but the patent will be mine...
Thanks for your time and
best regards
Klaus

[musicman691]

nto a power amp or some kind of outboard gear.

No, he actually did not say that or anything of the kind. Yes, you made a reasonable guess—but that's all it is.

I have extensive experience in matching and mismatching gear. I've been hooking up the impossible to the ridiculous since the late 1960s when my dad worked at AMPEX.

Nowadays, since I often use an iPad/iPhone/iPod as a sound source in ways that Apple and pro gear mfrs never designed, I may know of a simpler solution—once I know what he is trying to accomplish instead of how.

He actually did say what he wanted to do in his second post here.

[musicman691]

Hmmhh....
I thought to be 'technically' clear what I need...
Hardware wise , I need a transformer that 'converts' the headphone output power to a line level input - i.e. power amp input. I think the Mac headphone output is @ -12dB line level, while the power amp input levels are @ + 4dB level. ( Crest pro 7200 )
If my calculation is right, an upward ratio of about 6.3 ( + 16dB ) will transform a headphone output impedance of 75 ohms to about 3kohms - if the transformer can handle it 'power - wise'.
+12db voltage gain upwards ( 1:4 transformer ratio ) would be ok too...as a starting point

I know this is 'old sclool' and am trying to find transformer manufacturers that may have exactly such a thing in their product line.
I didn't find any until now...but maybe you guys know how could make them...
BTW
The Mac mini 1,1 / 2,1 has 24b convertors, and compared to what some DJs play nowadays, is ages ahead in quality against these MP3s...and sufficient to use a Mac mini as 'insert' for leveling and sound enhancement.
Unfortunately it works @ consumer level of -12dB, thus my needs.
OK now you got it, but the patent will be mine...
Thanks for your time and
best regards
Klaus

Once again I have to ask - have you looked at either of the two Radial products I linked to? If you can get your mind off of specifically having a transformer then the first Radial unit I linked to, which is a passive di, will do the job for you. A passive di is really just a transformer or two inside a metal case. And the Radial units are practically indestructable.

[Klaus]

Thanks, yes, I've checked the specs...
The Trim-Two hasn't stated a voltage ratio, but I don't think it has some upwards ratio according to the impedances.
It will *not* do the job of interfacing directly to a power amp @ +4dB sensitivity, I would say.
Please correct me if I missed something.

The JPC is active - and not what I want...I want the whole headphone power delivered converted to + 4dB - passively.
As I said, I need old school power-matching.

Thanks !
Klaus

[daniel.sneed]

I can't resist to suggest this one:
http://www.radialeng.com/usbpro.php

It's computer powered and, IMHO, high class sounding.
I use one on several dramatic shows, to feed the PA amp and am glad with it.

BTW, the transformers are to be disengaged unless needed (hum or 48V), for they lower somewhat high frequencies.

[Klaus]

Thanks Dan
best regards

Klaus