[alphaman]

I have built the passive Tangentsoft/Modified Linkwitz x-feed with good results (got this running in two Tangent amps).
Also have Jan Meier's version in a Meier Audio Corda II amp.
Also have whatever HeadRoom uses in a Max amp.
Finally, my Xin portable amp (2006) has x-feed.
And they all sound different. I think HeadRoom circuit may be my fave, because it actually improves the fidelity of the sound (not just the spatial improvement). All of the other amps (esp. Meier) worsen the sound fidelity -- but the increase in spatial acurracy and long-term comfort (less fatiguing sound) is worth the loss in fidelity.

I've seen a few digital crossfeed processors built into various amps or software players (Foobar, etc).
But I believe in analog crossfeed and that's what I'm looking for in an aftermarket product.
So where are they ... if there are any to be found? HeadRoom used to have one, but that company no longer exists AFAIK.
The device should be reasonably priced ... so no Phonitor x, please!

 

[technobear]

https://ifi-audio.com/products/micro-itube2/

 

[alphaman]

https://ifi-audio.com/products/micro-itube2/

Bass processing or tube buffer ... don't need those. I assume the 3D+ is x-feed. But $400 is crazy $$. At that $$, I'd way rather opt for "Monolith 124460 Portable Headphone Amplifier and Dac - Black with THX AAA Technology, Analog Input, Slim Design, Dirac Sensaround" .
Alas, I think the Monolith digitizes the analog input. Or does it .... anyone know?

 

[technobear]

Well you did say standalone...

How about this: https://ifi-audio.com/products/zen-can/

 

[alphaman]

Well you did say standalone...

How about this: https://ifi-audio.com/products/zen-can/

Nahhhh .... but I do believe the demand for high-quality analog (passive) x-feed definitely exists. Wonder why the usual Chinese sources on eBay and Ali aren't putting out such units?

How hard is it to mass-produce some thing like (Chu-Moy from headwize):

https://headwizememorial.wordpress.com/2018/03/09/an-acoustic-simulator-for-headphone-amplifiers/

 

[iFi audio]

How hard is it to mass-produce some thing like (Chu-Moy from headwize):

It's not, but each such project (even very basic!) is a resource sink for a fairly large audio company, thus it has to sell later. Perhaps one day we'll make a standalone crossfeed device, we never say never, but it's a niche subject for sure.

 

[alphaman]

It's not, but each such project (even very basic!) is a resource sink for a fairly large audio company, thus it has to sell later. Perhaps one day we'll make a standalone crossfeed device, we never say never, but it's a niche subject for sure.

I think you'll have best seller(s) if you:
Keep things in the analog domain (like the best vol. pots)
Use extremely HQ parts (Vishay metal film resistors, Panasonic poly caps)
Offer a variable (stepped) crossfeed -- see the Tangent site
Offer various topologies of crossfeed (the headwize site has many ideas)
Keep prices low. Frankly, iFi prices are, IMO, beyond ridiculous!

 

[iFi audio]

Keep things in the analog domain (like the best vol. pots)

If we only can, analog signal is processed in the analog domain, i. e. our 3D/XBass features.

Use extremely HQ parts (Vishay metal film resistors, Panasonic poly caps)

When we can, they're there. Really fancy stuff gets into our Black Label products.

 

[alphaman]

Dear iFi audio:

I'm confused.

Is your "3D" feature headphone-specific crossfeed? (or is it some sort of other surround processing: Dolby, DTS, SRS, QSound, etc)
Is it passive, is it active? (E.g. the headwize DIY project is passive)
Is the circuit implemented at the INPUT (right after IN jacks) or at the OUTPUT (just before the headphone out jack)? (E.g. the headwize DIY project is passive and at input)
Is the 3D circuit avail. for pure line out (as shown in the headwize DIY project in my prev. post)?

REFS:
https://en.wikipedia.org/wiki/Head-related_transfer_function

 

[iFi audio]

Dear iFi audio:

I'm confused.

Is your "3D" feature headphone-specific crossfeed? (or is it some sort of other surround processing: Dolby, DTS, SRS, QSound, etc)
Is it passive, is it active? (E.g. the headwize DIY project is passive)
Is the circuit implemented at the INPUT (right after IN jacks) or at the OUTPUT (just before the headphone out jack)? (E.g. the headwize DIY project is passive and at input)
Is the 3D circuit avail. for pure line out (as shown in the headwize DIY project in my prev. post)?

REFS:
https://en.wikipedia.org/wiki/Head-related_transfer_function

Please see here:

https://ifi-audio.com/faqs/is-xbass-3d-mode-dsp-or-asp/

 

[alphaman]

Please see here:

https://ifi-audio.com/faqs/is-xbass-3d-mode-dsp-or-asp/

Looks like this page was created in the past few days. Possibly in response to this thread???
Nice work.
But you'll have the clarify what you mean here:

the iFi 3D/3D+ is a separate system to reduce “in head localisation” and to present a more natural, speaker like soundscape. It is based on very different targets derived in large scale listening tests back in the 1980s in what was then East Germany, far in advance of anything published previously and up to now elsewhere. The results are distinct from and well in advance of “Crossfeed” of all variants.

What East Germany testing? Are there references to this--links?

 

[iFi audio]

Looks like this page was created in the past few days. Possibly in response to this thread???

Not really, it's an old document, published years back when the first 3D iteration was born.

What East Germany testing? Are there references to this--links?

I'd have to ask one of our engineers, but it might take him a while to answer

 

[alphaman]

I've heard that dCS top-line headphone amp/DAC (Bartok??) has quite a good x-feed. Anyone know the topology dCS uses?

 

[iFi audio]

I've heard that dCS top-line headphone amp/DAC (Bartok??) has quite a good x-feed. Anyone know the topology dCS uses?

Their DACs are all ladder types, which is not a secret, but their x-feed might be.

 

[acs236]

It's frustrating that there are no standalone crossfeed units anymore! Back in the day, I'd be able to commission one of the DIYers here to build one. Has anyone found anything that fits the bill?