[ChJL]

I currently have 3 OORs here (I was the one that found the issues originally and they sent me new revisions with fixes as they were discovered).
A friend of mine who had ordered his OOR at canjam Socal recently received his. It's an earlier serial number than any of the three I have here, but it has all the fixes.

This implies that Ferrum did actually recall units and apply the necessary fixes. So whilst I can't say for certain (I'm just some guy, don't take this as fact ), it does seem that any retail units received will have no issues.

Also, OOR sounds great

Great plus I now know probably not to get that Bartok!

 

[Menkau-ra]

Any amp with an upgraded power supply sounds significantly better from stock PSU right, including Oor. Have people tried other PSUs for the Oor other than the Hypsos? There’s a lot of good options available and I would be very curious how the Oor will sound when compared with Hypsos vs with a very good linear PSU.

Interesting if Oor can work iFi iPower Elite?

 

[chargedcapacitor]

Interesting if Oor can work iFi iPower Elite?

The ifi Elite voltage is too low to operate the Oor, unfortunately.

 

[OneEyedHito]

The ifi Elite voltage is too low to operate the Oor, unfortunately.

They make a 24v that would work but you’re out another $300. I’d hope the Hypsos beats it for the money!

 

[Delta9K]

They make a 24v that would work but you’re out another $300. I’d hope the Hypsos beats it for the money!

ifi Elite specs for the 24v version are 24v 2.5A; Hypsos can do 9A up to 30v max IIRC
Seems the Hypsos is worth its price

 

[iFi audio]

ifi Elite specs for the 24v version are 24v 2.5A; Hypsos can do 9A up to 30v max IIRC

That's true, iPower Elite is available in four fixed voltage versions and 24V/2.5A is the highest.

 

[deafenears]

Also, OOR sounds great

Does it bump the Holo Serene off the top of your list for best headphone amp?

 

[GoldenSound]

Does it bump the Holo Serene off the top of your list for best headphone amp?

Not quite no.

At the moment the serene is still my favourite. But the serene doesn't have the same power as the oor and so stuff like susvara sounds much better on the OOR

 

[FooFighter]

Holo Bliss is coming out one day this year but I could never wait that long even if that one will best the Ferrum stack

 

[Basco]

I currently have 3 OORs here (I was the one that found the issues originally and they sent me new revisions with fixes as they were discovered).
A friend of mine who had ordered his OOR at canjam Socal recently received his. It's an earlier serial number than any of the three I have here, but it has all the fixes.

This implies that Ferrum did actually recall units and apply the necessary fixes. So whilst I can't say for certain (I'm just some guy, don't take this as fact ), it does seem that any retail units received will have no issues.

Also, OOR sounds great

Hey Also interested to look into the OOR, can you tell the difference of the old and new serial numbers after the revision? Also what was the exact initial problem?!
Thanks for your help here

 

[GoldenSound]

Hey Also interested to look into the OOR, can you tell the difference of the old and new serial numbers after the revision? Also what was the exact initial problem?!
Thanks for your help here

Serial numbers will not answer anything as units with earlier serials than the ones I have here that are affected have already been recalled and fixed.
But if you buy a unit, it will have the fixes. Even the ones that people had ordered before I'd even found these issues got recalled and fixed before being delivered.

There was a problem whereby the amplifier would go into overcurrent protection too early as the protection circuit was misreading something after a change in supplier for a component on the board. Though this occurred at about 4-5w output so it's incredibly unlikely that anyone would ever have actually noticed/found this anyway unless they were trying to blow up their headphones and make themselves go deaf. I only found it as I was testing the max power output of the amp with a dummy load whilst measuring. (Which btw actually exceeds Ferrum's stated spec and I was able to get 9.5w @ 32 ohm and 8.3w @ 50 ohm.)

And the second was that there was some odd behaviour with ultrasonic content (like, over 200khz, not at all anything close to the audible range) which showed up whilst doing some square wave and bandwidth testing.
But again this is something that'd never actually impact any user in the real world as your DAC shouldn't be outputting anything at those frequencies, and also no human can hear 200khz. And even if they could it was fairly low level.
Ferrum found the cause and fixed it in less than a day though so no issues.

https://goldensound.audio/2021/10/27/ferrum-oor-and-hypsos-measurements/

It's a loooovely amp

 

[Basco]

Serial numbers will not answer anything as units with earlier serials than the ones I have here that are affected have already been recalled and fixed.
But if you buy a unit, it will have the fixes. Even the ones that people had ordered before I'd even found these issues got recalled and fixed before being delivered.

There was a problem whereby the amplifier would go into overcurrent protection too early as the protection circuit was misreading something after a change in supplier for a component on the board. Though this occurred at about 4-5w output so it's incredibly unlikely that anyone would ever have actually noticed/found this anyway unless they were trying to blow up their headphones and make themselves go deaf. I only found it as I was testing the max power output of the amp with a dummy load whilst measuring. (Which btw actually exceeds Ferrum's stated spec and I was able to get 9.5w @ 32 ohm and 8.3w @ 50 ohm.)

And the second was that there was some odd behaviour with ultrasonic content (like, over 200khz, not at all anything close to the audible range) which showed up whilst doing some square wave and bandwidth testing.
But again this is something that'd never actually impact any user in the real world as your DAC shouldn't be outputting anything at those frequencies, and also no human can hear 200khz. And even if they could it was fairly low level.
Ferrum found the cause and fixed it in less than a day though so no issues.

https://goldensound.audio/2021/10/27/ferrum-oor-and-hypsos-measurements/

It's a loooovely amp

Wow, thanks for the indepth infos, that will help me to make my decision. Actually have you compared it or owned any other Amps comparable before? I'm between Violectric V280 and the OOR (for now as standalone without the HYPSOS) for I rather spend the money in a DAC (Denafrips Ares II maybe?!) first.

I prefer a warm and hamonic soundstage over ultra analytical neutral soundstage. I would drive my Denon 7200, Focal Elegia and Audioquest NightOwl with it. Maybe in Future a ZMF Verite Closed or Meze Liric with it.

 

[Jarmel]

Is there a way of controlling the output like if you wanted to use either the headphone out and the preamp stuff at different times but had both plugged in?

 

[sawindra]

I prefer a warm and hamonic soundstage over ultra analytical neutral soundstage. I would drive my Denon 7200, Focal Elegia and Audioquest NightOwl with it. Maybe in Future a ZMF Verite Closed or Meze Liric with it.

try the v280, it has swappable op-amps so you can get the sound you are looking for..get the Orange amps dual-opamps ..4 of them

 

[Menkau-ra]

https://goldensound.audio/2021/10/27/ferrum-oor-and-hypsos-measurements/

It's a loooovely amp

are you gonna have a video review on Oor?