[DennyL]

I'm a newbie here, and just bought a pair of AKG K501s.

I've seen very enthusiastic reports of the T-amp driving speakers, and was wondering how it compares with other headphone amps when driving headphones. I had a bit of a search in these forums but didin't find much of a discussion of this, apart from someone saying that a resistance is needed in parallel with the phones to match the impedance.

Is there anyone out there who has tried using a T-amp as a headphone amp and can compare it with more conventional headphone amps?

 

[cosmopragma]

The amps based on Tripath chips are speaker amps.Due to their technical design they are not suited for being used as headphone amps.
The usual headphone plugs, no matter if 1/4" or 1/8", do provide a combined ground for both channels.You'd fry a Tripath amp by combining grounds.You can't simply add a resistor network and a headphone jack like with some other speaker amps.You'd have to recable ordinary headphones to balanced operation with separated grounds, and in most cases this means disassembling the headphones and soldering the new cables directly to the drivers.
What you've read about the T-amp being used as a headphone amp was in combination to an AKG K1000, but this is a very special headphone originally meant to be driven by a speaker amp.The K1000 cable is already a four wire cable with separated grounds, terminated in a 4 pin XLR plug.

 

[DennyL]

Thank you for that very clear reply, Cosmopragma. That makes a lot of sense.

 

[firefox360]

Also don't forget the possible DC-offsets which can be hazardous to headphones. There was a thread recently about some guy who thinks his T-Amp fried his K1000's.

 

[DennyL]

Quote:

There was a thread recently about some guy who thinks his T-Amp fried his K1000's.

Can't a DC offset be dealt with by adding in-line capacitors?

 

[smeggy]

I fed a crossfeed circuit >2020 through a volume control >ASL headphone transformer with no apparent damage to anything. The Tripath seemed quite happy with the transformer and has suffered no damage and sounded great.

 

[cosmopragma]

Quote:

Originally Posted by smeggy I fed a crossfeed circuit >2020 through a volume control >ASL headphone transformer with no apparent damage to anything. The Tripath seemed quite happy with the transformer and has suffered no damage and sounded great.

I once did something very similar.
I've connected an unmodded Sonic T-amp and a modded Sonic T-amp to an ASL signature, and at first it seemed to work without problems.
Both amps were defunct within 30 hours of usage, and both have worked for > 200 hours before.
Might be coincidence, but I won't risk my current Tripath based amp, an $100 Audiodigit T-2020.The latter is my second best speaker amp and it drives my secondary speakers well.

 

[chadh]

If you're interested, you could contact Vinnie Rossi at Red Wine Audio ( http://www.redwineaudio.com ). He produced the Clari-T, a modified tripath amplifier. I know that he has offered some sort of modification that allowed standard headphones to be used with the Clari-T, and I don't believe that this involved modifying the headphone cables themselves. I don't know if the process that Vinnie undertook was simple or not - but I know it can be done (even though the tripath chips can't have the grounds of the two channels tied together).

Chad

 

[fjf]

If I understand this correctly, those tripath chips would allow good sounding-cheap balanced amplifiers for headphones. If this is technically possible, why there is no headphone t-amp available?. It would be a killer deal!.

 

[smeggy]

Using headphones is not impossible with Tripaths as the old Griffin Powerwave had headphone out.

 

[philodox]

You can use it with balanced headphones without problems. [as someone already mentioned with the K1000 reference]

We tried hooking up some balanced jacks to the speaker outs of my t-amp to drive my K340's last weekend. It definately has enough power to push them, but the sound quality was less than perfect.

 

[kramer5150]

Quote:

Originally Posted by DennyL Can't a DC offset be dealt with by adding in-line capacitors?

I think the amp has DC filtering already, its just that its not effective at high impedence loads. At least that's my understanding. So, using it as a headphone amp is a risk, but no more risky than using any other amp that does not filter its output for DC, IMHO.

Garrett