Low impedance headphone amp

[goldenbeer]

Is there a build page for this one?

No build page, but a schematic.

Output power will be 27mW or 1.85Vpp into 16 ohms at 0.65% THD. Zout will be 3.4 ohms for a damping factor of ~5. Don't know if that will suffice for your cans or listening habits.

 

[Shoog]

This will do what you want and sounds rather good. However it is quite expensive in parts and is definitely overkill. If you chose an appropriate OT it would make a nice little power amp as well.

Shoog

 

[mdenacart]

Wow, information overload. Now I have a decision to make.

 

[mdenacart]

This will do what you want and sounds rather good. However it is quite expensive in parts and is definitely overkill. If you chose an appropriate OT it would make a nice little power amp as well.

Shoog

What would you think the cost would be? Do you have a parts list?

I am having a hard time understanding your schematic. I don't see watt and voltage ratings on a lot of the components.

 

[mdenacart]

I'd avoid the OTL with 16ohms.

I'd make something similar to the Bottlehead crack (or buy the kit), which means a 12au7 gain stage, a 6as7 ouput cathode follower. Then a pair of hammond 119DA at the output.

The output transformer will ensure you don't have too much gain and kill noise nicely.

Is there a schematic or build page? Thanks.

 

[famousmockingbird]

I see you have been looking into tube headphone amps as well.

I got rid of my Sennheiser HD 449's for some AKG K240 studios and I like them a lot so far.

Anyway I have a OP2134 amp that I built that sounds ok but currently I have been breadboarding something similar to the Starving Student amp with good results, but I am not finished.

I still plan to mock up something with bottles in the finals using the line transformers I have on hand, I am just worried about bandwidth.

I recently came across these: http://www.mouser.com/ds/2/405/snas422e-316847.pdf and would like to know if anybody has paired it with a tube common cathode gain stage? I am thinking use a 6SN7 for some gain in front of the buffer to drive some headphones, the datasheet for the lme49600 looks pretty impressive to me.

 

[Shoog]

What would you think the cost would be? Do you have a parts list?

I am having a hard time understanding your schematic. I don't see watt and voltage ratings on a lot of the components.

Your probably looking at about $200 for a build.
There are no particularly demanding components apart from the output cathode resistors which need to be about 3W. However if you don't feel confident don't build it.

Shoog

 

[jackinnj]

Senn 449's are 32 ohms -- these can be driven with the Marsh Headphone amp quite readily. (I love my Senn 650's).

You can use a smallish power transformer for a tube headphone amplifier --

BUF634 is preferred to the LME49600 by many "in the know".

The "starving student" caused the supply of 19J6's to disappear. I built a similar amp with 20EZ7.

 

[mdenacart]

Senn 449's are 32 ohms -- these can be driven with the Marsh Headphone amp quite readily. (I love my Senn 650's).

You can use a smallish power transformer for a tube headphone amplifier --

BUF634 is preferred to the LME49600 by many "in the know".

The "starving student" caused the supply of 19J6's to disappear. I built a similar amp with 20EZ7.

Thanks for the suggestion but it looks like it is all solid state. I wanted to build a tube one.

 

[famousmockingbird]

BUF634 is preferred to the LME49600 by many "in the know"

I just looked at the price at mouser and they are $9 each😱


At that price I might just spring for some small output transformers.

I have been doing lots of reading and it seems that what ruffrecords has been trying to tell us, that a high dampening factor is unnecessary with headphones is true. There are still the problems of voltage divider effect so lots of gain is needed, also if the cans do not have a flat FR then the sound can be colored.

It is so hard to nail down a topology, I still want all tubes, so back to the drawing board. I plan to try and wire up the line transformers this weekend so I will report back with my findings.