Sanity check needed for an amp build

[sbelyo]

Hi All...

I was cleaning up and found a pair of Electraprint OPT that I had wound for headphone impedance. I've attached the values.  I got these for a build of tubelab's TSE that has now changed to a TSE II.  My plan was to use 45 tubes for the output, that would give me 1-2 watts.  The headphones I use are HE-560 and HE-6 SE.  I have HD-650 and Beyer DT-770 (250 Ohm) as well.  My thinking was to start with the 32 ohm tap and connect them directly to the headphones.  I don't want to fry the headphones or blow my ear drum if something goes wrong so I'm looking for a sanity check.  Should I build it for headphones and use these OPT's or abandon them and get a new set for speakers?

[RonH10]

Hi Sbelyo. I have a Bottlehead S.E.X. with switches for output impedance. My HE-560 and HE-6SE V2 sound best off it at the 4 ohm output impedance setting. It's rated at 2 watts per channel. At higher impedance settings they sound muffled. Your other 2 cans may sound great out of your pair of transformers.

[simmconn]

For the same phone, the lower the secondary winding impedance tap you connect to, the lower the output and the lower the distortion (assuming class A SE output stage). The max power transfer happens when you have a matched impedance. It’s not recommended to connect to a tap that has higher impedance than the load.

[sbelyo]

On 4/7/2022 at 1:47 PM, RonH10 said:

Hi Sbelyo. I have a Bottlehead S.E.X. with switches for output impedance. My HE-560 and HE-6SE V2 sound best off it at the 4 ohm output impedance setting. It's rated at 2 watts per channel. At higher impedance settings they sound muffled. Your other 2 cans may sound great out of your pair of transformers.

I have that very amp and use the same settings as well.  I definitely don't want to let these go to waste

 

On 4/7/2022 at 2:20 PM, simmconn said:

For the same phone, the lower the secondary winding impedance tap you connect to, the lower the output and the lower the distortion (assuming class A SE output stage). The max power transfer happens when you have a matched impedance. It’s not recommended to connect to a tap that has higher impedance than the load.

I did some research and talked to some people that have built this amp for headphones.  The 32 ohm and 120 ohm are the taps I'm going to use.  From all accounts I should be good with that.