Hashimoto HL-20K-6 Line Output Transformers

[Osprey]

I made a simple headphone amp for my Sennheiser 580s using the Magnequest B7-15K transformer. I would think that any 15k:600 would work fine for these 'phones.

I like the combination enough to have spent many hours listening to them. I also have a couple of chip amps I use when traveling and I prefer the tube amp.

[korneluk]

[QUOTE]Originally posted by Osprey
[B]I made a simple headphone amp for my Sennheiser 580s using the Magnequest B7-15K transformer. I would think that any 15k:600 would work fine for these 'phones.

I like the combination enough to have spent many hours listening to them. I also have a couple of chip amps I use when traveling and I prefer the tube amp.

Original picture:

[JoshK]

I am going to use 801 with B7-10K and CCS load. That gives net gain of 6db. Pretty much perfect for line stage and was thinking probably enough for headphones too. Am I wrong?

[Osprey]

I am going to use 801 with B7-10K and CCS load. That gives net gain of 6db. Pretty much perfect for line stage and was thinking probably enough for headphones too. Am I wrong?

I think it would be fine, at least with the 300 ohm headphones like the Sennheiser. I have mine connected to the 600 ohm tap.

[nuhor68]

Hello,

One more question about HL-20K-6.

It has impedance ratio of 20000/600. Then turn ratio is sqrt(20000/600). Am I right?

Thank you.

[nuhor68]

Also, maybe somebody could please give me a reference (link) on how I can design and analyse SE OPT stage?

Many thanks.