TSE headphone amp

[MrJackson]

Hey guys and gals,

After having great success (albeit with a lot of work) with the 6SN7 Aikido kit from Glassware, I want to try my luck with a new tube project. This time, I want a "purist" SE headphone amp. After reading a lot on the Tubelab site, I decided 01A tubes would work fine for me. Also, I'm thinking 5AR4 rectifier.

I would have it work with some regular Audio Technica 32ohm cans and, maybe sometime in the future, a pair of HifiMan or Audeze LCD-2s. For these, I'm not sure I would actually need a separate tap on the OT - advice would be welcomed.

Right now, I'm trying to make a sort of project plan and put together a BOM. I was eyeing a Hammond 369AX (B+ and filament) and an 266M5 (rectifier filament).

As for the OT, I'm considering Electra-Print (going all out)... 5K:32, maybe silver wire.

I'd appreciate your advice/opinions on this plan, before I shell out the cash on something that won't work in my setup.

Cheers,
C

 

[MrJackson]

So... no-one?

 

[randytsuch]

Electra print makes nice iron, but shipping from US would probably be expensive.
If I was in Romania, I'd consider guys like Lundahl or Sowter. And I'm sure there are others in the EU that can wind good iron for your application.

For this project, I'd just keep in mind the impedance and sensitivity for any cans you might use with this amp. Hifiman cans tend to be less sensitive, so need more power to drive them.

In general, no reason you can't use a TSE to drive cans with the right iron.

 

[MrJackson]

Hey Randy,

Thanks for chiming in. I'll have a look at what options Lundahl and Sowter offer - I'm not keen on ElectraPrint, but reading about on tubelab made it stick in my head.

Still, I can't decide if I should get multiple taps on the OT. Should I get 32 and 64ohms? Or try to use the 32 for Audeze's LCDs and try to get a higher impedance tap for other cans? I would think that multiple taps will drive the price up considerably, but at the same time I'd try to future-proof it as much as possible... I can't say what cans I'll get in the future.

 

[moggi1964]

James do multiple taps on some of their range. Pretty too! Don't think they go to 32 ohm but I haven't checked.

 

[MrJackson]

Pretty indeed... but I just read they stopped doing business.

 

[randytsuch]

Hey Randy,

Thanks for chiming in. I'll have a look at what options Lundahl and Sowter offer - I'm not keen on ElectraPrint, but reading about on tubelab made it stick in my head.

Still, I can't decide if I should get multiple taps on the OT. Should I get 32 and 64ohms? Or try to use the 32 for Audeze's LCDs and try to get a higher impedance tap for other cans? I would think that multiple taps will drive the price up considerably, but at the same time I'd try to future-proof it as much as possible... I can't say what cans I'll get in the future.

Yeah, that is what makes it hard. If you want to try Senns later, they have much higher impedance.

multiple secondaries

Per the link above (from a really smart transformer guy), making a transformer with multiple secondaries may be the key here.

I remember a post somewhere where for cans someone recommended 3 or 4 eight ohm taps, I think its three.
Then you connect them depending on the output impedance you need.

Randy

 

[MrJackson]

That was a very informative link. It's obvious now that the best solution would be to have a multi-tap OT, but choosing the values is a very difficult problem.

I now wonder if going with "classic" tubes (300B or 45) together with an 8ohm OT, while adapting it for headphones (8ohm load resistor + pot) would work sufficiently well for this. It would make for a simpler build that's for sure...