Hi,
I have come around to same conclusions here. It's very unlikely that anyone pursuing the ultimate DHT HP amp, would compromise on iron. If on tight budget, this is likely not the project to pursue. A choice of valve on cost isn't going to move the needle on your budget. The OT will do. I would go for a Sowter, Lundahl or custom OT. Choice would be based on the valve of course and most of the ones mentioned are great choices. 801a/10Y/VT-25, 45/46, 2P29L, etc. The thoriated tungsten filament has a unique level of detail and timbre that would be my preferred choice these days. That's what am using.
Either way, as said multiple times before, the focus should be on the LT supply and the filament regulators (e.g. Coleman) where In my experience it makes most of the sonic impact after the right selection of OT.
If really on budget and/or struggle to find the right OT, you can build a hybrid mu-follower stage (a.k.a. gyrator load) and spend some dollars on the coupling output capacitor to drive your headphones (at least 300R ones).
Happy holidays.
Ale
Thanks for the tips.
Theres probably room for two DHT headphone design options here. One a no compromise all out effort and the other a value for dollar design.
It's 26 filament bias. https://www.diyaudio.com/community/threads/26-pre-amp.151421/post-1920445
Rod Coleman heaters regs.
Ale Moglia hybrid Mu-follower
Rod Coleman heaters regs.
Ale Moglia hybrid Mu-follower
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Ancient 210/10 always has TT filament.
10Y (improved version of 10)/VT-25 theoretically has TT filament (all of my Sylvania 10Y/VT25 tube has)... but some manufacturer made oxide coated filament with 10Y sign.
VT25A (larger anode, larger dissipation) always has oxidized filament.
Ask seller about it.
10Y (improved version of 10)/VT-25 theoretically has TT filament (all of my Sylvania 10Y/VT25 tube has)... but some manufacturer made oxide coated filament with 10Y sign.
VT25A (larger anode, larger dissipation) always has oxidized filament.
Ask seller about it.
https://www.die-wuestens.de/r3.htm
Possible (99%) this 10Y has TT filament, ... but as webpage says: Ask Jan First. 🙂
Ask Jan Phillip for filament type.... and for price too.
https://www.die-wuestens.de/contact.htm
Possible (99%) this 10Y has TT filament, ... but as webpage says: Ask Jan First. 🙂
Ask Jan Phillip for filament type.... and for price too.
https://www.die-wuestens.de/contact.htm
This is my current all DHT headphone project, just a spud 46 loaded with iron from all directions, overbuilt PSU.
First time using LCL instead of coleman's, much more of a hassle but at least I don't have to deal with heatsinks.
Filament PSU, just a simple dual mono LC with switches for both LV and HV. It has a female IEC connector at the back feeding the main chassis.
First time using LCL instead of coleman's, much more of a hassle but at least I don't have to deal with heatsinks.
Filament PSU, just a simple dual mono LC with switches for both LV and HV. It has a female IEC connector at the back feeding the main chassis.
Or that juicy H2 distorsion, whatever the case I just go where my heart tells me to, soon to be back problems.
Hello Ale,
just finding this post of yours, I read in your blog you were using a 45 HP amp, but it doesn't come a schematic or a blog post for us diy builder... Would you please share your design?
Thanks!
edit: looked that you're stressing the 2P29L as a valid alternative. I'll gather some info on this. I use mainly 64R headphones, think the 32R Sowter OT should't have any problems there... Or look for an alternative...
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