Hi,
I got an ifi micro idsd pre-/headphone amp paired with some AKG 550 headphones (32 ohms impedance). I want to built my own DIY tube headphone amp to add the special tube sound to it and well just for being able to make my own mods. any suggestions when it comes to some good kit or schematics which would improve the soundstage maybe a little and be point to point wiring (important)?
Thanks
I got an ifi micro idsd pre-/headphone amp paired with some AKG 550 headphones (32 ohms impedance). I want to built my own DIY tube headphone amp to add the special tube sound to it and well just for being able to make my own mods. any suggestions when it comes to some good kit or schematics which would improve the soundstage maybe a little and be point to point wiring (important)?
Thanks
You are going to need O/P transformers with those 32 Ω headphones, to use tubes. "Iron" is expensive.
Do the "cans" sound nice now? It's quite possible you are better off not using tubes.
Can you post a schematic of the equipment currently in use?
Do the "cans" sound nice now? It's quite possible you are better off not using tubes.
Can you post a schematic of the equipment currently in use?
Adding one valve is unlikely to get you the valve sound.
You really need a complete valve amplifier for that.
You could use a valve stage with a transistor buffer.
Otherwise it means a output transformer.
You really need a complete valve amplifier for that.
You could use a valve stage with a transistor buffer.
Otherwise it means a output transformer.
Plenty of designs out there use tubes and can drive 32 ohm headphones. The Morgan Jones Mini Tube Headphone Amplifier | HeadWize
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I read that despite the low impedance (32 ohms) the AKG 550s work lovely with the Bottlehead crack kit which is also designed primarily for higher impedance cans.
So my headphone preamp is able to deliver 950mW at 32 ohms and sounds good, but sometimes a little harsh which is why i want the supposedly warmer tube sound.
Input -> Ifi Micro iDSD (DAC and preamp) -> AKG 550 headphones
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I dont really see the complications? I mean the source (e.g. CD Player) gets amplified by a solid stage preamp and is then basically just a little loude. If you then were to add another tube amp (which wouldn't need a lot of power since the SS preamp already increased the volume) wouldnt the sound just change by running through the tube stage (amp) now ?
Yes it will definitely affect the sound. Chances are your source audio will have solid state somewhere down the line. Unless of course you are listening to a recording made on a medium when the studio was all tubes.
You don't need expensive transformers either. They only need to be rated for a watt or two. Heck you can get by with ungapped transformers if you keep the current low. Here's another transformerless design
6AS7 Headphone Amplifier
Do you by chance have an idea where I could find a DIY project (schematics) for that (valve stage with transistor buffer)? Thanks
contact Hartung amps ( doynoff@gmail.com )
His name is Plamen, very nice guy, he will sell you a ready made, or a kit.
He designs and makes OTL amps, for headphones too.
You may need to use some higher quality signal caps, for ultimate sound, but otherwise his amps are very good.
Hartung-Contact Us
His name is Plamen, very nice guy, he will sell you a ready made, or a kit.
He designs and makes OTL amps, for headphones too.
You may need to use some higher quality signal caps, for ultimate sound, but otherwise his amps are very good.
Hartung-Contact Us
it is possible to make a SS circuit that simulates a transformer - its even possible to violate energy conservation with the circuit
so you could reflect the scaled headphone load to the tube circuit with more general "impedance transformation"
this could be interesting if your theory of "tube goodness" involves this sort of load impedance interaction with the tube's operating curves
some of us are pretty sure that we can make op amp circuits that are pretty transparent for audio frequencies - its practically a slam dunk if your headphone's Z, sensitivity fits a CFA DSL driver op amp's output capabilities - several Watts into 32 Ohms
so you could reflect the scaled headphone load to the tube circuit with more general "impedance transformation"
this could be interesting if your theory of "tube goodness" involves this sort of load impedance interaction with the tube's operating curves
some of us are pretty sure that we can make op amp circuits that are pretty transparent for audio frequencies - its practically a slam dunk if your headphone's Z, sensitivity fits a CFA DSL driver op amp's output capabilities - several Watts into 32 Ohms
Define tubeamp sound.
I have ss headamp which sounds like my se300b amp or sounds my se300b amp like my ss headamp.
I have ss headamp which sounds like my se300b amp or sounds my se300b amp like my ss headamp.
Well I have gone OTL, and I have not looked back!
Why should anyone want to simulate a transformer sound anyway?
Is that what you think tube-sound is all about? shortcomings of it'd individual components added together
now you want to artificially create them ?
WTF!
Why should anyone want to simulate a transformer sound anyway?
Is that what you think tube-sound is all about? shortcomings of it'd individual components added together
now you want to artificially create them ?
WTF!
Thanks for the suggestion 🙂 How come that one needs a heater+heatsink though ? thats the first time I've ever seen that on a tube amp.
Yep.
The heatsink is needed because that design uses a linear regulator on the heater supply. The B+ also looks regulated but its not a requirement. I personally wouldn't even bother as the current draw never changes.
For 32 ohm headphones, avoid any amp using 6AS7G, or the Morgan Jones. That's just too low a load for a cathode follower to drive without distorting too much (then again, some people call distortion "the tube sound"...)
If you want good quality, you are limited to transformer output.
A solid-state buffer (LME49600, for example) after a tube stage also works, but that's no longer a tube amp, but a hybrid.
BTW, a capacitor coupled OTL will never ever sound as good as a transformer loaded triode (yes, I have built and compared many headphone amps).
If you want good quality, you are limited to transformer output.
A solid-state buffer (LME49600, for example) after a tube stage also works, but that's no longer a tube amp, but a hybrid.
BTW, a capacitor coupled OTL will never ever sound as good as a transformer loaded triode (yes, I have built and compared many headphone amps).
Since you are in the US, you can get parafeed transformers for headphones from Edcor for peanuts. And they sound very decent.
I'd avoid otl amps with 32r headphones.
I'd avoid otl amps with 32r headphones.
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Maybe just to start with try making a simple tube buffer and connect it in front of the ifi to see if it does anything desirable with the sound. I'm sure there are circuit suggestions available with a bit of internet search.
A 6DJ8, 12AU7, 6N23P - all can be run at quite low voltages (e.g. 24V) so you can mess about in safety.
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