[tomb]

 

   
The OP seems not to be interested in building a kit. So, he would have to build from a schematic. Hence my questions. 
 
A schematic will tell him what parts to use, in general. But, not the layout of the components in the circuit or the location of those parts on a chassis.
 
On anything other then a complete kit with detailed instructions including layout, some design will still be necessary.

 


The AMB amps aren't kits by any stretch but are very, very well supported.

 
 

 

  Why not this one: http://headwize.com/?page_id=427

I built that one years ago.  Good friend of mine built another at the same time.  I'm sure others had great success but It turned me off to OTL.  It sounded really good when I luckily acquired a very rare Telefunkin 6080 but it did not have a lotta life in it and I eventually had some issues with the tube.  All the old american 6080's, and I had a box at my disposal, sounded fine but not as natural/easy/detailed.  The output caps are also an issue - could not live with 'lytics, tried oil, then did a combo oil/film/silver mica and started to enjoy it.  
After that I built a simple transformer coupled amp, probably just luck, but it sounded rediculously good - end of story since.

 
Yep.  Transformer-coupled amps are much more transparent than any electrolytic.
 

 

   
The OP seems not to be interested in building a kit. So, he would have to build from a schematic. Hence my questions. 
 
A schematic will tell him what parts to use, in general. But, not the layout of the components in the circuit or the location of those parts on a chassis.
 
On anything other then a complete kit with detailed instructions including layout, some design will still be necessary.

 


The AMB amps aren't kits by any stretch but are very, very well supported.

 
??? AMB doesn't do tubes.

 

[audioboozer]

The HD650s maximum long lasting input power is 500mW. To reach that output (of 500mW), your amplifier needed to deliver 35 Vpp (peak to peak voltage) to HD650! That means you needed an amplifier with at least ±18V working voltage (or a single DC voltage above 36V). 

 

[Maverickmonk]

   
 
 
Yep.  Transformer-coupled amps are much more transparent than any electrolytic.
 
 
??? AMB doesn't do tubes.

Woops I had sworn they had a hybrid, my mistake

 

[tomb]

 

   
 
 
Yep.  Transformer-coupled amps are much more transparent than any electrolytic.
 
 
??? AMB doesn't do tubes.

Woops I had sworn they had a hybrid, my mistake

 
Well, Ti built a revMH Millett Hybrid* at one time and it's still on his ibiblio pages:
http://www.ibiblio.org/tkan/audio/millett.html .  However, that was back before he started designing any of his own headphone amps. 

 
* Drew Dunn/Nate Maher PCB mod (revMH Millett Hybrid) of Pete Millett's original design in AudioXpress magazine (Build a Low-Voltage Tube Hybrid Headphone/Line Amp).

 

[DutchGFX]

If you want a kit, albeit a little pricey, the bottlehead crack is pretty easy to make. It won't teach you much, though, since it's designed for people who know nothing. It walks you through each step.

 

[audioboozer]

This circuit (shows one channel only) comes from many comprehensive tests. The input stage has a triode single-ended structure with constant current load, which provides good linearity and enough amplification gain. The constant current source is formed by a low noise, 1.7V red LED and Q5 transistor. A blue LED is series connected in order to light up the bottom of the tube. The output of this single-end stage is directly coupled to the Q6 transistor base, an emitter follower stage, then directly connected to the PowerMOS Q2. This provides enough driving capability to headphones. By using direct coupling, we not only reduced our cost, but also eliminate quality issues (for example: leakage current, ESL, ESR, etc.) from coupling capacitors.

 

[chuckwheat]

Ok in learning a little more about amps, I've decided to not embark on this adventure until i'm many years into this hobby and know exactly what i'm doing.
Thanks everyone for the advice and knowledges... (that's a word now)

 

[audioboozer]

As other people suggestion, it is always not a bad idea to start with a kit set. 
What is your budget?