So how hot is too hot with respect to the heatsink?  After about an hour the heatsink is so hot that I can only touch it for about 1 second before I need to take my hand away...  is this normal?    

Quote: Interesting -  Thanks for the response!  

Amp #2 - need help on this one too (unfortunately I'm just not getting a break on these things...)   So I actually built 2 of these amps as Christmas presents...  The first one featured earlier is for the lovely Mrs Capernicus.  Number two is for the bro-in-law.  I had my father in law build...

That was it!  Thanks!  The cap and resistor tying the cathode to ground are twisted together and connected to a wire that went over to ground which turned out to be in the correct place but not soldered in...   Now I am enjoying the music - sounds terrific!  I look forward to putting it side...

Quote: OK so I've double checked that R10 is properly connected at both ends and reflowed the solder - no change.  Nothing happens when swapping tubes.  headphone jack is wired properly.  Replaced the MOSFET - till no change.  Both tubes glow nicely and voltages at the tube heaters...

that was an interesting dirt road... glad we have that issue resolved...

yes, i believe your e-bay link should work... you are correct, this should be an inexpensive purchase...   For comparison sake I purchased this one from Mouser: Link  I paid $1.65 US.  I have to think you should be able to get something like this for about the same cost in Australia.  

just studying the internal picture I see that I do have C8 installed backwards - I wonder if this could be contributing to my problem...    

  Ok, so I have this thing mostly complete.  Its Purple Heart and Maple in a 12AU7 build     Unfortunately, as I mentioned in my previous posts I can't seem to get the Right side working correctly...   I took a picture of the internal bird nest below - I'm the first to admit I...

I replaced the right MOSFET but not change in the observables.   I can't figure out why pin 1 / 6 voltages would be so different between L and R.  I measured the resistances of R1 and R7 and both are reading 33k.  Could my problem be a short in C2? - unfortunately I don't have any spares of...

  Ok y'all, I need a little troubleshooting assistance!!!   Left channel works gerat, right channel seems to only get some kind of cross talk - signal comes through but you have to crank it way up - the left channel is ear bleeding just to get audible sound out of right channel.  I don't...

Been busy getting this ready for my build - going to try something a little different - purple heart and maple.     So far I've laminated and rough cut the block as well as hogged out the inside.  Still had a lot of woodwork to do...   This one will be a 12AU7 build - wish me luck!  

The Beyers are very different from the D2000s - great detail but much less low end (although I personally would prefer them to the D2000s).  Which aspect of the D2000s makes you interested in them?  If its low impedance I would recommend anything Grado over the D2000, if it is a closed phone - I...

Update: just bought the HD650s to replace the D2000s I sent back.  HUGE improvement!!!  The detail is fantastic, sound stage is incredible, highs are crisp and detailed but not harsh, and the midrange is hugely improved over the D2000s, and the lows are very pleasant - slightly less punchy than...

I'll jump in on this one - looks like fun!   Fortunately there is a wide range of headphone brands and models out there allowing us the opportunity to find the best phone for our own taste and price range.   I have owned both the D2000s and HD650s.  I bought the D2000s as an upgrade from...