[FishHead]

I can feel your pain.  If you go back a page 118 you can see I experienced the same problem.   I metered the bias while turning the pot and I think that got me started turning it the right direction.
Clockwise, Counter-clockwise...it is just all so confusing.  The meter knows best.  Two other bits of advice I received which may or may not help.  Have the volume turned all the way down and let the amp warm up a little.  I think I left mine on overnight w/ no inputs.
 
I just checked and Counter-clockwise is reducing the bias voltage on mine.    

 

[rayk]

Turns out ("snicker") I had o turn the trimmers counter clock wise. Got them around 13.5V, powersupply at 27V and DBs running at around 109mV.
 
Posted the finished build in the other thread - http://www.head-fi.org/forum/thread/85561/post-pics-of-your-builds/7320#post_6975938
 
Thank you for all the support Tom! And for making such a well put together kit

!

 

[tomb]

Quote:

Turns out ("snicker") I had o turn the trimmers counter clock wise. Got them around 13.5V, powersupply at 27V and DBs running at around 109mV.
 
Posted the finished build in the other thread - http://www.head-fi.org/forum/thread/85561/post-pics-of-your-builds/7320#post_6975938
 
Thank you for all the support Tom! And for making some a well put together kit

!

Yay!!  Way to go!

 

[BlingBlingDr]

I built one of these bad boys about a year ago and am in the market for a new pair of headphones.  Anyone match a pair of ATH-M50 headphones with a Minimax?  I have the Grado S80s, but the bass can be underwhelming. 
 
Update: Went ahead an bought 'em.  Couldn't help myself.  I will let your know my impressions in comparison to the S80s.
 
PS: When is Beezar gonna come out with another big project for me to sink my teeth/soldering iron into?

 

[jdkJake]

Quote:

I built one of these bad boys about a year ago and am in the market for a new pair of headphones.  Anyone match a pair of ATH-M50 headphones with a Minimax?  I have the Grado S80s, but the bass can be underwhelming. 
 
Update: Went ahead an bought 'em.  Couldn't help myself.  I will let your know my impressions in comparison to the S80s.
 
PS: When is Beezar gonna come out with another big project for me to sink my teeth/soldering iron into?

Build a MOSFET-MAX and those Grado's will sing! You will not ever complain for lack of bass.
 
 

 

[tomb]

Quote:

 
PS: When is Beezar gonna come out with another big project for me to sink my teeth/soldering iron into?

Beezar is working on a big project and has been for a several months.

  Those of you that venture to that other forum (head-c*se) or have been to CanJam may be familiar with it.  It's had some growing pains, but the potential is enormous.  I'm hopeful that Dsavitsk and Beezar will have something to announce eventually that should interest a lot of people.  It's definitely unique and has not been something that's done in DIY on a large scale or kit basis up till now.  Just remember the name, "Torpedo."

 

[jdkJake]

And TomB isn't talking about an IPA from Chico CA!

 

[BlingBlingDr]

I am considering using my Minimax as a pre-amp. What should I take into consideration when doing this? I have read about output and input impedance considerations, but don't know exactly what I should be looking at. When it is time to build another headphone amp, I might modify my Minimax with RCA outs for use as a pre-amp. For the time being, I am just thinking of using the headphone out. Any thoughts? Thanks.

 

[tomb]

Quote:

I am considering using my Minimax as a pre-amp. What should I take into consideration when doing this? I have read about output and input impedance considerations, but don't know exactly what I should be looking at. When it is time to build another headphone amp, I might modify my Minimax with RCA outs for use as a pre-amp. For the time being, I am just thinking of using the headphone out. Any thoughts? Thanks.

Just keep the gain low.  The concern is that you can overdrive the inputs to a power amp.  12FK6 tubes might help in that regard.  There are several of us that have used the MAX/MiniMAX as a preamp.  It does well as long as you're careful about that gain.
 

 

[tomb]

Well, I'm embarassed at how long this took (why I don't offer it very often), but we now have music from BobSaysHi's MiniMAX:
 
 
I'll be shipping it back to him tomorrow.  Meanwhile, the problem had to do with many resistors that were installed in the wrong places.  This has happened to new MiniMAX builders more than once.  I've since added some additional warning notes to the notes included with kits and also made notes on the resistor parts bags that they are not the same and the values must be checked before locating them on the PCB!
 
P.S. Much to my chagrin, I actually swapped locations on the CCS resistors while fixing this.  I should've made myself some notes!

 

[gspence2000]

TomB, what is that object on the right side of the photo?  It doesn't look like a MiniMAX--can you tell us a little about it?

 

[Beefy]

That is the Torpedo. Been mentioned a few times......

 

[BobSaysHi]

Quote:

Well, I'm embarassed at how long this took (why I don't offer it very often), but we now have music from BobSaysHi's MiniMAX:
 
 
I'll be shipping it back to him tomorrow.

 

[jdkJake]

BobSaysHi, you are a very fortunate individual.

TomB, nice shot of the torpedo. Based upon what I have been reading, that project is progressing nicely. A very interesting design for sure.

 

[tomb]

Quote:

BobSaysHi, you are a very fortunate individual.

TomB, nice shot of the torpedo. Based upon what I have been reading, that project is progressing nicely. A very interesting design for sure.

Yes - some early toothing pains, but it's consistently improving thanks to Dsavitsk's expertise and some really great prototype builders.  It's already suitably impressive and fixing to get better with the latest refinement, thanks to a suggestion from cetoole, of all people.