[Willakan]

Please note there is a problem with some boards with the outside of the gain switch shorting to the feed-through via near R21. Just heat up the pin nearest the right (looking from battery side of board) side of the gain switch and move it up a bit, bending in the bit on the bottom that touches the via. Or snip/bend it if you haven't solder the switch in yet.

 

[cheapskateaudio]

 
Quote:

This sounds like 'bad amp karma"  :=)
 
After all, you have done everything to this amp that Voldemort said was unnecessary  to do. Indeed, he designed the amp to demonstrate that all your mods are a waste of time and money.
 
It has been entertaining though, and we thank you for that :=)

Did you build this amp? 
 
Do you think I immediately wanted to mod this amp because of how rich and fantastic the sound was? 
 
Oh yeah at first I bought into the hype, ohhh, it's my source, it's my harsh digital recordings. Look, my harsh digital recordings still have BASS, and MIDRANGE.... lol. They may be harsh but I know that bass and midrange should be there, and they just weren't there. Maybe it sounds great with a $10,000 source, I have no idea, I don't and won't own such a thing. If the concept here is that you make a cheap amp that only sounds good with insane source material, well, someone needs an economics lesson.
 
That being said, it sounded pretty good for a bit, I can say that I was basically happy with the sound I was getting at one point, after the mods.  
 
 
 
 
 
 
 

 

[tomjtx]

Quote:

 


Did you build this amp? 
 
Do you think I immediately wanted to mod this amp because of how rich and fantastic the sound was? 
 
Oh yeah at first I bought into the hype, ohhh, it's my source, it's my harsh digital recordings. Look, my harsh digital recordings still have BASS, and MIDRANGE.... lol. They may be harsh but I know that bass and midrange should be there, and they just weren't there. Maybe it sounds great with a $10,000 source, I have no idea, I don't and won't own such a thing. If the concept here is that you make a cheap amp that only sounds good with insane source material, well, someone needs an economics lesson.
 
That being said, it sounded pretty good for a bit, I can say that I was basically happy with the sound I was getting at one point, after the mods. 
 
 
Perhaps you should take a properly administered DBT under Voldemort's guidelines in his 500.00 challenge.
 
Properly administered is the key here. There is no doubt you haven't done that. Go to hydrogen audio to learn about that.
 
Please understand I don't begrudge the fun you are having. You are certainly entertaining me
 
 
 
 

 

 

[cheapskateaudio]

 
Quote:

Please note there is a problem with some boards with the outside of the gain switch shorting to the feed-through via near R21. Just heat up the pin nearest the right (looking from battery side of board) side of the gain switch and move it up a bit, bending in the bit on the bottom that touches the via. Or snip/bend it if you haven't solder the switch in yet.

I think I fixed and it was just a dirty board, I guess dirt and gunk are fairly conductive? 

 

[cheapskateaudio]

Quote:

Perhaps you should take a properly administered DBT under Voldemort's guidelines in his 500.00 challenge.

Properly administered is the key here. There is no doubt you haven't done that. Go to hydrogen audio to learn about that.

Please understand I don't begrudge the fun you are having. You are certainly entertaining me tomjtx /img/forum/go_quote.gif
 

Well stay entertained bud, I'm glad your happy. Here's the problem with that challenge, it's neat and all but you know, you kind of have to put $500 down also... It's not like he's just taking all challengers with $500 on the line. 
 

 

[cheapskateaudio]

 
Quote:

How about soldering thinner leads onto the thicker ones so you cant still mount through-hole!

To fix the channel issue I took the caps I had surface mounted off, cleaned the board in that area thoroughly, then put some thin leads through as suggested, worked well, sounds good so far.
 
 
Ok, I replaced the mosfets with I dunno, mosfets that looked "better", and the channel imbalance is still there, slightly, I think?? It sounds ok now though, I think it's possible a mosfet got zapped. Unfortunately we'll never know because I just used different mosfets with higher specs... At this point I trust nothing, someone give me a scope!
 
For the mosfets I used: FQPF10N20C & FQPF15P12
 
I also reseated all the op amps, everything seems good now in terms of channel balance, I *think* they're balanced, it's hard to tell after all this back and forth, I'm nearly 100% sure though.
 
 
 
 

 

[WhDemon]

Why was the other thread locked ?

 

[cheapskateaudio]

Quote:

Why was the other thread locked ?

Hey man, try a different op amp where the 2093 is, it'll probably get rid of the click, I had good results with OPA2134. You may need to order another voltage comparator.
 
4556 in the output stage is still defacto standard for this electricity amplification machine.

 

[jacobthellamer]

Parts for two - one desktop and one portable - just waiting on my boards
 

 

[LizardKing1]

Quote:

Parts for two - one desktop and one portable - just waiting on my boards
 
 

Are you going to make any alterations (1/4 jacks, anything)? I considered making 2x O2 as well and was interested in hearing what other people think there should be as differences.

 

[estreeter]

I guess its easy to sit back and wait for hundreds of impressions without having to pick up a soldering iron, but I'm surprised that so many builds are still waiting for boards (or inspiration ?). Anyone ?

 

[Paul Blythe]

Built my desktop version two weeks ago

 
As it was a 1000 piece GB over on diyAudio, you'd have thought impressions would've been coming in thick & fast by now. Read more about O2 build problems than listening impressions so far.

 

[jacobthellamer]

 
Quote:

Are you going to make any alterations (1/4 jacks, anything)? I considered making 2x O2 as well and was interested in hearing what other people think there should be as differences.

 
 Yeah I am going to use 1/4 jacks, RCA input, off board switches and a nice alps potentiometer for the desktop version. I will be running the desktop build off a toroid too

 

[mikeaj]

Mine's been done for a while.  I get the feeling that many builders just don't feel the need to post impressions since it has been documented so much already and given a few reviews before the large group buy was even finished.
 
If you want them...impressions:  it works well.  I'm not sure about sound quality, but I certainly don't hear anything wrong (including noise).  The end.

 

[estreeter]

Thanks for the feedback guys - I'm perfectly happy with 'it works well'. We have enough amps that 'make the magic smoke come out of your headphones' on Head-Fi .....