[wuwhere]

Your amp could invert phase. So just swap the left and right output to your headphone and listen if there is a change, listening to the same binaural recording. Make sure the amp is off when you do this.

 

[khaine1711]

Quote:

Your amp could invert phase. So just swap the left and right output to your headphone and listen if there is a change, listening to the same binaural recording. Make sure the amp is off when you do this.

Just the man I want to ask!
 
Have you tried/Is it safe putting 5751 and/or 12at7/12au7 in place of the 12ax7 input tube on your Copland?

 

[wuwhere]

Quote:

Just the man I want to ask!
 
Have you tried/Is it safe putting 5751 and/or 12at7/12au7 in place of the 12ax7 input tube on your Copland?

 
When I bought mine, the guy I bought it from was using Raytheon 12AU7. This tube has a lower gain than the 12AX7 and therefore has a lower noise compared to the 12AX7.
 
I also asked Tosh Goka, he is from Divergent Technologies, the importer of Copland in Canada. His reply was "[size=11pt]You are simply overdriving the 12AU7 with voltage  intended for the higher gain 12AX 7."[/size]
 
I'm now using Mullards 12AX7A, this tube supposedly has a lower noise than the regular 12AX7. From what I can hear, the Raytheon 12AU7 has a slightly lower noise than the Mullard 12AX7A.
 
The Mullards are neat, they all flash brightly when I first turn on the amp. I believe that this is also one way to tell that they are real. There are fake Mullards in the wild.

 

[khaine1711]

Quote:

 
When I bought mine, the guy I bought it from was using Raytheon 12AU7. This tube has a lower gain than the 12AX7 and therefore has a lower noise compared to the 12AX7.
 
I also asked Tosh Goka, he is from Divergent Technologies, the importer of Copland in Canada. His reply was "[size=11pt]You are simply overdriving the 12AU7 with voltage  intended for the higher gain 12AX 7."[/size]
 
I'm now using Mullards 12AX7A, this tube supposedly has a lower noise than the regular 12AX7. From what I can hear, the Raytheon 12AU7 has a slightly lower noise than the Mullard 12AX7A.
 
The Mullards are neat, they all flash brightly when I first turn on the amp. I believe that this is also one way to tell that they are real. There are fake Mullards in the wild.

Does overdriving mean bad then? Can we just lower the bias - I know the Cta 505 bias for the input tube is 114.2V
 
I'm always wondering about the 12ax7 family. Some say if the amp is designed for 12ax7, you can just drop whatever tube with lower gain without any hazardous (electrical) consequences.Others say 12ax7 and 5751 are direct replacement; but you can only roll 12ay7 and 12at7, but not the 12au7 in place of the 12ax7.

 

[wuwhere]

Quote:

Does overdriving mean bad then? Can we just lower the bias - I know the Cta 505 bias for the input tube is 114.2V
 
I'm always wondering about the 12ax7 family. Some say if the amp is designed for 12ax7, you can just drop whatever tube with lower gain without any hazardous (electrical) consequences.Others say 12ax7 and 5751 are direct replacement; but you can only roll 12ay7 and 12at7, but not the 12au7 in place of the 12ax7.

 
Like shorten the life of the 12AU7? Don't know.
 
I believe that it depends on the amp. You can ask Tash ([size=10.0pt]divergent@divertech.com). He answered my questions about my 504.[/size]

 

[vaed]

Quote:

 
Edit: nvm didn't see the both reversed part
 
Online test here http://www.audiocheck.net/audiotests_polaritycheck.php

Whoa. Okay. Out-of-phase is DEFINITELY more coherent than the inphase. 
 
Says to flip one of the wires, but there are four of them! Ahhhhhh

 

[khaine1711]

Quote:

Whoa. Okay. Out-of-phase is DEFINITELY more coherent than the inphase. 
 
Says to flip one of the wires, but there are four of them! Ahhhhhh

Like I said, find a multimeter and mark the correct wire once and for all 

 

[vaed]

Quote:

Like I said, find a multimeter and mark the correct wire once and for all 

I live in a college house, chances are the only "tools" we have are various contraptions for opening beers... 
 
I don't suppose I could switch them myself until it sounds right, can I?
 
EDIT: Blah, I'll just go on campus tomorrow and "borrow" one of the mechanical engineering multimeters... they'll understand...
 
EDIT2: My Mechanical Engineering housemate had a multimeter, so I borrowed his! I FOUND that damn culprit, and now everything sounds right! WOOT! Alright, back to listening. I'll see you all in a year.

 

[Happy Camper]

More amplification or changing dacs shouldn't make a difference there. 

My first thought: are you sure one of the channel polarities isn't switched?

Good call.

 

[Armaegis]

Yup. Just gonna pat myself on the back for that one.

 

[vaed]

Quote:

Yup. Just gonna pat myself on the back for that one.

You should! Thank you for the help, as well as khaine and wuwhere!

 

[vaed]

So an update for those who are interested: came home for the weekend for a job interview, and my Dad presented me with one of the toys.
 
A Dayton Audio DTA-100a amplifier. Anyone have any experience with these? It's a T-amp, and I believe I remember seeing these amps mentioned in this thread or the HE-6 Amplifier thread.
 
EDIT: Heh, scanning the amp on head-fi brings up not-so-flattering threads.
 
.
 

 

[rlawli]

Quote:

So an update for those who are interested: came home for the weekend for a job interview, and my Dad presented me with one of the toys.
 

 
Well it is certainly much more portable than the garage collection and much more modestly priced in purchase year constant dollars. Draw your own conclusions about its quality. Tell your Dad you need to do a listening comparison between the T-amp and the heavy metal. If he displays any resistance, tell him they were made to be used, not to hold down shelves in the garage and oxidize. Offer to pay the incremental cost in the electric bill ....

 

[vaed]

Yeah, my Dad is very supportive of me in these experiments--which I'm very thankful for--so I don't think it'll be a problem. I haven't brought my HE-6 since I was just visiting, so comparisons will have to be done later. I do agree with you though, part of the reason I got the HE-6 is because I knew there were some great components that my Dad wasn't using.

 

[Silent One]

To all you happy HE-6 owners out there: what gauge did you find satisfying for performance?
 
24
22
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18