REVIEW: Qinpu Q-2 and A-3 Amplifiers and V-5 Speakers
Apr 3, 2011 at 11:10 AM Post #121 of 140

Tequilasunriser

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Thank you, SkyLab. I'll look into that.
 
Do you also happen to know what the headphone impedance range is? Trying to find that specific info on this amp is difficult and the manufacturer hasn't responded to me. 
 
Apr 3, 2011 at 11:12 AM Post #122 of 140

Skylab

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Sorry but I do not know what the spec is there.  Shouldn't be a problem to use any headphone, although I am not sure how much power it would have for something like 600 ohm cans.
 
Feb 14, 2012 at 12:35 PM Post #124 of 140

iamnoone

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Hello,  Thanks for the review of the Qinpu A3.  Not that many to be found.  I have one question, can the Qinpu A3 drive the speakers and the 3.5mm output simultaneously?  Reason for that question is that I would like to connect a powered sub.  Trying to avoid putting in the signal path anything in between the amp and the mains, unless of course doing so won't affect the sound in anyway, then my question is moot.
 
Thanks for any input on this!
 
Feb 15, 2012 at 4:19 AM Post #125 of 140

HeadphoneAddict

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Quote:
Hello,  Thanks for the review of the Qinpu A3.  Not that many to be found.  I have one question, can the Qinpu A3 drive the speakers and the 3.5mm output simultaneously?  Reason for that question is that I would like to connect a powered sub.  Trying to avoid putting in the signal path anything in between the amp and the mains, unless of course doing so won't affect the sound in anyway, then my question is moot.
 
Thanks for any input on this!


Yes it can, or at least mine could last time I checked a few years ago.
 
 
Feb 15, 2012 at 8:59 AM Post #126 of 140

Skylab

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Thanks Larry.  Unfortunately I haven't had either of these units since shortly after the review ended so no way for me to check.
 
Feb 15, 2012 at 10:40 AM Post #127 of 140

iamnoone

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Thanks for the replies!  I have another noob question.
 
Is it a bad idea to wire 2 pairs of speaker wire into a single output on an amp to drive one pair of speakers and a powered sub.  I know it's bad to wire two speakers to one output which will halve the output and double the impedance, but what if that 2nd speaker is a powered sub?  I should still get full power,or at least something very close to it, to the mains right?
 
If the answer is favorable, I will consider getting a MiniWatt instead of the Qinpu.
 
Thanks for indulging my noobness :)
 
Feb 16, 2012 at 12:33 AM Post #128 of 140

HeadphoneAddict

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Quote:
Thanks for the replies!  I have another noob question.
 
Is it a bad idea to wire 2 pairs of speaker wire into a single output on an amp to drive one pair of speakers and a powered sub.  I know it's bad to wire two speakers to one output which will halve the output and double the impedance, but what if that 2nd speaker is a powered sub?  I should still get full power,or at least something very close to it, to the mains right?
 
If the answer is favorable, I will consider getting a MiniWatt instead of the Qinpu.
 
Thanks for indulging my noobness :)


I would not feed speaker level power into the line level input of a powered sub.  I would feed two speakers from the speaker outputs and one powered sub from the 1/8" output.  I tried this with a pair of Sony speakers and a Sharper Image Sub a while back.
 
Here is my review http://www.head-fi.org/t/416787/review-qinpu-a-3-headphone-and-speaker-tube-amplifier-from-head-direct-com
 
 
Feb 16, 2012 at 5:55 PM Post #129 of 140

iamnoone

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Thanks for your replies HeadPhoneAddict.  Your Qinpu review was pretty helpful.
 
I really don't want to be a pest here but why is it not preferred to feed both the L+R Line In on the powered sub and the main speakers simultaneously from the speaker outputs of the amp?
 
Digging around I found that this type of connection is considered "parallel" and it would actually halve the impedance.  The main speakers are rated at 8-4ohm.  No idea what the sub is but from what I've read, most subs present themselves to the amp as a high ohm load.  Not completely sure on that though.
 
The reason I ask is b/c another amp I'm considering, the Miniwatt S1, only has a set of speaker outputs in banana plug format.  No 3.5mm out like the Qinpu.  The idea is to make 1 set of speaker wires with the stackable banana plugs and connect that set to the main speakers with the stackable end on the amp side.  Then take another set of regular speaker wire and plug those into the stackable set on the amp end and into the Speaker L + R inputs of the sub on the other end.  The goal being to avoid putting the sub between the amp and the mains in the signal path.  I'm still not sure why that is not preferred either.  If it does not change or degrade the sound to go from amp -> sub -> mains, then I've been a pest over nothing.
 
Now to open up another can of worms, Audioengine makes an N22 (Solid State) amp, also priced at 199$.  How would one go about deciding between the Qinpu and the N22?  I've no way to audition either but both products seem to get consistently favorable reviews.
 
As always thanks for your patience.
 
Feb 17, 2012 at 1:23 AM Post #130 of 140

HeadphoneAddict

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Quote:
I would not feed speaker level power into the line level input of a powered sub.  I would feed two speakers from the speaker outputs and one powered sub from the 1/8" output.  I tried this with a pair of Sony speakers and a Sharper Image Sub a while back.
 
Here is my review http://www.head-fi.org/t/416787/review-qinpu-a-3-headphone-and-speaker-tube-amplifier-from-head-direct-com
 

 
Quote:
Thanks for your replies HeadPhoneAddict.  Your Qinpu review was pretty helpful.
 
I really don't want to be a pest here but why is it not preferred to feed both the L+R Line In on the powered sub and the main speakers simultaneously from the speaker outputs of the amp?
 
Digging around I found that this type of connection is considered "parallel" and it would actually halve the impedance.  The main speakers are rated at 8-4ohm.  No idea what the sub is but from what I've read, most subs present themselves to the amp as a high ohm load.  Not completely sure on that though.
 
The reason I ask is b/c another amp I'm considering, the Miniwatt S1, only has a set of speaker outputs in banana plug format.  No 3.5mm out like the Qinpu.  The idea is to make 1 set of speaker wires with the stackable banana plugs and connect that set to the main speakers with the stackable end on the amp side.  Then take another set of regular speaker wire and plug those into the stackable set on the amp end and into the Speaker L + R inputs of the sub on the other end.  The goal being to avoid putting the sub between the amp and the mains in the signal path.  I'm still not sure why that is not preferred either.  If it does not change or degrade the sound to go from amp -> sub -> mains, then I've been a pest over nothing.
 
Now to open up another can of worms, Audioengine makes an N22 (Solid State) amp, also priced at 199$.  How would one go about deciding between the Qinpu and the N22?  I've no way to audition either but both products seem to get consistently favorable reviews.
 
As always thanks for your patience.


The powered sub takes a 2v low-current line-level signal, and has it's own internal amp.  If you feed a speaker level high power signal into it you can over-drive the sub input and likely burn it up.  Use the sub as it was designed, with a pre-amp out and don't try to connect it to a speaker output.  Why is that so hard to understand?  
 
I haven't tried the N22 nor seen it's features, so I can't help there.  If you are worried that the A-3 won't have enough power, then consider one of the Nuforce Icon Desktop amps with 12 or 24 watts and a pre-amp output for the sub.  The problem is they cost a bit more than the Qinpu for a similar levels of sound quality.
 
Mar 21, 2012 at 6:53 AM Post #131 of 140

Joe Presto

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I've had the Q-2 for a while now and have been using it as my headphone amp mainly for my Grado's and AKG K400,. I recently acquired an AKG K1000 that I have been running from the headphone output once in a while, but have been considering running it from the speaker outputs. Will this make any difference on this amp? I know I need something more beefy for the K1000, but this is all I have for the time being. I also have an AKG K340, another one that might benefit from the speaker outputs?
 
Mar 21, 2012 at 8:30 AM Post #132 of 140

wje

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Quote:
I've had the Q-2 for a while now and have been using it as my headphone amp mainly for my Grado's and AKG K400,. I recently acquired an AKG K1000 that I have been running from the headphone output once in a while, but have been considering running it from the speaker outputs. Will this make any difference on this amp? I know I need something more beefy for the K1000, but this is all I have for the time being. I also have an AKG K340, another one that might benefit from the speaker outputs?


Usually, when people are going to run their headphones from the speaker outputs, they make a set of "speaker taps".  The speaker taps can include resisters that are installed on the "+" side of the Left and the Right connector to ensure too much current isn't pushed to your headphones to blow them.  If you do decide on making a pair of speaker taps, a wire wound resistor - 10W / 100Ohm variety can be used.  I read this information in another thread and plan on doing the same in a few days when I make the taps to get my receiver to drive a balanced set of cables for my headphones.
 
 
Mar 22, 2012 at 3:09 AM Post #133 of 140

Joe Presto

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Usually, when people are going to run their headphones from the speaker outputs, they make a set of "speaker taps".  The speaker taps can include resisters that are installed on the "+" side of the Left and the Right connector to ensure too much current isn't pushed to your headphones to blow them.  If you do decide on making a pair of speaker taps, a wire wound resistor - 10W / 100Ohm variety can be used.  I read this information in another thread and plan on doing the same in a few days when I make the taps to get my receiver to drive a balanced set of cables for my headphones.
 


Thanks WJE, that makes sense, I'll need to have a look to see if I can source the bits. the K1000 usually came with a pigtail to hook it up directly to speaker outputs though, I'm not sure I have read about many people making the taps for the K1000, but I might as well start that way... The Q2 is tiny so I'm not too concerned about it blowing up the cans, but I'll give it a shot regardless.
 
Mar 22, 2012 at 3:46 PM Post #134 of 140

wje

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Quote:
Thanks WJE, that makes sense, I'll need to have a look to see if I can source the bits. the K1000 usually came with a pigtail to hook it up directly to speaker outputs though, I'm not sure I have read about many people making the taps for the K1000, but I might as well start that way... The Q2 is tiny so I'm not too concerned about it blowing up the cans, but I'll give it a shot regardless.


You can always try connecting the wires directly to the speaker outputs - referring to the pigtail that came with your K1000.  The main thing to keep in mind is to watch your volume levels.  You don't want to push it too hard where distortion might be a factor or too much power is applied to your headphones to cook them.  I guess a little juice can go a long way.  Enjoy!
 

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