Maverick Audio TubeMagic A1 (Hybrid Amp) - Discussion and Review Thread
Aug 18, 2010 at 3:47 AM Post #46 of 232

Ultrainferno

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The weather here is so depressing I just need to upgrade (It's a legit excuse right?
wink_face.gif
)
 
Shortlisted are the A1, WA3 and Schiit Valhalla. Could someone maybe compare the A1 to the WA3 if possible? Or wouldn't it be fare to compare it to the Woo? I'm looking forward to some comparisons of the A1 and the upcomming Schiit Valhalla as well.
 
I'm really looking for a warm and dark amp for the dt990 and I'm a bit worried the A1 isn't like that
 
Aug 18, 2010 at 4:37 AM Post #47 of 232

_Spanky_

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Quote:
I'm really looking for a warm and dark amp for the dt990 and I'm a bit worried the A1 isn't like that


I don't know about warm and dark (I still haven't caught onto the lingo) but I will say the A1 has really made my DT770's shine. This is flat out the best I've heard from them. The bass really seemed to lack with the D1's headphone output but the A1 makes up for that and more. It's really comfortable and not shrill in the least. I was tempted to pick up a pair of better headphones but the A1 really pumped new life into these.
 
Aug 20, 2010 at 11:23 AM Post #48 of 232

project86

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I ordered an A1 a few days ago, and it is already almost here. If DHL delivers on Saturdays, I should have it tomorrow, if not then I'll get it Monday. So either 3 or 4 days transit. That's amazingly fast shipping from the other side of the world!
 
I got the Tung-Sol tubes as well. I plan on doing a thorough review when I get a chance.
 
Aug 20, 2010 at 11:53 AM Post #49 of 232

Mysteek

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Looking forward to it.  The amp looks very promising =]
 
Quote:
I ordered an A1 a few days ago, and it is already almost here. If DHL delivers on Saturdays, I should have it tomorrow, if not then I'll get it Monday. So either 3 or 4 days transit. That's amazingly fast shipping from the other side of the world!
 
I got the Tung-Sol tubes as well. I plan on doing a thorough review when I get a chance.



 
Aug 23, 2010 at 6:56 AM Post #50 of 232

DylanHall

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Hello people, my first post to head-fi :)
 
My A1 arrived this morning and I have to say, I'm rather disappointed :frowning2:
 
I ordered it with the Tung Sol tubes. My intention is to use it as a headphone amp at work hooked up to my PC via an AlienDAC kit.
 
First issue was only the right channel worked, the left was very quiet (faint sound). I popped the lid off and checked all the cables were seated and gave the tubes a gentle wiggle. This fixed the issue but I'm not clear how it fixed it. My best guess is one of the tubes wasn't seated right or had worked loose during shipping.
 
Putting the lid back on there were issues with the case. The holes in the lid didn't line up with the holes in the case. I had to pull gently on the speaker terminals to make the holes line up. A couple of the screws won't tighten properly, I think the threads are damaged, I suspect because the case was forced on in the factory. The unit doesn't sit flat either, it rocks slightly. I'm not sure if it was like this before I popped the lid off or if it's a result of opening the box.
 
None of the above worries me much, the real issue is the sound. There is a persistent hum/buzz in the background. It's not very loud, but loud enough to be annoying if I'm listening to quiet music.
 
Testing the unit at work today with the volume up a little the PC/DAC/A1 combo worked fairly well. Taking the unit home this evening I'm struggling to use it with my laptop. When I connect the DAC/A1 to my laptop there is a terrible background noise/interference. When I disconnect my laptop from it's power supply and run on batteries it's ok. I suspect some kind of ground loop or similar. I get the same issue if I remove the DAC and connect directly from the headphone jack on my laptop to the A1. Again, disconnecting the laptop power supply sorts the issue.
 
At the moment my intention is to leave it running over night (once I can find an audio source that doesn't cause excessive hum) and see if it sounds any better in the morning once the tubes have been run for a couple hours.
 
What's the feeling here, do I have a dodgy unit or is this normal and I've brought a bit of a lemon?
 
Thanks,
 
Dylan
 
 
Aug 23, 2010 at 8:11 AM Post #51 of 232

JustVisit

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Quote:
None of the above worries me much, the real issue is the sound. There is a persistent hum/buzz in the background. It's not very loud, but loud enough to be annoying if I'm listening to quiet music.
 
Testing the unit at work today with the volume up a little the PC/DAC/A1 combo worked fairly well. Taking the unit home this evening I'm struggling to use it with my laptop. When I connect the DAC/A1 to my laptop there is a terrible background noise/interference. When I disconnect my laptop from it's power supply and run on batteries it's ok. I suspect some kind of ground loop or similar. I get the same issue if I remove the DAC and connect directly from the headphone jack on my laptop to the A1. Again, disconnecting the laptop power supply sorts the issue.
 
At the moment my intention is to leave it running over night (once I can find an audio source that doesn't cause excessive hum) and see if it sounds any better in the morning once the tubes have been run for a couple hours.
 
What's the feeling here, do I have a dodgy unit or is this normal and I've brought a bit of a lemon?
 
Thanks,
 
Dylan
 

Hey Dylan, the problem you had before (right channel not working) is obvisouly caused by the tube was moved during transportation.
Don't worry, let me try to sort out the new issue:
 
- You mentioned you use the DAC/A1 combo with your laptop. What kind connection did you use between the DAC and your laptop? Did you have the same hum sound when you use the DAC's headphone output with your laptop? Do you hear the hum sound when you connecting your headphone directly to the laptop's headphone output?
 
- Will you be able to find another wall power socket to connect your laptop? Make sure there is no other electronics using the same power socket. Also, make sure the wall power socket is properly connected to the earth line.
 
- Make sure you use high quality audio cable to connect the A1 to the DAC. Low quality audio cable will cause interference.
 
I don't think your unit is a lemon, I personally tested your unit before the shipment. The minimum requirement for the unit to pass my testing is that I can not hear any noise from two headphones(one PX100 and one HD650) in a very quiet room. It has to be dead silence. Your issue, is probably due to bad power source or audio cable. As you did get it working very well in your office environment.
 
Let me know your testing result and I will help you further. You can leave your feedback here or reply directly on the support ticket.
 
Cheers,
 
Ryan

 
 
Aug 23, 2010 at 9:22 AM Post #52 of 232

patkhan

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Hi guys,
I got my A1 last week with the sotck chinese tubes.  I can also confirm a faint hum past 12 o'clock.  I am using different wall sockets for source(PC) and amp.  It does not bother me much but it is there.  I will try isolating the A1 power intake completely to see if the hum is from the tube or from the AC line.  Other than that the A1 is a pretty good amp, it kicked a ClassD CDA-224 60w into 8ohms amp without breaking a sweat.  Much better sound, more open, crisper, resolved and louder than the 60watter.  This was using Monitor Audio ref 700 pmc speakers rated at 90dbs.
Please report any hum issues so we can troubleshoot if necessary.
 
Aug 23, 2010 at 9:51 AM Post #53 of 232

JustVisit

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Quote:
Hi guys,
I got my A1 last week with the sotck chinese tubes.  I can also confirm a faint hum past 12 o'clock.  I am using different wall sockets for source(PC) and amp.  It does not bother me much but it is there.  I will try isolating the A1 power intake completely to see if the hum is from the tube or from the AC line.  Other than that the A1 is a pretty good amp, it kicked a ClassD CDA-224 60w into 8ohms amp without breaking a sweat.  Much better sound, more open, crisper, resolved and louder than the 60watter.  This was using Monitor Audio ref 700 pmc speakers rated at 90dbs.
Please report any hum issues so we can troubleshoot if necessary.

It is normal you get a bit "hum" pass 12 o'clock. It is from the vacuum tube, not from the circuit.  Depends on different pair of tubes, you might not get any hum until 3-4 o'clock position. Vacuum tubes are vintage analog components, each tube is a bit different. There is really no good way to complete "kill" the tube hum sound in very high volume as it is just a natural thing with vacuum tube.
 
Our standard is that there should be no hum under 12 o'clock as you will not be able to pass 12 o'clock when using headphone on the A1. The A1's headphone amplifier is very powerful and most of headphones will not even be able to pass 10 o'clock. We also test each unit with a very sensitive 32ohm headphone to make sure there is dead silence when the volume is set to 9 o'clock.
 
 
Aug 23, 2010 at 1:38 PM Post #54 of 232

patkhan

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Thanks for the prompt reply Ryan,
I was inclined to believe it was the tube causing the hum.   As mentioned it is hardly noticable through the speakers before 12 o'clock, even past 12 with a program running you will not notice it since the program will mask it.  I was just curious, since the D1, with tube output also, does not have much noise.  I am using the D1 with a p/p el34, and get no noise at all but that amp is so powerful that I can hardly go past 10 o'clock with that setup.
We are early adopters here, I like the Maverick approach to a sound business, we can cooperate to bring a better product for everyone involved, I loved the D1 discussion, tour, etc., threads.  Almost everything can be improved, my comments are on the spirit of constructive elucubration, if someone finds a glitch lets work together and solve it to everyones benefit.
I am happy with this amp.
 
Aug 23, 2010 at 3:16 PM Post #55 of 232

hodgjy

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I had exactly the same issues with my D1.  On first arrival, one channel was out.  Popped case, reseated some cables, sound back.  Probably caused during shipping.  So, no worries so far.  But, when putting screws back in, they would not all align and one was completely stripped out.  Also, after tightening the other screws, the case warped.  Wobbled the whole time.  Had a persistent background hum in my headphone jack.
 
I don't think you got a lemon.  You got what the Maverick line is.  Not bad for the price point.
 
Quote:
 
I ordered it with the Tung Sol tubes. My intention is to use it as a headphone amp at work hooked up to my PC via an AlienDAC kit.
 
First issue was only the right channel worked, the left was very quiet (faint sound). I popped the lid off and checked all the cables were seated and gave the tubes a gentle wiggle. This fixed the issue but I'm not clear how it fixed it. My best guess is one of the tubes wasn't seated right or had worked loose during shipping.
 
Putting the lid back on there were issues with the case. The holes in the lid didn't line up with the holes in the case. I had to pull gently on the speaker terminals to make the holes line up. A couple of the screws won't tighten properly, I think the threads are damaged, I suspect because the case was forced on in the factory. The unit doesn't sit flat either, it rocks slightly. I'm not sure if it was like this before I popped the lid off or if it's a result of opening the box.
 
None of the above worries me much, the real issue is the sound. There is a persistent hum/buzz in the background. It's not very loud, but loud enough to be annoying if I'm listening to quiet music.
 
What's the feeling here, do I have a dodgy unit or is this normal and I've brought a bit of a lemon?
 



 
Aug 23, 2010 at 4:26 PM Post #56 of 232

_Spanky_

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I will say that Ryan should work on case quality control. I hoped the A1 production units would be better and it kind of sounds like they are but IMO it still doesn't sound acceptable. On my pre-production A1, I absolutely cannot get the rear top screws back in. I've tried bending the case but it's pretty thick steel and while I can bend it, it just goes back to it's original warped state. My case also wobbles (which I believe is due to the bent case because before I opened the unit, it was perfectly flat sitting on my desk) but I've used a couple layers of foam tape under one of the feet and it's solid as a rock. I'd personally like to see how the factory gets the screws in, in the first place :p You should be able to get the front 4 screws and the bottom back 2 screws in. But, I do hope Ryan fixes this issue because there's some people that really really care about aesthetics and a minor non-sound related issue like this would be a deal breaker.
 
As for the hum... On the D1 it's kind of expected. It's a budget all-in-one unit. I would be surprised if a unit with the features and price of the D1 had absolutely no noise/hum. But the hum in the A1 is definitely not a fluke. I have it in mine, mostly past 12 o'clock but it's rare I go that high and if I do, the sheer volume output drowns it out easily. The hum in the A1 can be heard with no inputs connected and with an isolation transformer. I've only heard it with my headphones, never my speakers. I wouldn't call the hum in the A1 a deal breaker since it's considerably less to non-existant than the D1 at the same volumes.
 
Aug 23, 2010 at 6:39 PM Post #58 of 232

hodgjy

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I disagree that tube hum is expected and acceptable.  There are plenty of dead quiet tube amps out there.  Sure, some tubes hum.  Many others don't.  If a particular type of tube hums every time when used in a particular circuit, you either fix the circuit or find a tube type that doesn't hum.  In my tube amp, no matter how many copies of the same tube I try, it is noisy.  But, when I use a different tube manufacturer, there is no hum.  It appears that there is some interaction with certain tubes with certain circuits.
 
I do think it is poor of the manufacturer to blame all the hum on the tubes (for reasons listed above).  You can't pull wool over everyone's eyes. 
 
Quote:
But the hum in the A1 is definitely not a fluke. I have it in mine, mostly past 12 o'clock but it's rare I go that high and if I do, the sheer volume output drowns it out easily. The hum in the A1 can be heard with no inputs connected and with an isolation transformer. I've only heard it with my headphones, never my speakers. I wouldn't call the hum in the A1 a deal breaker since it's considerably less to non-existant than the D1 at the same volumes.



 
Aug 23, 2010 at 6:50 PM Post #59 of 232

_Spanky_

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Quote:
I disagree that tube hum is expected and acceptable.  There are plenty of dead quiet tube amps out there.  Sure, some tubes hum.  Many others don't.  If a particular type of tube hums every time when used in a particular circuit, you either fix the circuit or find a tube type that doesn't hum.  In my tube amp, no matter how many copies of the same tube I try, it is noisy.  But, when I use a different tube manufacturer, there is no hum.  It appears that there is some interaction with certain tubes with certain circuits.
 
I do think it is poor of the manufacturer to blame all the hum on the tubes (for reasons listed above).  You can't pull wool over everyone's eyes. 
 

 
No sarcasm intended but do you have an A1? While the hum exists, it's very minute, especially at typical listening levels. It is nowhere near the level of the original D1. Sure there's endless amounts of circuits and tons of tubes to choose from but are there comparable ones that Ryan could have gone with at this price point? I don't know, I'm not an engineer. Has anyone tried tube hum comparisons between the stock Chinese and the Tung-Sol or any other tube? When I had my stock Chinese tubes in, I didn't pump the volume so I didn't notice if there was hum or not. I may have to pop them back in to see, maybe it's just the Tung-Sol tubes. 
 
Aug 23, 2010 at 6:56 PM Post #60 of 232

hodgjy

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Good point.  No sarcasm received.  I have not auditioned an A1, but I have auditioned a few tube amps while researching which one I was going to purchase.  Many amps did not hum.  It's just my opinion that persistent hums should be remedied during R&D and not passed on to the customers (while blaming the tubes) at any price point.  
 
Quote:
 
No sarcasm intended but do you have an A1? While the hum exists, it's very minute, especially at typical listening levels. It is nowhere near the level of the original D1. Sure there's endless amounts of circuits and tons of tubes to choose from but are there comparable ones that Ryan could have gone with at this price point? I don't know, I'm not an engineer. 



 

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