[sp70]

See here:
 
http://www.head-fi.org/forum/thread/500237/maverick-audio-tubemagic-a1-hybrid-amp-discussion-and-review-thread

 

[reiserFS]

Anyone else smelling another "Skyline" mod on the Tube Magic A1?

 
Here's what you need for the D1 mod v2.0:
 
-50x50 cm plate of plexiglass with 2mm thickness
-4 screws
-a Dremel or a clone of one
-patience, lot's of it, don't hurry this.
 
1. Here are the exact sizes for the faceplate and case sides: 25x16cm | 2 x  5x16cm. If you don't have the tools for a clean cut, you can go to a specialized store that cuts it for you according to the sizes. Do not take off the protection foil, because we don't want scratches in it yet.
 
2. Take off the old casing, since we won't need it anymore. Here's what you do next: Place the faceplate on top of the D1 and try to fit evenly on all sides, after that go ahead and drill holes into the plexiglass for the hex screws.
Don't ever overtighten the screws, this will make the plexiglass bend a little and has chances to break off stuff on the edges.
 
3. Everything fitting nicely? Great, but we're not done quite yet. The sides are a bit more complex, you need to drill holes into the case endings on each side and better be very careful with that, especially near the transformer. Make sure that the screws should move "smoothly" into the case and not loose, they won't be able to hold the sides otherwise.
 
4. Fitting sides and faceplate? Check. Ventilation holes? Nope. Guess what comes next. Generally speaking, bigger ventilation holes let more heat out than smaller ones, but also have the chance to gather much more dust. In my first version of the mod I used big holes and the D1 was only warm to the touch, the second version features much more holes stretched across the PCB, but are way smaller and don't really change the heat distribution. The transformer section doesn't even feel warm at all after 6 hours. If you don't use the tube at all, you're probably better off drilling in some holes over the big caps and OPAs.
 
5. Take off the protection foil, clean leftovers from the drilling, plug in your D1 and enjoy your "Skyline" mod. Not only does this mod transfer heat better, but it also allows you to use Audio-gd HDAMs in the headphone and DAC section.
 
Be very careful when drilling plexiglass at high speed, it gets very hot and melts. If there's enough interest, I'll also do custom orders for the lazy ones.
 

 

 

[_Spanky_]

Haha, I'm going to pull out my old sheet of plexi for it.
 
Check it out:
 

D1 (DAC/Amp) Discussion and Review Thread	D1 (DAC/Amp) Condensed FAQ and Info Thread
A1 (Hybrid Amp) Discussion and Review Thread	A1 (Hybrid Amp) Condensed FAQ and Info Thread

 

[uelover]

finally i see something!
 
i do wonder though when connecting to active speaker, should I be using the pretube out from mav d1 or this amplifier?
sounds like double preamping is cool. lol.
 
Quote:

http://www.mavaudio.com/base/audio-and-hi-fi/tube-magic-a1-hybrid-amplifier-is-almost-ready-for-pre-order/
 

 

[ninjikiran]

Probably stick with the D1, since I am assuming by active they are already amplified.  Someone else might be able to elaborate reasons why to, and why not to but as a power amp I don't think active speakers would need it.
 
Quote:

finally i see something!
 
i do wonder though when connecting to active speaker, should I be using the pretube out from mav d1 or this amplifier?
sounds like double preamping is cool. lol.
 

 

 

[Ultrainferno]

A D1 thing I was thinking of:
 
Is it my mind that's playing tricks on me or is the sound quality of the D1 better when not using the Direct/volume control bypass?

 

[uelover]

hey Ultrainferno, care to elaborate a little more on the 'sound quality'?
 
The resolution of the sound coming out from my D1 is higher when I use the volume bypass. However, it also suffers distortion.
As of now, I have to make do with the volume control.
 
I wonder if it is due to the technical restrictions of the hardware in D1 or is it that the sound amplification level is too high for the receiving system to process.
 
Perhaps our dear Spanky could enlighten us. lol.
 
Quote:

A D1 thing I was thinking of:
 
Is it my mind that's playing tricks on me or is the sound quality of the D1 better when not using the Direct/volume control bypass?

 

[reiserFS]

Quote:

The resolution of the sound coming out from my D1 is higher when I use the volume bypass. However, it also suffers distortion.

Care to elaborate on this? Are you using a different OPA? Mine doesn't distort at all when acting like a stand alone DAC with the "Direct" button.

 

[Ultrainferno]

Like I said, I could be amagining it, but the sound seems a little more laid back, warm and detailed without the direct.
It is like with the direct all the sound has to go trough one door as fast and hard as possible, and without the direct they have this huge door where they can walk trough easyly at there own tempo. Sorry for the weird comparison, I'm not familiar with the english audiolanguage
 
But again, most likely I am amagining it

 

[uelover]

hey reiserFS,
 
I've got the opa627 2X mono to dual opamp which i think is the compatible version. I've been using them for a few months now and as long as I keep the volume dial below 1 o'clock, everything will be fine.
 
The distortion I experience now with the bypass button impressed is a clipping sound during the 'peaks' of the audio i play (regardless of cd/flac/dvd). i experience the same problem when I turn the volume knot to over the 1 o'clock. I'm using monoprice toslink so it can't be the cable. I am relying on my active speaker for the rest of the amplification needed to produce the sound of my desired level.
 
It seems that nobody else is experiencing this issue. It might be that my active speaker is 'crap' and can't handle the high current output. I don't know. I am still searching for a tube headamp to pair with Maverick for HD650.
 
I've the LT1364CN8 and LM4562NA on its way and I'll try out with them when I receive them.
 
With the bypass button, will we be bypassing the opamp on the DAC unit?

 

[cravenz]

Quote:

 

 

looks sweet mate. I'm still in search of a desktop DAC, if I get this, hint hint, I might look you up, not cos' I'm lazy, but I just wouldn't have the tools nor am I a DIY person. Wait, maybe I'm just lazy

 

[reiserFS]

Quote:

looks sweet mate. I'm still in search of a desktop DAC, if I get this, hint hint, I might look you up, not cos' I'm lazy, but I just wouldn't have the tools nor am I a DIY person. Wait, maybe I'm just lazy

   Sure thing, if you get one, just drop me a PM and we can work something out. I also do the mods with two Audio-gd HDAMs.


 
Quote:

hey reiserFS,
 
I've got the opa627 2X mono to dual opamp which i think is the compatible version. I've been using them for a few months now and as long as I keep the volume dial below 1 o'clock, everything will be fine.
 
The distortion I experience now with the bypass button impressed is a clipping sound during the 'peaks' of the audio i play (regardless of cd/flac/dvd). i experience the same problem when I turn the volume knot to over the 1 o'clock. I'm using monoprice toslink so it can't be the cable. I am relying on my active speaker for the rest of the amplification needed to produce the sound of my desired level.
 
It seems that nobody else is experiencing this issue. It might be that my active speaker is 'crap' and can't handle the high current output. I don't know. I am still searching for a tube headamp to pair with Maverick for HD650.
 
I've the LT1364CN8 and LM4562NA on its way and I'll try out with them when I receive them.
 
With the bypass button, will we be bypassing the opamp on the DAC unit?

You can't bypass the DAC OPA with the direct button, else you would not get any sound at all.
 

 

[_Spanky_]

Quote:

You can't bypass the DAC OPA with the direct button, else you would not get any sound at all.
 

I wish I could help more but I just don't know circuit design. From this point on, logic is speaking. If the above statement is true (I'm inclined to agree with it), then I see no reason why or how the direct button would change quality. We're talking enabling/disabling the volume pot's attenuation on the line. I guess it's possible for the pot to color the sound but add more detail? I'm not sure. I will comment more on this when I get the A1 amp.

 

[uelover]

 
Quote:

I wish I could help more but I just don't know circuit design. From this point on, logic is speaking. If the above statement is true (I'm inclined to agree with it), then I see no reason why or how the direct button would change quality. We're talking enabling/disabling the volume pot's attenuation on the line. I guess it's possible for the pot to color the sound but add more detail? I'm not sure. I will comment more on this when I get the A1 amp.

Hmm I was thinking that with a full bypass, the DAC (tube + opa as well) will be pushing at full force all the amplified electrical signal for the receiving unit to process. In that sense, the sound might be 'faster' and more colored by the tube and opa unit on Mav D1 as the receiving unit need not rely much on its own amplification on the weak signal it receives otherwise should we turn the dial on the Mav D1 to a mere 10 o'clock.
 
I guess if one is connecting his MavD1 to a decent amplifier, he might find that relying on the amplification on his amplifier unit might produce a different (better?/colored?) sound which he may like.
 
reiserFS, I think your skyline mod will look much nicer with a modded transformer XD

 

[_Spanky_]

I already have preordered. I'm thinking the tube output design goes a something like this:
 
Out of the DAC > Headphone Amp
                     > Direct Button (Enabled) > Tube > RCA Outputs
                     > Direct Button (Disabled) > Volume Pot > Tube > RCA Outputs
 
If think the difference you're experiencing may be the volume pot coloring the music. Keep in mind, this is just my logic guessing, nothing based on facts