_Spanky_
500+ Head-Fier
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- Nov 29, 2007
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TubeMagic A1 Hybrid Amp
Maverick Audio Website - Product Page
Information
Introduction
What is it?
FAQ's
User-Posted Pictures
Warranty-Breaking Modifications
Don't attempt any of these without experience with PCB soldering.
Spanky's Mod
Thread/Post Info
Maverick Audio Website - Product Page
Information
Introduction
First off, I, Spanky, am not an employee of Maverick Audio. I'm not getting paid or re-imbursed to write any of this. After the success of my Condensed FAQ and Info Thread for the TubeMagic D1 DAC/Amp, both me and sp70 thought that it would be a good idea to continue the quality and properly located information for the TubeMagic A1 Hybrid Amp. This thread (and the other condensed FAQ thread) may not be 100% accurate. I strive to add all information possible and make sure it can be verified. I can't be held responsible for anything that goes wrong from information you gathered in this thread. However, I'll gladly take credit for anything good that happens
On a personal note, I'm honored that this is my 500th post here on Head-Fi.
If for some reason I'm not updating this thread or something and someone else wants to take it over and update it, that is fine with me. There is a source included at the bottom of the post. I only ask that you try to contact me before taking it over. If I don't respond within a reasonable amount of time, then go for it. To the person that takes it over: I give permission for a mod to empty or delete this thread in case someone else takes it over. Also, try not to be biased or remove/modify helpful information.
If for some reason I'm not updating this thread or something and someone else wants to take it over and update it, that is fine with me. There is a source included at the bottom of the post. I only ask that you try to contact me before taking it over. If I don't respond within a reasonable amount of time, then go for it. To the person that takes it over: I give permission for a mod to empty or delete this thread in case someone else takes it over. Also, try not to be biased or remove/modify helpful information.
What is it?
The TubeMagic A1 is an amplifier. To be more specific, a hybrid amplifier. It amplifies a line-level audio signal and outputs it to bookshelf speakers or headphones via a 1/4" jack. The power amp for the speaker outputs is hybrid while the headphone amp is pure tube-driven. There is a 1/4" line-in jack, RCA line-input jacks, RCA tube pre-amp output jacks, and a 1/4" headphone output jack.
FAQ's
- 20 watts (30 peak) per channel of output power. [Ryan: "The maximum output of the A1 will be about 30 watt, however, we want to be a bit conservative about the power rating. In theory, it should have no problem to offer 30 watt / channel power, however in real world use, with different speakers, it may not be able to reach 30 watt in some cases. Therefore, we rated it as 20 watt to ensure we are not misleading any customer."]
- Uses a 80-Watt R-Core transformer.
- Uses 2 6AK5 / 6J1 tubes.
- Has National Semiconductor LM1876T used with the tubes to power speaker outputs.
- Both headphone and speaker output are a hybrid output, see here.
- Output power cannot be modified to push more watts.
- Same case and style as the TubeMagic D1 DAC/Amp
- Accessories included: Manual, 1/8" to 1/8" cable, 1/8" to 1/4" adapter, power cable. RCA interconnect is not included due to Ryan not wanting to give customers a cheap cable with the A1.
- Initial pricing will be $199 for the stock Chinese 6J1 tube and $239 for 2 matched NOS Tung-Sol 6AK5 tubes.
- First 30 pre-orders will be shipped on the 10th of August.
- Wire up to 9AWG in size will fit in the speaker posts in the back of the unit. Both spades and banana plugs can be used as well.
User-Posted Pictures
Warranty-Breaking Modifications
Don't attempt any of these without experience with PCB soldering.
Spanky's Mod
The purpose of my mod does several things. It's purposes are:
- Turn Line-In 1/4" jack into a 2nd headphone output.
- Use Source switch as a speaker on/off switch.
- Make rear RCA Analog In jacks the exclusive input.
Note: Before attempting any of this, you should be aware that there are high voltage capacitors inside the A1 to power the tubes. They can and will contain power even if the unit is turned off and unplugged. This power will slowly drain but I have no idea how long that takes. While modding my unit, one of the PCB screws touched a resistor that is attached to the 200v capacitor inside. A large spark came off and lightly schorched the resistor. Luckily everything was ok in my case but that voltage could have easily hit me instead. Using a bleeder resistor to drain the capacitors would be nice but due to the tight area inside the A1, I don't know if this is entirely easy. In order to perform these mods, I found that you must move the main PCB back or remove it from the case entirely to allow the front panel PCB to be removed. Also, if there is a revision change and wires are run differently in newer units (keep in mind, my unit is a pre-production model) I can't take responsibilty for you damaging your unit. If something doesn't seem right then don't do it. I'm just sharing what I did and what worked for me.
Disassembly Notes: To remove the case shell there are 4 allen screws on top and 4 philips screws underneath (near the 4 corners). On the inside, the main PCB is attached with 4 standoff screws. I had luck with a 7/32" socket to undo the nuts on the screws. (do not turn the screw itself, only the nuts) The front panel PCB is held on by 2 nuts outside on the pot and switch and 2 screws on the inside of the unit for the 1/4" jacks. To remove the knobs, simple pull them straight off, the nuts will then be visible.
Step 1: Disable Line-In 1/4" jack from being an input and turn it into a headphone output jack. (this step can be done by itself and requires no other mods)
This is by far the easiest mod. Simply lift one leg (or remove entirely) resistors R13 and R14 on the front panel PCB. You will find them inbetween the Source switch and Line-In jack like in the picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08786.JPG
This cuts the signal sent to the Source switch. To then turn it into a 2nd headphone jack, you need to piggy back it on the main one. You will have to flip over the front panel PCB to add jumper wires like the ones shown in this picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08787.JPG
Ground is shared so a jumper wire isn't needed for it. Do not use any other points to jumper. The ones I've used are after the resistors have been applied to the signal from the main PCB. These resistors tone down the signal for headphone use, if you use another point, it may damage your headphones.
Step 2: Use Source switch as a speaker on/off switch. (this step must be done with step 3)
Add jumper wires (copper wires in pic) and solder the speaker negative wires (black wires in pic) to the front panel PCB like in the following picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08811.JPG
Performing this step will make it so that "Analog In" will be "On" and "Line-In" will be "Off" for your speakers.
Step 3: Make rear RCA Analog In jacks the exclusive input.
In the back of the unit, the RCA input/output jacks have a small PCB. On this PCB are two wire groups. One is for the tube preamp output and the other is for the analog input. The analog input should be marked "IN-1". You will want to cut it and solder it to the group of wires (red to red, white to white, ground to ground) marked "J-1" near the tubes on the main PCB like seen in the picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08782.JPG
- Turn Line-In 1/4" jack into a 2nd headphone output.
- Use Source switch as a speaker on/off switch.
- Make rear RCA Analog In jacks the exclusive input.
Note: Before attempting any of this, you should be aware that there are high voltage capacitors inside the A1 to power the tubes. They can and will contain power even if the unit is turned off and unplugged. This power will slowly drain but I have no idea how long that takes. While modding my unit, one of the PCB screws touched a resistor that is attached to the 200v capacitor inside. A large spark came off and lightly schorched the resistor. Luckily everything was ok in my case but that voltage could have easily hit me instead. Using a bleeder resistor to drain the capacitors would be nice but due to the tight area inside the A1, I don't know if this is entirely easy. In order to perform these mods, I found that you must move the main PCB back or remove it from the case entirely to allow the front panel PCB to be removed. Also, if there is a revision change and wires are run differently in newer units (keep in mind, my unit is a pre-production model) I can't take responsibilty for you damaging your unit. If something doesn't seem right then don't do it. I'm just sharing what I did and what worked for me.
Disassembly Notes: To remove the case shell there are 4 allen screws on top and 4 philips screws underneath (near the 4 corners). On the inside, the main PCB is attached with 4 standoff screws. I had luck with a 7/32" socket to undo the nuts on the screws. (do not turn the screw itself, only the nuts) The front panel PCB is held on by 2 nuts outside on the pot and switch and 2 screws on the inside of the unit for the 1/4" jacks. To remove the knobs, simple pull them straight off, the nuts will then be visible.
Step 1: Disable Line-In 1/4" jack from being an input and turn it into a headphone output jack. (this step can be done by itself and requires no other mods)
This is by far the easiest mod. Simply lift one leg (or remove entirely) resistors R13 and R14 on the front panel PCB. You will find them inbetween the Source switch and Line-In jack like in the picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08786.JPG
This cuts the signal sent to the Source switch. To then turn it into a 2nd headphone jack, you need to piggy back it on the main one. You will have to flip over the front panel PCB to add jumper wires like the ones shown in this picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08787.JPG
Ground is shared so a jumper wire isn't needed for it. Do not use any other points to jumper. The ones I've used are after the resistors have been applied to the signal from the main PCB. These resistors tone down the signal for headphone use, if you use another point, it may damage your headphones.
Step 2: Use Source switch as a speaker on/off switch. (this step must be done with step 3)
Add jumper wires (copper wires in pic) and solder the speaker negative wires (black wires in pic) to the front panel PCB like in the following picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08811.JPG
Performing this step will make it so that "Analog In" will be "On" and "Line-In" will be "Off" for your speakers.
Step 3: Make rear RCA Analog In jacks the exclusive input.
In the back of the unit, the RCA input/output jacks have a small PCB. On this PCB are two wire groups. One is for the tube preamp output and the other is for the analog input. The analog input should be marked "IN-1". You will want to cut it and solder it to the group of wires (red to red, white to white, ground to ground) marked "J-1" near the tubes on the main PCB like seen in the picture:
http://dl.dropbox.com/u/464376/head-fi/mav_a1_condensed/smod/DSC08782.JPG
Thread/Post Info
Version: 0.9 | Date: 10/17/2010 | Backup File | PDF File | Content Download (All pictures, files and everything you see in this thread)
History:
v0.9 - Added tutorial for Spanky's Mod.
v0.8 - Fixed Head-Fi update bugs and added info about wire gauge size.
v0.7 - Added user pictures.
v0.6 - Added pre-order ship date and output power info.
v0.5 - Added info about pricing and accessories.
v0.4 - Added another picture, modified other images, and added a direct link to it's page on the Maverick Audio website.
v0.3 - Added internal picture, solid state chip info, more precise wattage numbers.
v0.2 - Added some FAQ info.
v0.1 - Initial Post.
History:
v0.9 - Added tutorial for Spanky's Mod.
v0.8 - Fixed Head-Fi update bugs and added info about wire gauge size.
v0.7 - Added user pictures.
v0.6 - Added pre-order ship date and output power info.
v0.5 - Added info about pricing and accessories.
v0.4 - Added another picture, modified other images, and added a direct link to it's page on the Maverick Audio website.
v0.3 - Added internal picture, solid state chip info, more precise wattage numbers.
v0.2 - Added some FAQ info.
v0.1 - Initial Post.
Yea, this amp is kind of an answer to the disappointments of people thinking that the tube in the D1 is in the headphone path. This new amp solves that and adds the ability to power speakers.
