aj-kun
500+ Head-Fier
- Joined
- Aug 7, 2009
- Posts
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- 24
[size=large][INTRO][/size]
I'm pretty much a poor ass uni student, but I reallly want a balanced rig, so I started searching round google, and stumbled upon this
http://www.pbase.com/n_maher/image/88451013.jpg
http://www.head-fi.org/forums/f42/fs...p-sold-406378/
It's balanced mini3.
[size=large][THE AMP][/size]
Intrigued by this discovery, I emailed Ti from AMB Labs and asking him howd I'd go by making this. and here's how it went;
Quote:
This is great, because that means I can save money but not populating certain sections of the boards =)
Now glassjaraudio sells one kit for US$88 including case and battery. I estimate that I could make this balanced amp for under US$120 and then another 5 for a wallwart and probably $40 or so for a Chassis.
The most expensive part will be the motorised 4 pot 10K RK27 potentiometer that I found.
I'm going with motorised because i intend to leave room for LCDuino-1. That one is AU$70 shipped. So all up it will probably cost less that US$300.(I know my math isn't perfect I'm leaving room for "accidents")
[THE DAC]
I need a balanced DAC to match this balanced amp, and was looking at both the Twisted Pear Opus and the Gamma1+2 offerings, I found the Gamma 2 would be better for me, as I could save money on shipping getting all the boards at once from AMB. Also it seems like I'd probably beable to get better support for my project from AMB labs and their page is full of information =D
Alternatively...if I get to lazy to make the DAC, I'll just buy a cambridge DACmagic.
[size=large][END][/size]
The time frame for this will begin once my Uni holidays start. This will be my first amp build ever, so I look forward to it =D - which is in 3 weeks. By then i should have all the parts.
http://img149.imageshack.us/img149/8595/balmini1vc5.jpg
This is how n_maher's balanced mini3 build ended up looking.
I'm pretty much a poor ass uni student, but I reallly want a balanced rig, so I started searching round google, and stumbled upon this
http://www.pbase.com/n_maher/image/88451013.jpg
http://www.head-fi.org/forums/f42/fs...p-sold-406378/
It's balanced mini3.
[size=large][THE AMP][/size]
Intrigued by this discovery, I emailed Ti from AMB Labs and asking him howd I'd go by making this. and here's how it went;
Quote:
| AJ Lazaro writes: > I was planning on making a balanced mini3, I'm sourcing a 4pot potentiometer, would you recommend ALPS Quad Potentiometer RK27114MC in the 10K or the 50K, I noticed that for the balanced beta22 you recommended a 50K. (it's the cheapest one i can find) Yes, a 4-gang 10K is good. For the Mini3, we want a 10K volume pot to minimize output DC offset shift as you turn the volume knob. This is due to the use of BJT-based opamps (AD8397 or LMH6643). > Also I've noticed that in someone elses build, he used 2 TREADS + a unregulated external powersupply. > could the onboard voltage regulator be used instead, along with one wallwart, that connects to both boards? Yes you can. Basically, omit all of the power supply stuff on the second board (except C3a, C3b, C5+ and C5-) and just run wires from the first board's V+ and V- to the second board. > Alternatively could a sigma11 be used? i've noticed it has a flexible voltage output is has 4 output terminals, so could 2 of those outputs be used to power this amp. Of course with the r10 removed and BZX55C9V1 zener diode so that it outputs 9V. Sigma11 is a bit overkill. > My aim is to replicate something like this > http://www.head-fi.org/forums/f42/fs...p-sold-406378/ but in the Combined Balanced/Unbalanced configuration with an active unbalanced ground. As shown in the other options of the Beta 22 amp page. You should populate the TLE2426 on one of the two boards only, and then connect the two boards' input grounds together with a wire. If you also want unbalanced active ground output, then you'll still need to populate U4 (OPA690 or LMH6642) on both boards. -Ti |
This is great, because that means I can save money but not populating certain sections of the boards =)
Now glassjaraudio sells one kit for US$88 including case and battery. I estimate that I could make this balanced amp for under US$120 and then another 5 for a wallwart and probably $40 or so for a Chassis.
The most expensive part will be the motorised 4 pot 10K RK27 potentiometer that I found.
I'm going with motorised because i intend to leave room for LCDuino-1. That one is AU$70 shipped. So all up it will probably cost less that US$300.(I know my math isn't perfect I'm leaving room for "accidents")
[THE DAC]
I need a balanced DAC to match this balanced amp, and was looking at both the Twisted Pear Opus and the Gamma1+2 offerings, I found the Gamma 2 would be better for me, as I could save money on shipping getting all the boards at once from AMB. Also it seems like I'd probably beable to get better support for my project from AMB labs and their page is full of information =D
Alternatively...if I get to lazy to make the DAC, I'll just buy a cambridge DACmagic.
[size=large][END][/size]
The time frame for this will begin once my Uni holidays start. This will be my first amp build ever, so I look forward to it =D - which is in 3 weeks. By then i should have all the parts.
http://img149.imageshack.us/img149/8595/balmini1vc5.jpg
This is how n_maher's balanced mini3 build ended up looking.
