Help me Decide What will build (1st Amp Build)

[Liquidretro]

I am fairly new to the higher end audio scene but having a good time reading the wealth of info out there on this subject. However I am a bit overwhelmed with the decisions of what I want/need. I have some Sennheiser HD595 headphones that I am currently powering with my Dell Inspiron E1505 notebook. I have decided that I want/need an amp while its probably not needed for my 595’s I will want one in the future. I have been looking at what I can build myself as I find this interesting and fun to do. I have quite a bit of experience with through hole soldering and very little surface mount soldering but I am willing to learn. I don’t want to spend a fortune doing this and I know audio is something where I can do that. I was originally looking to spend about $100 on an amp but with the additional stuff I am now looking at I think I might have to raise that or buy stuff over time. I want to balance price with performance.

Question 1
The SOAH amp looks like it has some of the characteristics I want plus I think the tube looks and sounds cool. I am looking at getting the basic kit from GlassJarAudio. On his price list it mentions this “Notice: This amp starts up with 12V DC offset on the output jack. This will damage headphones if they are plugged in during power on and power off.” I was wondering how important this really is? The last thing I want to do is ruin some good headphones with my new amp.

Question 2
So I was wondering if the “JISBOS unity gain buffer” would fix this problem mentioned above and be a good choice? Also could I put this in the same case as the SOAH amp? I don’t want to have a bunch of new boxes on my desk. Or would the AMB Labs ε12 work better for or be cheaper? Is there another alternative I am over looking?

Question 3
While reading all about headphone amps someone suggested getting a DAC/Amp combo. I have read that the Alien DAC is a good DAC especially for the money and DIY person. I was wondering if this would help power my headphones alone or could run my headphones straight out of it without an amp? Would this be a good place to start my DIY audio build?

Question 4
To further complicate things I have a friend who has a home music studio and is going through an equipment upgrade. He is getting rid of a Behringer basic mixer and he said that I could have sometime this summer. I think this is the one he has (Buy Behringer EURORACK UB802 Mixer online at Musician's Friend) Would this work as a decent headphone amp? Would this be an improvement over stock audio? I know this is a cheaper unit and does more than what I need. If I went this route I would probably add the Alien DAC to go infront of it.

[synaesthetic]

1) The SOHA, from the schematic as I have never built one before, looks like a fairly easy build. But I wouldn't recommend it as a first build. Try something more along the lines of a CMoy or a PIMETA, both of which can be constructed for under $100 provided you already own the required tools. It's best to source parts yourself the first few times you build so you can get a good idea of what each part is used for. Also it's important to note that Glass Jar's basic SOHA kit does not include an enclosure, so you'd have to get something to case it up in.

2) JISBOS takes the place of the op-amp used in the SOHA. It does not do anything to correct the DC offset on power on and off. To correct that issue you'd need something like AMB's Epsilon-12 muting and power-on delay offset protection circuit.

3) You wouldn't want to run the headphones right out of an Alien DAC. It's not designed for that. The Alien DAC uses a number of surface mount components which can be tricky to solder for someone not very experienced in electrical work. I wouldn't recommend it as a beginner build unless you already have experience soldering SMD components.

4) That particular amplifier would not work well for the application you have in mind. Those kind of things are distribution amps for monitoring and aren't really designed for audiophile-level listening. A well-constructed CMoy would work better for what you're looking to do and would be an educational build. They're quite fun to put together as well.

[Liquidretro]

Originally Posted by synaesthetic

1) The SOHA, from the schematic as I have never built one before, looks like a fairly easy build. But I wouldn't recommend it as a first build. Try something more along the lines of a CMoy or a PIMETA, both of which can be constructed for under $100 provided you already own the required tools. It's best to source parts yourself the first few times you build so you can get a good idea of what each part is used for. Also it's important to note that Glass Jar's basic SOHA kit does not include an enclosure, so you'd have to get something to case it up in.

2) JISBOS takes the place of the op-amp used in the SOHA. It does not do anything to correct the DC offset on power on and off. To correct that issue you'd need something like AMB's Epsilon-12 muting and power-on delay offset protection circuit.

3) You wouldn't want to run the headphones right out of an Alien DAC. It's not designed for that. The Alien DAC uses a number of surface mount components which can be tricky to solder for someone not very experienced in electrical work. I wouldn't recommend it as a beginner build unless you already have experience soldering SMD components.

4) That particular amplifier would not work well for the application you have in mind. Those kind of things are distribution amps for monitoring and aren't really designed for audiophile-level listening. A well-constructed CMoy would work better for what you're looking to do and would be an educational build. They're quite fun to put together as well.

Thanks for the info. I was looking around and saw the JDS Labs CMOY with Bass Boost which sounds very interesting. What do you think of this? JDS Labs

I have a lot of through hole solder experience and a little SMD mount experience. I am always willing to learn.

[rds]

you will learn a lot more building this one (and probably have more fun):
How to Build the CMoy Pocket Amplifier

[synaesthetic]

Yup, do the Tangentsoft one. It's a great intro to DIY audio.

[tomb]

Same answers from two forums - hopefully, that's sufficient.