[sdotfire]

I decided to try my hand at building a portable amp because I am capable of soldering and making LODs and ICs.  Any suggestions on which should be my first project?  I own a few portable amps already: TTVJslim, RX, P51, Lisa III, PicoSlim (pre-order), Arrow12HE and GoVibe Vulcan VB.  Opamps is really intriguing to me and I want to understand amp circuitry better in order to enhance my current amps and I thought building an amp would be a great DIY project.  Hopefully, leading to future amp projects and a better understanding of high end audio in general.  I have a ton of universal IEMS (TBPGolds/Coppers/MDs, IE8, 3, UM3X, VB, a few more and will most likely be purchasing the JH-16 at CanJam along with either the SM3 or EM3 or new UM3X with replaceable cable)
 
I have debated between the CMoy Pocket Amplifier, PiMeta v2, PPA or AMB lab's Mini Cubed Portable Amplifier (is this the mini^3 I'm assuming...).  All seem to be great start out projects, the CMOY obviously being the easiest.  Since I already have pretty good amps I don't think the CMoy would be the most feasable choice though and I want something more powerful such as the other amps mentioned but I am open to suggestions.  I know that I probably all of my current portable amps are better than anything I could build now but would like to learn and eventually be able to partake in rolling opamps, modding and creating the best possible amp/rig.
 
Only having basic knowledge of circuits I will need a step by step tutorial but want the best option that includes instructions.  I found the mini^3 (at least I think it is) at Glass Jar Audio for around %100 but was wondering what else is out there and if their are better deals from other suppliers.  The amps listed are the only DIY tutorials I could find and the PiMeta v2/PPA seem more complicated for first time amp makers.  Maybe the CMOY would be the better choice since I am a beginner but the mini^3 is very inticing.  Again I am open to suggestions, I am a chemical engineer and very interested, almost obsessed, with high-end audio and have a craving to learn and understand audio in its entirety.   One day I hope to have the best best possible portable rig/home rig.  For now, I feel compitent enough to make an amp, but to all you more experienced members out there: what do you think is a good initial DIY amp project for me? 
 
Appreciate any advice and help in advance

  

 

[weibby]

don't underestimate a cmoy, tweaked right it can sound very good.
So far I tweaked my cmoy to a point where no commercial amp can give me the same sound.

 

[sdotfire]

So the CMoy can be more powerful than the mini^3? How expensive is it with all parts abd what upgrades would you recommend? Since it seems like a good first DIY project it may be easier for me due to tangent's incredible directions. I just assumed the mini^3 was more powerful and capable of more through tweaking/modding.

 

[sdotfire]

I think I'm going to do both and then try out the pimeta v2 next. Is CMoy's PCB design different than their pocket amp, if so how? Thanks.

Any DIY amp kits out there with a bass boost feature or three gain-level adjustments? This may be too complicated for my initial project but would be nice to have for future referance. Any other suggestions for DIY amps would be greatly appreciated.

 

[Avro_Arrow]

Please don't mistake "powerful" for "good sound".
How powerful the amp needs to be depends on your
headphones. With many headphones, a CMoy
is all the extra power you need.
 
It is better to learn and tweak on a simple design like
a CMoy because it is easier to understand what each
part does and changing a part usually gives more
direct results.
 
A CMoy can be built for just a few dollars so if
you destroy it there is no big loss of investment.
 
The Mini^3 is an AMB design.
A Mini^3 is a very nice and well thought out amp.
It is probably not the best amp to start hacking
and slashing on it you don't know what you are doing.
 
Maybe you were thinking about Tangents PIMETE v2?
It is also a well thought out design.
Tangent also has a very good section on building and
modifying CMoys.
 
Good luck with your build and don't forget to keep
us updated on your results.
 
Quote:

So the CMoy can be more powerful than the mini^3? How expensive is it with all parts abd what upgrades would you recommend? Since it seems like a good first DIY project it may be easier for me due to tangent's incredible directions. I just assumed the mini^3 was more powerful and capable of more through tweaking/modding.

 

[Iniamyen]

The usual CMOY tutorial that everyone does on tangent's site doesn't use a PCB. In a way this is good because it can be tweaked more if you desire. I'd recommend going through the tutorial because it will teach you more about how the circuit works than just stuffing a PCB would. It will work just as well, too. It costs so little to do and is totally worth it IMO.

 

[Avro_Arrow]

Another really good first project would be the Szekeres VE3.
I have a design and building thread here.
It is also a very simple design that gives excellent results.
 
Quote:

I think I'm going to do both and then try out the pimeta v2 next. Is CMoy's PCB design different than their pocket amp, if so how? Thanks.

Any DIY amp kits out there with a bass boost feature or three gain-level adjustments? This may be too complicated for my initial project but would be nice to have for future referance. Any other suggestions for DIY amps would be greatly appreciated.

 

[jcx]

with sensitive iem the only "need" for amplification is to avoid the low frequency roll-off with most DAP too small value output coupling C - most DAP will already have internal op amps more capable of driving the low Z load to the minisucle signal level required than most portable op amp based project amps
 
unity gain buffer/follower circuits could be justified but I would watch out for dangerous output offset V when direct coupling to "simple" low feedback circuits - you could add higher quality, larger value DC blocking caps to the buffer outputs
 
bass boost eq can in principle extend DAP low frequency response by compensating for the coupling C, Zload corner frequency
 
series R or "Hiss Buster" divider can extend low frequency response too while cutting source noise

 

[stringgz301]

I concur on the Pimeta v2.  Very tweakable and lots of interesting design choices (overall voltage, battery power approach, biasing opamps to class A, ...).  Very good sounding amp and great learning lab.

 

[sdotfire]

So the question is which one: Pimeta v2 or CMoy (but which one, I'm assuming the most basic version) or Szekeres VE3 or mini^3? 
 
This is my first project and it seems like the CMoy is the most practical choice because it is the easiest.  Also, all the threads I've read about it claims it will provide me with the best basic initial knowledge for making portable amps.  One day I would love to be able to make my own design from scratch that would be complete my "ultimate" portable rig but am still uncertain if the research and development costs will exceed buying what's already available and modifying it.  Either way I am going to give these first few DIY amps.
 
Obviously, everyone here had to start somewhere and I think the CMoy would be a great first project but only if it will help me understand the basic knowledge of building/tweaking amps the most.  From my research, it seems like the mini^3 is something that you just put together, like when pieced together legos as a kid, and won't help me learn what I'm actually doing.  While the CMoy might provide a better education in amplification circuitry.  Also, I am still open to suggestions for my first project but I am very hungry and will indefinetely want to build more.  Essentially, for me that is inevitable.  So in what order should I build DIY amps or kits to help me reach my goal of being able to produce the ultimate amp? 
 
The reason I am exploring this DIY amp option, even though I have great portable amps, is because I realized how much cheaper DIY is when building LODs, ICs and DIYmods.  ALO Audio"s best LOD is nearly $200 when the components are less than $30 (probably even cheaper since they buy in bulk) and the RWA iMod is $250 when you can make a better one by yourself for around $20.  You can even purchase the 240G 5.5G for $275 and do the better DIYmod for around $300 while ALO sells their Super iMod for $675!  The savings is just unreal and outrageous, so you would think building an amp or anything for personal audio would be much cheaper on your own.  Of course I've had to experiment a lot using cheaper parts but after a while was able to produce good ICs.  However, I just bought an LOD from Twisted Cables because Qusp and Whiplash Audio are the only companies that sell TWag wire in their products and I am not nearly as good as Qusp yet

  
 
But I was truly blown away by the massive markup on these products and figured it was much more cost effective to make these on my own, especially if I am able to make them just as good.  Right now I am not as skillful as Qusp and will buy my most important cables from him but someday I might be able to bypass the extreme costs somewhat and DIY everything for myself.  It seems like building an amp would be much cheaper than purchasing one but that's what I am unsure of.  I have a huge curiousity for high-end audio, almost obsessive, and always want the best of everything.  The whole goal of this project is to be able to mod my current/future amps and, hopefully, one day be able to create a best amp out there.  But, is this even possible/cost effective or should I stick to ICs/LODs and tweak my current and future amps? 
 
Again, where should I begin this overwhelming endeavor?  Budget is not really an issue so I'm not opposed to buying a few of these kits or parts for an amp.  I can start with the easiest but eventually want to work my way up and accomplish my goal of creating an amp that is capable of competing with name brand companies, hopefully for a fraction of the pricec.  Unless anyone thinks this is not feasable and I should just tweak all the great amps that are being produced.  
 
I love RSA amps but wish they had a bass setting at the least, the Arrow12HE is my favorite amp in terms of adjustability (just ordered the newest generation today and have high hopes), but wish it was more powerful like the Lisa III and Protector.  Hopefully, the newer generation will satisfy me but I guess I will have to just wait and see... but learning how to impliment a balanced input. adjustable bass, gain and impedence is something I would love to figure out.
 
Sorry for the long post everyone but I am extremely eager to begin this project and again appreciate all of your help.    

 

[weibby]

Markup itself include man hours, business cost, skills set of the craftsman and initial investment.
You have to take into consideration - however I agree that some are quite crazily over priced.
 
Obviously doing it for yourself has it's perks but after a while looking at my tool box, I've invested hundreds of bucks worth of tools just to make my projects go alot easier and faster.
 
Don't mistake DIY to be cheaper, it can be if you're not a perfectionist or a tweaker..you don't spend the money upfront but slowly, like a woman who goes grocery shopping.
You still have to invest your time and effort which is another cost by itself, not to forget the misc materials you have to stock - heat shrink/hook up wires/etc..
But you get the kick out of modding and trying new things to your build that no one can buy.
 
It will be your sound.

 

[JamesL]

Between the Mini3 and Cmoy, I would say the mini3 is easier to build and performs better.
 
Additionally, the hammond case feels a lot nicer than a mint tin and the built-in rechargeable regulator and charging circuit is very welcome.
Likewise, it costs more to build.
 
As a learning experience however, you can't do better than a cmoy.  It teaches you how to pick parts, and is better project if you want to learn or understand the circuit.  The absence of a premade pcb and delicately tweaked circuit allows the builder to tweak the circuit however he/she wants; you can add a power supply or battery charger, you can add a third or fourth channel, put it in a nicer case, etch your own PC boards and use SMD parts, and the list goes on.

 

[Avro_Arrow]

You know, half the fun is in figuring out how things work.
The other half is fun of building and listening to what you
have learned.
Build a simple CMoy.
See how different op amps change the sound.
See how the feedback and gain resistors interact.
Build your own variable gain.
See how adding a cap in the feedback loop
can give you a bass boost.
Add it to your CMoy and soon you have an
amp that has all the features you were looking for...
See how adding a buffer changes the sound.
Build a Szekeres.
Build a Szekeres VE3.
Try adding your CMoy to the Szekeres.
Learn how to use a simulation program
Learn how to use Eagle to design your own boards.
 
The Szekeres is a scaled down Nelson Pass Zen amp.
Build an amp powerful enough to drive speakers...
 
The list could go on and on...

 

[sdotfire]

All right everyone, I ordered all my parts for tangent's CMoy pocket amplifier design!  I decided, with all of your help, that this will be the best place to start as I will not have a PCB to help me out and be forced to do everything on my own.  I will complete this then try various tweaks/mods...including the bass booster feature.  Thanks again to all the great feedback and advice I have gotten, it really helped me make this decision.  Which is definetely the right one if I plan on being able to design my own amps one day.  I'll see how this project goes then decide on taking on the mini^3 or maybe something more difficult and custom.  I have a lot of tweaks and modifications now to tailor the sound signature of the CMoy to my discretion.  I will keep everyone posted and decide where to go from here.
 
Kind of off topic, but I was wondering if anyone could post any pictures of internals of their DIY LOD.  Both low-profile, normal sized and ones including caps for DIYMod or resistors for iPhone so the airplaine mode isn't constantly prompted.  I have found a few on this forum but most of the low-profile tutorials are somewhat unprofessional looking, at least concerning the case/enclosure of low-profile versions.  That's been my biggest issue along with adding caps (probably not possible for a low-profile) and a resistor (does 68k work for the iPhone 3G-S also and which pins should it connect to?).  Thanks again everyone, you have made my first DIY amp project a much easier decision and it will provide the best education.  I know a lot of DIYer's are secretive in their designs or suppliers for custom made enclosures so I will understand if I don't get many responses in this department.  No worries though, you all have been extremely helpful....if posting on this thread pics of your hard-earned designs for an LOD is too much to ask then I am more than fine with that.  I do assure you that this is all for DIY and learning purposes.  PM me if this is an issue...from my understanding I am WAY behind the curve in building high-end audio and know that this is only a hobby, or an obsession

, for me.  I just can't stop spending time and money on all things regards personal audio.  I really should've become an electrical engineer as opposed to a chemical.....but I haven't felt this excited about something for a long time.  Can't wait for my CMoy components to come in and I already bought a cheap board from radioshack to practice on.  Regarding my LOD need for help, I just want to make them look more professional and sound better.  I have access to liquid Nitrogen so I guess I can try cryo-treating them myself....We will see, this has opened so many possibilities and I do not see anything changing my craving for the best audio equipment....whether it be through modding or DIYing (hopefully DIY since it seems cheaper except for the initial costs of tools, which I own). 
 
I will keep my experience posted.....I just want my CMoy parts!!!!!

 

[naptunian]

Here's a question from a newbie...  Will a CMoy improve the sound from a portable player to a pair of Ultimate Ears SuperFi 5 buds?  I understand that it can boost the power to drive bigger open circumaural type headphones but I haven't read anything about CMoys being used for earbud type headphones.