[Soymilk]

im trying to decide which amp to build for my (future) dt770/80. currently i'm just using ksc75's, but i figure my upgrade path will be diy amp, then dt770/80, then if i get bit by the upgrade bug a higher end diy amp, and if i'm still feeling the upgraditis probably something along the lines of a proline 750 or darth beyers. edit - actually i may go upgrade headphones then build better amp, whatever i feel like in the future.

so, can you guys recommend me something around the $100 price range? also, i plan on making either a STEPS or TREAD power supply to go with it (what's the difference / which one's better?), which will most likely be re-used if/when i build a better amp, and have this first one either turn into a portable one or sell it to cover for costs of the second one. so for the first recommendation, smaller size would be a bit of a plus

i'm currently leaning towards building a pimeta. i have no idea what i'd build down the road though; i was thinking along the lines of a millett? i might not want to go that expensive, i dont know, throw some suggestions at me

(hopefully this wont turn into just listing what DIY amps there are)

 

[balou]

100$ pricerange? yep, sounds like a pimeta. but a pimeta without buying first 20 different opamps, and no boutique parts. My pimeta will most likely cost about 200$...

A mini^3 has a stated price of 70$. if you add a rechargable 9v and a wallwart, and not the cheapest parts, it will cost about 100$

 

[AudioCats]

For the 80 ohm phones you probably want ALOT of currrent capability, otherwise it might not be worth it to build the amp, since commercial devices such as sound cards can output quite a bit already and 770/80 is easy enough to drive from those devices.

Pimeta sounds good, just make sure you can maximize it (stacking buffers or go discrete). Don't just read other peoples post, do the stacking experiment youself by "hot unplug" the stacked buffer (2 per channel -> 1 per channel with the music still going), then you will see how much difference it makes. Buffer stacking is at least 10X more important than op-amp biasing.

Power supply wise, use only the good caps. The quality of the caps can make the difference between bouncy bass (great)/ pounchy bass (ok)/ boomy bass (not acceptable). All headphone current eventually comes from the supply (just think the amp as a valve), so if the supply has junk juice the phones will only get junk juice, no matter how precise/fast the valve (the amp) is..........

Have fun

 

[Soymilk]

so is a maxed out pimeta my best bet? my price limit isn't set in stone; i just wanted it to be around there. i'll be able to source a lot of parts from work though, i'm currently interning at maxim-ic in the audio department

so my actual cost may be lower than the projected cost of needing to buy everything.

thanks for the tip about not skimping on caps in the power supply. still wondering though: what's the difference between the STEPS and TREAD power supplies on tangent's site?

thanks for the help

 

[Soymilk]

bump for more opinions ^^

 

[fordgtlover]

Steps is a regulated power supply. You plug a mains cable into it and it takes 110v AC (if you're in the US) in and converts it to a DC voltage. You choose the output voltage you want and then select an appropriate transformer to use.

The Tread on the other hand requires an AC-DC walwart to convert the power and the Tread then regulates it.

The tread is much cheaper because the walwart does part of the work (but you still have to buy the walwart).

Check this thread for more information
http://www.head-fi.org/forums/showthread.php?t=143447

Tangent has FAQs for both of these:
Tread
http://tangentsoft.net/elec/tread/faq.html

Steps
http://tangentsoft.net/elec/teps/faq.html

Both projects involve dangerous voltage.

Given that you can't figure the difference between them - no offense - but I suggest that you need to do a lot more reading before you conisder tackling either of them.

There is plenty of information available about both of them. Try using search here and Google.

The path I took was to build a Steps and a desktop Pimeta cased in separate cases. I then built an M^3 and used the Steps powers supply (still separately cased).

I haven't yet sold my desktop Pimeta - but I will.

 

[Soymilk]

ya, i'm definitely planning on reading up on it more before i build it. i remembered seeing pages somewhere on tangent's site about them, but i couldnt find them lol. thanks for the links and summary

 

[Soymilk]

hmm... upon further thinking, i may want to have the psu down the upgrade path instead of building it now. is there a quick and dirty solution for power other than just using batteries?

 

[AudioCats]

If you can build a large enough battery pack and charger to go with it, that is actually the BEST power source you can get. Absolutely the cleanest, purest DC juice........ It also reduce the required reservoir capacitor size (still need high quality though).

 

[Soymilk]

i was actually thinking along the lines of not needing to build anything extra outside of the amp (since i'll most likely be building the battery board with it so i can use it portably). what you're suggesting sounds like (correct me if i'm wrong) big battery pack -> psu -> amp, but that still has the psu to build in between.

 

[AudioCats]

No, it is: charger --> battery brick (charging)
or: Battery brick --> amp (operating).

due to the low internal resistance of the batteries, there is no need for voltage regulation at output. The section voltage will drop gradually when discharged, but that is only between +/-14V fully charged to +/- 12.5V fully discharged.

One thing needs to consider is Ni-MH batteries do require conditioning (at least one full discharge/charge every 3 month). So there is more maintenence than a plug and play PSU.

http://www.batteryuniversity.com/partone-4.htm

 

[Soymilk]

hmm, interesting. wait, i may be misconceiving something here. is the pimeta already set up to use batteries with portable use, or would i have to wire that up myself? cuz my current mindset of a quick and dirty solution (using a couple 9v batteries or something to hold me over until i build a psu) is based off there already being a battery circuit in the pimeta. however, now that i think about it, nowhere does it say that the pimeta already has a battery board circuit thing in it.

as for a battery brick, would the ppa battery board be good? it looks like it houses 18 AA batteries.

 

[AudioCats]

I thought the PPA uses AAA's which are much smaller in capacity.... could be wrong though.

9V will not work. A 9V Ni-MH rechargable is about 200mAH in capacity, with music going the amplifier current drain goes above 100mA, a rechargable 9v lasts less than a couple of hours.... Now how about the alkalines? Good alkalines 9V's are probably around 500mAH, that will last 4 hours, so we count that as one day worth of listening, but the 9v's are about $2 -$3 a piece..... The cost on alkaline in one month will be enough to pay for a PSU, whether the tread or steps.

 

[Soymilk]

unless i'm reading this wrong, the ppa battery board is separate from the ppa itself. i think it has the option between using AAA or AA, but AA's of course wont be able to fit as many. i cant see if it needs another psu to charge it or if it just plugs into the wall or uses a wall wart or what though.. i'll have to poke around a bit more