Anyone have experience with diy amps?

[Hdale85]

I currently dont own a reciever and im going to be building some speakers before too long and i was concidering buying a reciever. But then i thought if im going to have to buy equipment i want to do it right the first time especially seeing as most of the speakers i want to build are 4ohm speakers and i havnt seen one reciever im looking at that'll handle a 4ohm load. Well being as ive taken so many electronics corses and love soldering i said hey ive read a little about DIY Amps why not find a good one and build it my self so my question to you is have any of you had any experience with diy chip amps? not looking into tube amps really as this is for home theatre/music. My budget for the amp will most likely be ~1000 dollars give or take a little its probably pretty low for an amp not sure..if worse comes to worse i guess i can get some sort of amp off ebay let me know your thoughts on all things please! are diy amps worth the build over buying a commercial unit? Ive seen a few 7 channel rotel amps on ebay for under 1000 bucks but i figured i might be able to get better quality for the same amount of money through diy. anyways thanks for your thoughts in advance!

[ThomasW]

This will get you started

https://www.htguide.com/forum/showthread.php?t=16637&highlight=DIY+amplifiers

https://www.htguide.com/forum/showthread.php?t=15572&highlight=UCD+amps

[Cowanrg]

check out my site for more. i built a pair of monoblocks for around $300-$500 for the pair.

https://web.archive.org/web/20070930223255/http://www.cowanrg.mesanetworks.net/projects/

[JoshK]

I have built 6 channels of UcD 400s (for Arvo Part active amping), but I just ordered up a pair of SKA150 modules from Greg Ball for $100/pr. Here is the address...

Link not available

Basically the same PSU requirements as the UcD400, so in my case I can use one of my UcD400 psu's to make comparisons.

[Hdale85]

JoshK pls let me know when you get that amp setup it seems interesting..i may order the parts to build a 7 channel amp with those kits they are fairly cheap as well i wish the hypex kit could be orderd unassembled so it may be cheaper or somthing this is going to be the most money ive ever spent on a stereo and id like to keep it as low as possible for now lol keep in mind i fully intend to upgrade over the years as this is going to be a hobby of myne for a long time as it interests me a lot. Id really like to know how those SKA150 amps sound though i was reading through the page seems like it could be pretty nice especially let me know how they compare the the UcD 400's as they are just like the 180's i believe sept for different wattages. I dont think id need the UCD 400's as im going to be building most likely the Modula MTM 1's also i didnt see on the site if the SKA150's would support a 4ohm load? would you happen to know if they do or not? reason im most inerested in the SKA150's right now is price im getting tax returns back and i could order enough kits for 7channels with no problems and then order the rest of the parts later after i save some more so that im not spending 2k dollars all at once if it was spread over a few months i wouldnt have such a problem. thanks for the links guys great info!

[Hdale85]

Cowanrg what kit did you use for your Aleph 3 amps? i dont see them listed anywhere so wasnt sure? was kind of in a hurry so maybe i missed it. Also did you buy the final chasis or make them? what would it take to get one just like them? they look expensive probably out of my budget lol 60Watts per channel at 4ohm load should be plenty for the speakers i want to build.

[cjd]

I've got some chip-amp based stuff cooking. Different direction. And not approved by the Empire. But good sound regardless.

C

[BobEllis]

I've built several amps, my favorite so far is the Pass/Thagard A75. It will handle 4 ohm loads with ease. It cost me about $700 for a stereo amp.

The Leach amp is also a good sounding amp, and is fairly easy to get running right if you take your time. You can buy boards from Professor Leach, or there seems ot be another group buy brewing at DIYaudio of a board that uses plastic output devices.

For a first project, you might want to consider one of the kits from www.chipamp.com. Nice boards, easy to assemble. For 4 ohm loads use either 3 LM3886 amps in parallel or both channels of an LM4780 per channel.

[Hdale85]

how do the chipamps.com kits compare to the hypex? cause what im thinking about doing is ordering everything for a 7 channel hypex kit piece by piece and build it slowly as it will probably be a few months before i even order the stuff for the front 2 speakers...but then again if the chipamps.com stuff sounds as good or what not then i may go that route as i said i dont like to replace electronics very often so usually i spend a little more and get somthing nice of course when im building it...not sure how true that will be lol.

[Cowanrg]

Dougie085,

all the information is on my site, with links to the places i bought everything...

if you still missed it let me know.

personally (IMO), the chipamp stuff is low-fi. i was one of the first people to jump on that bandwagon many years ago when it was first getting started. i built several different version. i did them point-to-point, and with circuit boards. i used fancy resistors, bypassed by auricaps, etc. i compared them heavily with real amplifiers (commercially made stuff) and they didnt really even compare to the lower end stuff.

not only that, but they just dont have enough power to run anything reasonable. maybe for a bedroom and a small pair of bookshelf speakers, but any larger speaker will demand more than that little chip can handle. i was thoroughly unimpressed with them, and im amazed people continue to make them. its a neat little project amp, but it never sounded anywhere close to good.

obviously, i would go with the UCD (hypex). i am building a pair of stereo UCD400's, and they sound very good. not the best ive heard, but im making a few tweaks to maybe they will sound better. but stock, they sound very very good. this is of course my opinion, but i just dont think the chipamp stuff is in the same league.

[Hdale85]

thats what i figured and thats why i really didnt look into the chipamp.com stuff to much i mean i use to be big into car audio stuff and you could always tell how well a car amp was built by the circuitry and that just looks so simple so i figured it was more somthing simple that anyone could build and i can never find anything about their power rateings is another thing. the hypex kits just look awsome to me Im pretty sure im going to go with the UCD180's as the speakers im building should do fine off them they are 4ohm speakers and 180watts should be plenty i believe. Im going to do it piece by piece though im going to order a chasis and 3 of the of the UCD180 modules and maybe a transformer? curious what size transformer would you use for a 7 channel amp? i was thinking maybe id use 2 chassis and put 3 channels in one for the fronts and the other would have 4 channels for the surrounds that way i wasnt putting such a big load on one transformer. Of course i could build them all in single chassis as mono blocks im sure that would be best but...that adds alot to the cost as id have to purchase 7 transformers and 7 chassis. anywyas thanks for all the info this site is much better about info on these then other places ive tried.

[Hdale85]

ok i was just checking the page that you get your chassis from very nice and very cheap but i dont see a place for Black Annodized bench top cases? they have the ones that are 19" wide in black annodized? do you have to call and special order or somthing? just curious as they have really great prices and they look pretty nice

[cjd]

Bob: The LM3886 has NO trouble driving 4ohm. In fact, that's where it is capable of its best ouput. It's designed to drive 4ohm specifically. No need for even two paralleled (that would get you the ability to drive 2ohm stably on a high voltage power supply).

Cow: What chip? My own comparisons with the non-audiophile basic chipamp.com LM3875 suggests that it's much better than your description of your experience would lend me to believe. It's not the end-all be-all, but it's not anywhere close to garbage. In basic form, it's mid-fi. In top form, it's capable of playing with the hi-fi crowd. In my experience, anyhow.

I have not tried UCD yet, though it's on my list of things to do for sure.

C

[BobEllis]

I've heard that the 3886 is good at 4 ohms, but my experience with a LM4780 amp (two LM3886 in a single package) seemed to indicate clipping problems with a driver that dips to around 6. Never put it on a scope to figure it out though. I ran it on +/- 35 volts. I really wasn't pushing it, in a small room with 88 db efficient drivers. The circuit was straight out of the application notes, wired point to point.

I suggested LM3886 as a fairly inexpensive way to get a bunch of channels. I agree that the fidelity may not be the best, I noticed quite a bit of low level detail missing with my LM4780s in a direct comparison to my Leach amps. I haven't used the UCD modules, so I cannot offer any opinion there. ALthough it doesn't fit the all in one case idea, Leach for at least the front channels would be my recommendation if the budget supports it. Parallel LM3886's fits with my philosphy that you can never have too much current capability. Remember, my favorite amp is an A75 with arc welder like current capability.

[Hdale85]

anyone else have any sorces for chassis? lol been looking at this site that cow used but they dont seem to have a 17" wide chassis anymore.....be nice to get one about 17.5 inches wide they do custom sizes but im sure it costs a bit more 17.5 is close to how wide the preamp i want to get which is an Outlaw anyways just curious thanks

[Hdale85]

okay cowanrg i was just reading through that site for chassis some more and was that a custom chassis? i just saw that part lol if it was a custom chassis what was the price on them with the annodized black? just curious i might order a couple here pretty soon they really are decent chassis for the money.

[Vikash]

Bob: The LM3886 has NO trouble driving 4ohm. In fact, that's where it is capable of its best ouput. It's designed to drive 4ohm specifically. No need for even two paralleled (that would get you the ability to drive 2ohm stably on a high voltage power supply).

Cow: What chip? My own comparisons with the non-audiophile basic chipamp.com LM3875 suggests that it's much better than your description of your experience would lend me to believe. It's not the end-all be-all, but it's not anywhere close to garbage. In basic form, it's mid-fi. In top form, it's capable of playing with the hi-fi crowd. In my experience, anyhow.

I have not tried UCD yet, though it's on my list of things to do for sure.

C

I have to agree. A single LM3886 can pump plenty enough current for 4 ohm loads. Check out the datasheet too. Not sure how you derived to your conclusion Cowrang, but to each his own. With good implementation and PSU it's certainly above midfi stuff. It's been praised by few as bettering some of the big boy amps in best implementation - the Krells etc, although I don't put much weight on that kind of opinion personally.

If you're unwilling to give it a shot, then your other options include the Alephs, the Krell clones, and AKSA's OTTOMH.

If you're tempted to give the National chips a shot (found in 47labs, and Jeff Rowland amps amongst others - so don't compare to car stuff!) then check out in no particular order:
www.audiosector.com for high quality kits and chassis

Carlos FM's lm3886 amp and snubberised hi-cap psu on diyaudio.com (my favourite out of the ones I've tested so far)

Mauro Penasa's design is highly regarded alternative approach for the lm3886.

[Hdale85]

I wasnt really compareing to car audio anything i know its completely different and didnt mean it that way sorry

[Branwell]

Hi,

I had the UcD180s on the mids of my active three ways. The mids are a pair of drivers which run about about 3 to 4 ohms once connected. The 180s had no problems. In fact, I liked them enough that I now have a pair of 400s and another pair on the way.

Cownarg : The Hypex modules have a pair of electrolytic caps at the input of the signal path( C7 and C8 on the 180, and C23 and C24 on the 400s). They are there to stop DC destroying the speakers should the source output DC to the amp.

I replaced these with Auri caps and got major rewards. Later I measured my source and discovered it was not outputting DC, so I removed the caps altogether. Again, big benefit in sound quality. ( If you use the Hypex power supply, it monitors the amps output and will cut power in the event of DC, so running no input caps is relitively safe ).

Branwell McClory

p.s. The UcDs are replacing an ATI-1806 in my system.

[Cowanrg]

Hi,

I had the UcD180s on the mids of my active three ways. The mids are a pair of drivers which run about about 3 to 4 ohms once connected. The 180s had no problems. In fact, I liked them enough that I now have a pair of 400s and another pair on the way.

Cownarg : The Hypex modules have a pair of electrolytic caps at the input of the signal path( C7 and C8 on the 180, and C23 and C24 on the 400s). They are there to stop DC destroying the speakers should the source output DC to the amp.

I replaced these with Auri caps and got major rewards. Later I measured my source and discovered it was not outputting DC, so I removed the caps altogether. Again, big benefit in sound quality. ( If you use the Hypex power supply, it monitors the amps output and will cut power in the event of DC, so running no input caps is relitively safe ).

Branwell McClory

p.s. The UcDs are replacing an ATI-1806 in my system.

yeah, i am taking those caps out altogehter in my final revision of the amps.

plus, im replacing the onboard power supply caps (the large ones near the "heatsink") with panasonic FC. im also comtemplating replacing the output filter cap. im working on a guide for how to tweak the amps, its here:

http://www.cowanrg.mesanetworks.net/projects/ucd_tweaking.htm

[Hdale85]

i really enjoy this forum. ive been on many other forums regarding diy and home theatre stuff in general and ive never gotten as much help as i have here everyone that knows more then me on the other forums just doesnt want to deal with me and it makes me wonder what they are there for if its not to help other people as well as them selves? lol but anyways just wanted to put that out there

[JoshK]

yeah, i am taking those caps out altogehter in my final revision of the amps.

plus, im replacing the onboard power supply caps (the large ones near the "heatsink") with panasonic FC. im also comtemplating replacing the output filter cap. im working on a guide for how to tweak the amps, its here:

http://www.cowanrg.mesanetworks.net/...d_tweaking.htm

Excellent guide! I've been reading the hotrodding thread (but not yet in entirety) but a pictures worth a thousand words you know?

[TacoD]

I also want to add that UCD is very easy to build and good sounding.

[jdybnis]

Cowanrg,

Have you goine through any of the ungodly huge hypex threads on diyaudio.com? Lots of tweaking info.

[Hdale85]

yea.....lol how much can you do with these things...they dont have THAT many parts to them oh well im sure i'll be happy with the stock configuration at least until i listen to them a few months and decide i want more lol and then i'll start tweaking till im satisfied again i think im going to build 3 amps now 1 3 channel with 3 UCD180AD modules for front duty 1 4 channel with 4 UCD180AD Modules for rear surround duty and then a Dual Mono Block with 2 UCD700 Modules and seperate transformers and powersupplies for both for running my subs i figure if 700 watts isnt enough for the subs i could figure out how to wire them to 2 ohms and get some more from the amps lol but i think 700 watts should be plenty...has anyone played witht eh UCD700 modules? of course this would be the very last amp i build first im building the 3 channel then the 4 and then later the sub amp this way i spread out the cost over several months lol easier on the budget

[JoshK]

Doug,

I'd got with the 400s for the front, just for the hellavit. It isn't that much more and extra power in reserve is always a good thing.

[cjd]

See, all this tweaking is exactly why I've stayed away from Hypex so far: I can't just build it right the first time, because I can't truly DIY a Hypex. As if it's even considered DIY at that level.

The ears some folks must have... I believe every time a veil is lifted from the sound of one of these systems, it is placed between the neuro-transmitters in the listener's brain. :rofl:

C

[Hdale85]

Well its diy to an extent i mean you have to design a power supply....well you dont have to but i am rather then useing their 200 daller per 2 channel power supply so at least i get to do some diy work :-D lol and i have to mount it all in chassis and cut and drill holes into the chassis for all the connectors switches and led's i found some bi color led's i want to use as well they are blue/red and difused so they wont be overly bright like those Hyper Bright blue led's lol

[Cowanrg]

jdybnis,

yep, ive read every single thread, start to finish. its a task, but i like to know what im doing. ive followed the hot-rodding thread from the beginning too.

Dougie085,

only a few parts are showing. what you dont see is the backside of the board. its all surface mount components, and there are a LOT of them. its not as simple as it looks.

the ucd400 is tempting for the extra power, but you need to figure out if you need it first. most people can make do with the 180 just fine. and if you decide to build 2x ucd400's, and the rest of them 180's, it gets complicated because they dont use the same power supplies.... if you use all 180's, you can use the same parts.

cjd,

this post is ignorant on so many levels, its not worth replying to.

Dougie085,

this project is very much DIY. even though the amp board is designed and built, there are other apsects to it. i hear a lot of people criticize it as not diy, or just "plug and play". but i dont hear those same criticizms with speaker projects where you buy a kit with drivers, designed crossover, and plans for the box dimensions. sure, you are "building it", but you arent adding any originality to the design at all. at least with these amps, you can customize the module, add your own power supply, and arrange it in a case, and build the case. even if you buy the case, you still have to make a layout and choose quite a bit of parts inside.

[Cowanrg]

Excellent guide! I've been reading the hotrodding thread (but not yet in entirety) but a pictures worth a thousand words you know?

thats what i thought!

i have read through all the hypex threads, and they just started to get confusing because parts were always referred to by name, but no one had ever explained what the part was! so i tracked down where it is on board, what value it is, what it does, and why upgrade it. soon all of that will be on there, with suggestions of what to buy.

[Hdale85]

yea i dont think for my main speakers i'll need more then the UCD180's and the only reason for the UCD700's is for my subs i just figured id rather have a external amp for my subs rather then use a plate amp only problem is i'll need to build a crossover for my subs then...lol oh well i enjoy doing this stuff so no problems

[cjd]

cjd,

this post is ignorant on so many levels, its not worth replying to.

I'll reply to you anyhow, because I do think it worth replying to.

If you were (as I suspect) referring to my post and not your own, well... it was tongue in cheek. I get sick of hearing about "veils lifted" when that does nothing at all to describe what actually changed in the sound.

I mean, I could have described the change in what I was able to "see" as being "like a veil was lifted" back when I first got glasses. It doesn't do a thing to really describe what changed.

However, the vitriol evident in your post? I don't get it. Get up on the wrong side of bed this morning or somethin?

I should add that I DO consider the UCD stuff DIY in the same way I consider the speaker kits DIY. Or building a sub DIY (since it amounts to not much difference from a speaker kit).

Hell, I wonder if I really DIY speakers because I still start out with manufactured drivers. Not to mention wire, caps, etc.

But the level of tweaking on the UCD's sure *does* make me wish I could DIY it at a lower level (i.e. never pay for the parts tossed).

Dougie: have fun with the power supply. Even there, it seems to be an art. With folks that argue it isn't. And everywhere in-between.

Who knows. I only know enough to be very slightly dangerous. And to have fun. Sometimes I share the results. Sometimes I don't.

C

[thylantyr]

I like DIY amps perhaps more than the average guy, but
everytime I see used proamps on the market it makes me
wonder why I want to DIY the amp in the first place. Is it to
save money? To get equivalent proamp quality/power it will cost you
more. A 2400w proamp cost about $400 used, a toroid for a
similar project using similar VA ratings can cost you $150-$200. If you want the 'high end' toroid, then it's double,
triple that amount.

If you want to do it for fun, then yeah.. do it. If you want to do it
because you think there is better sound quality then you are in
for a big surprise if you were to ABX the two

The only way to get a deal on DIY amps is to;

a. buy surplus parts and adjust the design accordingly.
b. buy bulk, but then you need many interested parties unless you plan to make many amplifiers yourself.
c. steal parts 8O

[cjd]

If you want to do it for fun, then yeah.. do it.

That and the ego trip.

Plus, I like my boxes better. Cherry face, maple sides and dovetail joints?

C

[mikec]

anyone else have any sorces for chassis?

Maybe not as fancy as some of the others, but the ParMetal Series 20 aluminum chassis are well made and don't cost a fortune. They will even custom make them to your specs for not a whole lot more than the cost of their off-the-shelf units. I used these for my 3-channel UcD amps.

Images not available

[Hdale85]

what size chassis did you use? how much were they? what size transformer did you put in it? i should call them....but maybe you'll reply quicker lol

[mikec]

There is a price list on the ParMetal site. The ones I used measure 16W x 12D x 2.75H. They also sell the divider shown in these photos, which provides some shielding and also a convenient place to mount the filter caps.

Images not available

[Hdale85]

hmm your pics arent clickable lol no bigger versions i guess =/.... yea but they dont show the prices of the annodized black versions.....so just curious i need to call and place an order probably =/...just not sure how big i want them to be lol id like them to match the size width wise of the preamp im going to get which will probably be an outlaw audio processor/pre amp

[Hdale85]

OK well here's a parts list of what im ordering lol....from like 5 different places...be fun picking up 5 different packages *sarcasim* let me know if im forgetting anything or changes on some of the parts like if youd recommend useing something else ?

Exodus Binding Post-Short x3 $31.50

Softstart Module x1 $69.50 (this is the hypex sofstart anyone know of anything cheaper and better please let me know)

Exodus EX-FRCA x2 $10.50

UCD180AD x3 $350.85 includeing shipping

AVEL Y236851 625VA 30V+30V TOROIDAL TRANSFORMER x1 $65.88

RUBBER CABINET FOOT 1-1/2" DIA. x 3/8" x4 3.56

IEC POWER JACK CHASSIS MOUNT x1 $1.24

LITTELFUSE 3AG PANEL FUSEHOLDER x1 $1.55

NEUTRIK NC3FD-L-1-B XLR "D" SERIES PANEL MOUNT FEMALE BLACK x3 $10.14

DPDT ROCKER SWITCH x1 $2.80

Cornell/Dublier 12,000Mfd 80V Snap in Caps x6 $29.70

Bridge Rectifier x6 $12.00

20-17155x-B Black Annodized Almuminum Chassis x1 $60.00 (this is a guesstimate not sure they have this size even lol)

DIFFUSED Bicolor LED: Blue (2,000 mcd) & Red (3,000 mcd) 75 Degree Wide Angle x15 $25.20 (minimum order is 15 so if anyone wants some of these lemme know lol)

Total Price - $674.43 (add a little shipping and some odds and ends parts from ratshack)

If you know of anyways to cust some costs on this it would be greatly appreciated If the bennifiets are better with the more expensive part then i'll probably stick to this list rather then the cheaper part thanks!

well let me know if i screwed up somwhere...lol i figured i could buy wire and what not at the local ratshack thanks a ton

[thylantyr]

Softstart Module x1 $69.50 (this is the hypex sofstart anyone know of anything cheaper and better please let me know)

The cheaper method could cost you $0 if you post your schematic.

What vendor is selling you the CDE big caps for $5 ea?

[Hdale85]

eh......i dont really have a schematic atm lol was just a basic powersupply with one transformer 6 caps (2 per ucd module) 6 rectifiers (2 per channel) so basically each ucd module would think it has its own power supply. the caps are from apexjr.

What do you draw up schematics in? just curious? if i can get a program for it maybe i'll try and make up a schematic of how i think this will look like? lol

One reason i like the hypex softstart is i can put the amp in standby mode and use the bicolord led's and what not kind of a nice feature....but idk

[thylantyr]

eh......i dont really have a schematic atm lol was just a basic powersupply with one transformer 6 caps (2 per ucd module) 6 rectifiers (2 per channel)

Looks like +/-42V rails. Subtract about 1.4V for bridge
recitifier, you are close to 40V. Apexjr shows some fat
36,000uF 40V caps for $3.95. If it was me, I'd be willing
to use those instead, more capacity for less dollars. Will
they fit in the chassis? Are you brave to try a 40V cap
in a ~40V application? //lol // ... typically what happens
when you over-voltage a capacitor is that it heats up.
Most people don't worry about a few volts of over-voltage
though, it's when you really exceed ratings that the cap
gets hot and explodes.

so basically each ucd module would think it has its own power supply. the caps are from apexjr.

There are many ways to make a power supply, the method
you describe I have done before with chipamps. The 'how to build a better supply' is a topic for another thread. But
you can simplify if you wanted to and just make one
central power supply using one rectifier and all the caps,
then each module feeds off of it. There are pros/cons to
each method. Depends on how cute you want to make the PS design. If you were to use true dedicated supplies
per module {tranny, diodes, caps}, that is pretty sweet
and can't get better.


What do you draw up schematics in? just curious? if i can get a program for it maybe i'll try and make up a schematic of how i think this will look like? lol

*paper, pen
*OrCAD
*Circuitmaker 2000

One reason i like the hypex softstart is i can put the amp in standby mode and use the bicolord led's and what not kind of a nice feature....but idk

What does standby mode do in your application?
Anyways, soft soft can be done with as little as

*spst relay
*power resistor
*two diodes
*capacitor {for timing}

Maybe $5 - $15 cost, but not as pretty as a PCB design.

[Hdale85]

well i'll probably leave the amps on most of the time or in "standby mode" for less power consumption which they dont have much anyways lol but still and the softstart would be nice also as i live in a 100 year old apartmetn building and im not so sure how much the breakers can take lol

[thylantyr]

For reference. One DIY amp I made had 2000VA and 100,000uF
per rail. Two AC input cords as one house breaker would trip early.
{driving 1/2 ohm per channel}. I didn't add an inrush protection,
but the house lights did flicker when power up. {15+ year ago project}.
This is about 422 Joules of energy. A few years back I made a +/- 150V
power supply with perhaps 1000 Joules with no inrush. There is
no issues other than a test bench light flicker upon start up {since it's on the same breaker}.

Your power supply is about 63 Joules so I don't see a need to
get paranoid about leaving the amps on all the time or stressing
home breakers and I don't see any capacitor damage
being inflicted :twisted:

Think about the inrush inflicted when your fridge kicks on, table saw, home AC, etc. .. we don't complain :T

[cotdt]

Most of my DIY amps blew up and set fire (3 foot high blue flames), but some of them did work. I really like the 41hz AMP5, and now I'm building a hypex UcD400, which is much much easier to build than a Tripath. The ClassD DIY amps really blow away the commercial offerings which are usually the Class A resistor-controlled type, especially when it comes to treble and warmth, but also bass.