A|G Electronic RG-402 Build Thread

[joetama 5,000+ posts]

I agreed until you posted what you'r budget was around. There have been plenty of good Mos-Fet designs in the past that, on the used market, would cost well under $1k..... but you wouldn't have the satisfaction of calling it your own, so I commend you on taking the plunge //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

There have been a lot of good MOS-FET designs in the past. But, unless you want Adcom or Hafler then you are pretty much SOL. (And people are overpaying through the nose for those amplifiers) I have and use the H||H V800 currently and it sounds great but it has problems because of its age. Instead of rebuilding that amplifier or one of my dad's old Haflers (which most are cooked like a turkey) I opted to build my own. There are a couple of reasons why. Lower noise floor, faster transistors, easier to find parts (unlike some of the old Vertical Fets), better dynamics, lower THD, etc etc.

To be honest my orginal budget was in the $500 range. Then I started pricing parts. Could I have built it for $500? Sure, but there would have been corners cut and preformance sacrificed; smaller transformer, smaller caps, lower quality transistors, standard resistors, ceramic caps everywhere. And building it for my own use there is no way I'm going to cut corners.

PEN15 man. Can't wait to see/hear it...
nG

Indeed... GOing to be a while since the next week or so is busy busy busy busy...

 

[Beat_Dominator 5,000+ posts]

It's understandable... but you said there were "none" so I thought some chop-busting was in order //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Good heat sinks are mega pricy, you did well to recycle those.

 

[joetama 5,000+ posts]

It's understandable... but you said there were "none" so I thought some chop-busting was in order //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Good heat sinks are mega pricy, you did well to recycle those.

Indeed on the heatsinks being expensive.

I was going to get some from Conrad Heatsinks, BUT the cost of shipping was more than the heatsinks. So I looked for another solution.

 

[Speedbump3]

oic

 

[desertheat 10+ year member]

Sounds like your reasoning for mosfet over bipolar is flawed, no worries most non electronicsfolks make the mistake. /muah

One of the biggest rewards with lateral mosfets [ancient technology btw] is the ease

of paralleling without doing transistor matching, as needed with vertical mosfet, therefore

you can probably 'double up' the output stage transistors to have a lower impedance rating

on the amplifier design, provided you double up on your power supply. /muah

The most I have done is 4x over the stock design, ie the stock design had 4 transistors

per channel, I used 16 transistors. At thing point the predriver transistor is being stressed

and may require more heatsinking *and/or* a 4th stage added to the design, a buffer stage

to drive the heavy duty output stage. I think 2x is doable without additional worries. If that

design has 4 transistors per channel, it can support 8 transistors per channel easy, unless

Rod gimped the predriver circuit design [doubt it].

All you have to do is figure out how to install a few extra transistors and run some jumper

wires to the main board, but make sure you add the additional gate resistor needed.

This version would make a nice second project unless you want to mod this one later. /evil/

This stuff stopped being fun after you realize there are plenty of dumb humans selling

used proamps on ebay for cheap [sometimes not that cheap], but nonetheless, a used PLX3402 for $600 -

$650 is a much better amplifier in general than these $1k DIY projects. A DIY'er just can't compete with

all the good stuff found in proamps, the protection circuits, the high pass filters, the SMPS design, and the

class H, which is sweet. /rawr

I respect DIY 10x over any used prosound amp or off the shelf unit. Do you always have to go stick your @ss into everyones posts with your opinions? I guarantee NO ONE CARES that you like used prosound amps and think they are gods gifts to audio, what does that have to do with this post? This guy is showing his stuff and the direction he wants to go. He will also get a lot more enjoyment out of it knowing he built it and it will be a great learning experience.

Seriously man, you need to stop badgering peoples posts with your BS & opinions. Annoys the living sh*t out of everyone around you.

Now get this back on topic and let us know how it turns out and what you think of the project! I am looking at a nap140 clone for the next toy. Just another DIY to have some fun with.

 

[ballstothewall 10+ year member]

Good lord people, if you don't like Thy's posts, don't read them. That fricking simple.

 

[joetama 5,000+ posts]

I respect DIY 10x over any used prosound amp or off the shelf unit. Do you always have to go stick your @ss into everyones posts with your opinions? I guarantee NO ONE CARES that you like used prosound amps and think they are gods gifts to audio, what does that have to do with this post? This guy is showing his stuff and the direction he wants to go. He will also get a lot more enjoyment out of it knowing he built it and it will be a great learning experience.
Seriously man, you need to stop badgering peoples posts with your BS & opinions. Annoys the living sh*t out of everyone around you.

Now get this back on topic and let us know how it turns out and what you think of the project! I am looking at a nap140 clone for the next toy. Just another DIY to have some fun with.

Just don't listen to him... He's a troll the more you post the more he 'knows'. Plus anyone with a brain and two ears that work knows you can't really trust the advise of a guy who reccomends Behringer if he also says he knows electronics and listens for sound quality.

Anyway, he really has no idea why I prefer MOS-FETs over BIPolar. Nor will I discuss that other than every well built MOS-FET amplifier I have ever heard sounds worlds better than any pro-audio amplifier, unless the MOS-FET amplifier was a Pro-Audio amplifier in the case of my H||H V800. I have however discussed the useage with many people includeing several electrical engineering professors which I am friends with, my father who has been in the audio business for 30 years, emailing with several designers online who support the use of MOS-FETs. But, anyway I guess the transistor as a whole is pretty old and out dated technology...

If MOS-FET is good enough for John Meyer's UPA-1 (one of the best sounding pro-audio speakers I've ever heard) & almost all of the Self-Powered Ultra series then well then it probably is good enough for me.

Good lord people, if you don't like Thy's posts, don't read them. That fricking simple.

Truth to a point... He is a d-bag & we all should know "Don't feed the Troll". But, some people don't know of his posts well enough to know this. I sure do enjoy this forum a lot more when he isn't around. It also seems funny that this is true with a lot of other people on a lot of other forums too... //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[andrewmoore13 10+ year member]

less typing more working!

want more pics! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[joetama 5,000+ posts]

less typing more working!
want more pics! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

I wish I had more time to work on it. I had a 17 hour day today and will be out of town and at jobs working for the next while. So far since I got off for summer break I have been working around 70 hours a week and the last two weeks I've worked almost 204 hours total.

This week and next are pretty much already out the window. My brother, who I work with, has a broken wrist and a cracked rib. Which means I am doing my job (which normally gets me a good solid work day) and parts of his job which he can't do (AKA anything that requires him to move around or lift a lot). So hopefully this will be finished by the end of July but more realistically August sometime. The good news is I like my job and get paid well. //content.invisioncic.com/y282845/emoticons/woot.gif.aaa6090e619a97b6090d16dd863c5a69.gif

I will post pictures as I update from here on out.

Oh and thanks for the interest!

 

[silvercookie 5,000+ posts]

I wish I had more time to work on it. I had a 17 hour day today and will be out of town and at jobs working for the next while. So far since I got off for summer break I have been working around 70 hours a week and the last two weeks I've worked almost 204 hours total.
This week and next are pretty much already out the window. My brother, who I work with, has a broken wrist and a cracked rib. Which means I am doing my job (which normally gets me a good solid work day) and parts of his job which he can't do (AKA anything that requires him to move around or lift a lot). So hopefully this will be finished by the end of July but more realistically August sometime. The good news is I like my job and get paid well. //content.invisioncic.com/y282845/emoticons/woot.gif.aaa6090e619a97b6090d16dd863c5a69.gif

I will post pictures as I update from here on out.

Oh and thanks for the interest!

in order

daaaam

wtf? workaholic much lol

*****, hope he gets better

thats all that matters, no wonder you can afford all this.

 

[joetama 5,000+ posts]

As one of my friends said once "I tried the workaholic anonymous meetings but they were entirely too unproductive."

 

[silvercookie 5,000+ posts]

As one of my friends said once "I tried the workaholic anonymous meetings but they were entirely too unproductive."

lol

if you ever start producing them let me know.

 

[joetama 5,000+ posts]

lol
if you ever start producing them let me know.

That would be fun and all but I'm thinking producing them isn't going to be in the near future...

 

[joetama 5,000+ posts]

I purchased a few more pieces yesterday when I was going past parts express. //content.invisioncic.com/y282845/emoticons/woot.gif.aaa6090e619a97b6090d16dd863c5a69.gif

So, I just need to mutilate an old powersupply I have and we should be on the road to audio!

 

[PV Audio 5,000+ posts]

Do you mind if I stop by and uh...touch your transformer? //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif