Should I DIY or just buy a commercial amp?

[iScream]

Hey guys,

First, I apologize if this is a FAQ. I did search a little before starting the thread.

I need 4 channels of high quality amplification. Something with a minimum of 100 Watts RMS per channel into 4 Ohms.

Before I buy something like an Emotiva XPA Gen3, I figured it can't hurt to check in with you guys and see if you would suggest I go with a DIY, or more likely AIY (assemble it yourself), solution.

Anything you would recommend I check out? I know how to solder and read at least a basic schematic. But I have my hands full right now trying to learn about speaker design so I just don't have time to go off and study too much amp stuff.

And I need something pretty efficient because I'm pushing the limits of the one 15 amp circuit in my listening room right. So I'm asking in the Class D forum.

I don't mind spending $500 and a couple hours a day for a week or two if I'm getting something good back for my money and time.

My guess is the advice will be go buy something commercial but I'm willing to listen to other ideas.

Thanks for any help.

-Chris

 

[gabdx]

how are you pushing the limits of the 15 amps ? did you changed the breaker?

 

[iScream]

how are you pushing the limits of the 15 amps ? did you changed the breaker?

Hi end desktop computer with big graphics card plus four other required amp channels to run my 3-way active plus subwoofers setup.

Not sure what you mean by change the breaker. Are you suggesting I use a higher amp breaker without upgrading my wiring?

-Chris

 

[iScream]

I just realized I priced that Emotiva with only 2 channels rather than the 4 I need. Probably not looking to spend $1300 on a commercial amp.

-Chris

 

[gabdx]

You need to calculate the charge of the equipment before you think you overloaded your 15 amp breaker. Also a 20 Amp breaker is legal with proper wire and gives you the extra power.

P=VI, 120X12A = 1500 watts,
550 watts for computer
300 watt for sub
650 watt left for the amp
expecting peak power from all the above
300 watt of headroom before breaker trips

RMB-1555 | Rotel 650 watt peak 5 channels 120 watt class AB

 

[iScream]

You missed two channels of amplification, the lights and ceiling fan for the room, two large monitors, etc.

 

[nigelwright7557]

Best bet is to buy in ready built modules then build them into a working amp.

I have done the irs2092 design my own pcb route and got bogged down in pcb layout issues and decoupling issues. It took 3 goes to get a fully working pcb.

 

[xrk971]

This is not class D, but sounds better than any class D or any other amp I have built or own for that matter. It is a unique current drive but voltage amplification topology so very quiet. Superb dynamics, low distortion, great soundstage and superb transparency. Dead silent when no signal.

VHex+ MOSFET amp 90w at 8ohms. Probably 150w at 4ohms. Amp parts and pieces no case is $150.

I doubt any $500 commercial amp can keep up with this amp.

http://www.diyaudio.com/forums/solid-state/286992-irfp240-9240-amplifier-simulated-tina.html

 

[Bare]

1) Move ? all your Paraphernalia to a room with More than One circuit
2) Run an extension cord to another plug on a different breaker.
3) ease up on your Gear expectations.


PS. in above photo.. Heatsinks and Torroid ...alone ...~ 100+ $...
if one had to buy them 😉

 

[gabdx]

Receiver | A/V Receiver | Stereo Receiver | AVR | TX-NR646 | Onkyo CANADA

7 channels;
100 watts per channel;
All included, for 750 watt peak, I bet it sounds better than class D and for 600$ big max,
I doubt building your own class D 7 channels will look that good and cheaper!

 

[xrk971]

1) Move ? all your Paraphernalia to a room with More than One circuit
2) Run an extension cord to another plug on a different breaker.
3) ease up on your Gear expectations.


PS. in above photo.. Heatsinks and Torroid ...alone ...~ 100+ $...
if one had to buy them 😉

300va trafo $36+$12s/h =$48
AN-3236 - 300VA 36V Transformer - AnTek Products Corp

Heatsinks by the inch, $2.63/in X 3in X 2 + $5cut fee and shipping. $30.

http://www.heatsinkusa.com/7-280/

$78 total.

PCB's $41

BOM $45

Ok $164.

 

[iScream]

Best bet is to buy in ready built modules then build them into a working amp.

I have done the irs2092 design my own pcb route and got bogged down in pcb layout issues and decoupling issues. It took 3 goes to get a fully working pcb.

Thanks. Where do I look for modules? I know about the Hypex stuff but that's about it.

-Chris

 

[iScream]

This is not class D, but sounds better than any class D or any other amp I have built or own for that matter. It is a unique current drive but voltage amplification topology so very quiet. Superb dynamics, low distortion, great soundstage and superb transparency. Dead silent when no signal.

VHex+ MOSFET amp 90w at 8ohms. Probably 150w at 4ohms. Amp parts and pieces no case is $150.

I doubt any $500 commercial amp can keep up with this amp.

http://www.diyaudio.com/forums/solid-state/286992-irfp240-9240-amplifier-simulated-tina.html

What kind of investment in time would I be looking at for something like this? And how steep of a learning curve would there be?

Thanks,
Chris

 

[nigelwright7557]

Thanks. Where do I look for modules? I know about the Hypex stuff but that's about it.

-Chris

Ebay sell loads.
A reputable dealer might be better though.

 

[iScream]

1) Move ? all your Paraphernalia to a room with More than One circuit
2) Run an extension cord to another plug on a different breaker.
3) ease up on your Gear expectations.


PS. in above photo.. Heatsinks and Torroid ...alone ...~ 100+ $...
if one had to buy them 😉

If we weren't leasing this house I would just run a new circuit up to this room since it's right above the garage and the breaker panel.

 

[iScream]

Receiver | A/V Receiver | Stereo Receiver | AVR | TX-NR646 | Onkyo CANADA

7 channels;
100 watts per channel;
All included, for 750 watt peak, I bet it sounds better than class D and for 600$ big max,
I doubt building your own class D 7 channels will look that good and cheaper!

I've got home theater receivers sitting around already. An old Harman Kardon AVR-55, a Yamaha, and a newer, lower end Harman Kardon. I'm using the main amp channels of the AVR-55 for one of my current 3 ways right now since it has jumpers on the back that let me bypass all the receiver circuitry.

But it only let's me do that with the main two channels and I'm about to add a 4th way.

-Chris

 

[xrk971]

What kind of investment in time would I be looking at for something like this? And how steep of a learning curve would there be?

Thanks,
Chris

This was about the 7th SS amp I built and has some SMT soldering - they are big ones so easy. I built it in one night and got one running the next day. The second one had a problem that took another night to debug (cold solder joint). It's probably not a first amp if you have never soldered before. But if you are handy with an iron no problem. You need to know how to drill and tap 4-40 threads in the heatsink for the transistors. You need to know how to put together the PSU for the power supply. I have schematics for that too. So everything considered about 5 nights worth of work. 4hrs a night.

If your very first amp - I can suggest the Apex FX8 - very easy to make. The Dx amp is also very easy and both sound vey good.

 

[FriscoDTM]

I used the Icepower 50ASX2BTL board for my Atmos amp and have no complaints with the performance, and I think something like this would fit your request constraints. I got 11 boards into a 3U Modushop case, plus one MiniDSP2x4 for my subs, three 90mm Noctua fans, and hopefully I still have space for one additional Amp that I will add for some Crowson transducers. The sheet metal work and machining was the only moderately hard part; the rest was just assembly. If you only need four you could pretty easily build them into a 2U chassis mounted flat to the perforated baseplate. These boards can be purchased for $90-100 each on eBay, and all other parts I used were from Modushop, Redco, Grainger, McMaster Carr, and Digikey. If you can use the Neutrik style connectors on the back you can get pre-punched panels that would allow you to use XLR, speakon, power con, etc..

A couple example photos of my amp are here: Ice power 11 Channel Amp Build - Album on Imgur

 

[vzaichenko]

Thanks. Where do I look for modules? I know about the Hypex stuff but that's about it.

-Chris

We offer the modules (a number of options) - please see the link in my signature below for more details.

Cheers,
Valery

 

[dannyjmf]

Hi

Using TDA8950 will provide at least 150W x2 for 8ohms each channel ... get two of these class D ready made modules will provide what you will need ... best of all i've been letting them to handle bass duty (12" car subwoofer driver)at home ... does the job nicely ... hooked up in BTL mode ...