Home Forums DIY Speakers and Subwoofers Looking for a good amp.

  • kanaaudio

    October 7, 2021 at 4:30 pm

    Am looking for the same – just following this discussion.

  • sb-woo

    October 7, 2021 at 4:54 pm

    This looks interesting but, quite expensive for my project. Not that it’s overpriced or anything. I dont think it can do stereo if I had 2 though.


  • 123toid

    October 8, 2021 at 5:26 pm

    @sb-woo That looks awesome!  I haven’t even seen that yet.  That could make some pretty cool speakers

  • tallyfeli

    November 24, 2021 at 4:18 pm

    Hi…. I for the most part use “EL34 World” otherwise called the Hoffman amp building gathering. Amicable and strong amp building gathering. There are some amazing developers there who are liberal with data and helping other people. I’ve watched this discussion be strikingly useful and thoughtful to “novices” in amp building. I likewise incessant “the Amp Garage”.

  • ajc9988

    November 24, 2021 at 5:21 pm
    Posted by: @sb-woo

    I want to build a pair of stereo speakers for my daughter as an X-Mas present.

    Probably gonna go with the new 7″ Dayton Epique woofers (8ohm) and the Peerless 1″ corundum tweeters (8ohm) in a ported box w/passive x-over.

    I hope I can find some kind of all inclusive 200w/ch@8ohm w/bluetooth and wi-fi and make a simple to use integrated powered speaker system but im not really seeing anything standing out to me.

    I was looking at the ICEpower amp board (1x200w) but then I would need bluetooth and wi-fi. Plus it looks like the wiring harness is out of stock.

    Any thoughts or ideas appreciated. 

    Products I’ve looked at:








    I cannot finish this examining and comparison of amps until sometime in Dec. But this shows roughly what you can do.

    For a cheap external amp, if you build the speakers to be bi-amped, would be to grab 2 of the 300A2 or 400A2 from the IcePower website ($155 and $165, respectively). If only grabbing two, you might be able getting away with the SSMPS1200A400. If not, then the 3k is a good choice. Or you could get an SMPS somewhere else.

    But the 4 channels for $310 or $330 (plus power supply, case, connectors and wiring, etc.) would do well and would be better performance than the 200ASC and 200AC (which what I label as usable is lower than rated but is for keeping distortion lower).

    So, just comparing those to what is seen in the other products’ spec sheets (https://toidsdiyaudio.com/community/postid/8400/ has the same images for those in the excel sheet I attached at the beginning of my post; along with links to where you can get the spec sheets for yourself at the bottom), we are talking around 20dB difference by going with the higher cost products.

    Now, if money is a concern (when is it not), the 200ASC and 200AC can be used, but that is around $400 if integrating into each speaker yourself. If you set the speakers up to be bi-amped, you could go with the 4 channels with the 300A2 or 400A2, buy a power supply, get more usable wattage range (the 200Axx products seem to have a usable 30W before distortion jumps up significantly, meaning you are not getting the full 200W, whereas the other two brings the usable amount to 100W or so with distortion much lower, meaning much better sound). And that is before discussing the intermodulation distortion (IMD) and other factors. Now, you should also factor in how loud the speakers can play and how loud they will be played most of the time to decide if the distortion, on its face, will exceed not just the audibility threshold but also pass the threshold where most claim to be able to hear the distortion readily (0.75-1%). So, at 0.1% THD+N, you have -60dB. If you are playing the speaker at 95dB, then the THD+N at 0.1% should be around 35dB. Then comes the question on if the music will mask the harmonic distortion. But the IMD is not so easily masked, and the 200ASC and 200AC has much more IMD than the other ICE amps.

    Then you can ask how many years will these be kept and used, etc.

    Sorry to belabor the point. What you could do is get the bluetooth radio pre-amp from parts express (bluetooth radio https://www.parts-express.com/5-VDC-Bluetooth-4.2-FM-Radio-MP3-WAV-FLAC-Audio-Preamp-Board-with-Remote-320-347), over to your amp (it all winds up with the amp), then to the speaker.

    Ignore the needing two boards for the 300A2 or 400A2 if the speakers are passively cross-overed. If using an active crossover, then a cheap dsp like the ADAU1701 ( https://www.parts-express.com/Dayton-Audio-DSPB-K-DSP-Kernel-Board-and-DSPB-KE-Kernel-DSP-Expansion-2-In-3-Out-325-1300 ) and the ICP1 ( https://www.parts-express.com/Dayton-Audio-DSPB-ICP1-In-Circuit-Programmer-USB-325-132 ) before the amplifier, then bi-amp each speaker.

    Sorry, I really should have paid attention to you mentioning you were doing a passive crossover.

    But, you could basically have the bluetooth pre-amp without worrying about syncing two bluetooth speakers at the same time, have a better amplifier, and if you care to, use an active crossover or passive crossover.

    Just wanted to throw that out there since you were considering the 200Axx products from ICE, even though that is one of the cheaper ways to go active speaker ($200 for a 2-way, $276 for a 3-way, abouts).

  • sb-woo

    November 26, 2021 at 3:47 am

    @ajc9988 wow! Very informative. I’m going to have to look this post over a couple times to fully  dissect everything you’re saying here, but thank you for checking into my issue. 

    At this time I’ve decided to build my daughter a corner desk with a built in 2.1 system. Hopefully I may have it done sometime around x-mas. 

    I will probably still try to do something with the Epique woofers in the near future though.

    I also just ordered a couple FatalPro 5″ woofers and a couple Dayton reference silk tweeters basically just to play around with and see how room gain affects the bass region and wether or not i can get away with sealed speakers with an F3 around 110hz in my room. Messing with a couple ideas.

  • ajc9988

    November 26, 2021 at 4:19 am

    @sb-woo – Well, if you are wanting to use the 300A2 or 400A2, I would recommend doing a sample order off of the IcePower website soon (300A2 and 400A2 links) as they ship from Thailand, and depending on customs and how it is being shipped, getting it by Christmas could be cutting it closer than an order off of parts-express.

    Another thing I realized when looking over the amplifiers, other than the intermodulation distortion levels, was that the Hypex Ncore and IcePower 300/400A2s have around 26dB gain, whereas the Orchard and the Purifi both have lower gain values in the teens. This effects pairing with a pre-amp to hit target wattage to fully stretch the legs of the amps. That means the Hypex Ncore and IcePower will be easier to pair and feed, which also explains part of the reason you have less wattage on the IcePower amps versus the ones I put in the top tier. Even getting the 280W at that low of distortion while having the higher gain levels shows, in part, why I put it in the higher category. With the two amps from IcePower being lower in Watts, but being affordable and the distortion levels, it is commendable, but still in a separate tier (although, it is clearly above the UcD regarding distortion levels, etc.).

    What I might do is buy a carton (with cable kits) sometime early next year. If you weren’t time constrained, I’d ask if you could wait until then if you wanted to do a group buy ($92, then just figure out shipping costs for divvying up after the carton arrived, but $2K for 20 400A2 and cable kits really isn’t a bad price). Then again, I have creative juices for an amp design using 3 x 400A2 (have to double check the exact nuances of the Hypex SMPS3kA400, as it mentioned not being as good at half-bridge, which is what these amps would count as, and with 6 channels on it with it saying that, I would need to verify the viability before diving in). But that means I could, in theory, build 4 amps with 6 channels, then keep the other 8 for deployment either in active speakers (2 per, 4 channels, three used) or to make an 8 channel amp. Should also be noted that it has an attenuation circuit to help with clipping, can have Vu monitors hooked up per channel (if you want), and a couple other things like that.

    I also need to contact the sellers of the 21489 Sharc DSP on AliExpress to see if I could change the firmware to allow (and that the hardware is wired so I can swap a DAC slot for an ADC card) to have 6 input and 6 output. If I can, then it would be 6 in, DSP, these amps, then out. That would be a very interesting amplifier indeed.

    I just don’t know how much interest a person would have in picking up an amp that needs a 20A breaker in order to fully stretch its legs (a 15A can only do around 1800W, but the 6x400W channels, if all run at 4Ohm, would exceed that in such a way that you need a 20A breaker, and if fully cranking it, even that is running it close; although if keeping it to the wattage I recommended, 15A house circuits would be fine). I’d hate to buy a carton, then have to sit on the amp I built for months, you know?

    But glad I could be of help.

  • sb-woo

    November 26, 2021 at 11:04 pm


    I may be interested in 1-2 of those amps. My only issues are that they require balanced input and with that being the case I wouldnt be able to use the simple fmod 30hz hp in line rca filter I was eyeballing. But i do understand there are ways around those issues.

  • ajc9988

    November 26, 2021 at 11:46 pm

    @sb-woo – Just posting this segment from the spec document for others watching the discussion on the point you just made:

    The audio inputs can be used in both a semi-balanced input configuration and in a fully balanced configuration. In semi-balanced configuration, it is recommended to connect the non-inverting input to a single ended signal source and use the inverting input as ground sense on the signal source ground reference. In both semi-balanced and in fully balanced configuration, the signal ground should be connected to ground on the front-end PCB.

    To prevent ground loop related noise and hum problems, the signal ground is fitted with low value series resistors on the module i.e., the signal ground wire must not carry any additional current. The recommended connection to the audio input is shown on Figure 33 in Section 13.

    The two audio signal inputs share the same connector on the 400A2 module.

    So you are correct on that point. The semi-balanced configuration gives a bit of guidance on what is needed when not using a balanced input. Meanwhile, the loudspeaker output is unbalanced (not relevant here, but a heads up so people interested have an idea that inputs are balanced and semi-balanced while the output is not). “The loudspeaker output is in an unbalanced configuration, bridging of the two channels is possible.

    That information is on Page 25 of the spec sheet.


  • sb-woo

    November 28, 2021 at 1:44 pm


     Who else wants to get in on this?

  • ajc9988

    November 28, 2021 at 3:53 pm

    @sb-woo – I’ll start a thread when I get closer to buying. Those that get it when I do (or commit to buy) I’ll give at my cost plus shipping to get to them (which the website says $92 and the wire set is like $8 or $9, so $100 or so plus shipping per unit; but the wire set is sold separately without breaks, so if a person doesn’t want it, just let me know and I will order fewer than one per unit). Any others, well I would price it after that slightly under what the sample cost from IcePower is ($165 without wire set, so like $140-150 plus shipping to get it to those who want it).

    But I won’t be able to do it until Jan. or Feb. of next year (most likely Jan.).