In 2021 I bought a $35 TPA3116 2.1 amp for portable music. I was actually quite impressed with it. It really made a set of SLS (Superior Listening System) ribbon bookshelf speakers sparkle. I used the trio for camping for a few years and to shut up those obnoxious shrill pill box speakers that friends would bring camping.
I decided to build a passive 6" sub with a pair of 7" radiators and the cheap TPA3116 broke down. So I bought a WONDOM AA-JA33286 JAB5 4x100 Watt Class D (i.e. Dayton Audio KABD-4100 4 x 100W) with DAU1701 DSP and dual TDA7498E amp chips for 2 x 100w + 200w subwoofer. I am very impressed! The SLS speakers aren't noticeably cleaner (still REALLY impressive though) but my DIY passive sub really came to life! So it is time to integrate the amp board, sub, radiators, 12x18650 batteries (29vdc), and 36v 10A ps into a boombox format with mounts for attaching the SLS speakers where they are easily removable for better imaging. After a week with the separate pieces in my shop (I am a woodworker) I REALLY grew fond of the setup while building the box. Now that it is time to wire everything into the box I am really missing having music in the shop.
So I pulled out my ancient Yamaha RX-V2090 receiver. MAN IT SOUUNDS LIKE CRAP!!!! My old RX-V890 was no better. My current Yamaha Aventage 2010 is no better than the old Yamahas either. I can't believe how bad the old Class A/B amps are in comparison to a Class D! I had a Threshold 400A amp, Anthem pre and Magnepan II speakers when I was using the Yamaha receivers for HT and I knew the Threshold Class A 400a amp blew the Yamaha away for clarity, detail, and imaging but these Class-D amps are rivaling my "memory" of my "hi end" music system of my youth. Unfortunately my 400a has a dead channel and the Magnapans need new mylar so I can't compare side by side.
Are Class D amps really that much better than solid old Mid-Fi Class A/B amps? Do they push into the realm of classic Class A amps?
My Magnepans haven't seen the light of day since I moved to my current house 20+ years ago and I still don't have room for them. What I am wondering is if my Threshold 400a is worth rebuilding for use with good quality bookshelf speakers in the bedroom?
I am also seriously considering dissecting the 2090 for the power supply board and transformer to experiment with other Class D boards (or Chinese Class A amp boards - KSA-50). Can anyone think of any reason I shouldn't? My 2090 really feels like it is just trash now.
Wondom 4x100w + dsp: https://store.sure-electronics.com/product/756
Much cheaper then the same board from Parts Express: https://www.parts-express.com/Dayto...uetooth-Amp-Board-with-DSP-325-434?quantity=1
I decided to build a passive 6" sub with a pair of 7" radiators and the cheap TPA3116 broke down. So I bought a WONDOM AA-JA33286 JAB5 4x100 Watt Class D (i.e. Dayton Audio KABD-4100 4 x 100W) with DAU1701 DSP and dual TDA7498E amp chips for 2 x 100w + 200w subwoofer. I am very impressed! The SLS speakers aren't noticeably cleaner (still REALLY impressive though) but my DIY passive sub really came to life! So it is time to integrate the amp board, sub, radiators, 12x18650 batteries (29vdc), and 36v 10A ps into a boombox format with mounts for attaching the SLS speakers where they are easily removable for better imaging. After a week with the separate pieces in my shop (I am a woodworker) I REALLY grew fond of the setup while building the box. Now that it is time to wire everything into the box I am really missing having music in the shop.
So I pulled out my ancient Yamaha RX-V2090 receiver. MAN IT SOUUNDS LIKE CRAP!!!! My old RX-V890 was no better. My current Yamaha Aventage 2010 is no better than the old Yamahas either. I can't believe how bad the old Class A/B amps are in comparison to a Class D! I had a Threshold 400A amp, Anthem pre and Magnepan II speakers when I was using the Yamaha receivers for HT and I knew the Threshold Class A 400a amp blew the Yamaha away for clarity, detail, and imaging but these Class-D amps are rivaling my "memory" of my "hi end" music system of my youth. Unfortunately my 400a has a dead channel and the Magnapans need new mylar so I can't compare side by side.
Are Class D amps really that much better than solid old Mid-Fi Class A/B amps? Do they push into the realm of classic Class A amps?
My Magnepans haven't seen the light of day since I moved to my current house 20+ years ago and I still don't have room for them. What I am wondering is if my Threshold 400a is worth rebuilding for use with good quality bookshelf speakers in the bedroom?
I am also seriously considering dissecting the 2090 for the power supply board and transformer to experiment with other Class D boards (or Chinese Class A amp boards - KSA-50). Can anyone think of any reason I shouldn't? My 2090 really feels like it is just trash now.
Wondom 4x100w + dsp: https://store.sure-electronics.com/product/756
Much cheaper then the same board from Parts Express: https://www.parts-express.com/Dayto...uetooth-Amp-Board-with-DSP-325-434?quantity=1
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I made a unity gain stable mosfet amp, not much comes close. I am getting a TPA 3255 based amp ro test.
Yamaha HT receivers are crap on music but fine for HT and I've had a few over the years. IMO it's the pre section and I'm sure if you hooked up the TPA to it's pre outs it would not sound as good. As a test you could try running the source to the power amp section only to hear how that sounds and mine had external inputs for this purpose.
I've tried several cheap TPA amps and nowhere near a good Class AB from Aspen, Neurochrome, Holton, ESP etc.
I've tried several cheap TPA amps and nowhere near a good Class AB from Aspen, Neurochrome, Holton, ESP etc.
You will find that technologies tend to converge in terms of ultimate technical capability. What finally differentiates them are factors like efficiency and cost & component availability. Class D lagged behind for many years, but not these days. All technologies have examples of bad to excellent implementations, though, so generalisations are not helpful.
Are all Home Theater receivers still Class AB or are there some with decent Class D amplifiers these days? My Yamaha Aventage 2010 is getting pretty long in the tooth and I am pretty much done with Yamaha receivers. P.S. I haven't purchased a new HT receiver in 35 years, I always buy late model used. It looks like accessories4less.com has some good deals on refurbs.
I tried the whuzi audio amplifiers named ZK xxx and they sound good enough for portable hifi.
They already sound well with good loudspeakers that a listening test with the more sophisticated designs would be interesting just to learn about the audibility of differences.
They already sound well with good loudspeakers that a listening test with the more sophisticated designs would be interesting just to learn about the audibility of differences.
The Dayton Audio KABD-4100 has built-in DSP - I wonder if what you hear and prefer (the mention of the subs coming to life) may be the result of accentuated frequency response extremes?
My experience with HT receivers was mostly negative, but the limitations were not a problem of the AB output stages specifically. They’re the result of the price point they were designed to.
My experience with HT receivers was mostly negative, but the limitations were not a problem of the AB output stages specifically. They’re the result of the price point they were designed to.
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A friend of mine who rebuilt his Magnepan Tympani IV uses now a BEHRINGER 4x900W Class D amplifier with them in multi-amplification - with active crossover, DSP, etc...
When we shifted to a 2x70W RMS tube amp plus the orginal passive crossovers in simple stereo and no more DSP, the tone was smoother and more balanced... With the BEHRINGER, active crossover and DSP, it sounded clearly agressive to most of us, and unbalanced in the highs, the agressivity could be the consequence of that imbalance. My friend was not shocked, used to that tone, but came in some doubt though.
We simply balanced the volumes between the two setups with a pink noise and a sound level meter. Given that the two setups were very different, I'd rather think that this comparison is inconclusive, I mean : with different settings - non-automated - a better balance would have been achieved on the multi-amp setup...
That said, I really appreciate the obvious qualities of a Class D ATOHM S-250 sub amp module, on my DIY "Omega Ripole" subwoofer :
But it's me, OK ? 🙂 😉
T
When we shifted to a 2x70W RMS tube amp plus the orginal passive crossovers in simple stereo and no more DSP, the tone was smoother and more balanced... With the BEHRINGER, active crossover and DSP, it sounded clearly agressive to most of us, and unbalanced in the highs, the agressivity could be the consequence of that imbalance. My friend was not shocked, used to that tone, but came in some doubt though.
We simply balanced the volumes between the two setups with a pink noise and a sound level meter. Given that the two setups were very different, I'd rather think that this comparison is inconclusive, I mean : with different settings - non-automated - a better balance would have been achieved on the multi-amp setup...
That said, I really appreciate the obvious qualities of a Class D ATOHM S-250 sub amp module, on my DIY "Omega Ripole" subwoofer :
But it's me, OK ? 🙂 😉
T
Behringer isn't exactly the finest example of a DSP or a class D amplifier though.
BTW, nice looking ripole sub, I miss mine in many ways!
BTW, nice looking ripole sub, I miss mine in many ways!
A friend of mine who rebuilt his Magnepan Tympani IV uses now a BEHRINGER 4x900W Class D amplifier with them in multi-amplification - with active crossover, DSP, etc...
When we shifted to a 2x70W RMS tube amp plus the orginal passive crossovers in simple stereo and no more DSP, the tone was smoother and more balanced... With the BEHRINGER, active crossover and DSP, it sounded clearly agressive to most of us, and unbalanced in the highs, the agressivity could be the consequence of that imbalance. My friend was not shocked, used to that tone, but came in some doubt though.
We simply balanced the volumes between the two setups with a pink noise and a sound level meter. Given that the two setups were very different, I'd rather think that this comparison is inconclusive, I mean : with different settings - non-automated - a better balance would have been achieved on the multi-amp setup...
That said, I really appreciate the obvious qualities of a Class D ATOHM S-250 sub amp module, on my DIY "Omega Ripole" subwoofer :
But it's me, OK ? 🙂 😉
T
My Magnapan MGII's always did an excellent job of highlighting other weaknesses in my system. I would imagine Typani's with a real ribbon and extra panels would be even better at accentuating the flaws in the rest of a system. Even so I REALLY loved my Magnapans and would love to have room for to set some up again.
Nice job on the sub! Are you happy with your choice of using hardwood for the cabinet? I am using a thick maple dinning room table for the sub / electronics enclosure on my digital boombox. I don't have it all together yet so I don't know if I made the right choice in with the maple vs MDF. The table was only $20 off CL and cleaned up very nicely with a trip through the planer.
I look forwards to playing with the DSP crossover on the Wondom JAB5 DSP/AMP. My first venture into changing the crossover points on the ADAU1701 DSP with SigmaStudio was very intimidating and not very productive. Then I found that Wondom has a very cool utility for tuning the just the DSP crossover functions that is much less complex than SigmaStudio:
They even have a BlueTooth tuner for their JAB2 boards with Android and Apple tuning apps capable of making on the fly changes. The future of DSP's and Class-D amps looks really bright and I look forwards to seeing this market progress and mature.
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Thanks @oughtsix !
What I use is Beechwood Glulam.
Below - complete Beechwood Glulam construction, like for my Omega Ripole :
Below - only the "belt" is Beechwood Glulam, front and back are Plywood with simili covering :
The finish is only sanded / oiled : durable, repairable, abuse-resistant enough. No issue whatsoever... 😎
T
Everything is done the same way in Sigma Studio without any problems. Well, that doesn't matter.
Based on my little experience in setting up a multi-band speaker system, I see one problem: mixing the bands by ear is very difficult if you do not have a lot of experience in mixing speakers. So this application looks more like a toy than something useful. To mix speakers, it is better to use not your ears, but a microphone and automatic equalization in Sigma Studio.
https://wiki.analog.com/resources/t...udio/toolbox/adialgorithms/automaticspeakereq
https://ez.analog.com/dsp/sigmadsp/f/q-a/64304/adau1701-sigmastudio-rew-auto-eq
Tpa amps seem pretty good, not as good as class a/b biased properly.
I have a $35 tpa3255 board on its way to test.
I have a $35 tpa3255 board on its way to test.
Yes it's clear...the crossover distortion...Idle current slipping...The majority of people don't know it...Advantage to class D on this point!👍
No. Poorly implemented DSP kills music.
My experience is the exact opposite. Properly implemented DSP is a huge leap in performance over a passive system.
Thanks @oughtsix !
What I use is Beechwood Glulam.
Below - complete Beechwood Glulam construction, like for my Omega Ripole :
Below - only the "belt" is Beechwood Glulam, front and back are Plywood with simili covering :
The finish is only sanded / oiled : durable, repairable, abuse-resistant enough. No issue whatsoever... 😎
T
I love the look! I hope my box turns out as nice!
The lamination pattern of the glulam beech is very similar to the glue up pattern in the kitchen table I am repurposing. I am a little concerned about the resonance and liveliness of hardwood vs the deadening characteristics of MDF. I know glulam is stronger than a chunk of solid wood and I would assume this also extends to less resonance of glued up wood. My gut feeling is that the liveliness won't be problem but I could apply measures to the inside surfaces of the box if it is too lively (not that I would know how to tell if it is too lively LOL!).
What is "simili covering"?