Class D amp and integrated recommendations

[Jfaustus]

I have a pair of Fosi V3 monoblocks. They have driven everything I've thrown at them including a pair of Quad ESL 989s. Would deinitely recommend. And they are near the top of the big list of amp measurements at ASR.

 

[Raphaz]

The Q500 should work well in a fairly large space? For a modest sum a pair of Fosi V3 monos will give you a taste of what is possible. For a little more your could buy four of them and bi-amp the speakers. I think you will be impressed with the power and drive of a decent class D amp. Unlike most class D amps, the V3 monos perform well independent of the impedance of the speakers.

For a bit more coin, and an amp that handles the more delicate content in tracks, you may try something that uses Purifi modules.

More independence of impedance would definitely be a plus. Less restricted speaker choices.

 

[Bruins]

A have a SMSL AO-300, it has a sub out, 1 analog, 4 digital and BT.
This is my first D class & I really like it.

 

[stoutblock]

More independence of impedance would definitely be a plus. Less restricted speaker choices.

Probably a better wording is that it overcomes load dependency. Fosi claims it can handle 2-8 ohms nominal (probably more like 4-8 ohms?) but whats more important is it has respectable specifications during load swings common to most any speaker. Typically class D amps have more difficulty performing well to load swings compared to class A/B. Currently Fosi uses Post Filter Feedback (PFFB) only on the V3 mono to accomplish this.

 

[Raphaz]

I’m intrigued by the monoblock (or dual mono) concept but I’m new to it.
Let’s say I go with two Fosi V3 monoblocks. How do I connect the Wiim Pro+ (currently used as a DAC, streamer and transmitter), and the other sources like TT and CD?
How do I connect my two main speakers and the active sub?
Do the monoblocks need to be connected in some ways to be in sync?
Do I need a preamp or can I add that later (I currently use a simple switch to change sources).

I googled but I can’t seem to find clear information.

 

[twiiii]

I m not a fan of class D amplifiers. I don't care if its Crown, Mcintosh, Carver and a lot of others. It's just like there are great tube amps but most don't cut the mustard for me . I had my share before transistors came along that were dependable. Knight, Scott, Fisher and Mcintosh, but didn't always sound great. Oh! I had a Dynaco or two and the only one worth its salt was the MK III 60 watt mono amp.

Just like anything else when it comes to integrated amps its who makes them. I really liked Pioneer back in the 70's and 80's. Sansui at the time was special. Back in th days of tubes, Sherwood didn't always measure that well, but I found the sound to be enjoyable. Even more than my Scott and Fisher stuff. I have always liked the sound of the 6000 series Mcintosh integrated amps with out autoformers. The 9000 Mcintosh and the 8900 sound great with most speakers, but not so much with others. They are good with Magico for instance even if a 275 in mono is better. Its about the midbass sound in this case. The big Macs sound great with Magnepan as those speakers are inefficient. Accuphase Class A integrated are super if you have semi efficient speakers and a lot of spare coin. I would say 95+ db 1 watt 1 meter at 8 ohms. I have always been suspicious of Yamaha. I prefer Marantz most of the time. Denon can be good with one model and the next even better or worse. I can't explain that as its just the way the cookie crumbles for me. I wouldn't have a Sony if you paid me. I basically gave up on integrateds after my MA 230 Mcintosh when I changed from very efficient speakers, 98 db 1 watt 4 feet, to 94 db 1 watt 4 feet. Finding a Great integrated with over 40 watts per channel both channels operating with less the .5% distortion was impossible back in the 60's. So I have used separates ever since. That also applies to modern HT stuff where a lot of folks use AVR's. They are not for me. There have been a lot of new Brands that have come along that I haven't auditioned. It seems thru ought that past 60+ years a lot of brands have come and gone. Some I miss others are a faint memory. B&K is one, Haffler, Dynaco, Sansui, and Onkyo is here one day and gone the next. I worry with Mcintosh being sold to Bose just like I did when they were sold to Clarion. What ever you buy make sure it can be serviced by a local dealer with a great reputation for service after the sale. 10 to 20 years can fly by pretty fast and that is when you can start having issues with some pieces. Stay away from tubes unless you have money in the bank.

 

[mrehorst]

I’m aware that there are already threads about Class D amplification here on AK and elsewhere, but I was wondering if folks here have experience with some of the latest D class gear they’d be willing to share.

So I started looking into D Class. Measurements and reviews seem to suggest that, with some of the latest GaN, Nilai, Hypex, NCore X and Purifi based offerings, I may get the performance I’m looking for with a moderate budget. But I’m neither super tech savvy nor do I have experience with D class.
I was hoping to get more insight here as to what to look for and how to make sound (pun intended) decisions.

It’s a bit early in the game for me but I was hoping to keep the budget for amplification plus pre below $ 1,400.
Not sure yet how much additional dough I need to fork out for periphery on top of that. I’m hoping to integrate streamer, DAC, transmitter, switch box and sources from my current system, but who knows...

As some of the leading D Class vendors and makers are rather entrepreneurial and boutique (vs big box brands) and the tech still evolving, are lemons rare occurrences or rather common? What are your experiences with customer support and warranty?

Besides the core amplification modules, since these still need to be enclosed and connected, what else do I look for, what are other crucial factors influencing sound quality?

Should I go separates, integrated or are there any good D Class receiver options by now?

Generally, are there differences when driving speakers with D vs good old AB class? What do I need to consider for a good match. Does impedance still matter when driving speakers with Class D power?

I have a Wiim Amp Pro. Besides being a class D amp with PFFB that delivers 60W/ch and sounds great, it has a streamer and high quality DAC built in, and has very flexible bass management, including the option to be a 4th order LR crossover that sends only mid/high frequency content to the speakers while sending lows out through the sub woofer output. It also has RoomFit with a 10 band parametric EQ, and has a manual graphic EQ available. I have used all except the graphic EQ, and they all work very well.
It doesn't support Apple Music streaming, but does support just about every other streaming service you can name, as well as DLNA, so you can use it with your own server (which I also do). It also has BT tx/rx, but currently only basic codecs are supported.

If you're going to drive bookshelf speakers with a sub, the crossover feature is awesome. By keeping the lowest octaves out of the bookshelf speakers they will be able to play louder with lower distortion. I use it to drive my Quad ESL-63s and SVS sub and it sounds great and works perfectly. The amp also measures and syncs the sub with the main speakers.

I've never seen a class D receiver, but with a built in streamer you can listen to internet radio streams including your local radio stations (via TuneIn). The Wiim Amp Pro spits out a relatively large signal at 595 kHz with many harmonics (and I suspect others class D amps do, too), so I think it would be difficult to include a conventional AM receiver in a class D box. FM might be doable.

It's anyone's guess if these things will last, but class D amps are similar to switching power supplies that have been used and reliable for decades, so I think they will probably go the distance.

My Wiim worked perfectly out of the box and I've only had it for a few weeks, so I can't comment on reliability or after sale support. All the manuals and other info (and there's a LOT of it) is written in English, not translated from another language, so instructions are clear. They have active user forums that are moderated and supported by employees.

The way I have it set up right now, with the amp driving the Quads and the sub, when I want to listen to music, I select it using my phone or tablet (from Tidal or LMS) and the amp and sub wake up and start playing. When the music ends the amp and sub go back to standby mode. There are no buttons to push, no remotes to juggle. It's a very clean interface. The front panel controls on the amp are minimal, and not really needed, so the amp can be put into a cabinet or under furniture, out of sight. It has a minimally functional BT remote control that works even if it can't "see" the amp.

All the RoomFit, bass management, input switching, volume, etc. is remotely controlled via the Wiim Home app that runs on your phone, tablet, or computer. It can all be adjusted from your listening chair.

 

[Raphaz]

I’m intrigued by the monoblock (or dual mono) concept but I’m new to it.
Let’s say I go with two Fosi V3 monoblocks. How do I connect the Wiim Pro+ (currently used as a DAC, streamer and transmitter), and the other sources like TT and CD?
How do I connect my two main speakers and the active sub?
Do the monoblocks need to be connected in some ways to be in sync?
Do I need a preamp or can I add that later (I currently use a simple switch to change sources).

I googled but I can’t seem to find clear information.

Can someone comment on these questions? That’d be super helpful.

 

[Raphaz]

All great opinions, comments and suggestions. Thank you.
I think I need to understand the way I would use and set up two monoblocks, specifically how one set them up for stereo (two passive/analog speakers)

 

[OldJBL]

Can someone comment on these questions? That’d be super helpful.

You need to look at the various class D amps because the have different feature sets. Basically, most of these amps have single RCA inputs and some also have single XLR inputs. If you want to connect multiple devices then you will need a DAC and/or pre-amp. I am familiar with Fosi's offerings and they now have about every product you might need to setup a system.

 

[Raphaz]

I have a Wiim Amp Pro. Besides being a class D amp with PFFB that delivers 60W/ch and sounds great, it has a streamer and high quality DAC built in, and has very flexible bass management, including the option to be a 4th order LR crossover that sends only mid/high frequency content to the speakers while sending lows out through the sub woofer output. It also has RoomFit with a 10 band parametric EQ, and has a manual graphic EQ available. I have used all except the graphic EQ, and they all work very well.
It doesn't support Apple Music streaming, but does support just about every other streaming service you can name, as well as DLNA, so you can use it with your own server (which I also do). It also has BT tx/rx, but currently only basic codecs are supported.

If you're going to drive bookshelf speakers with a sub, the crossover feature is awesome. By keeping the lowest octaves out of the bookshelf speakers they will be able to play louder with lower distortion. I use it to drive my Quad ESL-63s and SVS sub and it sounds great and works perfectly. The amp also measures and syncs the sub with the main speakers.

I've never seen a class D receiver, but with a built in streamer you can listen to internet radio streams including your local radio stations (via TuneIn). The Wiim Amp Pro spits out a relatively large signal at 595 kHz with many harmonics (and I suspect others class D amps do, too), so I think it would be difficult to include a conventional AM receiver in a class D box. FM might be doable.

It's anyone's guess if these things will last, but class D amps are similar to switching power supplies that have been used and reliable for decades, so I think they will probably go the distance.

My Wiim worked perfectly out of the box and I've only had it for a few weeks, so I can't comment on reliability or after sale support. All the manuals and other info (and there's a LOT of it) is written in English, not translated from another language, so instructions are clear. They have active user forums that are moderated and supported by employees.

The way I have it set up right now, with the amp driving the Quads and the sub, when I want to listen to music, I select it using my phone or tablet (from Tidal or LMS) and the amp and sub wake up and start playing. When the music ends the amp and sub go back to standby mode. There are no buttons to push, no remotes to juggle. It's a very clean interface. The front panel controls on the amp are minimal, and not really needed, so the amp can be put into a cabinet or under furniture, out of sight. It has a minimally functional BT remote control that works even if it can't "see" the amp.

All the RoomFit, bass management, input switching, volume, etc. is remotely controlled via the Wiim Home app that runs on your phone, tablet, or computer. It can all be adjusted from your listening chair.

Thank you!
Two follow up questions:
Besides the Apple compatibility, how does the Wiim Amp Pro differ from the Ultra (and from the Pro+ I have)?
Is there a way to still use Apple devices to control/play the Amp Pro or/and the Ultra?

 

[Raphaz]

Maybe I have to compartmentalize or simplify that monoblock question.
How does one set up two monoblock amplifiers to power two passive speakers and an active sub.
Let’s skip my specific setup and sources for a sec. I mainly try to conceptually understand how one wires things to get from 2x mono to stereo.
Monoblock amp A powers the left speaker and Monoblock amp B the right one, each connected via + and - out?
Are the two monoblocks connected in some ways to be in sync?

 

[stoutblock]

I’m intrigued by the monoblock (or dual mono) concept but I’m new to it.
Let’s say I go with two Fosi V3 monoblocks. How do I connect the Wiim Pro+ (currently used as a DAC, streamer and transmitter), and the other sources like TT and CD?
How do I connect my two main speakers and the active sub?
Do the monoblocks need to be connected in some ways to be in sync?
Do I need a preamp or can I add that later (I currently use a simple switch to change sources).

I googled but I can’t seem to find clear information.

You can use the Wiim Pro+ for volume control and most source selections. You can use the coax digital (SPDIF) input on the Wiim Pro+ to connect to the coax digital output from your CD player (most modern CD players have a coax digital output). This connection requires a special digital 75ohm RCA cable. This will bypass the DAC in your CD player and use the DAC in the Wiim Pro+. You cannot connect a TT directly to the Wiim Pro+ (you can on the Wiim Ultra). You would connect the left and right RCA analog outputs on the Wiim to the RCA inputs on the V3 monos. Left to one amp and right to the other. There is a switch on the front of the V3 to select XLR or RCA input. There is also a switch on the back of the V3 to select gain level needed for acceptable volume with your speakers. You can buy the V3 with either dedicated power supply for each amp (48v 5amp) or a double power supply (48v 10amp) for a pair of V3 monos. Depending on the sub you have, you would probably need the Wiim Ultra to connect.

 

[stoutblock]

Maybe I have to compartmentalize or simplify that monoblock question.
How does one set up two monoblock amplifiers to power two passive speakers and an active sub.
Let’s skip my specific setup and sources for a sec. I mainly try to conceptually understand how one wires things to get from 2x mono to stereo.
Monoblock amp A powers the left speaker and Monoblock amp B the right one, each connected via + and - out?
Are the two monoblocks connected in some ways to be in sync?

What sub do you have?

 

[ejman]

Maybe I have to compartmentalize or simplify that monoblock question.
How does one set up two monoblock amplifiers to power two passive speakers and an active sub.
Let’s skip my specific setup and sources for a sec. I mainly try to conceptually understand how one wires things to get from 2x mono to stereo.
Monoblock amp A powers the left speaker and Monoblock amp B the right one, each connected via + and - out?
Are the two monoblocks connected in some ways to be in sync?

I don't know if this will help you or not but here it goes: I have two Fosi monoblocks powering 2 Magneplanar 1.7's. via regular speaker cable. The Fosi monoblocks in turn are powered by a tube preamplifier that has two sets of RCA outoputs. One set of RCA outputs go full range to the Magneplanars. The other set of RCA outputs goes to a Rolls SX95 subwoofer crossover (analog) that in turn feeds a Fosi Za3 amplifier (in mono mode) that in turn feeds an ancient passive HSU barrel subwoofer. If you have an active subwoofer with its own crossover then you don't need the Rolls Subwoofer crossover or the Fosi Za3 amp.

The system I described above is all analog. If you are using a media server such as WIIM pro or ultra then the description above doesn't apply and ignore what I said above. BTW I do occasionally listen to streaming sources but for that I use a laptop hooked up to my preamplifier

 

[mrehorst]

Thank you!
Two follow up questions:
Besides the Apple compatibility, how does the Wiim Amp Pro differ from the Ultra (and from the Pro+ I have)?
Is there a way to still use Apple devices to control/play the Amp Pro or/and the Ultra?

The Wiim Amp Ultra delivers 100W/ch at 8 ohms, has a different DAC, and a couple more inputs. It also has a touchscreen display in case you want to control things from the front panel. AFAIK, the functions like RoomFit and bass management are there, too.

I don't know how to deal with the Apple situation. Maybe someone with an iPhone and Apple Music can answer your question.

 

[Lavane]

What sub do you have?

I have the same question. If the powered sub has speaker level connections, just use those, you don't need a line level sub out in an integrated amp. I've ran all my subs with the speaker level connections.
The sub draws very little from the signal being fed to the speakers.

 

[Raphaz]

You can use the Wiim Pro+ for volume control and most source selections. You can use the coax digital (SPDIF) input on the Wiim Pro+ to connect to the coax digital output from your CD player (most modern CD players have a coax digital output). This connection requires a special digital 75ohm RCA cable. This will bypass the DAC in your CD player and use the DAC in the Wiim Pro+. You cannot connect a TT directly to the Wiim Pro+ (you can on the Wiim Ultra). You would connect the left and right RCA analog outputs on the Wiim to the RCA inputs on the V3 monos. Left to one amp and right to the other. There is a switch on the front of the V3 to select XLR or RCA input. There is also a switch on the back of the V3 to select gain level needed for acceptable volume with your speakers. You can buy the V3 with either dedicated power supply for each amp (48v 5amp) or a double power supply (48v 10amp) for a pair of V3 monos. Depending on the sub you have, you would probably need the Wiim Ultra to connect.

I have a little phono preamp that’s pretty good, so that should not be an issue.
As far as the sub, I don’t have a Wiim Ultra (yet), just a Pro+ and two Minis. Not sure if I want to buy the Ultra just for the sub alone (unless it replaces the Pro+, but then I wouldn’t be able to control things through an Apple device). Hmmm…

 

[Raphaz]

The Wiim Amp Ultra delivers 100W/ch at 8 ohms, has a different DAC, and a couple more inputs. It also has a touchscreen display in case you want to control things from the front panel. AFAIK, the functions like RoomFit and bass management are there, too.

I don't know how to deal with the Apple situation. Maybe someone with an iPhone and Apple Music can answer your question.

Sounds like the Ultra is a Pro+ with a touch screen, a better(?) DAC, more power, and some more control functions, minus AirPlay2.
So maybe, if the Apple issue could be solved, it could replace the Pro+ and act as a preamp. Maybe?
The amp section in the Fosi seems superior.

 

[Raphaz]

I have the same question. If the powered sub has speaker level connections, just use those, you don't need a line level sub out in an integrated amp. I've ran all my subs with the speaker level connections.
The sub draws very little from the signal being fed to the speakers.

The Klipsch R-112SW is a powered sub and has L/R line-level/LFE inputs.
I may replace with a better active sub sometime further down the road.