When are we getting 100% digital amps for crying out loud??

[Radian]

A review of sorts, posted by request:

I've got two SA-XR57's personally.

Came sooooo close to getting an SA-BX500, I'll never forgive myself for passing on that one But the 57 suffices.

I think the problem with the lack of solid reviews of the Equibit amps is purely a matter of demographics. Most audiophool reviewers turn a blind eye because the brands that use the technology are too cheap to purchase significant ad space that their media hosts rely upon. Those that do review them, f*** it up by trying to play their granite turntables and vinyl through them. The usual result is, "They sound flat, or harsh."

Well, duh of course! Plus they'd have to eat ten years of blowing smoke up our a****. The truth is they sound utterly amazing when playing digital sources, especially through high-sensitivity speakers.


I've made a point of previewing a lot of demo-systems in store over the years (McIntosh, Rotel, Krell, Audio Research, Carver, etc.). But I've only had a few different amps hooked up to the La Scalas, my main system in-home. Sessions there would be the fair comparison, and that has only been with a Sony and a Yamaha RX-V595.

I thought the Yammy sounded pretty damn good. Having listened to that amp for over 13 years. Plugging in and firing up the the Panny had my jaw on the floor. Velvet smooth. In direct comparison, it had the Yamaha sounding harsh on top. Now that I've had the Panasonic for some time, the occasional visits to the Hi-fi stores have had me wincing. Wincing from the sound, wincing from the price tags for that sound.

Wind up a digital amp with no input signal...pure darkness..hit "play", and it literally explodes in front of you. It's quite an experience. Recently, the cat sat on the remote and cranked it to reference level while I stepped to the kitchen, I came back and resumed listening to some B.E.P. I nearly shit myself. The cat is scarred for life. No hiss or hum to warn you that things are revved up for business.

With only an honest 18 dB of gain available. High sensitivity mains are the only way IMHO. Magnapan owners, for example, would probably be left asking for much more. But owners of TLAH, SLA, David, and the like would be very pleased.

So all in all, it's a systems review. It's always the amp and speaker. An amp with no speaker doesn't make much noise and vice versa. But between amps on my rig, the Panasonic has been nirvana. As Francis Vale has put it so eloquently describing the early Toccata-based amps," It was the best I-have-to-shut-this-off-or-I-will-never-get-any-work-done audio system I have yet encountered."

[Drey Chennells]

I got my paws on a couple SA-XR57's so I can stop griping for now. One is featured in this video

Man those Taiko drummers were going off. Sounded crispy clean in my office...I had to crank it to 11 get up and do some kung fu...back to work now.. i.e.reading more threads ; )

[subharmonic]

I had the pleasure of owning a lower end Panasonic digital amps. I was using some Polk Audio R50 speakers in a 2 channel setup. I had bought it open box from BB and had to return it for some reason after a couple weeks, I really can't remember why, it was like 7 years ago.

I do remember the sound though. That thing sounds remarkable. It is really hard to describe the sound, in particular with a set of just mediocre speakers like that. Warm and smooth, very clear, my setup was not special and no real care was taken to place the speakers very well either.

Just my 2 cents and a bit of audio reminiscing.

[BassMe]

Hey Radian,

Did you look into the SC-BT series any more closely? I can pickup a whole HTIB sc-bt200 here for $300, and would swap in TLAH, SLA and THT. I like the fact that I could run the subwoofer from the receiver as well instead of putting in a plate amp. Chances for grounding issues or any other kind of hum would be slim. I only need 2 optical inputs and the blu ray player already built in. This is a link to the manual for the receiver if anyone is interested. http://service.us.panasonic.com/OPERMANPDF/SCBT200.PDF

I think the most important question is are the cross overs between satellites and subwoofer adjustable? I don't want to cross to a tht at 140Hz, seeing as my TLAH would have much more extension than 2.5" full range drivers. I am going to ring my local panasonic customer care line tomorrow and see what works out. I'll post it up, would be a great little package for us people who want bang for buck.

All the best.

Mitch

[Radian]

Mitch,

I haven't seen anything regarding an adjustable crossover in their literature. It is why I've been hesitant about recommending them to enthusiasts for that very reason. Great combination of integrated technology, but apparently no adjustable bass management. Please keep us posted with what you find. It would certainly be the ticket for the budget savvy golden ear.

Cheers,
Radian

[BassMe]

Well, I just have a very frustrating 15min conversation with a Panasonic customer care rep. He didn't know a whole lot about audio it seems......

I had to contend with questions such as: "What do you mean by high-pass/low-pass filter?". My Response: Needless to say I didn't get any information about the built in cross over point from him. He was very sincere and trying very hard to help me, but had absolutely no idea what he was on about.

We did manage to nail down that the response from different speakers is unadjustable. He was also very worried about the amp exploding if I put in the wrong ohm speakers etc. Other than that he was talking more about sound engineers deciding what you are going to hear etc. The system can be adjusted for listening distances, and do have some very basic preset EQ options, but no graphical EQ. I tried 3 or 4 different ways ( ) of explaining that the subwoofer has to be crossed over to at some point because the satellites would simply tear themselves a new one trying to produce 30Hz tones but he managed to deftly side step this question.

Maybe someone else can try panasonic and get an audio specialist.


On a side note: Stupid day light savings time. It's like 7:30am here, I have been asleep for all of 6 hrs and my customer rep dude rings me from sydney where it is 8:30. You southern ppl need to remember daylight savings dammit.

[BassMe]

Gotta hit the sack so I haven't looked into the full application of this, but came across it just now. http://www.minidsp.com/products/miniamp

While not an AV receiver, it can handle 2.1 output and is supposedly a full digital chain. 2x10 watts @ 4 ohms for L/R + 1x20watts @ 8 ohm for sub woofer. I know these are seriously low power levels, but 2 TLAH with 10watts will produce 105-110 db (according to my dodge math assuming 96dB SPL for TLAH) @ 3 feet. I don't understand minidsp etc yet, but I will look into it. I think you can combine a number of these boards bridged and with a minidsp run 2.1 with more omph. If you are only aiming for 100ish dB noise levels, would 20watts be enough dynamic room for a corner loaded 18" TT?

I'm tired an rambling, I'll those who understand all this more have a look and play with it myself on the morrow.

All the best.

[BassMe]

Ok , So i donno if I am typing to a non-existent crowd. But my research has provided the following:

Using a miniDSP, miniDIGI + miniAMP you can easily create a fully digital signal chain. Using the 2.1 PEQ or advanced software for the miniDSP, you have full control of cross over between tops and bottoms, with both high and low pass filters for all outputs. Using a single miniAMP in 2.1 mode you can have 2x10watts @ 4 ohms and 1x20watts @ 8 ohms for tops and sub respectively. You can also run 2.2 setup with this in effect creating a 2 way cross over setup between tops and bottoms. This setup also integrates a 6 band parametric EQ on all output channels (individual PEQ on ea channel so 12 bands across the full Hz Range), delay, gain control, a analog log pot option for master volume control across all channels that is built into the DSP (converts analog input into digital volume control, high bit rate digital control as well to avoid compressing source and cutting out dynamics). Crossovers in the DSP are up to 8th order (48dB/oct) cross overs. I believe these would be steep enough for us to not need an analog cross over in place for the subs? A fairly fine tunable system I thinks.

Questions I have asked:

Is it possible to run with 2 miniAMP's combined with 1 DSP + 1 DIGI? Simple answer is yes you can they provide you with a custom connection cable. Long answer: I have still to find out if you can run top channels into 1 miniAMP for 2x20watt @ 8 ohm outputs and the summed sub output into the 2nd miniAMP for another 20watt channel. I believe you can but I am going to wait for confirmation. I believe this would be a software issue that miniDSP (company) would help you sort out if you asked nicely. I'm actually sincere about this, they charge $10 for software packages but are incredibly active in adding user requested features into everything they do.

The 2nd question I have asked, out of blatant curiosity: Is it possible to run active cross overs for the tops and also provide a summed mono sub output through 2 miniAMPS. This would essentially provide 4x 10watts@4ohms channels for the tops and a 20watt@8ohm channel for the mono sub output. If all you want is 2.1, you could have fully active cross overs. Allowing for on the fly customization of cross overs for the best performance in your 2.1 system. Then just lock it in and off you go. I know it only saves you $50 in passive crossovers for 2 TLAH or SLA, but if the ability is there why not know about it/use it?

10volts @ 8ohms (i hope I have this right) is only 12.5watts. Reports on here say that TT's, TLAH and SLA with this much power in avg lounge rooms can be pretty damn loud, reaching 110+ dB very rapidly. I know I would be reported to my real estate agent damn quick if I ran that loud for long.

So total cost?

miniDSP + miniDIGI + miniAMP = $200 US

2nd miniAMP $60

Plug-In software $10

+ shipping

Expensive? Kinda, seeing as you can get entry level receivers for that kind of money (at least in the states, harder to find here in AUS), but that doesn't give you the possibilities this system does. If you need em.....

I know I am seriously considering selling my CDA-254 Kit from Class D Audio and purchasing this setup. Reports I have read indicate when using the full digital chain (S/PDIF in) there is essentially no noise in the system as radian has remarked. Dead silent to boom.

All these wattage ratings have been continuous power ratings drawn from the companies literature. I'm not sure what this means? Yes I am an audio newb, I just have a talent for research. I have been at uni way way way too long.

I'll report back tomorrow hopefully with more info. All the best.

[Radian]

Ok , So i donno if I am typing to a non-existent crowd.

Nah, there's just not much of a HT / 2 channel presence on this forum...There are certainly interested parties here, but not in droves like DIY audio and AVS.

+1 on the MiniDSP

Haven't used one yet, but I really see merit in the concept. As you say, reports have been quite favorable.

I have been at uni way way way too long.

Me too bro.

[Drey Chennells]

Ok , So i donno if I am typing to a non-existent crowd.

i build, therefore i am.

[Tom Smit]

Ok , So i donno if I am typing to a non-existent crowd. But my research has provided the following:


So total cost?

miniDSP + miniDIGI + miniAMP = $200 US

2nd miniAMP $60

Plug-In software $10

+ shipping

Expensive? Kinda, seeing as you can get entry level receivers for that kind of money (at least in the states, harder to find here in AUS), but that doesn't give you the possibilities this system does. If you need em.....

This was my thought...expense. But then again, I'm still waiting for my HT . I can definitely see the possibilities for that set-up.

[BassMe]

A living breathing miniDSP review using BFM tops and bottoms:

While not specifically an answer to your question (can I do this with two mini-amps), I did want to share my own experience. I just bought one Mini-DSP and one Mini-Amp and the 2.1 module to drive two BFD SLA's for mains and a single Tuba18 for the sub. She gets plenty loud for my living room. I did have to turn the mains down a little to balance the sub. I'm driving the SLA's with 10 watts each and the sub with 20 watts. I did put an HPF at 40Hz to my T18 (LPF at 80 Hz).

The bass can get plenty loud (for me) with this much (little?) power. If I truly need it louder, I'll drive the mains with 20 watts each channel from the mini-amp and connect my 100W sub amp to the T18.

I don't see needing that anytime soon.

-Brian

Interesting interesting. Still waiting for the miniDSP dev's to get back to me about full active setup for tops and more. And confirming that you can spread 2.1 over 2x miniAMP for 20watts to every channel. We will see.


If you had the option of going full active on some TLAH (at no added expense, actually saves your cross over parts) would it be worth it. Would you get better response from 10watts @ 8ohms to woofer and tweets seperately or 20watts @ 4 ohms into a cabinet as a whole with passive xover in place. Obviously I would just select the appropriate amount of drivers and wiring solution to match the amp impedance.

I am looking into more efficient woofs to match tweeters or piezos. Something around 90+ SPL 1watt/meter. Would be nice to drag the whole cab up to 100dB efficiency.


EDIT: I have since received a reply from the devs. You can easily hook 1 DSP + 1 DIGI to 2 AMP letting you put out 2.1 with 20 watts per channel @ 4 ohm. Still trying to find out if you can split the tops for 2 way active.

[BassMe]

Also got my eye on this project by hifimediy on diyaudio.com

Fully integrated DAC + digital amp with a number of selectable amp chipsets. Base set is 2x 50watts @ 8 ohms and 1x 100watts @ 4 ohms. With higher power options available. No active crossovers etc, but will have remote control, LCD display and a number of other things going for it.

Check out:

http://www.diyaudio.com/forums/class-d/ ... ifier.html

During this thread he also references a fully digital 5.1 chipset that he is planning to release shortly after the 2.1, same thing digital in, PWM amp out selectable cross overs, selectable amp sections for more or less watts etc etc.

[BassMe]

So finally finished all my enquiries with miniDSP company.

You cannot go active without adding in more DSP etc. The DSP is limited to handling 4 channels of output either digital or analog.

You are perfectly capable of producing 4x 20 watts of output across 1 miniDSP, 1 miniDIGI & 2 miniAMP. LPF, HPF, delay, gain, 6 bands of parametric etc etc etc. even running 10 watts your getting 10dB of gain.

I will continue to work on my design for Semi-Pro TLAH (pole mounts, higher SPL, Rigorous cabinet, carry handles but good for HT and under $200ea ~ goal is 100dB SPL) as my pet project until I am ready to buy everything and I'll make my decision then. Going to keep my eye on the DDX Amp project by hifimediy, in a perfect world i'd have a true 100-200watts per channel on tap with a fully integrated digital system. S/PDIF from computer/laptop with digital cross overs etc. We will see what happens.

All the best, from an overly keen forum lurker

[Radian]

My apologies for digging up an old thread, but if there's any doubt of these amplifiers' capabilities....Here's a video of a recently acquired XR-57 and an XR-700 hitched up to some el'cheapo Yamaha dorm speakers I dragged out of storage.



*updated YouTube link