Yamaha DSP-A2070 Digital Sound Field Processing Amplifier

[sports]

I got lucky. Very luck. Why?

Coz I got a deal to have a Yamaha DSP-A2070 7.1 channel integrated amplifier at USD $160.

Yamaha DSP-A2070

This previous owner bought this amplifier back in 1996 in U.K and was using it since. Last year he thought of an upgrade and outsourced a Marantz SR6003 A/V receiver to replace the DSP-A2070.

He says after some months of extensively using the SR6003, he found though it supports all the latest movie formats and provide options like USB so he can connect his iPod, it crucially lacked in terms of audio performance and the level of sound quality that the DSP-A2070 was able to achieve. According to him 2-channel performance of this Yamaha is something special and the SR6003 cannot hold a candle to it. Later he got a Krell and decided to sell both the SR6003 & DSP-A2070.

For starters DSP-A2070 is not a A/V Receiver like SR6003, actually you cannot call it a receiver since it lacks a tuner, and it has no video processing capabilities. It is just a 7.1 channel integrated amplifier purely devoted to audio & its digital sound field processing.

The amp is plane Jane & conservative looking. But it weighs a hefty 21kilos [46 lbs]. The power supply section must be almighty which is denoted by its weight.

Stats of Yamaha DSP-A2070
----------------------------------
1) Full name : Yamaha DSP-A2070 Digital Sound Field Processing Amplifier

2) Released : 1993

3) Price on release : $2000

4) Awards : In 1993 won the best Home Theater System award given by European Imaging & Sound Association(EISA) www.eisa.eu --> Awards

5) Minimum continuous power per channel(RMS) @ 20Hz~20kHz @ 0.015% THD @ 6 ohms:

Main stereo speakers(2 units) : 100 watts/ each

Center speaker(1 unit) : 100 watts

Effect speakers (4 units) : 26 watts/ each

Total minimum continuous power of the system : 100 + 100 + 100 + 26 + 26 + 16 + 26 = 404 watts @ 6 ohms

6) Minimum dynamic power per main channels : 130 watts @ 8 ohms / 160 watts @ 6 ohms / 215 watts @ 4 ohms

7) Dynamic Headroom : 2.0db @ 6 ohms

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[sports]

Auditioning the DSP-A2070 + Internal Amplifier Performance

As audiophiles love to provide audition, he was more than happy to connect the DSP-A2070 main left and right channels to his awesome Bower & Wilkins Diamond 800 floor-standers, while the four effect channels at the four corners of the room was Dali Lektor's having 8 inch drivers. The center channel was a Klipsch with two 8 inch drivers but I was not able to identify which model.

Mind you all the audio channel of main + center + effect speakers connected to the DSP-A2070 can individually travel throughout the entire audio frequency bandwidth of 20Hz~20kHz.

For me what good is a feature packed receiver/ amplifier or any A/V gear for that matter if it cannot deliver the goods in sonic performance? My viewpoint is sound first, features second. With that here is my subjective impression of the DSP-A2070.

One area Yamaha flagship multi channel amplifiers/receivers have always excelled in my opinion is two-channel audio. Unlike many lesser products, Yamaha never disappoints anyone in this regard. In my latest experience the DSP-A2070 it was no different.

I was immediately overwhelmed by the almost limitless dynamic range I was hearing in two-channel stereo with this amplifier. Its big, bold sound never lacked refinement or poise even when driven to my personal listening limits with these full range awesome speakers at a moderately large listening room.

The auditioning was done without any use of subwoofer. This did not seem problematic to me since the DSP-A2070 has a superb noise floor in all listening modes, partly attributed to careful circuit layout and implementation of the absolute best DAC's on the market of its time. The good news is Yamaha spared no expense and implemented these high quality Burr Brown DAC's on all channels , including the presence and subwoofer channels - and in balanced configuration!

SACD: Patricia Barber - Café Blue

This remains one of my benchmark SACD's for good reason - lumpy jazz in a smooth jazz environment. You won't find repetitive and annoying saxophone scales, single stroke drumming, and simplistic guitar rifts. Instead you're showered with snappy jazz and provocative lyrics, slamming drums and memorable instrumental solos. The SACD layer of Track #2, "Morning Grace" sounded about as good as I've ever heard which in one word would best be summed up as "phenomenal".

CD: Brazilian Bossa Brazilian Bossa

I was stunned by the quality of the recordings of track #'s 1, 3 and 6.I constantly had to convince myself by looking at the front panel of the DSP-A2070 that I was listening to amplifier belonging to the 90's. The music was pristinely clean and dynamic, and the surround experience with the DSP modes was really involving, not artificial sounding, while the bass was tight and deep. This was just about one of the best multi channel audio experiences I could remember having at any home. To me there was nothing missing as the surround field was fully enveloping.

CD: Dianne Reeves Never Too Far

While playing the bass track in Track #2 “Never Too Far” with the DSP-A2070 I was pleasantly surprised by how snappy and articulate the upper bass response was. Overall, I found it well controlled and retained excellent the decay properties. The tonal balance was warm and inviting and regardless of how loudly I listened, I never heard the DSP-A2070 amps run out of gas. Stereo separation was about as good as I’ve ever heard, portraying Dianne’s powerful vocals dead center as they should be with plenty of width and depth to the soundstage. The drums had a the requisite pop to them while the saxophones exhibited a nice bite giving you that “live” feeling.

CD: Fourplay Chant

Next up was Fourplay’s “Chant” track which slams with a dynamic kick drum sending wimpy woofers to oblivion and lesser designed amps into hard clipping. As I listened, I requested him to crank up the volume, intoxicated watching those dual woofers of the B&W Diamond 800's flex in and out as the Yamaha pumped pure unadulterated power into them. It was as if Yamaha was convincing me of the flagship status of this receiver as it was able to power those large floor-standers and the four effect speakers without any complaint. The Rock Concert & Jazz Club DSP modes sounded brilliant with this track.

----------------------------------------

DSP-A2070 Internal Amplifier Performance

After this audition the DSP-A2070 proved to be a very competent 7.1 channel amplifier. I was a bit concerned with the DSP-A2070 driving such hulking floor standers along with those big full range center speaker. Mind you the four effect speakers were also connected to big full range speakers too, so these 7 speakers was asking a lot from the internal power amp of DSP-A2070.

My concerns were soon subdued after listening to a few two-channel CD's & SACD's since DSP-A2070 belonging to Dolby Pro Logic era accepts stereo channels only. I was in awe that the Yamaha amp was delivering such solid amplification performance typically found in much costlier and bulkier separates. It sounded as good as many high end rigs I have ever listened in the past. I was shocked by the refined and authoritative bass reproduced by those large B&W floor-standers when driven by the DSP-A2070's internal amps in stereo mode. All of the subtleties and nuances were equally conveyed, demonstrating a very low noise floor and excellent linearity. Granting the fact the Krell separates did yield a bit more slam and dynamics when driven to the limits of comfortable listening levels, but the DSP-A2070 never sounded bright or fatiguing to me like many other receivers typically do.

Channel separation from a two channel audio input was excellent and tonal consistency and dynamics was also impressive when all the seven speakers began to play with different DSP modes.Even pushed very hard and those seven individual full range speakers blasting out, I cannot hear the DSP-A2070 amp run out of gas. May be it is due to the amazing 2.0db dynamic headroom this amp comes with.

In different DSP modes like Rock Concert & Jazz Club for music and Movie Theater & Concert Video for movies the DSP-A2070 amazingly did a bang up job at turning the room into a surround sound live concert or real movie theater.

Even though it was using a quite obsolete Dolby Pro Logic technology to be used for movies, I never felt out of place while watching movies and the overwhelming power from the internal amps was just phenomenl. It just showed to me how advanced the Yamaha DSP modes where back in 1993.

 

[FloridaSam]

Welcome to AudioKarma! Man of few words huh?

All I can add is that I own a DSP-A3090 and use it everyday for my severly outdated HT setup. It has to be good at nearly 70lbs!!! I love the way these old Yammies sound for both HT and stereo setups. If I only had this one amp and all my others were gone, I would still be very happy with its sound.

 

[sports]

Yamaha DSP-A2070

Welcome to AudioKarma! Man of few words huh?

Thanks FloridaSam. This is my first thread in AudioKarma, so I was quite worried how I will be accepted here.

I have gone through quite a few audio forums, but AudioKarma is something different & stands out from the rest. It is simply the best audio/video forum in the world and i am proud to be a member of it.

Thank you all.

All I can add is that I own a DSP-A3090 and use it everyday for my severly outdated HT setup. It has to be good at nearly 70lbs!!! I love the way these old Yammies sound for both HT and stereo setups. If I only had this one amp and all my others were gone, I would still be very happy with its sound.

The Yamaha DSP-A3090 is a hell of an 7 channel amp. It is the successor of my DSP-A2070 and retains its strength.

Both A2070 and A3090 weighs 46 lbs or 21 kg and are back breakers for sure.

 

[sports]

Insight to Yamaha's Digital Sound Field Processing (DSP) Technology

After acquiring this DSP-A2070 amplifier I became quite interested in knowing Yamaha's past and especially how this DSP technology came into existence. Digging into the net for a few days I was quite surprised to find out that they manufactured musical instruments since 1887!!! I am dealing with a 125 year old company!

Having this expertise since then, it was from 1970’s onward that they ventured into acoustic designing of concert halls, movie theaters so that accurate sound can be reproduced. Later on they also started custom fittings of audio gear in many famous churches, clubs & even live concert.

Yamaha involved in acoustic designing of concert halls:

While designing the acoustic environment of all these “unique places” Yamaha sound engineers had to study and carry out a lot of tests regarding how their audio equipment should be placed in order to achieve the best possible sonic experience. Test regarding sonic fidelity, echos & reverberation patterns not to mention the liveliness of music as it reaches back of the hall were performed & studied. From all these cumulative experiences they gathered huge amount of raw measurement data in digital format.

Yamaha involved in acoustic designing of churches:

The question now arises as to what is Yamaha DSP?

DSP as we all know stands for “Digital Signal Processing”. But in case of Yamaha this stands for “Digital Sound Field Processing”. This technology deals in reproducing an audio signal in a way that it mimics the sonic signature i.e. “sound field” of any “unique place” be it concert hall, churches, live performances, clubs, movie theater, concert video, etc.

This may sound very simple but in order to mimic the “sound field” of any “unique place” at our home, extremely complex algorithms/ software’s were needed and at the same time the hardware needs to be powerful enough to process it in real time. No other audio brand had this feature set back in the 80's. And please do not mix this incredibly complex Yamaha DSP technology with what their competitors were offering back then, those were simple technologies that added some random ambiance & echo’s to the audio signal and nothing more.

Let take an example of a professional high quality movie theater audio system back in the 80's. It generally consisted of a single and very powerful left, center and right speaker behind the screen while having multiple surround speakers engulfing the sitting area. The same surround signal was sent to these multiple surround speakers at a slightly different time creating a sense of spaciousness or liveliness inside the movie theater. And the sound engineers take this factor into account while mixing the sound track of a movie.

Yamaha DSP technology helps to re-create this same "audio experience" aka "sonic signature" aka “sound field” of this “unique place” i.e. movie theater in our home by treating each and every audio frequency of the entire audible frequency range (20~20,000Hz) in real time and making it sound just like the way it sounds in a real professional movie theater in our own home theater. In other words the DSP recreates the “sound field” of a movie theater in our home theater.

In order to achieve this feat the Yamaha engineers used the huge amount of raw digital data that they collected while acoustically designing hundreds of movie theaters around the world. The same principal were followed for other “unique places” like concert halls, concert videos, churches, live concerts, clubs and even TV theaters!!!

But what is this digital data? Actually this data is a sonic signature of each individual audio frequency of the entire audible frequency range (20~20,000Hz) collected in a “unique place”.

This actual digital data collected from every “unique place" is stored in the Read Only Memory (ROM) of the Yamaha DSP engine. Now the input audio signal is processed along with the actual digital data found in ROM by executing extremely complex algorithms inside the Yamaha DSP engine thus generating a unique audio frequency based correlation data. This correlation data gets stored in the Random Access Memory (RAM) of this engine.

Say if we choose the “Movie Theater” DSP mode, a unique correlation data will be generated after comparing the input audio signal with the actual digital data as taken from a real "Movie Theater". This real time and ultra fast process needed truly powerful DSP processors which went on improving with time generating around or over 2 million instructions per second (MIPS)!!!

Later on a final error correction processing is performed on the generated left, center, right & surrounds channels of the correlation data. Now each audio frequency of the entire audible frequency range(20~20,000Hz) should sound like it sounds in an actual "sound field" environment, be it concert hall, movie theater, church, etc.

Yamaha also happens to be the only company to have worked with Dolby Laboratories in the early days (70's & 80's) regarding multi channel audio technology. Yamaha was an active technological partner in developing the actual four channel “Dolby Stereo” in 1976 having Left, Center, Right, and Rear channels.

Later in 1982 a consumer version of this famous “Dolby Stereo” was released, and to keep the costs down these consumer Dolby Stereo decoders dispensed the center channel and the corresponding logic circuitry as found on the professional decoder as used in movie theaters, but did include the surround delay. To distinguish these decoders from the professional units found in cinemas they were given the name "Dolby Surround" decoders. When a Dolby Surround soundtrack is created, three channels of sound (Left, Right, and Rear) are matrix-encoded into an ordinary stereo (two channel) sound track.

A newer a much improved & more successful consumer version followed in 1987 named as “Dolby Pro Logic”. While Dolby Surround dropped the center channel of actual Dolby Stereo for cost reasons, the Dolby Pro Logic retained it, and was more true to the actual Dolby Stereo as used in professional movie theaters. When a Dolby Pro Logic soundtrack is created, four channels of sound (Left, Center, Right, and Rear) are matrix-encoded into an ordinary stereo (two channel) sound track. The new centre channel is encoded by placing it equally in the left and right channels; the rear channel is encoded using phase shift techniques, typically an out of phase stereo mixdown.

Since Yamaha was involved with Dolby in developing these technologies there was a special DSP mode called “Dolby Surround Enhanced” or “Dolby Pro Logic Enhanced” and was available only on Yamaha receivers. These algorithms were a joint effort of Dolby Labs and Yamaha.

 

[sports]

Why do we need Yamaha DSP? Isn’t true blue stereo good enough for our home?

Think of a big concert hall.

The size or shape of it, image localization, and echoicness or anechoicness can be appreciated even with our eyes closed. This is because sonic reflections from all directions are heard besides the direct sound emitting from stage (instruments & voices) simultaneously. Our auditory sense can recognize the extent of the hall by the time difference between the direct sound and its reflections, the shape of the hall by the directions of the reflections, and the echoic or anechoic characteristic by the attenuations of the sound.

What really creates the rich, full tones of a live instrument are multiple reflections from the walls of the room. In addition to making the sound "live", these reflections enable us to tell where the player is situated, and the size and shape of the room in which we are sitting. We can even tell whether it is highly reflective, with steel and glass surfaces, or more absorbent - wood panels, carpeting and curtains.

Therefore, simulating the time difference or direction of the reflections and attenuating time may reproduce the sound field of an actual concert hall in our home. As sound produced by performers is reflected by all objects in the hall, it is heard not only from the direct front but also from the sides, rear or ceiling.

In Yamaha DSP terminology “concert hall” will be treated as a sound field. A sound field is defined as the “characteristic sound reflections of a particular place”.

These reflections cannot be reproduced by the conventional stereo channel (2-speaker) system, but require extra speakers to reproduce sound reflection which Yamaha called effect speaker.

Yamaha DSP requires four effect speakers to recreate the sound fields. They are designed to reproduce the realistic sound field experienced in a concert hall in a normal listening room by simulating sound reflections from all directions based on actual measurement data, using extra effect speakers surrounding the listener. Furthermore, the digital signal processing circuit adopted in these units can be used to produce special sound effects, such as combining phase difference signals, changing pitch or changing imaging position periodically.

 

[sports]

Yamaha's few elite DSP models

Getting hold of how the Yamaha DSP technology works & why do we need it in our home, I spent some time digging the net to find out some path breaking early Yamaha DSP units that I believe revolutionized the audio industry by shifting from the “old is gold” stereo to focus on multi channel spatial realism. Yes, I am taking about mid 80’s and early 90’s when multi channel was a distant dream.

Yamaha DSP-1

The Guru of all the Yamaha DSP models was undoubtly the Yamaha DSP-1, released way back in 1986. On release it immediately created a sensation in the audio industry since it amazingly supported multi channel speaker arrangement from a single analog stereo source giving birth to multi channel sound later known as ‘home theater”.

It was for the first time in audio industry a company was bold enough to step out from the “old is gold” stereo and focus on multi channel spatial realism. It left Yamaha’s competitors scratching there heads unable to understand this complex technology & how Yamaha was able to release a consumer model.

By then exceptional sonic fidelity had been realized through the digital recording technology used in compact disc players. What Yamaha achieved was a comparable breakthrough in audio spatial realism by developing one of the significant innovations since stereo, the DSP-1 Digital Sound Field Processor.

The DSP-1 was able to recreate the actual acoustical characteristics of 13 live performance environments by digitally reproducing the depth, imaging and spatial of those environments using recorded reverberation and echo patters. They newly developed DSP Engine for DSP-1, which included a high-speed 24-bit X 13-bit multiplier and a 24-bit adder/substractor, was used to process sonic reflections in real time, while digital signals were processed at a sampling rate of 44.1 kHz by 16-bit linear quantization A/D and D/A converters.

DSP-1 accepted an analog stereo signal and the DSP Engine processed it in real time generating a 6.1 channel output for different sound fields. The channels were divided into main left, main right, the two front effect, two rear effect & subwoofer channels.

The four effect speakers at the four corners of the room were used to create the sound field effects generated by the DSP Engine while the main left & right stereo speakers were left untouched. The subwoofer channel was mix mono low pass signal below 200 Hz of left & right stereo channels.

DSP-1 was also the first consumer product ever to support Dolby Surround where a three channel sound (Left, Right and Rear) were created from a matrix-encoded analog stereo input. The Left & Right of Dolby Surround were handled by the main left & main right channels where as the two rear effect channels took hold of the Rear. No sound was produced from the two front effect speakers in this mode.

Yamaha MVS-1 Master Volume Controller

Since the DSP-1 was dedicated to DSP processing only Yamaha had to design a new separate 6 channel master volume controller named MVS-1 to attenuate the incoming 6 channel (main left, main right, two front effect, two rear effect) output signal of DSP-1 and feed them to the power amplifiers.

Yamaha M-35 4-Channel Power Amplifier

Incidentally, Yamaha also developed a 4-channel power amplifier named M-35 in order to drive the four effect speakers used with DSP-1. It was rated at 22 watts (6 ohms @ 0.08% THD)/ per channel.

6-Speaker DSP-1 System Setup

Main analog stereo audio signal from a hi-fi or video source is routed through the control amplifier and enters the DSP-1, where the DSP Engine creates a unique correlation data that results in a unique pattern of reflections and reverberations mimicking a sound filed of a “unique place”.

This newly processed signal to be sent to the four effect channels, together with the main stereo signal is passes through the MVS-1 where master volume adjustment is made for all these 6 channels. The processed signal then proceeds through the M-35 4-channel power amplifier and out to two front and two rear effect speakers, while the main stereo signal is fed through the power amplifier like Yamaha MX-600 to the main stereo speakers.

Images from the DSP-1 brochure:

 

[sports]

So Watts the Problem?

Gene : "I totally understand and respect the tradeoffs between amplifier power and features in budget A/V receivers. Heck just a few years ago, you couldn’t get a 7.1 A/V receiver with HDMI 1.3a A/V processing and decoding for under $2k, now you can get them for under $500 with OSD support via HDMI no less. That’s progress!

What I do take issue with however is when a receiver company releases their next generation of receivers at the same price points with virtually the same operational features, but costs reduces the power supply in attempts to increase profit margins.

Let’s take a look at the differences between two $549 Yamaha receivers as an example. Yamaha isn’t the only brand I’ve noticed this trend with mind you.

Yamaha RX-V663


Yamaha RX-V665


Yamaha RX-V663 | Yamaha RX-V665
Retail : $549 | $549
Power Spec : 95wpc x 7 full bandwidth | 90wpc x 7 at 1kHz
HDMI (I/O) : (2/1) | (4/1)
Component Video (I/O) : (3/1) | (2/1)
A/V inputs : 5 with s-video | 4 (composite only)
Digital inputs : 3 opt / 2 coax | 2 opt / 2 coax
HDMI Up conversion : Yes | to 1080p
HDMI Pass thru : No | Yes
Speaker a/b : A + B | A only
Dimensions (W x H X D) : 17 1/8” x 6 3/4” x 15 1/2” | 17 1/8” x 6” x 14 3/8”
Weight : 26.2 lbs | 18.7 lbs

The upgrades for the new model (RX-V665) includes HDMI up-scaling to 1080p, HDMI pass thru to enable video when your receiver is turned off, and 2 more HDMI inputs. The downside is no s-video, one less optical input and a significantly reduction in power. When a receiver company rates their amp at 1kHz, this usually means a full bandwidth(20Hz-20kHz) measurement will be about 10-15% lower. Thus I suspect if we were comparing apples to apples, the RX-V665 would only output around 70wpc compared to the 95wpc rating of its predecessor. Of course with nearly an 8lb weight reduction and considering both receivers use linear A/B amplification, this also likely means the RX-V665 doesn’t have the power reserves to drive multiple channels with as much poise and finesse as the RX-V663.

For the above example, the consumer must decide whether or not the upgraded features of the new receiver are worth the sacrifice in amplifier quality. I suppose it depends if the end user leans more towards emphasis of video features than audio. If they desire both and one day have intentions of adding external amplification, than doesn’t this become a moot point?

Not always. From my testing of A/V receivers from various manufacturers, most of them simply slap preamp outputs on the back of their receivers for a marketing feature. It is a very inexpensive way to impress the unsophisticated user into being awed. They usually don’t put decent op-amps that have enough output to drive external power amplification to its full potential without the internal preamp of the receiver first clipping and going into gross distortion. Remember these receivers are designed as a closed loop system to work optimally with their own internal components. If the manufacturer is cutting costs in the power supply of their product to offer you more features, it’s a safe bet they aren’t giving you a higher quality preamplification section to power an external amplifier.

Conclusion

Having done this job for some time now, I’ve noticed this trend with many of the major brands over the years. Companies go through up and down cycles and as a result lose market share. As long as technology keeps evolving, manufacturers will do their best to cram in features of next generation products that were only previously found in their flagship models. While IC integration will trickle down technology, reducing production costs making it easier to achieve this, there will usually be other compromises in the lower end models to realize the feature count.

Finding that balance of basic performance compromises vs. relevant features is the equation that receiver manufacturers must figure out when launching their new platforms. It seems Yamaha has upset this delicate balance with their latest RX-Vxx5 series of receivers. We will be paying careful attention to this trend for all manufacturers during our product evaluations to recommend whether or not these new dream machines have the audio chops of their predecessors or if they’ve got the tools to adequately drive external amplification for those looking for more power in their next home theater experience. Don’t just run out and buy the latest model because it’s newer.

Stop and think if the model you currently have meets the performance vs feature balance that is right for your needs and how the newer so called “improved” model fits into that equation. All the features in the world can’t replace clean undistorted dynamics which we believe makes up most of the WOW and magic in the newer HD audio formats."

Gene DellaSala Biography

The above content belongs to two of the Gene's articles as below:

Product Managing Receiver Platforms & Power Ratings

Trading Amplifier Quality for Features – A New Trend with A/V Receivers?

 

[ouimetnick]

Welcome to AK, and nice long thread. I love long interesting reads.:yes:
Do you know much about the RX-V990? I have it, and love it. It has mood swings it seems, but when its happy, it sounds amazing!

 

[musictech77]

Hi
I received yesterday a used yamaha dsp A2070 amp.Iam interested to use it with a stereo set of speakers,mostly for music.My speakers are the Dali oberon 5.

-Which input is the best to use with a high quality dac with big dynamic range?Which sounds best with this kind of signal?My dac is the new topping dx5ii.

-can you describe me please which is the best and safest way to use this amp as a simple stereo amp in order to achieve a high quality sound ?

---Dx5ii can operate also as a preamp.Which is the way to do it ?Iam a bit confused with the proper settings regarding the jumpers etc in order to use the dsp a2070 as a power amp.It is something i want to try.
I read the following in the manual:
''12) Main Out Jacks Main-channel line output. Connected with jumper bars to MAIN IN jacks when the built-in amplifier is used. Connected to input jacks of external stereo power amplifier (MAIN IN or TAPE PLAY jacks of integrated amplifier or receiver) when using external amplification.

13) Main In Jacks Line input to built-in main-channel amplifier. Connected with jumper bars to MAIN OUT jacks when the built-in amplifier is used. Not connected when using an external power amplifier.''

I also read:
''CONNECTING THE MAIN SPEAKERS TO THIS UNIT

Connect the MAIN speakers to the MAIN speaker output terminals of this unit. Make sure that the jumper bars between the MAIN OUT and MAIN IN jacks on the rear panel are in place. It is also possible to use an external power amplifier if more power is desired. In this case, remove the jumper bars and connect the MAIN OUT jacks to the INPUT jacks of a stereo power amplifier with a stereo pin cable—making sure to connect the left and right channels correctly. Connect the MAIN speakers to the speaker output terminals of the power amplifier.

NOTE: If an external amplifier is used for the main speakers, it is recommended to use the MAIN speaker terminals of this unit for the rear effect speakers.

Connect the REAR EFFECT OUT jacks to the MAIN IN jacks with the pin cord. This combination is highly upgraded and ideal for the division of sound quality, because the rear channel output of the Audio/Video system is equally important as the center channel.''

Could you please explain me all the above functions?I find this part of the manual not very well written....

--Can the cd input be adjusted with the input trim or it is at a fixed-reference value?

--I received this amp without a remote.Can i access all parameters without it?is it neccessary for setting a stereo operation?

--As a future plan ,i may add a sub in the system.Is there any way to apply a low cut filter to the main speakers in case i want to use a passive sub in a 2.1 set up?I d like to use a sub with variable crossover.I do not want the sub to operate at frequencies above 50-60hz.I d like oberon5s to play frequencies above those frequencies.I know that there are active subs with variable crossover , i do not know if there are passive with this function though...

Thanks in advance!

 

[Quadraflex65]

I got lucky. Very luck. Why?

Coz I got a deal to have a Yamaha DSP-A2070 7.1 channel integrated amplifier at USD $160.

Yamaha DSP-A2070

This previous owner bought this amplifier back in 1996 in U.K and was using it since. Last year he thought of an upgrade and outsourced a Marantz SR6003 A/V receiver to replace the DSP-A2070.

He says after some months of extensively using the SR6003, he found though it supports all the latest movie formats and provide options like USB so he can connect his iPod, it crucially lacked in terms of audio performance and the level of sound quality that the DSP-A2070 was able to achieve. According to him 2-channel performance of this Yamaha is something special and the SR6003 cannot hold a candle to it. Later he got a Krell and decided to sell both the SR6003 & DSP-A2070.

For starters DSP-A2070 is not a A/V Receiver like SR6003, actually you cannot call it a receiver since it lacks a tuner, and it has no video processing capabilities. It is just a 7.1 channel integrated amplifier purely devoted to audio & its digital sound field processing.

The amp is plane Jane & conservative looking. But it weighs a hefty 21kilos [46 lbs]. The power supply section must be almighty which is denoted by its weight.

Stats of Yamaha DSP-A2070
----------------------------------
1) Full name : Yamaha DSP-A2070 Digital Sound Field Processing Amplifier

2) Released : 1993

3) Price on release : $2000

4) Awards : In 1993 won the best Home Theater System award given by European Imaging & Sound Association(EISA) www.eisa.eu --> Awards

5) Minimum continuous power per channel(RMS) @ 20Hz~20kHz @ 0.015% THD @ 6 ohms:

Main stereo speakers(2 units) : 100 watts/ each

Center speaker(1 unit) : 100 watts

Effect speakers (4 units) : 26 watts/ each

Total minimum continuous power of the system : 100 + 100 + 100 + 26 + 26 + 16 + 26 = 404 watts @ 6 ohms

6) Minimum dynamic power per main channels : 130 watts @ 8 ohms / 160 watts @ 6 ohms / 215 watts @ 4 ohms

7) Dynamic Headroom : 2.0db @ 6 ohms

-----------------------------------------------------

Some great questions. I bought a used A2070 ten years ago at a thrift store for 75 bones for my bedroom system and found it to be a muscular yet refined amp in 2 channel mode. Really full, powerful, rich sounding amp. Just had some work done on it (bad selector switch) and getting it back next week. Im excited to pair it some vintage KEF’s or my Klipsch Forte 4’s with some large bookshelf B&W’s for the rears. I’ll let u know if i can answer any of your questions when i get it set up. Did u get your system working well?