Lexicon DD8 Review (Multichannel Amplifier)

[Rebelhifi]

What do you see out there that get's you 8 channels over 100w in one chassis? Maybe a multichannel home theater amp? Actual curiousity here, no snark.

I have looked in the past. The 8 channel Emotiva (cheapest stereo module version) does not quite hit the power performance for $1400. Monolith 9 channel powerhouse amp (back breaker ATI amp) for $2000. Nord (MP122 Hypex) for $1900 with similar power and should perform better. So if you are looking new, there are better options. But used, I got my 2 year old Crown CT8150 for $600 (I wanted XLR connections). I see these Lexicon DD8 on eBay for $400.

 

[Rebelhifi]

Amir, Doesn't the graph show 97.7watts into 4 ohms @ -79 db? It is backwards in the report 79 watts at 4 ohms.

 

[hyfynut]

I have looked in the past. The 8 channel Emotiva (cheapest stereo module version) does not quite hit the power performance for $1400. Monolith 9 channel powerhouse amp (back breaker ATI amp) for $2000. Nord (MP122 Hypex) for $1900 with similar power and should perform better. So if you are looking new, there are better options. But used, I got my 2 year old Crown CT8150 for $600 (I wanted XLR connections). I see these Lexicon DD8 on eBay for $400.

Thanks, and for what it's worth I love the look of that Crown. I don't see xlr connections, just barrier strip/phoenix.

 

[Rebelhifi]

For the Crown, you have to buy the XLR to Phoenix adapter (Amazon $8). They worked great.

 

[jhaider]

Thanks, and for what it's worth I love the look of that Crown. I don't see xlr connections, just barrier strip/phoenix.

I prefer those connectors to XLR. No expensive crimp tooling (though I do crimp ferrules onto the leads) or soldering required.

 

[amirm]

Amir, Doesn't the graph show 97.7watts into 4 ohms @ -79 db? It is backwards in the report 79 watts at 4 ohms.

You are right. Corrected the review.

 

[DualTriode]

Speaking of this, I am thinking of eliminating the 20 kHz test. It screws up the visual display if one doesn't take the bandwidth into account. If there are no objections, I will do that in the next review.

Hello @amirm and All,

I take the alternate view. I like seeing the margins. The margins are well capable of being captured by the instrumentation. If the margins are not pretty there may well be value to be examined.

I am rather sure that not everyone understands the meaning included in the words: Harmonic and Inter Modulation Distortion. A particular high frequency Harmonic may not be audible, to human ears, alone by its self however that particular Harmonic frequency will interfere with other tones to generate new completely different interference tones that are well within the range of human hearing.

My preference is to include the 20k test results. Perhaps the manufactures will improve their products to improve the test results at the 20k margin.

Thanks DT

https://www.physicsclassroom.com/class/sound/Lesson-3/Interference-and-Beats#:~:text=The beat frequency is always,2 Hz will be detected.

 

[amirm]

Hello @amirm and All,

I take the alternate view. I like seeing the margins. The margins are well capable of being captured by the instrumentation. If the margins are not pretty there may well be value to be examined.

Hello there. The issue here is not to test 20 kHz source signals. I like to do that. It is just that as a matter of instrumentations, only its second harmonic is captured compared to lower signals where more harmonics are used to compute the graph. As a result, the 20 kHz line shows lower distortion than say 15 kHz making one think distortion has gone down when in reality it has not. Likely distortion has gone up. In other words, the graph is lying about what is going on in the system. Only if you understand the measurement bandwidth and concept of harmonic distortion do you realize that the reality is different.

I could increase measurement bandwidth but that creates another problem in that noise shaping in class D systems winds up in those frequencies and then incorrectly gets used to compute harmonic distortion leading to another problem. And here, it would impact most of the graph if not all. 45 kHz was a good balance here to capture ultrasonic harmonics but not that noise.

 

[DualTriode]

.... snip....

I could increase measurement bandwidth but that creates another problem in that noise shaping in class D systems winds up in those frequencies and then incorrectly gets used to compute harmonic distortion leading to another problem. And here, it would impact most of the graph if not all. 45 kHz was a good balance here to capture ultrasonic harmonics but not that noise.

Complete agreement. The 22.4k (48kHz SR) BW selection is a good choice. All that noise from extended BW is excluded from the THD+N and SINAD numbers. That is what people expect to see.

Multi-tone test plots show the inter modulation distortion products (interference beat frequencies) as well as Harmonics within the selected BW. Multi-tone tests with up to 20kHz test frequencies look to be useful to me. The more we see multi-tone test plots the more accepted and understood they will become.

Thanks DT

 

[DualTriode]

Hello All,

Today FedEx delivered a used DD8 to my door. Paid $399. I give it a test drive and we will see.

If it functions okay I will set it up in a tri-amp configuration with a 3-way active crossover.

Thanks DT

 

[Rebelhifi]

Hello All,

Today FedEx delivered a used DD8 to my door. Paid $399. I give it a test drive and we will see.

If it functions okay I will set it up in a tri-amp configuration with a 3-way active crossover.

Thanks DT

My CT8150 (only difference is balanced connection) is working great so far ($600). Let us know.

 

[jhaider]

My CT8150 (only difference is balanced connection) is working great so far ($600). Let us know.

The other difference is trigger type. Do you have yours set up to turn on with an upstream component’s 12V trigger? I recently ordered this relay to take a 12V trigger output and operate the contact closure on a different Crown amp with the same contact closure on/standby.

https://www.elkproducts.com/product/relay-module-spdt-12-vdc-912-91212/

 

[Rebelhifi]

The other difference is trigger type. Do you have yours set up to turn on with an upstream component’s 12V trigger? I recently ordered this relay to take a 12V trigger output and operate the contact closure on a different Crown amp with the same contact closure on/standby.

https://www.elkproducts.com/product/relay-module-spdt-12-vdc-912-91212/

No. I went simple with a Meross WIFI plug. I control from my iPad HomeKit ($40 for 4 plugs)

 

[hyfynut]

I prefer those connectors to XLR. No expensive crimp tooling (though I do crimp ferrules onto the leads) or soldering required.

I'm a residential audio guy so I prefer traditional input connectors. Still dig that amp though. It's the toughest looking of the bunch.

 

[hyfynut]

Hello All,

Today FedEx delivered a used DD8 to my door. Paid $399. I give it a test drive and we will see.

If it functions okay I will set it up in a tri-amp configuration with a 3-way active crossover.

Thanks DT

That sounds fun. What speaker?

 

[DualTriode]

That sounds fun. What speaker?

The speakers are in a rotation, currently:

Sub JBL2242
Woofers two times JBL 2217H
Mids two times JBL 2123H
Tweeters JBL D2 compression Drivers with M2 horns
(Mids crossover to Horns at 1,600Hz to match dispersion angle of about 120 degrees.)

Currently there is a Rane 31 Band 1/3 octave Equalizer, a Rane AC23S active crossover, and Crown amps driving the speakers.

Thanks DT

 

[s0larius]

Amir, you may not remember this, but a few yrs back you brought this amp up in a discussion at AVS. Fast forward a couple of yrs I was looking to purchase an 8 channel amp in a compact enclosure and I noticed Savant had decided to license the design (AMP 8125). I also noticed they were being sold cheaply on ebay ($200-$300). When I looked at the specs I noticed the issue with their frequency response (-1.5 dB at 20kHz); however, since my hearing is poor above 14 kHz I figured "why not". I purchased 2 for 200 and another 2 for 50 (PS problem). For what it is, it has served me well. I can't think of many 8 ch amps in this type of enclosure for a couple of hundred dollars.

PS I'm actually a little surprised at some of its good measurements, I did not expect this all things considered
PPS For those considering purchasing, my units have been very reliable, but please notice I also was able to purchase units with PS issues, so I cannot confirm how reliable these units may or may not be.

Hi, I seem to be having one of the DD-8s and unfortunately have some sort of power supply issue where pressing the power button doesn't cause the power led to go from red to blue. Not sure who I can reach out to get it fixed either. Can I know if the PS issue that you experienced had similar symptoms and did you manage to overcome them?

 

[MerlinGS]

Hi, I seem to be having one of the DD-8s and unfortunately have some sort of power supply issue where pressing the power button doesn't cause the power led to go from red to blue. Not sure who I can reach out to get it fixed either. Can I know if the PS issue that you experienced had similar symptoms and did you manage to overcome them?

They are very similar to the Crown CT 8150 amps. Find a Crown service center near you and they should be able to repair it.

 

[Rebelhifi]

Hi, I seem to be having one of the DD-8s and unfortunately have some sort of power supply issue where pressing the power button doesn't cause the power led to go from red to blue. Not sure who I can reach out to get it fixed either. Can I know if the PS issue that you experienced had similar symptoms and did you manage to overcome them?

I use the equivalent Crown CT8150 (it has balance inputs for slightly improved SNR). It has a trigger input but is a PIA to set up. I use an WIFI plug and leave the power button engage (turn on/off with WIFI). The crown cycles on and off just fine (not using the button). By the way, I picked up a used CT8150 ($600) and replaced my XLS1502 amps for my surround channels. It is almost as quiet as my Hypex NC400 on the main channels. This is comparing based in ear to the tweeter. I am very happy with this amp so far.

 

[Ro808]

How does the CT8150 (subjectively) compare to the NC400?
We already have the data, I'm interested in your personal opinion.

The reviews of the Lexicon were mostly positive. Stereoplay even awarded the DD 8 a 'Highlight' for its price-performance ratio (fwiw).