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Denon DRA-800H Review (Stereo Receiver)

SoundsGood64

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@User_22 Those faulty transistors that you are attributing to the L sided distortion--how do you know the problem is due to the transistors and can you replace them in your machine? Or if new enough maybe it's good for warranty?

Are there any other interesting measurements you're planning?

Did you ever figure out what happened to All Zone Stereo with your device? I suspect Denon took the feature away. You could try toggling that "Stereo Receiver" vs "TV Audio" setting I mention in Post 226, although I suspect since you were measuring from the speaker post that the setting was already "Stereo Receiver" (All Zone Stereo is an option) and not "TV Audio" (All Zone Stereo is not available as an option).

Can you explain why your initial measurement (post 200) at the Z2 pre-out was downstream the PCM5100A (coaxial digital, CD in Main Zone, Z2 source as SOURCE, DIRECT Mode), whereas later you had the same settings and found that it was PCM1690 (post 228)? It would be good to confirm in a post that under these settings you consistently find PCM1690--rather than PCM5100A--upstream of the Z2 pre out, or at least that the SINAD is consistent so you don't have to repeatedly contact the DAC IC analog out pin.

Thanks for these great posts.
 

User_22

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@User_22 Those faulty transistors that you are attributing to the L sided distortion--how do you know the problem is due to the transistors and can you replace them in your machine? Or if new enough maybe it's good for warranty?

Are there any other interesting measurements you're planning?

Did you ever figure out what happened to All Zone Stereo with your device? I suspect Denon took the feature away. You could try toggling that "Stereo Receiver" vs "TV Audio" setting I mention in Post 226, although I suspect since you were measuring from the speaker post that the setting was already "Stereo Receiver" (All Zone Stereo is an option) and not "TV Audio" (All Zone Stereo is not available as an option).

Can you explain why your initial measurement (post 200) at the Z2 pre-out was downstream the PCM5100A (coaxial digital, CD in Main Zone, Z2 source as SOURCE, DIRECT Mode), whereas later you had the same settings and found that it was PCM1690 (post 228)? It would be good to confirm in a post that under these settings you consistently find PCM1690--rather than PCM5100A--upstream of the Z2 pre out, or at least that the SINAD is consistent so you don't have to repeatedly contact the DAC IC analog out pin.

Thanks for these great posts.
In post 200 I shortened the PCM5100A to ground, the signal in Z2 did not change. I concluded that it goes through the PCM1690. Logically, there is no other way. In addition, SINAD is about 100 dB. Practically what more is needed? I wanted to shorten the ground output of the PCM1690. If the signal changes, there will be a guarantee that it will pass through the chip. PCM1690 output much more difficult to shorten, can make yourself a problem. If I find the right place for the PCB I will try later.
I started the measurements on the Z2 output. I do not need ZONE 2. Need a preamp direct output, but its not there.
 
Last edited:

GiBo61

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I do not need ZONE 2. Need a preamp direct output, but its not there.
It is less convenient as it needs more configuration but I guess you can actually use the Zone2 output as a pre-out to drive an external power amplifier to be used in place of the (mediocre) internal one.
 

User_22

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It is less convenient as it needs more configuration but I guess you can actually use the Zone2 output as a pre-out to drive an external power amplifier to be used in place of the (mediocre) internal one.
There is no way to measure the HEOS signal quality. It only goes through the PCM5110A to the Z2. I'm thinking of PCM1690 output instead of PHONO input (I don't need it). The PHONO PCB can be easily removed, only a screwdriver is required.
 

GiBo61

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There is no way to measure the HEOS signal quality. It only goes through the PCM5110A to the Z2. I'm thinking of PCM1690 output instead of PHONO input (I don't need it). The PHONO PCB can be easily removed, only a screwdriver is required.
Say it again? What can you do if you remove the Phono PCB?
 

GiBo61

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Where there is a Phono input, there will be a PCM1690 output.
Ok but even if you remove the Phono input I guess there is no way to force the Heos signal through the main DAC (PCM1690 or AKM).
 

User_22

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Ok but even if you remove the Phono input I guess there is no way to force the Heos signal through the main DAC (PCM1690 or AKM).
Why force? Heos and so goes through the PCM1690 to the MAIN ZONE. The ZONE 2 goes through the PCM5100A.
 

SoundsGood64

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Ok but even if you remove the Phono input I guess there is no way to force the Heos signal through the main DAC (PCM1690 or AKM).
There is a possibility for HEOS to output from the Z2 pre out using the upstream Main DAC (PCM 1690 in revision) but it would have to be tested.

Here's a summary of what User_22 has reported, measuring from the Z2 pre-out:
DIGITAL AUDIO IN: Coaxial
MAIN ZONE: CD
ZONE 2 Source: Source, Signal NOT via PCM5100A (by logical elimination via PCM1690), SINAD -99dB
ZONE 2 Source: CD, No Signal (expected behavior based on user manual)
ZONE 2 Source: Tuner, Signal from radio
ZONE 2 Source: HEOS, Signal via PCM5100

The following is a possible way by which Z2 pre-out can play HEOS from upstream Main DAC (PCM 1690 in revision)
MAIN ZONE: HEOS
Zone 2 SOURCE: Source (mirrors the main zone and therefore might go via PCM1690).
 

User_22

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There is a possibility for HEOS to output from the Z2 pre out using the upstream Main DAC (PCM 1690 in revision) but it would have to be tested.

Here's a summary of what User_22 has reported, measuring from the Z2 pre-out:
DIGITAL AUDIO IN: Coaxial
MAIN ZONE: CD
ZONE 2 Source: Source, Signal NOT via PCM5100A (by logical elimination via PCM1690), SINAD -99dB
ZONE 2 Source: CD, No Signal (expected behavior based on user manual)
ZONE 2 Source: Tuner, Signal from radio
ZONE 2 Source: HEOS, Signal via PCM5100

The following is a possible way by which Z2 pre-out can play HEOS from upstream Main DAC (PCM 1690 in revision)
MAIN ZONE: HEOS
Zone 2 SOURCE: Source (mirrors the main zone and therefore might go via PCM1690).
DRA-800H modification done. PHONO input is replaced by "PRE OUT MAIN DAC". The signal is output directly from the PCM1690 op amp.
Checked Operating Inputs:
CD Coaxial SINAD about 100-101 dB
CD Analog SINAD about 91-92 dB (Theoretically without signal)
FM Signal of good quality (Theoretically without signal)
HEOS Signal of very good quality

DRA-800H_mod1.jpg
 

SoundsGood64

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DRA-800H modification done. PHONO input is replaced by "PRE OUT MAIN DAC". The signal is output directly from the PCM1690 op amp.
Checked Operating Inputs:
CD Coaxial SINAD about 100-101 dB
CD Analog SINAD about 91-92 dB (Theoretically without signal)
FM Signal of good quality (Theoretically without signal)
HEOS Signal of very good quality

View attachment 177658
Let me confirm what you did:
There is no longer an analog input for PHONO.
Instead, you have turned what used to be the PHONO input into a Main Zone (PCM1690) pre-out.
That is awesome.
 

User_22

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@User_22, can you show us on a block diagram, perhaps from the service manual with your drawings on it, your new connection?
You can see everything in the photo. Output directly from PCM1690 Main DAC. Interesting measurements and surprises tomorrow.
 

ttt

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You can see everything in the photo. Output directly from PCM1690 Main DAC. Interesting measurements and surprises tomorrow.
In summary: the PHONO input turned to be the MAIN DAC output. Right?
 

User_22

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Modifications made, defects removed, housing closed.
An interesting measurement to finish.
Input - CD Coaxial. Zone 2 - ON. Zone 2 Source - Source.
At the top of the PRE OUT Main Zone.
At the bottom PRE OUT Zone 2.

Meas_MZ_vs_Z2.jpg
 

ttt

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Modifications made, defects removed, housing closed.
An interesting measurement to finish.
Input - CD Coaxial. Zone 2 - ON. Zone 2 Source - Source.
At the top of the PRE OUT Main Zone.
At the bottom PRE OUT Zone 2.

View attachment 177797
Did you try to swap your generator / measurement eqipment input/output left/right to be sure, the 800H has defects not your stuff? I'd do first it. It's strange the similar difference seen on poweramp measurement.
 

GiBo61

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Modifications made, defects removed, housing closed.
An interesting measurement to finish.
Input - CD Coaxial. Zone 2 - ON. Zone 2 Source - Source.
At the top of the PRE OUT Main Zone.
At the bottom PRE OUT Zone 2.

View attachment 177797
These DAC measurements look excellent! to me, almost 15 db better than Amir's original values!
 
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