Integra DHC-80.3 processor came into the market in 2011. Its complete analog is Onkyo PR-SC5509.

The difference between Integra DHC-80.3 and Onkyo PR-SC5509 is insignificant. Integra DHC-80.3 has a 15-channel equalizer for room acoustics calibration, and fine tuning on the device’s menu. Onkyo PR-SC5509 has an 8-channel equalizer, but on the other hand it has a Pure Audio button. As for me, Integra seems to be more carefully and reliably assembled.


The sound of these processors “out-of-the-box” is not very pleasing – I’d rather say it is shrill and rough. A typical tweet-and-boom. There are objective reasons for such sound. It was easily outplayed by AV processors by Marantz and Yamaha. But as a potential upgrade donor it is definitely second to none of its competitors. In the end of this article I will name all models suitable for upgrade by this technology with slight variations.

Let us find out why it so happens.

1. Excellent standard power supply: 3 transformers (2 of them being E-type for digital circuits, and one being a toroidal Japanese BANDO for analog circuits). BANDO manufactures transformers for Accuphase.
2. +-14V power of the analog circuits provides for installation of better operating amplifiers.
3. Preamplifier on the basis of CS3318 volume control has a good potential. It’s an analog to CS3310 stereo version installed in many Hi-Fi integral amplifiers and preamplifiers. CS3318 has even higher performance.
4. PCM1795 D-to-A converter is installed in the processor. It is in itself a good high-performance D-to-A converter, but it can be replaced by a better one - PCM1792 – which is a top D-to-A converter by Texas Instruments.


These are the device’s basic modules. They are hardly replaceable – the competitors have a significantly lower potential. For example, Marantz AV8801 comprises the same D-to-A converter microchips PCM1795, but the power is 7-9 V, which is partly supplied from switching power supply units. Preamplifier in Marantz AV8801 is a microassembly containing the volume control, input selector, almost a radio! There’s not much to expect of it, especially in view of the unlikeliness of any changes. Yamaha CX-A5000 is more or less the same in structure. However, the engineers in these companies have taken the most of these devices. Their bottleneck is the preamplifier.

Several upgrade options have been developed for Integra DHC-80.3 / Onkyo PR-SC5509 – to be more specific, there were 5 options. They differ in sound quality and switching possibilities, especially in the “super-upgrade” version.

All upgrades have been developed for years. I can call them 2011, 2012, 2013, 2014, and “super-upgrade” versions – a new version every year, so to speak.

2011 version. It is very much alike to what I made with Onkyo PR-SC886.


1. Removal of all electrolytic capacitors in the analog signal circuit.
2. Replacement of D-to-A converter microchips pcm1796 by pcm1792 in all channels. In total there were six.
3. Replacement of all operating amplifiers by higher quality ones.
4. Replacement of electrolytic capacitors in the analog part by better quality ones.
5. Upgrade of analog parts’ power supply in order to minimize the influence of video part.
6. Upgrade of preamplifier power supply on the base of CS3318.
7. Elimination of VLSC – a proprietary Onkyo filter, which is actually a nasty thing for the sound as it comprises several operating amplifiers in the analog signal circuit. Onkyo engineers might have оverintellectualized or chased some abstract characteristics that have nothing to do with good sound, or maybe it’s just a marketing trick.

2012 version.

The same as in 2011 version with some essential alterations.


1. Complete remake of the analog part of D-to-A converter board – one additional board installed over the host board, which is a big step forward.
2. Created a new buffer board for preamplifier board.

2013 version.


1. Minor improvements is the D to A converter board compared to 2012 version. Removed the buffers at D-to-A converter board output – I thought they were excessive, signal path may be shortened by one operating amplifier in every channel.
2. Created an all-new buffer plate on the basis of a preamplifier.
3. Designed a new power unit for CS3318 volume control.
4. Designed an additional power supply board for the analog part of D-to-A converter board. In general, this upgrade was rather massive and far more expensive than the previous one.

2014 version.


1. This version preserved all the best features of the 2013 version, plus frontal stereo channels were improved. In 2012 and 2013 versions all 11 channels were completely the same, but in 2014 version I decided to upgrade frontal stereo channels for music to the maximum. Since these channels took twice more space on the additional boards than in older versions, I had to somewhat sacrifice the upper frontal channels. They were upgraded in 2011 on the D-to-A converter motherboard. This castling seemed acceptable, for main frontal channels are more important than the upper frontals.
2. I also remade the buffer board in order to make it cheaper without deterioration of sound quality. It has power modules of CS3318volume control mounted on it. Basically, 2013 boards could be installed, but this would be more expensive.

2014 super-upgrade.

This version aggregating the best features of 2013 and 2014 versions was designed for the most ardent audiophiles.


1. I utilized the 2013 additional D-to-A converter board, where all channels are upgradeable, including the upper frontal, and also designed a small board superstructured over it. The circuitry of this unit is similar to that of 2014 version for frontal channels, but it was altered following the audiophiles’ requirements regarding circuitry and components. Individual power for all channels, audiophile resistors, and some minor changes.
2. Essential alterations in the preamplifier board. All analog inputs were removed due to their irrelevance. In fact, signal was now directly transmitted from D-to-A converter board to volume control, bypassing all the switches, which substantially improved sound quality.

2015 super-upgrade.

In the middle of 2015 I designed a board for frontal and upper frontal channels, where AK4390 D-to-A converters were installed along with the analog part. Why would I do that?

Since the solutions implemented on the basis of PCM1792 D-to-A converters allowed for no further improvement of frontal channels’ sound, I decided to replace the D-to-A converter by a better one suitable for this circuit. A Japanese Asahi Kasei AK4390 D-to-A converter was chosen. Analog part with maximum quality of all units was developed for it.


Listening. Sound was compared to that of 2014 super-upgrade version.

We listened to different styles of music, including jazz. pop, classics. So, what did we hear? High-frequency range became even more precise, the sounds were neatly shaped, the music became denser, the performers’ mood was excellently rendered. I was really content with the outcome.


By the time of writing this article (October 2015) these upgraded AV processors are unsurpassed in terms of stereo sound and multi-channel in one box. Different comparisons were made in various studios in Moscow and Saint-Petersburg, with various players and D-to-A converters, in different price ranges, and with various approaches to sound (tube – transistor). So far, this processor yielded to none. The sound is very smooth, dynamic and neutral. The ear catches no defects. Probably, there are none; probably this is just a coincidence. However, fortune favors the daring. This upgrade is suitable for many older processors and receivers by Integra and Onkyo. It should be noted that the result of receiver upgrade is slightly inferior to that of processor upgrade. Unfortunately, big toroidal transformers inside a small box do nothing good to the sound.

References to other sources: 1 2 3 4 To my regret, not all people do and want to write reviews. I would like to thank all those who did. Upgradeable receivers and processors:

Onkyo PR-SC5507, Onkyo PR-SC5508, Onkyo PR-SC5509, Onkyo TX-NR1007, Onkyo TX-NR3007, Onkyo TX-NR5007, Onkyo TX-NR3008, Onkyo TX-NR5008, Onkyo TX-NR3009, Onkyo TX-NR5009.

Integra DHC-80.1, Integra DHC-80.2, Integra DHC-80.3, Integra DTR-80.1, Integra DTR-80.2, Integra DTR-80.3, Integra DTR-70.3, Integra DTR-70.2, Integra DTR-70.1.

Author: Timur Sheykhov