This is a review and detailed measurements of the Integra DTM-7.4 stereo amplifier with HDMI/ARC and streaming support. It is on kind loan from a member and costs US $900.
The unit looks half-way between an integrated stereo amplifier and an AV Receiver. Thankfully it is lighter in weight than AVRs due to use of Class G amplifier. This topology keeps amplifier voltage rails low until more power is needed in which case, it switches to higher voltage to deliver that. This has the major benefit of sharply reducing idle current/power consumption. Measured power consumption at idle was around 37 watts (dropping to 3.7 watts in standby mode).
The controls generally feel OK although I found them a bit too light, especially in the input selector where I would fly past the choice I wanted and had to switch back. Back panel shows comprehensive feature list which is lacking in typical stereo amplifiers:
Automation control is front and center in the advertising indicating that the unit is targeted toward home automation companies where such products are routinely installed in living rooms and bedrooms. Stereo output is all that is needed and using an AVR just complicates things as far as size and heat generation.
While a subsystem of an AVR is included in the form of HDMI inputs, all the signal processing including bass management is deleted. This is a miss.
Overall I like the unit as it somehow looks more friendly to use than the complexity that an AVR brings.
Integra DTM-7.4 DAC Measurements
Since we have pre-amplifier output, I was able to measure the performance of the DAC by itself, driving it both with HDMI and Toslink which produced similar performance:
Notice that I had disconnected the speaker as the amplifier was well into clipping at this point. With speakers connected, SINAD was essentially the same and the amplifier kept going without shutting down which is impressive. Then again, it is a shame that when you use an external amp, the internal one is going nuts driving nothing. Best to stick with the internal amplifier than. Anyway, performance as shown, just edges into "OK" category:
I am showing the rankings of AVRs rather than DACs as this unit better fits there. For a music focused stereo device, I would have wanted something in the green category.
Dynamic range is decent though if we relax our standards as we often do for AV products:
Linearity gets lost at lower levels as again, is typical of AVRs:
Jitter was pronounced using HDMI or Toslink (latter worse):
Likely not audible though but a shame to see it nevertheless.
IMD shows performance well below even budget DACs:
Multitone tests shows sidebands as frequencies increase, delivering disappointing performance:
Frequency response shows a strange rising response:
I later verified that the amplifier doesn't do this so tone controls is not responsible for this despite my notation.
Filter response is typical although attenuation should be better:
That is partly responsible for rather high noise+distortion vs frequency:
I wonder if the rise in distortion at low frequencies is due to amplifier clipping harder.
Integra DTM-7.4 Amplifier Measurements
Performance was the same with either HDMI or analog input indicating the DAC is good enough for the amplifier:
The performance is "competent" as AV products go:
That said, noise at 5 watts is nothing to write home about:
Crosstalk was unusually poor:
Mutlitone distortion is OK:
Frequency response is nice and flat:
Here is the effect of tone controls:
There is good bit of power to be had:
Here is a sweep by frequency:
At the end of testing, I took a snapshot of the heat profile:
The amplifier heatsink is spring steel instead of extruded aluminum. That is where the hottest spot is observed at 50 degrees C/122 degrees F.
Integra DTM-7.4 Phono Stage Measurements
I made some quick measurements of the phono stage. The dashboard was dominated by mains hum and was hard to optimize:
Fortunately RIAA equalization is implemented well:
Conclusions
Integra AV products used to have a premier reputation among the Custom Integration (CI) channel. So much so that it was very hard to get dealership for them. I have not kept up to see if that is still the case. The DTM-7.4 shows awareness of the company's brand reputation there, delivering broad support for integration and power efficient Class G amplifier (these units are routinely stuffed in closed entertainment centers/cabinets with little air flow). Measured performance is not deserving of that reputation though. Across the board, the results are either below average or average. I am confident if some emphasis was put on this aspect of design, better performance could have been had with no increase in cost. Sigh.
I can't recommend the Integra DTM-7.4 Stereo Integrated Amplifier. This is a borderline assessment as the feature set and power efficiency could push me over to recommend it so.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The unit looks half-way between an integrated stereo amplifier and an AV Receiver. Thankfully it is lighter in weight than AVRs due to use of Class G amplifier. This topology keeps amplifier voltage rails low until more power is needed in which case, it switches to higher voltage to deliver that. This has the major benefit of sharply reducing idle current/power consumption. Measured power consumption at idle was around 37 watts (dropping to 3.7 watts in standby mode).
The controls generally feel OK although I found them a bit too light, especially in the input selector where I would fly past the choice I wanted and had to switch back. Back panel shows comprehensive feature list which is lacking in typical stereo amplifiers:
Automation control is front and center in the advertising indicating that the unit is targeted toward home automation companies where such products are routinely installed in living rooms and bedrooms. Stereo output is all that is needed and using an AVR just complicates things as far as size and heat generation.
While a subsystem of an AVR is included in the form of HDMI inputs, all the signal processing including bass management is deleted. This is a miss.
Overall I like the unit as it somehow looks more friendly to use than the complexity that an AVR brings.
Integra DTM-7.4 DAC Measurements
Since we have pre-amplifier output, I was able to measure the performance of the DAC by itself, driving it both with HDMI and Toslink which produced similar performance:
Notice that I had disconnected the speaker as the amplifier was well into clipping at this point. With speakers connected, SINAD was essentially the same and the amplifier kept going without shutting down which is impressive. Then again, it is a shame that when you use an external amp, the internal one is going nuts driving nothing. Best to stick with the internal amplifier than. Anyway, performance as shown, just edges into "OK" category:
I am showing the rankings of AVRs rather than DACs as this unit better fits there. For a music focused stereo device, I would have wanted something in the green category.
Dynamic range is decent though if we relax our standards as we often do for AV products:
Linearity gets lost at lower levels as again, is typical of AVRs:
Jitter was pronounced using HDMI or Toslink (latter worse):
Likely not audible though but a shame to see it nevertheless.
IMD shows performance well below even budget DACs:
Multitone tests shows sidebands as frequencies increase, delivering disappointing performance:
Frequency response shows a strange rising response:
I later verified that the amplifier doesn't do this so tone controls is not responsible for this despite my notation.
Filter response is typical although attenuation should be better:
That is partly responsible for rather high noise+distortion vs frequency:
I wonder if the rise in distortion at low frequencies is due to amplifier clipping harder.
Integra DTM-7.4 Amplifier Measurements
Performance was the same with either HDMI or analog input indicating the DAC is good enough for the amplifier:
The performance is "competent" as AV products go:
That said, noise at 5 watts is nothing to write home about:
Crosstalk was unusually poor:
Mutlitone distortion is OK:
Frequency response is nice and flat:
Here is the effect of tone controls:
There is good bit of power to be had:
Here is a sweep by frequency:
At the end of testing, I took a snapshot of the heat profile:
The amplifier heatsink is spring steel instead of extruded aluminum. That is where the hottest spot is observed at 50 degrees C/122 degrees F.
Integra DTM-7.4 Phono Stage Measurements
I made some quick measurements of the phono stage. The dashboard was dominated by mains hum and was hard to optimize:
Fortunately RIAA equalization is implemented well:
Conclusions
Integra AV products used to have a premier reputation among the Custom Integration (CI) channel. So much so that it was very hard to get dealership for them. I have not kept up to see if that is still the case. The DTM-7.4 shows awareness of the company's brand reputation there, delivering broad support for integration and power efficient Class G amplifier (these units are routinely stuffed in closed entertainment centers/cabinets with little air flow). Measured performance is not deserving of that reputation though. Across the board, the results are either below average or average. I am confident if some emphasis was put on this aspect of design, better performance could have been had with no increase in cost. Sigh.
I can't recommend the Integra DTM-7.4 Stereo Integrated Amplifier. This is a borderline assessment as the feature set and power efficiency could push me over to recommend it so.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Thank you.
