• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Parasound HCA-1000a Measurement

dumpingg

Member
Joined
Dec 1, 2019
Messages
52
Likes
75
I am new to measuring amps. My first effort and the software and test setup are described here:
https://www.audiosciencereview.com/...ement-setup-panasonic-xr57-avr-example.10589/

I have an older Parasound HCA-1000a Power Amplifier that I decided to measure. Specs are here:
https://www.parasound.com/vintage/hca1000a.php

  • Continuous Power Output - Stereo:
    125 watts RMS x 2, 20 Hz - 20 kHz, 8 Ω, both channels driven;
    200 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven
  • Continuous Power Output - Mono:
    400 watts RMS, 20 Hz - 20 kHz, 8 Ω
  • Current Capacity:
    45 amperes peak per channel
  • Slew Rate:
    >130 V/µsecond
  • Power Bandwith:
    5 Hz - 100 kHz, +0/-3 dB at 1 watt
  • Total Harmonic Distortion:
    < 0.03% at full power; < 0.01 % typical levels
  • IM Distortion:
    < 0.03 %
  • TIM:
    unmeasurable
  • Dynamic Headroom:
    > 1.5 dB
  • Interchannel Crosstalk:
    > 80 dB at 1 kHz; > 60 dB at 20 kHz
  • Input Sensitivity:
    1 V for 28.28 V, THX Reference Level; 1.1 V for full output
  • Input Impedance: 33 k Ω
  • S/N Ratio: > 116 dB, full power; > 96 dB, THX Reference Level

Test Overview Photo:
1577824012494.png



At here are the results, HCA-1000a, 4ohm dummy load, 5watt power, 1khz sine 0dbfs
Parasound HCA1000a 4ohm 5watt 1khz tone.jpg



Comments on my test and measurement setup welcomed. I have a few more pieces of audio equipment I plan to measure in the coming weeks.
 

pkane

Master Contributor
Forum Donor
Joined
Aug 18, 2017
Messages
5,632
Likes
10,205
Location
North-East
I am new to measuring amps. My first effort and the software and test setup are described here:
https://www.audiosciencereview.com/...ement-setup-panasonic-xr57-avr-example.10589/

I have an older Parasound HCA-1000a Power Amplifier that I decided to measure. Specs are here:
https://www.parasound.com/vintage/hca1000a.php

  • Continuous Power Output - Stereo:
    125 watts RMS x 2, 20 Hz - 20 kHz, 8 Ω, both channels driven;
    200 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven
  • Continuous Power Output - Mono:
    400 watts RMS, 20 Hz - 20 kHz, 8 Ω
  • Current Capacity:
    45 amperes peak per channel
  • Slew Rate:
    >130 V/µsecond
  • Power Bandwith:
    5 Hz - 100 kHz, +0/-3 dB at 1 watt
  • Total Harmonic Distortion:
    < 0.03% at full power; < 0.01 % typical levels
  • IM Distortion:
    < 0.03 %
  • TIM:
    unmeasurable
  • Dynamic Headroom:
    > 1.5 dB
  • Interchannel Crosstalk:
    > 80 dB at 1 kHz; > 60 dB at 20 kHz
  • Input Sensitivity:
    1 V for 28.28 V, THX Reference Level; 1.1 V for full output
  • Input Impedance: 33 k Ω
  • S/N Ratio: > 116 dB, full power; > 96 dB, THX Reference Level

Test Overview Photo:
View attachment 44185


At here are the results, HCA-1000a, 4ohm dummy load, 5watt power, 1khz sine 0dbfs
View attachment 44186


Comments on my test and measurement setup welcomed. I have a few more pieces of audio equipment I plan to measure in the coming weeks.

Good start! The noise floor appear a bit high, can you post the details of REW RTA settings (FFT size, etc.)? You can just have the window with the settings opened when taking and posting the screen shot.

What was the bit depth of the 1kHz signal?

You can improve the distortion values a bit if you set the measurement range to 10-22k instead of up to 45k.
 

Cahudson42

Major Contributor
Joined
Sep 21, 2019
Messages
1,083
Likes
1,556
Really great that ASR members with the knowledge and capability are posting their results.

Amir can't do everything, and I really appreciate these new efforts.

One thing might be useful: Guidelines and recommendations on each test, so that we are able to compare to Amir and each..

A 'sticky' somewhere?
 

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,591
Likes
10,727
Location
Prague
Hi @dumpingg , as a small comparison, here is my measurement of Parasound Halo A21 at 100W, 4ohm, 1kHz. It meets the specs. I find noise floor and mains components elevated to high in your measurements. Power amps are not easy to measure, ground loops must be avoided (otherwise you get false elevated noise and PSU related lines), in case you measure in a loop, measuring input must be balanced. No I/O groundloop, they must be avoided.

1577839193035.png
 
OP
D

dumpingg

Member
Joined
Dec 1, 2019
Messages
52
Likes
75
thanks all for the comments. I also have a Behringer UCA202 sound device. The focusrite is a balanced sound card that I was using RCA to 1/4in adapters. For some reason the UCA202 seems to be giving a better reading on the HCA1000. It looks like I have some work to do on my setup. I also dropped the sensitivity of the 1khz tone to -12dBFS to more closely match pma's sample chart.

Parasound HCA1000a 4ohm 5watts 1khz UC202 sound device.jpg


And my REW RTA settings:



1577893919899.png
 

pkane

Master Contributor
Forum Donor
Joined
Aug 18, 2017
Messages
5,632
Likes
10,205
Location
North-East
thanks all for the comments. I also have a Behringer UCA202 sound device. The focusrite is a balanced sound card that I was using RCA to 1/4in adapters. For some reason the UCA202 seems to be giving a better reading on the HCA1000. It looks like I have some work to do on my setup. I also dropped the sensitivity of the 1khz tone to -12dBFS to more closely match pma's sample chart.

View attachment 44247

And my REW RTA settings:



View attachment 44251

That looks much better! I generally go through different dBFS settings to see where they appear to be best. It’s almost never at or close to 0dBFS. At least a -1dB, but this may have more to do with my interface unit.

Sometimes the level of input to the ADC is too high and causes clipping, so I either have to use a pad or lower the input level of the generated sine until I get the best result.

Balanced interconnects help reduce the chance of any ground loops, so should be used if available.

Can you also please remeasure the Aleph 3 clone?
 

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,591
Likes
10,727
Location
Prague
thanks all for the comments. I also have a Behringer UCA202 sound device. The focusrite is a balanced sound card that I was using RCA to 1/4in adapters. For some reason the UCA202 seems to be giving a better reading on the HCA1000. It looks like I have some work to do on my setup. I also dropped the sensitivity of the 1khz tone to -12dBFS to more closely match pma's sample chart.

Yes, it is much better now. If you have a soundcard with balanced input, please try setup as below
1577896357738.png


If you have a TRS input, use only Tip and Ring, leave Sleeve unconnected. You have to avoid the ground loop, because voltage drop on the signal ground wire is added to the measurement and creates false PSU lines and elevated LF noise. Also please make sure that soundcard input is not overloaded by power amplifier output. Voltage divider may help then. Please do not use RCA-TRS or RCA-XLR adapters, they short (-) signal to ground.
 

NTomokawa

Addicted to Fun and Learning
Forum Donor
Joined
Jan 14, 2019
Messages
779
Likes
1,334
Location
Canada
There's a Parasound HCA-1000A for sale on my local classifieds right now... Hmm...
 
OP
D

dumpingg

Member
Joined
Dec 1, 2019
Messages
52
Likes
75
Yes, it is much better now. If you have a soundcard with balanced input, please try setup as below
View attachment 44256

If you have a TRS input, use only Tip and Ring, leave Sleeve unconnected. You have to avoid the ground loop, because voltage drop on the signal ground wire is added to the measurement and creates false PSU lines and elevated LF noise. Also please make sure that soundcard input is not overloaded by power amplifier output. Voltage divider may help then. Please do not use RCA-TRS or RCA-XLR adapters, they short (-) signal to ground.

Thanks PMA for the feedback. I had already tried a setup similar to you suggested. I have a XLR M/F cable and I cut off the female end and then connected the tip/ring wires to a RCA connector. The results unfortunately where the same as my first RTA screen shot shown in this thread. The male end was plugged into the Focusrite solo input 1 which is XLR based.

some additional things I have tried:
REW software running on laptop disconnect laptop from power and run off battery.
Powervar isolation transformer for AC power on the amp (and laptop) ( ref https://www.powervar.com/products/power-conditioners/standard-power-conditioners)
EBTECH HUM-X ground lift adapter on Amp (ref https://www.amazon.com/Ebtech-Hum-Ground-Voltage-Filter/dp/B0002E4YI8)

Also, just as a reminder both the UCA202 and Focusrite Solo are USB powered only (they do not have a separate power/ground connection)
 

LTig

Master Contributor
Forum Donor
Joined
Feb 27, 2019
Messages
5,760
Likes
9,442
Location
Europe
thanks all for the comments. I also have a Behringer UCA202 sound device. The focusrite is a balanced sound card that I was using RCA to 1/4in adapters. For some reason the UCA202 seems to be giving a better reading on the HCA1000. It looks like I have some work to do on my setup.
You should also make a loopback measurement of the test equipment (same setup without the DUT). This tells you the best result you can expect. If distortion products are less than 10 dB higher than in the loopback measurement then their real values may be lower than shown and you need better test equipment.

If unsure just post the loopback measurement together with the real mesurements. In REW you can overlay several measurements easily.
 

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,591
Likes
10,727
Location
Prague
Thanks PMA for the feedback. I had already tried a setup similar to you suggested. I have a XLR M/F cable and I cut off the female end and then connected the tip/ring wires to a RCA connector. The results unfortunately where the same as my first RTA screen shot shown in this thread. The male end was plugged into the Focusrite solo input 1 which is XLR based.

I am not sure, from the written description, if we have the same setup. A drawing similar as I posted would help most, but it is up to you.
2nd, what is the maximum allowed voltage at Focusrite XLR input? Usually it is only about 1-2V. TRS inputs usually have maximum input voltage higher, like 6-8V. To measure power amplifier, voltages up to some 30V may be expected and input divider (or double divider for XLR) are to be used.

I posted a thread on analog interface for the soundcard
https://www.audiosciencereview.com/...-measuring-interface-for-the-soundcard.10445/
but there seems to be no interest on HW in this forum. Detailed schematics may be posted to show input dividers etc.
 
OP
D

dumpingg

Member
Joined
Dec 1, 2019
Messages
52
Likes
75
I have made some additional experiments. I went back to my RCA to 1/4in adapter cable on the input to my focusrite solo sound device. However for a 1khz source I switched to an old Maverick Audio D2 DAC and used a TOSLINK optical (creating a electrically isolated source connection). Here is the loopback (Windows 10 REW 1khz source UCA202 USB-TOSLINK to TOSLINK D2 DAC to RCA DAC output to Focusrite Solo RCA 1/4in adapter input):

MAVAUDIO 1khz using toslink isolated source focusrite solo input.jpg



And here is the updated Parasound HCA1000a measurement with the Focusrite Solo but using the TOSLINK optically isolated DAC as the 1khz source input:

Parasound HCA1000a 5watts 4ohm 1khz using toslink isolated source -10dBFS.jpg


The UCA202 still looks like a better measurement. But all this goes to show that the problem with a DIY approach like this is getting good repeatable measurements can be a challenge and is setup dependent.
 
OP
D

dumpingg

Member
Joined
Dec 1, 2019
Messages
52
Likes
75
I am not sure, from the written description, if we have the same setup. A drawing similar as I posted would help most, but it is up to you.
2nd, what is the maximum allowed voltage at Focusrite XLR input? Usually it is only about 1-2V. TRS inputs usually have maximum input voltage higher, like 6-8V. To measure power amplifier, voltages up to some 30V may be expected and input divider (or double divider for XLR) are to be used.

I posted a thread on analog interface for the soundcard
https://www.audiosciencereview.com/...-measuring-interface-for-the-soundcard.10445/
but there seems to be no interest on HW in this forum. Detailed schematics may be posted to show input dividers etc.

My test setup shown in the photo in the top of this thread includes a voltage divider selector knob to allow me to attenuate the voltage from -3db to -18db before going into my Focusrite sound card. The focusrite in turn has a input knob which has a green/orange/red LED ring that allows me to detect under/overvoltages going into it's interface. A combination of my voltage divider selector switch and the gain knob on the focusrite allows me to tune in the measurement voltage range.

Here is a photo of my RCA to XLR cable with the RCA plug wired up to tip and ring (note that the shield on the RCA end is unconnected):
xlr to rca cable.JPG
 

pkane

Master Contributor
Forum Donor
Joined
Aug 18, 2017
Messages
5,632
Likes
10,205
Location
North-East
I have made some additional experiments. I went back to my RCA to 1/4in adapter cable on the input to my focusrite solo sound device. However for a 1khz source I switched to an old Maverick Audio D2 DAC and used a TOSLINK optical (creating a electrically isolated source connection). Here is the loopback (Windows 10 REW 1khz source UCA202 USB-TOSLINK to TOSLINK D2 DAC to RCA DAC output to Focusrite Solo RCA 1/4in adapter input):

View attachment 44258


And here is the updated Parasound HCA1000a measurement with the Focusrite Solo but using the TOSLINK optically isolated DAC as the 1khz source input:

View attachment 44260

The UCA202 still looks like a better measurement. But all this goes to show that the problem with a DIY approach like this is getting good repeatable measurements can be a challenge and is setup dependent.

Good idea to try optical for some galvanic isolation. You can also try to use a battery powered laptop as the measurement PC, this can help eliminate some of the ground-related issues.
 

milosz

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
583
Likes
1,643
Location
Chicago
Ground loops aren't only a problem when measuring stuff, that's for sure. The more complex the hifi setup, the more likely you'll get a ground loop causing a hum-buzz. And some components have only 2-prong AC cords, other have that third prong for ground which provides not only safety but a path for a ground loop to be established. Ground loops are a real pain.

One thing I found helpful in my headphone setup which is PC to DAC via USB, then DAC to headphone amp - I had nasty ground loop noise until I put a USB galvanic isolator in line with the USB connection from the PC to the DAC.
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
Gleaned some good tips here. Evaluating my equipment that is getting long in the tooth. (Re-cap time?) Anyway, one thing I found in setting up was how horrible my sound card was. I have just ordered a SMSL Sanscrit DAC* as a bit of an upgrade to the old Muse I have. I use a Focusrite 2i2 for my input. Currently running an old Nak C5AII preamp and my own Exicon MOSFET amp, my own Seas based mains and Peerless sub. I notice the new V3 of the Focusrite has an even cleaner mic input, but even my older one is better than a power amp. Not a good 10X, but better.

FWIW, I am getting lazy in my old age. If my amp does need work, I may just buy new. Probably a new Parasound. The Halo is out of my budget, but I did love my old 2200's. It was John Curl who lead me to enough information to understand why my Rotels sounded better on cheap speakers and his HCA much better when I built better speakers. That led me to a years work culminating in a Miller stabilized MOSFET.

* My first purchase made based on a review. Ever. If it works out, I'll be chipping in. Now, I did order the blue one, so don't be offended; they did not come in pink.
 

tvrgeek

Major Contributor
Joined
Aug 8, 2020
Messages
1,017
Likes
566
Location
North Carolinia
Ordered some cheap USB isolators. They only supply 50mA power, so if your DAC is USB powered, that is a problem. But, easily solved by following it with a USB powered hub and DIY a really clean 5V supply. Seems isolators are $9 or $45 for a $9 in a box, or $350 for, well who knows what.
 

milosz

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
583
Likes
1,643
Location
Chicago
I have had one of these HCA 1000a amps that I bought used years ago. Has worked flawlessly until just recently when it refused to turn on. I dug around in the thing and found the low voltage transformer that supplies the power-on relay has an open primary. This transformer is connected directly to the AC line input and energizes the power rela when you switch the amp to "ON." I contacted Parasound and they connected me with their spare parts vendor, he had the board in stock and sold me one for $75. Nice to see support like this for older gear.
 
Top Bottom