This is a review and detailed measurements of the Advent Model 300 Vintage Receiver. It is on kind loan from a member. I believe it came out in 1970s. The original cost was US $270. That would be $1,300 if adjusted for inflation.
I love the tuner knob on the 300, reminding me of what you would find in a HAM radio:
There is no detent on various tone adjustments and balance. The slide switches are par for the era but don't feel nearly as nice of Japanese gear of the time.
The back side is decidedly cheap:
Those tiny speaker screw terminals were on the cheapest 8-track tape/receivers, not on serious hi-fi. The RCA terminals all look tired but work.
Receiver Audio Measurements
I opted to use the Aux input for my testing. I used an RCA cable to feed the pre-amp to power amp. Not sure if they came with a special shorting connector or not. Let's feed a 1 kHz tone to the 300 and see what comes out:
Distortion is below 80 dB but because we have a lot of power supply harmonics, it degrades SIAND to just 68 dB which places the unit pretty low in our amplifier rankings:
Signal to noise ratio is poor due to aforementioned power supply noise:
These are yesterday's amplifiers so don't look for hundreds of watts into 4 ohm load:
Yes, just 23 watts! No wonder the unit runs so cool in use. If we allow distortion to peak higher, we still don't get much output:
Switching to 8 ohm load reduces available power even more as it normally does:
Ironic though that it has less noise than a modern AVR, albeit, not a very good one (NAD T758).
Pre-amplifier Performance
I disconnected the power amp and measured the output of the preamplifier using our 1 kHz tone and got this:
Distortion is similar to when we were driving the power amp but noise is much lower so SINAD improves 10 dB.
EDIT: by request, here are the phono input measurements.
Phono Input Measurements
As usual we start with our dashboard:
Distortion is quite low at -90 dB but SINAD suffers due to high level of noise where the gain is the highest (low frequencies).
RIAA equalization is very good except for the high pass filter which is causing some peaking:
Here is the saturation point vs level:
And how distortion (no noise) varies with frequency:
We see a typical rise with frequency but there is also some increase in low frequencies, likely caused by the peaking of the level there.
Conclusions
The inefficient speakers of today won't be kind to the Model 300 due to lack of power. With non-competitive noise and distortion, there is not much of a reason to use this amplifier. It does have a vintage look though so perhaps someone would be interested in that aspect of it.
And yes, it is possible that the power supply noise is higher due to age. I can only test what I am given.
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As always, questions, comments, recommendations, etc. are welcome.
if I had a day job, I could just do this review and get paid. But no, this being the Internet age, I have to be measuring a speaker while I am doing this test. Surely this qualifies for overtime. So please donate what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I love the tuner knob on the 300, reminding me of what you would find in a HAM radio:
There is no detent on various tone adjustments and balance. The slide switches are par for the era but don't feel nearly as nice of Japanese gear of the time.
The back side is decidedly cheap:
Those tiny speaker screw terminals were on the cheapest 8-track tape/receivers, not on serious hi-fi. The RCA terminals all look tired but work.
Receiver Audio Measurements
I opted to use the Aux input for my testing. I used an RCA cable to feed the pre-amp to power amp. Not sure if they came with a special shorting connector or not. Let's feed a 1 kHz tone to the 300 and see what comes out:
Distortion is below 80 dB but because we have a lot of power supply harmonics, it degrades SIAND to just 68 dB which places the unit pretty low in our amplifier rankings:
Signal to noise ratio is poor due to aforementioned power supply noise:
These are yesterday's amplifiers so don't look for hundreds of watts into 4 ohm load:
Yes, just 23 watts! No wonder the unit runs so cool in use. If we allow distortion to peak higher, we still don't get much output:
Switching to 8 ohm load reduces available power even more as it normally does:
Ironic though that it has less noise than a modern AVR, albeit, not a very good one (NAD T758).
Pre-amplifier Performance
I disconnected the power amp and measured the output of the preamplifier using our 1 kHz tone and got this:
Distortion is similar to when we were driving the power amp but noise is much lower so SINAD improves 10 dB.
EDIT: by request, here are the phono input measurements.
Phono Input Measurements
As usual we start with our dashboard:
Distortion is quite low at -90 dB but SINAD suffers due to high level of noise where the gain is the highest (low frequencies).
RIAA equalization is very good except for the high pass filter which is causing some peaking:
Here is the saturation point vs level:
And how distortion (no noise) varies with frequency:
We see a typical rise with frequency but there is also some increase in low frequencies, likely caused by the peaking of the level there.
Conclusions
The inefficient speakers of today won't be kind to the Model 300 due to lack of power. With non-competitive noise and distortion, there is not much of a reason to use this amplifier. It does have a vintage look though so perhaps someone would be interested in that aspect of it.
And yes, it is possible that the power supply noise is higher due to age. I can only test what I am given.
-----------
As always, questions, comments, recommendations, etc. are welcome.
if I had a day job, I could just do this review and get paid. But no, this being the Internet age, I have to be measuring a speaker while I am doing this test. Surely this qualifies for overtime. So please donate what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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