This is a review and detailed measurements of the ROLLS VP29 budget phono preamplifier. It is on kind loan from a member and costs US $49 on Amazon including Prime shipping.
I must say, very clever use of color and style for a budget case and price:
As you see, the unit is made in USA which is a rarity at this price.
Power naturally comes externally in the form of a DC 12 volt power supply:
There is a TRS connector on the left which we don't usually see. No wonder a lot of DJs seem to be using it based on Amazon reviews I read. Speaking of which, there are 551 reviews with average of 4.5 stars!
ROLLS VP29 Measurements
Let's see how the VP29 does on our usual dashboard made for moving magnet cartridges:
OK, this is puzzling. The FFT shows very little mains noise and distortion is down to -90 dB. So why on earth is our SINAD down to just 49 dB??? Something is going on there that we can't see. As you see at the bottom of display, I am using the "AC>10 Hz" filter in my audio analyzer. If we defeat that and go down to DC, this is what our FFT looks like:
As you see, it shoots way up indicating DC offset. I took a snapshot of the DC as overlaid in the graph. The value was constantly changing though and was quite unstable. This is terrible as if your amplifier is DC coupled, you risk amplifying that and feeding it to your speaker and cooking its voice coil. It could also generate audible noise.
Putting in a 20 Hz filter in my analyzer ignores that and SINAD value is as expected then:
This looks reasonable -- even good -- but let's look at frequency response:
What on earth is this? The RIAA filter is completely screwed up here. As a result the tonality is going to be bright with so much attenuation of bass. At this point, I did not see a point in continuing.
Conclusions
If there was a definition of a broken phono stage, the VP29 is it. Could it be a broken sample? Sure. At this price anything is possible. But we have two channels both doing the same thing. The odds of both being miss-wired becomes quite low. How people find this a good preamp, I don't know.
Needless to say, I can't recommend the ROLLS VP29 phono stage. There are budget phono preamps that are not broken. A shame as it looked nice and would have been nice to have a US made product to recommend.
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As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I must say, very clever use of color and style for a budget case and price:
As you see, the unit is made in USA which is a rarity at this price.
Power naturally comes externally in the form of a DC 12 volt power supply:
There is a TRS connector on the left which we don't usually see. No wonder a lot of DJs seem to be using it based on Amazon reviews I read. Speaking of which, there are 551 reviews with average of 4.5 stars!
ROLLS VP29 Measurements
Let's see how the VP29 does on our usual dashboard made for moving magnet cartridges:
OK, this is puzzling. The FFT shows very little mains noise and distortion is down to -90 dB. So why on earth is our SINAD down to just 49 dB??? Something is going on there that we can't see. As you see at the bottom of display, I am using the "AC>10 Hz" filter in my audio analyzer. If we defeat that and go down to DC, this is what our FFT looks like:
As you see, it shoots way up indicating DC offset. I took a snapshot of the DC as overlaid in the graph. The value was constantly changing though and was quite unstable. This is terrible as if your amplifier is DC coupled, you risk amplifying that and feeding it to your speaker and cooking its voice coil. It could also generate audible noise.
Putting in a 20 Hz filter in my analyzer ignores that and SINAD value is as expected then:
This looks reasonable -- even good -- but let's look at frequency response:
What on earth is this? The RIAA filter is completely screwed up here. As a result the tonality is going to be bright with so much attenuation of bass. At this point, I did not see a point in continuing.
Conclusions
If there was a definition of a broken phono stage, the VP29 is it. Could it be a broken sample? Sure. At this price anything is possible. But we have two channels both doing the same thing. The odds of both being miss-wired becomes quite low. How people find this a good preamp, I don't know.
Needless to say, I can't recommend the ROLLS VP29 phono stage. There are budget phono preamps that are not broken. A shame as it looked nice and would have been nice to have a US made product to recommend.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/