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ROLLS VP29 Review (phono stage)

amirm

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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:

ROLLS VP29 Review Phono preamp.jpg


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:

ROLLS VP29 Review Phono preamplifier.jpg


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:

ROLLS VP29 Measurements Phono preamp.png


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:

ROLLS VP29 Measurements Phono preamp DC Offset.png


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:
ROLLS VP29 Measurements Phono preamp AC 20 Hz.png


This looks reasonable -- even good -- but let's look at frequency response:

ROLLS VP29 Measurements Phono preamp frequency response.png


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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Grotti

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Looks like a rumble filter, badly calculated of course. But shouldn't this eliminate the DC offset also? Strange....
It could indeed work for some "DJ" with a slightly darker and therefore bass heavy sounding Ortofon Concorde. But no way to explain all the stars at Amazon, if the unit is supposed to work as measured.
Anyway: thank you for warning :)
 

pavuol

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Take this, add some "shiny & untamed" set of speakers, pick some suitable "sunny track" like this one..
Ten Years After - Good Morning Little Schoolgirl (Live) / album Don't Treat Me Wrong (live 1969)
..and you can imagine how Amir's nightmare sounds like :p
 

restorer-john

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Here's the schematic for it.

rolls vp29.PNG

The DC offset issue is clear. With a high 200K AP load on it and a signal on the input, there's good reason it was wandering at DC. No resistors to Gnd for the output decoupling caps. The opamp is run single rail with no regulation, just a 1000uF cap, with a voltage divider to bias the input at 1/2 V+. There's also an issue with the front end as there could be a small DC offset put on the cartridge too.

Here's a shot of the innards:
vp29.jpg


It needs work. Some resistors, a better regulated PSU, a few 1% resistors for the voltage divider instead of 5%, etc. Basically a broken design as it stands IMO.
 

restorer-john

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Waste of time this article.

I would argue it is the complete opposite. A low cost current model RIAA stage is an excellent candidate for reviewing. Many RIAA stages are sold for people wanting to add a turntable (for nostalgia's sake) to an AVR and most have no phono stage built in.

Don't underestimate how many people want to listen to their old vinyl. There's a reason all the big manufacturers have started making the odd turntable again- people buy them and pay way too much for them (lots of profit).

We now know it is a basic and unfinished design. IMO, not worth the money. We didn't know that before did we? Consider each review has a cost both in Amir time (opportunity cost) and in AP run-time cost. It is a USD$28,000 analyzer that must be calibrated and certified periodically at vast expense. I appreciate all classes of HiFi gear being tested, especially legacy gear.

This little phono stage is also way easier on Amir's back than a giant Revel speaker or a big power amplifier. ;)
 

Nango

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We @restorer-john are talking about different things. It would have been more than enough if @amirm had published the picture of this item with the correspondent panther and finished the review. No one in this world really needs to go thru this lecture on something that is clear crap. It adds absolutely nothing to the "Science". It's totally waste of time.
 

DSJR

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It's only 2db or so down at 30Hz and +0.5dB at 5khz ffs ;) In the 1980's UK era, this'd be normal and deliberately tailored in many UK-popular low cost amps, especially the bass rolloff (Arcam, Cyrus, Naim)

Just DON'T ever review a vintage Naim Nait mk1 here :D RIAA response is very similar and was all but praised due to the inverse response error of many pickups fitted to lesser turntables of the period (many cartridges had low bass lift of 2 - 4dB and a drop in the mid kHz. Having it flat instead would have wasted it's meagre 15 - 20WPC. Doesn't stop Naim fans paying several hundred quid for working examples today though...

Perhaps a phono stage like this should bve tried with a cartridge like an AT3600L and see what the combined output response would be.
 

Razorhelm

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We @restorer-john are talking about different things. It would have been more than enough if @amirm had published the picture of this item with the correspondent panther and finished the review. No one in this world really needs to go thru this lecture on something that is clear crap. It adds absolutely nothing to the "Science". It's totally waste of time.

So the analysis and evidence of whats going wrong which lead to @restorer-john diagnosing the issue has nothing to do with science?

That's exactly what science is! Theory and evidence it's the whole point!

It's not a waste of time by any means. Its good to know the mechanism by which it failed.

Many of us are here to learn not just get told what not to buy.

I don't listen to vinyl but I still found this very interesting.

Are you just saying the product is shit in a way that is confusing me and making me think you are saying the review is a waste of time?
 

Rja4000

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let's look at frequency response:

index.php


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.
To be fair, if main use is for DJ on stage, this is not surprising.
The last thing you want on earth is a drunk DJ having a low frequency feedback on a multi-kW PA...

So cutting a few DBs out of low frequencies is already a few DBs further away from this catastrophic scenario.
 

anmpr1

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Rolls (Bellari) is in the 'how cheap can we sell something to the semi-pro, home hobbyist recording market. That is their reason for existence. Some of their stuff is so cheap it makes you wonder how anyone can make any money selling it at all? And they sell through dealers that are taking their cut. I mean, there has to be a point where you just open your doors and give it away. Rolls has to be approaching that.

For the consumer that needs something, but has no money, Rolls is there for them.

They were also one of the first outfits, maybe they were the first, to realize that you can make something 'exotic' by sticking a tube through the top of the metal casework, and getting a guy like Mr. Analog himself to extol its sonic merits. What Fremer didn't tell you (probably because he didn't know it himself) was that the device was a simple opamp, with a tube in the circuit as an afterthought. Not for amplification, but for 'conditioning' the sound.
 

anmpr1

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Thank you for this review. The ART DjPre II seems to be the best option at its price.
At the fifty dollar level, the Rolls is a bit better than the Pyle P444, at least on an absolute basis. If you only have (or only want to spend) fifteen or sixteen dollars, Pyle is definitely the way to go! :)
 

Helicopter

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Thanks Amir. I used to have one of these. Now I feel a little guilty about selling it. I should have given it away with the turntable I sold to the guy.
 

Jim Taylor

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Thank you for this review!!!! About a year ago, I picked up one of this company's model PM50s headphone amps from a local pro shop. Although it seems to be powerful, it also seems to lack bass. Now I know the possible reason why.
At that time, I wasn't browsing here. Now I'll know better.
I'm sure thankful you didn't follow @Nango's advice! I like to learn. Jim
 
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