Rega IO Review (stereo amplifier)

[maverickronin]

VAT in UK is 20%. Sales tax in US is at most 8%.

Anywhere from nothing to 10+% depending on where you live.

Sales Tax Rates in Major Cities, Midyear 2021

Neither Anchorage, Alaska, nor Portland, Oregon, impose any state or local sales taxes. Honolulu, Hawaii, has a low rate of 4.5 percent and several other major cities, including Milwaukee and Madison, Wisconsin, keep overall rates modest.

taxfoundation.org

 

[ad_fletch]

Aw.

I still have an example of the original Brio - the clamshell one from the 90s. I recall being super chuffed to get it for AU$300 (marked down from MSRP of $999) as NOS.

Last time I compared it with another amp (Topping), it was obviously quite rolled off and warm, but I figured that was age rather than design. Now I’m not so sure….

It was an idiosyncratic design, like a big heatsink with 3 (!) legs. Still, it gave me many hours of listening pleasure in my teens. Maybe it went well with my speakers at the time, which seemed to have a rising treble response.

Anyway it’s in the office now - haven’t been in there for months due to lockdown, so here’s a borrowed pic for some nostalgia (esp the “precision crafted in Britain” tag):

 

[mcdn]

I have been hesitating if to reply, as it is an off-topic in this thread. So shortly, "very unusual load" would be almost any speaker. Here is the measurement with JBL Control1 Pro

AIYIMA A07 TPA3255 Amplifier Measurements and Review - LM4562 (and OPA2134) option

AIYIMA A07 TPA3255 Amplifier Measurements LM4562 option I received my A07 yesterday, on January 6, 2021, shipped from Italy. Purchased at Amazon.de and as stated on their website, it arrived without a power supply. I am testing the A07 with 2 different power supplies. One of them is a linear...

www.audiosciencereview.com

and attached as a thumbnail measurement into 4ohm, 8ohm and my complex dummy load. I plan to make a comparison with Hypex UcD soon.
View attachment 162563

Definitely worth a new thread, the Control 1 Pro is a very common speaker so it would be good to understand how it and other common speakers are driven by class D amps without PFFB.

 

[DanielT]

How is it, based on what Rega themselves state regarding technical data about the amplifier and what Amir reports? When does it deviate and how much does it deviate? Is there anyone who can make a brief summary?

What I'm looking for is IF Rega talking about performance that is not met? If Rega does NOT claim that IO can manage to reach X level then well then at least Rega has not made a false statement. In fact, very important to sort it out.I think, anyway.

Most people can probably agree that the amplifier itself, price performance, seems lousy (compared to other alternatives), but what does Rega say, what do they claim it should be able to do?

 

[pma]

Definitely worth a new thread, the Control 1 Pro is a very common speaker so it would be good to understand how it and other common speakers are driven by class D amps without PFFB.

Basically, it is a mere interaction of class D output LC filter (usually 10uH+1uF or 20uH+0.5uF) with the complex impedance of the speaker (crossover + drivers). When you put this data into circuit simulator (MicroCap, LTSpice) you get precisely same plots as you measure under real world conditions. It is simple and straightforward and there is no need of investigations, circuit designers are of course aware of this fact and Bruno Putzeys describes the same in his public accessible papers. I think I also posted some results even here in ASR.

 

[antcollinet]

How is it, based on what Rega themselves state regarding technical data about the amplifier and what Amir reports? When does it deviate and how much does it deviate? Is there anyone who can make a brief summary?

What I'm looking for is IF Rega talking about performance that is not met? If Rega does NOT claim that IO can manage to reach X level then well then at least Rega has not made a false statement. In fact, very important to sort it out.I think, anyway.

Most people can probably agree that the amplifier itself, price performance, seems lousy (compared to other alternatives), but what does Rega say, what do they claim it should be able to do?

As far as I can say - Rega's statements match measurements quite well.

Power output meets Rega's spec
Rega clearly states that if driving 4Ω speakers, it is going to get hot.
They don't seem to claim any THD figure.

 

[pma]

As far as I can say - Rega's statements match measurements quite well.

Power output meets Rega's spec
Rega clearly states that if driving 4Ω speakers, it is going to get hot.
They don't seem to claim any THD figure.

That is correct, however I am sure that the amp would not pass a continuous 2 x 10W/8ohm test and that it would get overheated.

 

[mcdn]

Basically, it is a mere interaction of class D output LC filter (usually 10uH+1uF or 20uH+0.5uF) with the complex impedance of the speaker (crossover + drivers). When you put this data into circuit simulator (MicroCap, LTSpice) you get precisely same plots as you measure under real world conditions. It is simple and straightforward and there is no need of investigations, circuit designers are of course aware of this fact and Bruno Putzeys describes the same in his public accessible papers. I think I also posted some results even here in ASR.

The mechanism is clear, but the interaction with individual speakers is not necessarily well understood or acknowledged, as you saw from my previous underinformed comment! I had assumed that most 'normal' speakers had a pretty flat impedance above the crossover region, and that the crossover would usually be below 4KHz. On that basis there wouldn't be much interaction with the output filter, but the Control 1 Pro clearly doesn't meet my assumed characteristics. If you could post the impedance of the control1 pro into a new thread we could check out some other speakers as well?

 

[DanielT]

As far as I can say - Rega's statements match measurements quite well.

Power output meets Rega's spec
Rega clearly states that if driving 4Ω speakers, it is going to get hot.
They don't seem to claim any THD figure.

.. so what exactly is this fuzz about IO about then? Rega says: Look here we have an amplifier that can handle this. And if what Rega says is true, it is up to the buyer to weigh in if there is something that is enough.Given that it works well when played, so it does not get too hot, reduced performance and so on.

Yes I know there are other options with better price - performance ratio. But it is still a buyer's responsibility to find out and weigh different alternatives against each other.

More information before a decision to buy is good so it is great that Amir tested IO.

 

[antcollinet]

I think it is because we expected - or perhaps just hoped for - more from a Rega designed and built amp.

 

[antcollinet]

That is correct, however I am sure that the amp would not pass a continuous 2 x 10W/8ohm test and that it would get overheated.

Yep - that would be a similar current output to Amirms test condition. Not sure how many people listen at a continuous 10W though. I suspect this is what Rega rely upon.

 

[Phorize]

What has become of British hifi?

As a British citizen I’d be delighted if the self parody stopped at hifi Self-flagellation aside I think it’s genuinely difficult for a company in Rega’s position to bring a product like this to market. The story of this amplifier is one of lack of investment in product R and D, it self driven by high production and export costs, distributed through a dealer network that would go bust if products at this price point became the mainstay of the hifi niche.

 

[Whitecanhifi]

Yep - that would be a similar current output to Amirms test condition. Not sure how many people listen at a continuous 10W though. I suspect this is what Rega rely upon.

I measured the IO while playing the Wharfedale 12.2 speakers at 100db. Using approximately 16 wpc at this level for over two hours, the Rega IO never got above 33.6 C. Speaker performance was excellent with inaudible distortion.

Again, the IO performs as advertised. And as advertised, the Rega IO is exceptional.

 

[DSJR]

Aw.

I still have an example of the original Brio - the clamshell one from the 90s. I recall being super chuffed to get it for AU$300 (marked down from MSRP of $999) as NOS.

Last time I compared it with another amp (Topping), it was obviously quite rolled off and warm, but I figured that was age rather than design. Now I’m not so sure….

It was an idiosyncratic design, like a big heatsink with 3 (!) legs. Still, it gave me many hours of listening pleasure in my teens. Maybe it went well with my speakers at the time, which seemed to have a rising treble response.

Anyway it’s in the office now - haven’t been in there for months due to lockdown, so here’s a borrowed pic for some nostalgia (esp the “precision crafted in Britain” tag):

View attachment 162651

Well, we had and sold the clamshell Rega era products and subjectively, I didn't care for the original brio as I found it weak and 'meh' frankly but not unpleasant. The Luna amp was rather better but the amp we sold with ease was the £500 or so Mira, which had a bit of power and the remote was popular. Far better than an equivalent Arcam, but maybe that was never saying much back then.

By the way, Rega's turntables HAVE improved and the current 6 model (where the proper models start) has an external 24V supply (the Neo) with fine speed adjustment at long last. Got to say I'd love to try a Technics SL100C or the sibling 1210mk7 though,.

 

[sound_of_thunder]

I measured the IO while playing the Wharfedale 12.2 speakers at 100db. Using approximately 16 wpc at this level for over two hours, the Rega IO never got above 33.6 C. Speaker performance was excellent with inaudible distortion.

Again, the IO performs as advertised. And as advertised, the Rega IO is exceptional.

Do you still have it? What's so special about this amp, sound-wise, compared to other amps around this price?

I've been quite interested in it for a while but reports of hum / buzz and power limitations have turned me off somewhat.

 

[DanielT]

As a British citizen I’d be delighted if the self parody stopped at hifi Self-flagellation aside I think it’s genuinely difficult for a company in Rega’s position to bring a product like this to market. The story of this amplifier is one of lack of investment in product R and D, it self driven by high production and export costs, distributed through a dealer network that would go bust if products at this price point became the mainstay of the hifi niche.

What is that? Skip the Self-flagellation.Rega has made one amplifier with poor price vs performace ratio. Rega still seems to make good turntables. Besides, you have Kef and Wharfedale.Very popular speakers sold worldwide. Measures well many of the Kef and Wharfedale Amir have tested and evaluated. You can be proud of them. How English they nowaday are, being manufacturing in other countries and so on, but still.

Edit:
I'm Swedish, but I'm not Volvo. If they make a bad car model, I get angry. Not because Volvo is a Swedish company (which, incidentally, it is not nowadays) but because it is a bad model.

Volvo by the way the majority owner of the company is Chinese Zhejiang Geely Holding Group.

 

[Whitecanhifi]

Do you still have it? What's so special about this amp, sound-wise, compared to other amps around this price?

I've been quite interested in it for a while but reports of hum / buzz and power limitations have turned me off somewhat.

Yes. I still have it and I’m also fortunate to have the new Technics Su-g700m2. And by comparison, the Rega is a great little amp that needs a subwoofer. And doesn’t hold the clarity like the technics. But it is also almost 2k less.

I have never heard the ‘hum’ that others have stated. If I did, I would take advantage of the warranty asap.

The remote is fine. But it does increase/decrease gain more aggressively than I’d like, so I often change the volume by hand. Also, the range of the remote is lacking, you need to be straight in front of the amp.

Headphone Jack. Quite good, but I rarely use it and hate being tethered to anything. The amp is great for speakers. As stated earlier, 8-6 ohm are it’s sweet spot. And it sounds excellent.

As good as the Cambridge axr100? Yes. But I’d audition both the Cambridge and the Rega to see which one sounds better to you. I like the Rega (w schiit modi 3+).

 

[Tks]

Always surprising to see how little attention is given to thermal management in audiophile products.

 

[dougi]

Always surprising to see how little attention is given to thermal management in audiophile products.

Yeah, I remember I had an Arcam Delta 290 amp (mosfet based). I used to take it to small parties to amp my turntabling and it always went into thermal protection, until I added some fans in a non-invasive way.

 

[sarumbear]

Always surprising to see how little attention is given to thermal management in audiophile products.

Very true. I had a fan behind my NAP 250s that I switched on at parties