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Joined: Sep 2009
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I need a cheap, small stereo amplifier for use with a pair of Polk RT15 bookshelf speakers.

I don't think I'll need much power.
I'd like to hold it to $50 USD max.
It must be small. For example, not much bigger than the Focusrite/Presonus/M-Audio audio interfaces that we all use.
It must have line-level inputs, preferably RCA jacks.
I don't need features. Maybe bass and treble controls, that's all.

Maybe bluetooth to capture sound from a phone. But it has to be reliable bluetooth (which I've never seen before). frown

I've looked at many units on Amazon and on Parts Express.
Some have ravaging bad reviews.
Some have semi-good reviews (example: sounds great, but the speaker terminals broke off).

Recommendations?

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Those little amps use a Tripathi class D amp on a chip, hence called class T. If you can increase your budget and relax your size constraints:

Audiosource AMP100VS
Audiosource AD1002
Cambridge Audio AXA25
Dayton Audio APA150
Dayton Audio APA102BT

Of the little Tripathi-based amps, the ones made by Topping have the best reputation. I've not used or listened to them, but I think Topping uses higher quality filter caps and maybe torroidal transformers.

Some of these newer and/or cheaper amps are not 4-ohm stable, but your speakers appear to be rated at 8 ohms average impedance from what I can see.


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If you will feed the amp with a pro line level source:

Samson 120A
used Alesis RA-100


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Thanks guys. But those are all too big, or too expensive, or both.

It will be driven by consumer line-level signals.

I've just made a measurement. I need it to be no more than 8" wide and 8" deep.

Something sort of like this ... but with good quality and without all the bad reviews:
https://www.amazon.com/Audio-Amplifier-Receiver-Integrated-Speakers/dp/B076P2VS9H

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Originally Posted by MacMacMac
Thanks guys. But those are all too big, or too expensive, or both.

It will be driven by consumer line-level signals.

I've just made a measurement. I need it to be no more than 8" wide and 8" deep.

Something sort of like this ... but with good quality and without all the bad reviews:
https://www.amazon.com/Audio-Amplifier-Receiver-Integrated-Speakers/dp/B076P2VS9H

I have something like that, a 6"x6" made by Pyle. Not very powerful, decent quality. This is something that you will not find recommended on this forum for two reasons:

1) at that price point, many corners need to be cut, and as such there will always be somebody who finds something wrong with the thing and have something bad to say about it (hence the bad reviews on Amazon)

2a) these products are created by a "race-to-the-bottom" by the manufacturers against each other. The race is harsh and always ongoing and does not settles on a winner, not even for a moment (as it does at higher price points).
2b) Partially to offload the bad reviews, partly to further reduce price, partly to the increase the thin margins these products are changing faster than they can make a "name" and become famous enough for one of us to recommend it to you. If one gets good reviews on Amazon, it may "appear" to exist for long enough, but I guarantee you that the one you buy will be different in all aspects (perhaps and only perhaps besides the externals) from the first one which sold there with that name.

So in conclusion pick one which seems adequate from description and reviews, without concentrating too much on the reviews, besides the ones in the last 6 months. If you don't like it, take advantage of Amazon generous return policy.

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Hmmm ... good advice.

We have an amp of this type, purchased several years ago from Parts Express. It's used by mother-in-law.
She's hard of hearing and had the TV turned up LOUD. So I bought a small amplifier fed from the TV.
It could drive speakers, but she uses my old Beyer headphones. She can turn it up without disturbing anyone.

It has worked flawlessly, but as you suggest, Monsieur Vento, they don't sell that model anymore.

Note that I won't buy this sort of thing from Amazon. They're just a dumping ground for anybody's junk product, as you suggested.
So I'll stick with Parts Express and keep my fingers crossed. I saw a couple of these priced at $50.

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BTW ... is it possible to add a cheap bluetooth receiver?
One that will receive audio from an Iphone and feed line level audio to this type of amplifier.

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Originally Posted by MacMacMac
Hmmm ... good advice.

We have an amp of this type, purchased several years ago from Parts Express. It's used by mother-in-law.
She's hard of hearing and had the TV turned up LOUD. So I bought a small amplifier fed from the TV.
It could drive speakers, but she uses my old Beyer headphones. She can turn it up without disturbing anyone.

It has worked flawlessly, but as you suggest, Monsieur Vento, they don't sell that model anymore.

Note that I won't buy this sort of thing from Amazon. They're just a dumping ground for anybody's junk product, as you suggested.
So I'll stick with Parts Express and keep my fingers crossed. I saw a couple of these priced at $50.
Buy a headphone amp for MIL to replace her amp, and then use the one she has now. You could even just get a bluetooth headset and bluetooth transmitter for her for the TV.

Last edited by Sweelinck; 06/26/21 11:31 PM.

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Parts Express is a good company. They honor their return commitments and sell quality products, in my experience.

The last time I looked, Bluetooth had become almost an industry standard, with bluetooth enabled amplifiers seemingly outnumbering the non-bluetooth offerings. There are many bluetooth amplifiers offered by Parts Express.


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I would trust parts express. Among those class T bluetooth amps, if I were purchasing one, I would look at Topping, Dayton Audio (parts express's brand) and SMSL, and avoid Lepai and Pyle Pro. I perhaps would choose a Dayton Audio one for their 5-year warranty. The other brand of these they carry is Tangband. This company makes good speaker drivers, so it may also be worth a look.


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I agree ... Lepai and Pyle get terrible reviews ... right there on the Parts Express web site.

So I'll try to stick to Dayton or SMSL. I see a suitable SMSL model now: https://www.parts-express.com/SMSL-...0W-Stereo-Amplifier-w-12-VDC-PSU-230-212
And judging from the 2 x 20 watt spec, these guys seem to be honest.

Similar crap-brand models boast hundreds of (phony) watts.

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2x20W into 4 ohms. 2x12W into 8 ohms.


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Your going to need bass/treble controls. An amp that small will sound pretty bad in the upper frequencies... and those Polks... your gonna need to shelve down the high frequencies... while it may not sound bright, it will sound harsh.

I have no recommendation for an amp that small. Let us know what you found and how it works out.

eBay has a bunch of options... but I dunno.....

Peace
Bruce in Philly

Last edited by Bruce In Philly; 06/28/21 07:54 AM.

Peace
Bruce in Philly

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