2nd hand Amplifier recommendations
2nd hand Amplifier recommendations
Author
Discussion

Roony

Original Poster:

378 posts

252 months

Monday 8th April 2013
quotequote all
Hi..

I am on a budget and looking for an indegrated amplifier to run either a CD player or Tuner through an 8 speaker switched box that feeds my home ceiling speakers. Nothing too fancy, and more than likely some thing that I could find on Ebay?

Just really need some advice on what to look for..... Upto a £100 (second hand)

Thanks for any advice

Crackie

6,386 posts

265 months

Monday 8th April 2013
quotequote all
For 100 pounds a Class D / Tripath amp is the way to go imho. A brand new class D is likely to have far far better sound quality than any 100 pound S/H amp; the ones I've heard have sounded very good indeed. A new 'chip' amp will have the added benefit of having sophisticated protection systems on-board such as short circuit protection, over current protection, over temperature protection. They are very robust and cope with low / awkward impedances very well so should handle 8 ceiling speakers better than most S/H 100 pound amps. 12 month warranty with a new amp too.

Search for reviews of Tripath TA2020 / TA2022 / TA2024 / TK2050 or TDA7498 depending on how many watts you need i.e. how loud you want to play.

Something like this http://www.ebay.co.uk/itm/Upgrade-40Wx2-TDA7498E-T...

or

http://www.amazon.co.uk/MUSE-DT-50-2x50W-AMPLIFIER...

Edited by Crackie on Tuesday 9th April 07:24

telecat

8,528 posts

264 months

Tuesday 9th April 2013
quotequote all
You could get a Cambridge Audio AM1 New for Under a £100 at Richer Sounds. It's predecessor the A1 should be pretty cheap as well. Both get good reviews and the A1 was a good amp at it's price point.

Roony

Original Poster:

378 posts

252 months

Tuesday 9th April 2013
quotequote all
Thanks for the advice... This is probably a better route to go down if its an ok amp.. The amp that I was using I think has over heated (B & W Aura V40) It gives out a great sound and I really like it! However it could be the switching from speakers that is causing it to fail? I will look at this amp on some reviews.. but you think it ok for mederate ceiling speakers (back ground music) ..



Crackie said:
For 100 pounds a Class D / Tripath amp is the way to go imho. A brand new class D is likely to have far far better sound quality than any 100 pound S/H amp; the ones I've heard have sounded very good indeed. A new 'chip' amp will have the added benefit of having sophisticated protection systems on-board such as short circuit protection, over current protection, over temperature protection. They are very robust and cope with low / awkward impedances very well so should handle 8 ceiling speakers better than most S/H 100 pound amps. 12 month warranty with a new amp too.

Search for reviews of Tripath TA2020 / TA2022 / TA2024 / TK2050 or TDA7498 depending on how many watts you need i.e. how loud you want to play.

Something like this http://www.ebay.co.uk/itm/Upgrade-40Wx2-TDA7498E-T...

or

http://www.amazon.co.uk/MUSE-DT-50-2x50W-AMPLIFIER...

Edited by Crackie on Tuesday 9th April 07:24

Crackie

6,386 posts

265 months

Wednesday 10th April 2013
quotequote all
Here is a review of an amp using the TA2022 Tripath chip which is reasonably powerful. I'm not sure if the ceiling speakers will be used for background music or for parties so some of the lower power unit Tripath chips may be enough.
http://www.tnt-audio.com/ampli/power_ts_e.html
The TA2020 is a low power unit and may not have enough power in all circumstances; the 15w TA2024 is better and is held by many to be the best sounding Tripath chip but still may not have enough power for you. Here's a link to Temple Audio's website; their Bantam amplifier uses the 2024 and has a great reputation for sound quality. The Customer testimonials are glowing too.

TonyRPH

13,471 posts

191 months

Wednesday 10th April 2013
quotequote all
Lots of amplifier recommendations - but not one person has suggested that you check your speaker load impedance.

You stated in your OP that you are switching 8 speakers.

If you are using more than one pair simultaneously, it's important to check what impedance (resistance) you are presenting to the amp.

The Aura is a pretty decent amp, and being mosfet, is relatively immune to overload and short circuits.

So, with what you describe - it does sound like you may be overloading the amp - and a new amp isn't going to help....


Roony

Original Poster:

378 posts

252 months

Wednesday 10th April 2013
quotequote all
Hi.. thats a good shout and you may be right... any suggestions on how to put it right?

I've normally got 2 pairs running at any one time.

The speakers are 60w and 8 ohms each....

I'm a newbie to this sort of thing... but the amp had been working fine for around 4-5 months?


TonyRPH said:
Lots of amplifier recommendations - but not one person has suggested that you check your speaker load impedance.

You stated in your OP that you are switching 8 speakers.

If you are using more than one pair simultaneously, it's important to check what impedance (resistance) you are presenting to the amp.

The Aura is a pretty decent amp, and being mosfet, is relatively immune to overload and short circuits.

So, with what you describe - it does sound like you may be overloading the amp - and a new amp isn't going to help....

Crackie

6,386 posts

265 months

Thursday 11th April 2013
quotequote all
TonyRPH said:
Lots of amplifier recommendations - but not one person has suggested that you check your speaker load impedance.

You stated in your OP that you are switching 8 speakers.

If you are using more than one pair simultaneously, it's important to check what impedance (resistance) you are presenting to the amp.

The Aura is a pretty decent amp, and being mosfet, is relatively immune to overload and short circuits.

So, with what you describe - it does sound like you may be overloading the amp - and a new amp isn't going to help....
Fair enough Tony, it is worth double checking the load the amp sees after switching various speakers in and out because there may be a fault somewhere. If there isn't a fault then imho a Tripath is going to be perfectly happy into any switchbox that is wired / configured correctly, particularly with Roony's 8 ohm speakers. My first post explains why I thought a suitable Tripath amp would be ideal for Roony i.e Stable into low impedance loads + protection systems incorporated into the chip.

TonyRPH

13,471 posts

191 months

Thursday 11th April 2013
quotequote all
Roony said:
Hi.. thats a good shout and you may be right... any suggestions on how to put it right?

I've normally got 2 pairs running at any one time.

The speakers are 60w and 8 ohms each....

I'm a newbie to this sort of thing... but the amp had been working fine for around 4-5 months?
Buy / borrow a multimeter - any cheap one capable of measuring resistance will do.

Disconnect the speaker cable from the back of the amp - and then measure across the left and right channels (of the cable) you should see around 4 - 8 ohms.

If you see 0 ohms - then you have a short.

Depending upon how the speakers are wired - you may even see a value as low as 2 ohms (or you may see a value as high as 16 ohms) - 2 ohms is not a real problem - you'll just need an amp capable of driving a 2 ohm load reliably.

Be sure to check the resistance on different settings of the switch - just to be sure your load is consistent.

Also be sure to check the left and right channels independently - so I would disconnect one channel at a time, to ensure there is no confusion.

It goes without saying - ensure any power to the amp is disconnected.

Here's a guide to demonstrate how speaker impedances interact with series / parallel wiring.

For the purposes of this post - impedance = resistance. (resistance is just a simple DC measurement).



Edited by TonyRPH on Thursday 11th April 15:14

Roony

Original Poster:

378 posts

252 months

Thursday 11th April 2013
quotequote all
TonyRPH said:
CHeers Tony........... I will check it out this weekend....
Buy / borrow a multimeter - any cheap one capable of measuring resistance will do.

Disconnect the speaker cable from the back of the amp - and then measure across the left and right channels (of the cable) you should see around 4 - 8 ohms.

If you see 0 ohms - then you have a short.

Depending upon how the speakers are wired - you may even see a value as low as 2 ohms (or you may see a value as high as 16 ohms) - 2 ohms is not a real problem - you'll just need an amp capable of driving a 2 ohm load reliably.

Be sure to check the resistance on different settings of the switch - just to be sure your load is consistent.

Also be sure to check the left and right channels independently - so I would disconnect one channel at a time, to ensure there is no confusion.

It goes without saying - ensure any power to the amp is disconnected.

Here's a guide to demonstrate how speaker impedances interact with series / parallel wiring.

For the purposes of this post - impedance = resistance. (resistance is just a simple DC measurement).



Edited by TonyRPH on Thursday 11th April 15:14

Crackie

6,386 posts

265 months

Friday 12th April 2013
quotequote all
TonyRPH said:
Roony said:
Hi.. thats a good shout and you may be right... any suggestions on how to put it right?

I've normally got 2 pairs running at any one time.

The speakers are 60w and 8 ohms each....

I'm a newbie to this sort of thing... but the amp had been working fine for around 4-5 months?
Buy / borrow a multimeter - any cheap one capable of measuring resistance will do.

Disconnect the speaker cable from the back of the amp - and then measure across the left and right channels (of the cable) you should see around 4 - 8 ohms.

If you see 0 ohms - then you have a short.

Depending upon how the speakers are wired - you may even see a value as low as 2 ohms (or you may see a value as high as 16 ohms) - 2 ohms is not a real problem - you'll just need an amp capable of driving a 2 ohm load reliably.

Be sure to check the resistance on different settings of the switch - just to be sure your load is consistent.

Also be sure to check the left and right channels independently - so I would disconnect one channel at a time, to ensure there is no confusion.

It goes without saying - ensure any power to the amp is disconnected.

Here's a guide to demonstrate how speaker impedances interact with series / parallel wiring.

For the purposes of this post - impedance = resistance. (resistance is just a simple DC measurement).



Edited by TonyRPH on Thursday 11th April 15:14
Good advice on how to check from Tony........I don't agree about 2 ohms not being a problem though. As Tony says you'll be fine with an amp that will drive 2 ohms reliably but that is not many domestic amps in the price range and a 2 ohm load it will limit your amp choices. Car audio output stages can cope with 2 ohms but domestic amps are much happier with 4 ohms as the lower limit imho. If the Aura amp was working fine for months but eventually overheated when only playing at background levels then a 2 ohm load would do it imho.
When checking loads as per Tony's check method it would be good to check what happens as the speaker selector switches are being turned/pressed; there may be a momentary short as the contact poles are moving. Unless something has physically moved or been knocked then it doesn't sound like there is a full short anywhere in the system otherwise there would be no sound from one or more of the 8 speakers and the setup wouldn't have been performing fine prior to the Aura failing.