HiFi amp, what do I need?

robgilmo

A good way to get cheap gear is to go on EBay, look in the hifi section at complete systems and choose nearest first, people wont post these and sometimes you can get lucky.


If you could push the boat out or put in a cheeky offer I can vouch for these, really really good little amps, apparently designed by Quad , the dual concentric potentiometer is pretty much unobtainable unless you do away with separate volume controls for left and right so make sure the volume knob works and its not dropping out on either channel.

http://www.ebay.co.uk/itm/wharfedale-2050a-amplifier-/282367391537?hash=item41be687731:g:CMQAAOSwtfhYqtd~

ToneControl

that amp looks worth about £10, and is too  shallow. Big PSUs need more height unless it is digital, which it isn't and you don't really want that anyway for this.
for mass-produced  Japanese/far east amps/receivers,  just look for the weight
if you need both hands to lift it,  the PSU  will be  meaty.  Makers don't add that for no reason
some  AV amps sound ok, but either way, ideally get a high power  plain amp,  100w a channel or more

robgilmo

Toroidal transformers take up no space at all and weigh very little.

ToneControl

robgilmo said:

Toroidal transformers take up no space at all and weigh very little.

not the ones in the amps I have had - they were powerful amps and thus weighed a lot, even though  toroidal. My NAD C370 weighed plenty

I'm just pointing out the easiest thing to check when buying used cheap hifi amps:
no one makes really heavy low-spec amps

you can find high spec low-power amps that aren't cheap
but looking for bargains,  just look for  a heavy amp from a brand you know 


btw 
to save me typing it, here's why 150w-200w a channel amps are excellent for hifis:
http://www.enjoythemusic.com/magazine/manufacture/0907/

robgilmo

I had an old Pioneer SA-7500 a fair few years back, Lovely big thing, weighed an absolute ton, sounded like crap,  massive big transformers in it.
This is the inside of a Wharfedale 2050A, lovely sounding thing, quite a low profile and not very heavy at all, but really, its a lovely sounding amp. They don't really need to be heavy unless for damping reasons or you want something with a lot of power, 50WPC is way way more than Ill ever use.



I have a Marantz PM6010 KI here and its got a massive toroidal tranny in it, does it need it? I'm not convinced it does. 

ToneControl

robgilmo said:

I had an old Pioneer SA-7500 a fair few years back, Lovely big thing, weighed an absolute ton, sounded like crap,  massive big transformers in it.
This is the inside of a Wharfedale 2050A, lovely sounding thing, quite a low profile and not very heavy at all, but really, its a lovely sounding amp. They don't really need to be heavy unless for damping reasons or you want something with a lot of power, 50WPC is way way more than Ill ever use.



I have a Marantz PM6010 KI here and its got a massive toroidal tranny in it, does it need it? I'm not convinced it does. 

wrong, unless you listen to music very quietly, or enjoy distortion. 50w is way too low for CDs with proper dynamic range

ToneControl

robgilmo said:

I had an old Pioneer SA-7500 a fair few years back, Lovely big thing, weighed an absolute ton, sounded like crap,  massive big transformers in it.
This is the inside of a Wharfedale 2050A, lovely sounding thing, quite a low profile and not very heavy at all, but really, its a lovely sounding amp. They don't really need to be heavy unless for damping reasons or you want something with a lot of power, 50WPC is way way more than Ill ever use.



I have a Marantz PM6010 KI here and its got a massive toroidal tranny in it, does it need it? I'm not convinced it does. 

just looked up the  Pioneer SA-7500 
all the reviews are good
you must have had a duff one

robgilmo

ToneControl said:

robgilmo said:

I had an old Pioneer SA-7500 a fair few years back, Lovely big thing, weighed an absolute ton, sounded like crap,  massive big transformers in it.
This is the inside of a Wharfedale 2050A, lovely sounding thing, quite a low profile and not very heavy at all, but really, its a lovely sounding amp. They don't really need to be heavy unless for damping reasons or you want something with a lot of power, 50WPC is way way more than Ill ever use.



I have a Marantz PM6010 KI here and its got a massive toroidal tranny in it, does it need it? I'm not convinced it does. 

wrong, unless you listen to music very quietly, or enjoy distortion. 50w is way too low for CDs with proper dynamic range

Really? Perhaps my speakers (Yamaha NS670) are too efficient, so considering the operating power is 6.3 watts to obtain 96dB at one meter, I cant be arsed, can you do the math? Put it this way, my amp never gets driven at very high volume, it doesn't have to.
The Pioneer, don't get me wrong , it was a nice amp, but by todays standards it was pretty coloured and muddy, but its one of those things, like guitar tones, one mans poison is another mans audio nirvana, some will like it and some will like the opposite. I was sad to see it go though.

Sambostar

I got an Arcam Delta 290 as I've always wanted one, the selector switch gets buggered over time so you run the phono inputs through the tape loop and use record selector to choose source. Great phono stage, Aux, CD, Tuner and AV inputs and four speaker outputs and preamp outputs so you can wire an active sub in on the preamp out.  Have a Sony BM10 bluetooth receiver in the aux and the TV was in the AV.

The BM10 does Apt-x codec apparently, not that I'd know or use it and hooks up to Android devices easily with no drop outs and also the Logilink Bluetooth V4.0 USB adapter for a computer running Windows 7 or 10.  The Sony has phono out and a some sort of DAC in it, so you simply just connect it to the aux with phono plugs.  The Logilink also does Apt-x. apparently, although I mostly just stream YouTube.

So yeah, I'd focus on getting a good amp or maybe a more modern receiver, depending on what your speaker set up is and what you primarily want to use it for and not worry about digital connections at all, just buy a separate bluetooth receiver.

Alpha 9's are similar amps.


PS. Mine looks bigger than yours.

ToneControl

robgilmo said:

ToneControl said:

robgilmo said:

I had an old Pioneer SA-7500 a fair few years back, Lovely big thing, weighed an absolute ton, sounded like crap,  massive big transformers in it.
This is the inside of a Wharfedale 2050A, lovely sounding thing, quite a low profile and not very heavy at all, but really, its a lovely sounding amp. They don't really need to be heavy unless for damping reasons or you want something with a lot of power, 50WPC is way way more than Ill ever use.



I have a Marantz PM6010 KI here and its got a massive toroidal tranny in it, does it need it? I'm not convinced it does. 

wrong, unless you listen to music very quietly, or enjoy distortion. 50w is way too low for CDs with proper dynamic range

Really? Perhaps my speakers (Yamaha NS670) are too efficient, so considering the operating power is 6.3 watts to obtain 96dB at one meter, I cant be arsed, can you do the math? Put it this way, my amp never gets driven at very high volume, it doesn't have to.
The Pioneer, don't get me wrong , it was a nice amp, but by todays standards it was pretty coloured and muddy, but its one of those things, like guitar tones, one mans poison is another mans audio nirvana, some will like it and some will like the opposite. I was sad to see it go though.

It's surprising to most people
I've done the math before,  not enough time this morning, dBs/dBv/dBw and are hard to explain, that link I posted covers most of it, but I'll summarise:

To handle transients properly on a hifi you need a lot of headroom
Good CD masters have  far more headroom than LPs, 7 or 8dB more I think
to play at the same apparent volume as an LP with a good CD needs about 3 or 4 times the max power to avoid distortion
Most hifi speakers are not very efficient, 86dB at most  at 1w/1m
My 1970s tannoy Ardens  were 91dB, nevertheless, I drove them first with a 160w or 200w  mosfet power amp on each side, then using a NAD C370, which peaks at 180w a channel. This was for studio monitoring and pleasure
Eventually, the NAD failed, and I had to use a lower power amp for a while. Immediately, the drum samples sound wrong, the  overall sound on a good mix was distorted, since  now the peaks were  being cutoff by distortion. This is a real thing.

Have a look  at the power rating on near and mid-field studio monitors: these are not made powerful  because of a hifi cork sniffer's fad, it's a fact that studio engineers demand  headroom to be able to hear the music properly

My ones  are here:  http://www.focal.com/sites/www.focal.fr/files/shared/catalog/document/CMS-65-specification-sheet-2962.pdf
100w for the woofer and 60w the tweeter on each side
Even with that, it's not enough to handle bass properly, so most use an add-on subwoofer, as I do:
http://www.focal.com/sites/www.focal.fr/files/shared/catalog/document/CMS-Sub-Specification-sheet-3014.pdf
that is 300W, and enables me to filter some  bass from the  near/mid speakers, which are a bit weedy on 100w each  to be able to do bass properly

Main studio monitors are  far larger and more powerful,  I've seen  200W+ 

see this:
https://www.sweetwater.com/insync/studio-monitors-buying-guide/#power

Power – How Many Watts Do I Need?
In a studio monitoring system, the power handling of the system is going to have a big effect on the overall sound, and not just in terms of volume. It also determines your dynamic range, the amount of headroom you have before signals peak. Higher wattage means you’ll be able to hear more transient detail, and you’ll be better able to make precise adjustments to compressors, limiters, and gates.
Said another way, if you listen to a mix on two monitoring systems with different wattages at the same average volume level, the higher wattage system will give you more headroom. Many people are unaware that music peaks (transients like snare hits or kick drums) can demand as much as 10X (yes, TEN TIMES) as much power as average music program material. So for a given volume level that might demand an average of 20 watts, the program peaks could require as much as 200 watts. If you have an amp that can deliver a clean 70 watts, then you’ll be 130 watts shy of what you need. That results in greater distortion and possibly clipping during that musical peak, and for a kick drum in most pop music, that happens very often. While you don’t necessarily need the highest possible power rating, keep in mind that more wattage will produce more definition and dynamic range, not just overall volume.

ICBM

This is exactly the same reason as why a lot of people don't understand why some of us still like 100W guitar amps when a cranked 15W amp is loud enough.

ToneControl

ICBM said:

This is exactly the same reason as why a lot of people don't understand why some of us still like 100W guitar amps when a cranked 15W amp is loud enough.

yes, my real amps are 30w up to 100w, which I play in the house - but clean

I'll start on Fourier analysis of OD signals next if you want ;-) 

robgilmo

This is all interesting stuff, I'll check those links out Tc when I get a chance to.

ToneControl

http://www.chuckhawks.com/speaker_spl_amp_power.htm

Required Power: The RMS watts per channel required to produce music at the desired SPL at the listening position.

speaker sens. (1w/1M)	listener distance	desired SPL	amp. headroom	required power
104db	15' (4.6M)	90db	15db	27 watts
101db	15' (4.6M)	90db	15db	53 watts
98db	15' (4.6M)	90db	15db	106 watts
95db	15' (4.6M)	90db	15db	212 watts
92db	15' (4.6M)	90db	15db	422 watts
89db	15' (4.6M)	90db	15db	842 watts
86db	15' (4.6M)	90db	15db	1681 watts
83db	15' (4.6M)	90db	15db	3354 watts
80db	15' (4.6M)	90db	15db	6691 watts
77db	15' (4.6M)	90db	15db	13,351 watts
104db	8' (2.46M)	80db	15db	1 watt
101db	8' (2.46M)	80db	15db	2 watts
98db	8' (2.46M)	80db	15db	3 watts
95db	8' (2.46M)	80db	15db	6 watts
92db	8' (2.46M)	80db	15db	12 watts
89db	8' (2.46M)	80db	15db	24 watts
86db	8' (2.46M)	80db	15db	48 watts
83db	8' (2.46M)	80db	15db	96 watts
80db	8' (2.46M)	80db	15db	191 watts
77db	8' (2.46M)	80db	15db	382 watts

robgilmo

Just had a quick play, got up to 77 dB then got shouted at, 1 meter away, amp at 1 o'clock.

Axe_meister

If you could go to £100 or £150
http://www.ebay.co.uk/itm/PIONEER-A-400-stereo-integrated-amplifier-HIFI-AMPLIFIER-/201831591014?hash=item2efe19ac66:g:zIMAAOSwdGFYsCZ4

robgilmo

Got to 82 db, speakers started to distort, amp at 1-2 o'clock, that was well beyond any kind of comfortable listening levels. If that's what it takes to bring out the full potential of a CD then WTF? Really?
Its not that I doubt what you are saying, but for home listening do you really have it up that loud?


Speakers specs are Crossover: 800Hz, 6,000 Hz (12db/Octave)
Fundemental resonance frequency 45Hz
Impedance 8 ohms
Output sound pressure level 96db/1m 6.3 watts input
Normal capacity (Maximum input capacity) 50W
Frequency response 40-20,000 (50-20K + - 3db)

Gagaryn

Sambostar said:

I got an Arcam Delta 290 as I've always wanted one, the selector switch gets buggered over time so you run the phono inputs through the tape loop and use record selector to choose source. Great phono stage, Aux, CD, Tuner and AV inputs and four speaker outputs and preamp outputs so you can wire an active sub in on the preamp out.  Have a Sony BM10 bluetooth receiver in the aux and the TV was in the AV.

The BM10 does Apt-x codec apparently, not that I'd know or use it and hooks up to Android devices easily with no drop outs and also the Logilink Bluetooth V4.0 USB adapter for a computer running Windows 7 or 10.  The Sony has phono out and a some sort of DAC in it, so you simply just connect it to the aux with phono plugs.  The Logilink also does Apt-x. apparently, although I mostly just stream YouTube.

So yeah, I'd focus on getting a good amp or maybe a more modern receiver, depending on what your speaker set up is and what you primarily want to use it for and not worry about digital connections at all, just buy a separate bluetooth receiver.

Alpha 9's are similar amps.


PS. Mine looks bigger than yours.

I recently got the new wee Arcam. Not particularly heavy, not particularly powerful but sounds really nice - looks reasonably similar still!

 -

robgilmo

Less is more.