A little experiment with great results

[nonuffin]

Those of us that have integrated amplifiers are pretty much stuck with what the manufacturers have stuffed into the box, unlike the folks with pre and power amps who can mix and match until they obtain their desired sound.

I am currently running a fairly oldish Yamaha A-S201 integrated with around 100 odd watts per channel power output, which isn't too shabby to be truthful. At my recent bakeoff I took along my FX Audio valve pre which to my ears sounded very nice into Radford Revival's STA-100 power amp. The FX sounded excellent with the Lyngdorf SDA2175 I had until recently.

So today I decided to plumb in the FX Audio pre into the Yamaha amp, crank up the volume to maximum on the Yam and see what transpired. Holy heck, the sound has moved up in quality by a not insignificant amount and what was a silly inpromptu dabble will now be a permanent addition. The amount of detail revealed and greater bass heft is simply amazing, with a sharpening up of timing and ambience too for good measure.

For a measly £22 delivered it is a billy bargain and if it can liven up my Yammy integrated it will certainly liven up your integrated too.

https://www.ebay.co.uk/itm/FX-AUDIO-...oAAOSwiYlaPG4V

[Yatsushiro]

They are a great little unit, and go well with Class D amps. There's a whole thread over on AudioKarma covering tube rolling and power supplies:

https://audiokarma.org/forums/index....wonder.848535/

[nonuffin]

How exactly did you achieve this - does the Yamaha have the ability to separate the pre and power amp sections?

All you need is an extra pair of interconnects to make it work. Disconnect i/c's from CD player to amp and connect those to the FX Audio output, then add a pair of i/c's from CD player output to FX Audio input. To effectively turn the integrated into a power amp stage then it's a simple case of cranking up the integrated amps volume to maximum and use the FX Audio's volume control only.

[nonuffin]

But that doesn’t bypass the Yamaha’s pre section - it just means you are running two in series. There must be a hell of a lot of gain in the system!

It must be the Yam's volume control that is being bypassed on it's own because it is at maximum. Whatever it is, it is paying dividends with the sound for sure.

It is particularly important to me as a few drops of CBD oil has made my tinnitus completely disappear today and after 3 years of having it I am having a top hole listening sesh right now without that bloody ringing in the ears to contend with

[Made in 1968]

Dom
Good on you. Never mind what shit other come with, If you think its an improvement so be it..

[scotty38]

Aren’t a lot of line level integrated amplifiers little more than a power amp with switching and volume control?

[southall-1998_mk2]

Dom
Good on you. Never mind what shit other come with, If you think its an improvement so be it..

Well said, Andre.

S.

[nonuffin]

Aren’t a lot of line level integrated amplifiers little more than a power amp with switching and volume control?

The Yamaha has all sorts of digital trickery for volume, balance, bass and treble controls so the signal path is probably short.

I can't be arsed to analyse what is going on technically, but I do know the sound to me is utterly sublime. Jolly sight cheaper than swapping amps too

[dave2010]

At the price mentioned, under £30, if the results are as stated this could be worthwhile. I could try it, though I’m not sure it’d make a difference with some of the kit I’ve got. Are there any more details/reviews of this or similar valve amps?

I’m trying to figure out why putting a valve amp in before the rest of the system would give an improvement, unless gain is otherwise low, or the volume control is giving noise. There’s also a risk of getting input overload distortion if the gain on the pre-amp is too big. Otherwise perhaps the pre-amp “simply” acts as a filter, and modifies the frequency response. Transient response could be affected, but then the following amp would still have to track transients. Slightly puzzled, though not disbelieving this.

[Made in 1968]

That is probably what he likes the louder input. I have a unit plumbed between my source & input. Does the same for me but god forbid this kind of behaviour is looked down on by conditioned Hi-Fi enthusiasts