Amplifiers: A Nerd Thread

[Mowl]

So I'm using a TEAC A-X75MkII amplifier that offers seventy-five watts per channel and is by far the sweetest, warmest amplifier I've ever used. Sound quality is vital in my game, but even as a studio musician I have to have at least as good an amp at home as those I use in the studio. Obviously speaker quality is vital too, and I use a pair of Finnish designed Salora speakers from around the late seventies/early eighties that are simply sublime. I got them from a neighbour who was moving out and I did mention that they were highly sought after on the national market but he gave them to me anyway.

I previously used a quirky late seventies-issue Pioneer amplifier which was great at peak volume but pretty much lousy at low volume playback. The inputted sources, whether analogue or digital, always sounded cleaner, warmer, and fuller after around two to three hours, depending. I prefer my amps to have tubes rather than solid state, but of course the tubes take time to warm up, but when they do it's excellent. I find solid state rather turgid and cold, no matter how long they've been switched on. But with the TEAC I notice lately that it's taking longer to power up (even though I usually switch it on in the evening but don't use it until I'm ready, so around sixty to ninety minutes generally gives a good result.

I've been advised to swap out the tubes for new ones but I'm reluctant to do that just yet as the main function I love from the TEAC is the 'Loudness' function, which - when it's added to any style of music I might listen to, gives the most awesome sound I've used at home probably ever. From classical to industrial, everything sounds delicious, really warm and live: it fills the room perfectly and the bass/tone/treble EQ can be added for fatter bass rumble down around 200Hz and high-end up to around 17KHz without any distortion or loss of finesse. Loudness operates a bit like a gate, a standard recording studio staple: it basically acts as a gate slamming shut after a certain point in the signal - for reference think the drum sound on the world's best known drum fill ever by Phil Collins. The concert-type toms he uses are single headed, as in they have a head only on the top-side. The bottom-side has nothing, and these type of toms are generally a bit louder as well as more defined. Heads on both sides is softer, warmer, fatter, and can be tuned into key with the song if required. Phil's tom sound is based on an 'accident' which occurred one day when Genesis were recording and he went to take a break. AS he was leaving the studio, the engineer turned off the speakers but left the intercom on (from studio control to studio floor) and the speaker was so small it couldn't handle the entire scope of frequencies from the drums and instead it acted like a garden gate does when you slam it shut - nothing can pass. Phil loved the sound and forgot all about taking a break and instead concentrating on making the drums sound as good on the intercom as they did on the main speakers. These days it's a simple digital plug-in everyone uses for a variety of tasks but in credit to Phil he did manage to find it before anyone else. And it is an awesome sound - when used sparingly and tastefully.

In effect, this is what the 'Loudness' function on the TEAC A-X75MkII does, only on a smaller scale but with all the warmth and softness a domestic system has to offer.

I'm interested to know which amplifiers you guys use and what in particluar it is about them that you like the most.

I was actually on the verge of throwing the TEAC out a while back one day when I switched it on and an hour later it still wasn't warm. Then I spoke to other users who all said the same thing: if you're listening 'seriously' to your music, then turn it on a few hours before you're going to use it so the tubes are fat and warm and the signal to noise ratio is keenly balanced. So even though it takes so long, the sound one gets when things are just right is fucking phenomenal.

Do you turn your amp off when you're done with it and do you notice that the sound quality is lousy/meh at first but gets better as things warm up?

Or do you even give a bollocks?

 

[roc_abilly]

Haven't had a proper amp for a while.

Last one was a Sugden A48. A UK hand built amp. It had class A circuitry but would blow over to a class B circuit for extra oomph.

Another project I have waiting, until I have the time, and the kids are old enough not to suffer too much when it's 1am and they wake up with the room shaking with the bass, is a speaker build.

Did you ever hear of the LS3/5a bbc designed small monitor speaker. It's a classic from 1975, they still fetch big money today for the quality of their sound.

Well I had the drivers used in that design from another old speaker set, along with a big kef b139 bass driver (these drivers were all used in countless classic speakers in the 1970s and 1980s).

My idea was to use the ls3/5a design for the tweeter and midrange and integrate that with the b139.

Turns out I was not the first to think of that. I had done some work on the crossovers and then found someone selling similar on the internet.

It turned out to be Malcolm Jones, the chap who actually designed these legendary drivers for kef, and I must have spent two days on the phone talking to him about the design considerations.

You should see the crossovers on the ls3/5a. They're massively complex. Anyway the final crossovers to match my cabinet design with these drivers was even more so. I also upgraded all the inductors and other components to use top end stuff (electronics).

Anyway, they're still sitting in my garage. Waiting until the bowels of my kids are developed enough so as not to piss and shit themselves when I turn the sound up at 1am in the morning after a few snifters.

Ah don't get me started. I also at this stage of my thought think the real magic is in the source. The turntable or these days your DAC, taking the digital source.

 

[Mowl]

Highly complex work that, Dude. You sound like a man after my own heart: you know what you're looking for and can tell the difference between shite and Shinola. Years back I tried an expensive experiment with a pair of Yamaha NS10s (which are normally used for near-field monitoring in the recording studio booth) to hear how they might sound in a domestic setting using an ART thirty-one band graphic EQ. Turns out they were horrible in every possible way. What works in a designed and custom built studio does NOT work in a home situation.

Even after doing the standard industry trick of one layer of tissue paper covering the tweeters, it was nasty, cold, clinical, and without any sweetness or warm characteristics at all. The NS10s are amazing in the studio but outside of that, forget them. I still have that 31 band ART graphic up in my Mam's loft and will collect it next time I'm home, along with a few cases of cymbals and drums. I also need to collect my ear goggles, an 1/4'' TEAC open reel, an old analogue mixer by Yamaha, and a DCC (Digital Compact Cassette) player which I used to use for bouncing simple mixes off and storing them for future additional work.

It's good to know there are others out there who still care about sound quality in a time where everyone's listening to shitty digital versions of things straight off their phone device. Fuck that, I use my phone for in/out communications with NO added internet features. In fact, the singer in the current project has selected me an Android (brand new, never used) mobile phone to drag me out of my 'Luddite' phase and into the new world. In reality, it'll still be offline and used for dumping as many mixes onto as it'll hold so I have access wherever I go.

Call me what you like, but I still prefer old school for many things.

Digital is hollow, lacks body, warmth, human feel, and delivers only a small percentage of the original signal the more it's bounced from one device to another.

If there was a way to listen to vinyl on the move, then I'd happily carry a turntable in my backpack.

 

[roc_abilly]

Digital is hollow, lacks body, warmth, human feel, and delivers only a small percentage of the original signal the more it's bounced from one device to another.

This is another element.

You start from a lossless format of course, usually FLAC. If it's recorded from vinyl you need to be on top of that, but mostly today the records are released in digital format.

Moving on, the key is your DAC. How you convert from digital to your analogue signal.

You can go crazy on these DACS. Big, expensive all tube affairs and so on.

But I used to have this Chinese jobbie. I bought it for around £150 but I see the same model goes for much more now, perhaps on account of the reputation they got.

It had a big heavy power supply, and that is always key. But it also allowed me to play around with the op amps, swapping in different types, each of which affect the sound to give different qualities, like warmth, or spaciousness, or detail, or increased definition of the sound stage, and so on.

I also had a nice CD player. A classic old Naim player. Again, it gave a sound very unlike what you get from these modern small devices with their tiny DACs and undersized power supplies, and too "efficient" low power circuits etc.

So, yes, there is something about turntables. But you can very close, and get some advantages, if you focus on the digital to analogue conversion.

 

[roc_abilly]

Yes, I suppose that is what made the LS3/5a speaker so special. It is rare to get a speaker that is so accurate and detailed, as a monitor speaker needs to be, yet sound so beautiful and easy to listen to.

 

[roc_abilly]

Nice Japanese review of a very high end tube DAC. Notice it has a digital read out telling you it is "preheating", same as your TEAC, Mowl.



Compare the innards with the DAC chip in your phone!

 

[roc_abilly]

... I've been advised to swap out the tubes for new ones...

Sometimes it's best to leave things alone. If it ain't broke, don't fix it.

You may find it difficult to get an exact matching replacement vacuum tube, and the sound may change, for better or worse.

Same goes for recapping an old amp, which some people also advise, I.e. to put in new capacitors.

Perhaps on the power supply, if you turn up the volume without an input signal, and hear a 50hz hum, well then go ahead and change out the main electrolytic capacitors in the power supply.

But if it sounds sweet, well don't mess with it. Also understanding that the "hifi" hobby is a rabbit hole, you can keep going forever in the quest for "better sound". If the sound rocks your boat, well that's it.