Dipping a toe into the world of Hi-Fi

[Norgarth]

I've still got a load of CDs and cassettes that I occasionally listen to, Never bought an Ipod or MP3 player.

[nocarename]

I have a collection of CDs and cassettes and records.

I don't listen to them enough and, frankly, most of the time the weak point in my audio chain right now is the speakers. But before I migrate off listening to podcasts on my phone and music off youtube I'm going to need a job to fund better gear and more space to put it in.

[Dartz]

Most of this stuff is found on ebay for pennies. Nobody wants these old receivers because they've no HDMI ---- getting modern HD stuff to run them is a pig, but as an audio amplifier they're fine.

Doesn't even need to be good speakers --- just something you don't have to max the volume on so you don't feel attacked by the music. You can hear it even with the volume down.

[Dartz]

The next addition. Not much. A Bluetooth hookup to Alexa/Laptop/Phone. Also a 3.5mm jack connector for the phone - once I bolt a cradle to it.

Also tidied shit a little bit and re-arranged the room to give more space for it. The cables are fused in multiple ways so it's not going to burn despite looking a bit funky

I've 2 spare modes left to assign on this thing and I'm sort of at a loss for what to add. It already has a built-in FM tuner. At this point I'm just adding curios for shits and giggles. I can handle Analogue inputs, or SPDIF as needed. I'm out of Toslink inputs.

So anyway, I've got two ideas off the top of my head:
A DAT deck
A Minidisc deck


Also - because Alexa's hooked to it I can open the Spotify and rattle the absolute fuck out of people while I'm at work.

I also might need to build a proper power bus. There're twelve plugs and a USB needed to power this thing - most drawing less than an Amp.

[Dartz]

Bought a load of blank cassettes.





This is kinda fun and they sound good.

[Dartz]

Spend Sunday rewiring everything with proper banana-plugs, and good quality cable.

-----

Speaker cable is one of those things that can get rediculously expensive really quickly. How about more than I spent on this entire system, and the CD's and records I play on it for one 2 metre cable. There's snake oil, and there's high Octane, leaded and mixed with 1,4 dioxane snake-oil

And of course, above a certain point, you're getting well into diminishing returns. Copper, after all, is copper.

But more than that - you get into things like Bi-Amping and Bi-Wiring, where you either run two sets of cables to the speaker (For high and low frequencies, respectively), or even have a dedicated amp for the highs and lows. Speakers set up for it will have two pairs of terminals on them, like below:



The tweeter in the speaker will have a high-pass filter on it
The driver will have a low-pass filter.
And properly set up, they sort of meet in the middle and everything's okay.

The idea with bi-wiring is that you run two sets of cables from the amplifier to the speaker. One set of cables is only every carrying the high frequencies. One set is only ever carrying the low frequencies.

I think I just changed the impedance characteristics of the speaker a little. Less current flow in each leg means less power lost in the cable itself. Some people thick there's less interference between the high and low frequency side of things as they're effectively now seperate from each other. I can't tell the difference.

There're other effects like capacitance of the cable and inductance that might be affecting its frequency response - but probably not at audio frequencies, and not over such short runs. (I had to consider them running an M-bus network over maybe 4 kilometres of cable in a building----)

Dropping the impedance a bit it does make *some* difference. Half the system was run off old alarm cable which is pretty thin stuff - maybe .25mm2 if even. It's about 1.5 ohms over the full length of the circuit. A fair bit when the speaker itself is 8ohms

The newer cable is 0.1 ohm over the same distance. And it's doubled up - to use both sets of posts on the speaker, so the actual resistance will be about half that again. Which is within the margin of error of the meter I'm using. (Sorry - not a Fluke - just an automotive multimeter that I spilled coffee on....)

A former McIntosh engineer seems to agree that this is the thing that actually matters with speaker wire. (Not Macintosh) . Just drop the resitance and none of the other quantities matter over domestic runs.

----

So, what difference did a few hours fucking around make?

The cabling is neater.
The banana plugs make it easier to break down and rebuild. Or swap out speakers
The amp runs less hot (But in no way cool), so there's some physics happening.
I'm getting fine strand of copper in my feet.

[robkelk]

I'm getting fine strand of copper in my feet.

They keep telling me that pain is good for the soul.

[Dartz]

"It sounds great, until someone convinces you it could sound 'better'. "

Or until it doesn't sound at all.

The SR7400 died. It looks like a power transistor fried. 20 years is a good life for a modern electronic device. The thing ran hot as fuck anyway.

After a few weeks of normal-fi we've managed to scrounge enough money to sale the seas of eBay and find a replacement. The hardest think was to find something functional that:
-Offered an analogue output that can drive a recording input into a tape deck
-Offered enough I/O to hook up a tape deck, an Xbox, a PC(as a blue-ray player) with 7.1ch discrete audio, a CD player and a record player
-Actually had HDMI hookups.
-Had enough power to drive 7 x 100 watt speakers

I found a nearly-new Marantz SR5006 from 2012 so. It's a bit tetchy to use - it relies on the telly screen for its control display but it works. And it doesn't run anywhere near as hot. But the thing self-calibrates to the room, it sounds alright and it does work right out of the box.

Also finally tracked down the cause of an intermittent humm from the record player. It hadn't forgotten the words - the was a bogey cable picking up mains. A new one is needed.

It cost me more than I would've liked, but came with all it's original accessories. The only problem was a slightly ruined remote. I could fix the most important contacts with foil tape - but not all of them

---




It's also about 5 kilos lighter since it doesn't have as much discrete I/O to support. But it does have enough.

[Dartz]

The tape - it's moving. It's alive. It's alive, IT'S ALIVE.

In the name of God, now I know what it feels like to BE God.

Ahem.

Anyway. I've been off work for a bit and - expecting the weather not to be cooperative towards doing anything outside, picked up a cassette deck to tinker with and 'restore'. It was in mostly running condition when I finally tracked down where the postman had hidden it. Except that, five minutes into playing it started to go berserk, slowing down, speeding up to normal speed, or locking itself in a strange semi-fast forward mode that prevented the front door from opening.

Cracked it open to see what it was like inside, to find that the little belt that drove the tape-counter had been converted into an odious tar-like substance, and it'd been chewed up inside the drive gears.

It's a Yamaha - which means the insides are somewhat pretty, despite very few people ever getting to see them. The white PCB's are unique, and everything is tidily laid out, with the Trafo far away from anything.


The offending belt. Any pressure on it and it dissolves into an infuriating tar-like substance.




Cassette transport - with remnants of the belt still smeared across the drive gears. It actually took two attempts to clean it - using 85% volume absinthe as a solvent since nothing else would do it. More black tar hid under the white yoke in the centre of the mechanism and that was impossible to get out without complete dissaembly


Someone in Yamaha clearly considered servicing. The entire transport pops right out once unscrewed with no additional dismantling. Behind are all the earbuds needed just to clean the centre gears. This was the second time I dismantled it.


And, proof of life.


As it is, I've been plugging into the telly to test it and it sounds fine. Still a little bit of 'wow' but it seems to be dependant on the individual cassette rather than the deck. Some tapes slip on the capstan and leave behind a residue of oxide for reasons I don't fully understand.

And blinkenlights are always fun.

I'm guessing both main belts will need to be replaced in the near future. Not a big job, but annoying.

[Dartz]

Being an idiot, I managed to break it.

It chewed a tape badly enough that the only way to clear it was to dissasemble the pinchroller. It wound around the roller several times before it stopped. Straightforward enough you might say - but the axle pinged off the pinchroller and vanished.

More importantly, I had to figure out why it ate the tape. It means something's mechanically wrong with the deck. Usually it's a sign that the take-up torque winding the tape onto the spool isn't right - or that the tape is sticking to the pinchroller, or something else more complex is afoot

The take-up torque on this deck is provided by an electric motor, so it shouldn't be going wrong, should it?

Ran a old unloved tape through it on the inkling that something might've been off with the takeup. Running it without the pinchroller would run it at whatever speed the second motor would drive it at. The speed ramps down naturally as the tape gets towards the end. Sure enough right at the end of the tape - the takeup started to hunt and stall strangely before eventually stopping. It jerked, sped up and slowed down.

When I cleaned the mechanism originally, some of the paint wore off the back of supply side gear. There's a pattern on it that's used for a sensor for the auto-stop. It seems that pattern might also perform some sort of speed control. At least, I guessed as much and restored it with a little permanent marker.

Received a replacement pinch-roller assembly from eBay - ones form a KX580 fit well enough. I needed it solely for the axle - but swapped the entire assembly because why not? There was a slight difference between the two - the old one from the 300 seemed to taper of lightly on one side - the one from the 580 had a slight dome. I'm guessing there might've been a bit of wear on it.

Oiled everything a second time with silicone oil, and a little lithium grease on anything that slides.

Somewhere in there was the solution. It's definitely a lot happier now. Though, a few tapes are still leaving marks of oxide on the capstan - it's only newer tapes so I suspect this is the cause more than anything. They did it on the Nikko deck too

----

Recording 'works'. Haven't done more than verify that it works and sounds fine.

The Freiren soundtrack hits a little different on tape --- the tape rolls ever onward.