The HiFi chat, build and modification thread!

[apache]

Re:

The pre-outs are working already. There's a load of text in the service manual on how to do it if they're not though. There's also a pair of relays which are on the board if you can use it as a pre, which aren't there - but as I say, mine works anyway... weird.

 

[xerxes]

Re:

Give the LM4562 a whirl

I was aware that the LM4562 was equivalent to the LME49720; both my preamp and my power amps use LM4562s. My headphone amp uses single channel op-amps, hence the LME49710.

I've come across NwAvGuy before as well; I recall he caused a bit of a stir at Head-Fi that lead to him getting banned. To be fair, I don't think you have to do much to get banned at Head-Fi; read through some of their old threads and you'll see a "Banned" badge on quite a lot of member's posts.

Nice job on the Rotel and Audiolab. I wish I had kept my old Inca Tech Claymore, I sold it cheap years ago because it had a crackly volume pot, long before I ever started messing about with a soldering iron. I can only really do electronics by numbers, so replacing a faulty pot and maybe replacing some tired 20 year old capacitors would be within my limits.

 

[apache]

Hehe, yeah he's great!

Have to say Head-Fi is full of wnakers and snake-oil though (my wire's better than your wire - my wire sounds better now I've dipped it in liquid nitrogen etc), and I suspect I would find myself banned within a short space of time also.

Got another couple of Rotels on the way now. Another with one channel out, and a more interesting one with one channel quiet and distorted.

The original volume pot on the Audiolab is a 30k one, which are as rare as rocking horse poo, so I ended up replacing it with a 25k linear one and loading it to give it a quasi-log response. Bit complicated, but as sure as hell cheaper and quicker than trying to find a 30k log pot that fits!

 

[legrandefromage]

yes, the original pot was very expensive

 

[apache]

Re:

Hard to understand why they went for 30k. Not really a low enough value to be 'low noise', certainly not low enough to present a difficult load for the previous stage. It's not a particularly good quality pot either...

 

[grumpycommuter]

Re:

Sorry to interrupt the flow but advice, derision, scorn etc required. I'm a grown man so don't spare it....

I listen to a lot of music via Spotify sent through an aptx streamer as well as cd's again now my player sounds lovely

I'm putting some pennies away to do some hifi stuff but can't really decide what to do. I fancy maybe....

A. Getting an external dac to put the aptx streamer through and maybe try the cdp through it as well (although this would bypass Apaches lovely work)

B. See if the cdp can be improved further by fitting a new low jitter clock and separate power supply.

C. Be satisfied with what I have

From what I understand in simplistic terms A is pretty much the same as B...no?

 

[legrandefromage]

not a fan of wireless/ bluetooth streaming just yet, it still sounds a little odd to me but then thats me, a little odd.

 

[grumpycommuter]

not a fan of wireless/ bluetooth streaming just yet, it still sounds a little odd to me but then thats me, a little odd.

A little odd...hmmm!

I was in the same camp but it was great for listening to stuff without the kids garrotting themselves as they tore around the house.

But the aptx codec is a bit of a revelation. It's very very close to a cd, worth a listen if you get the opportunity.

 

[apache]

Close to CD? OK, but with CDs at between £1 - £3 a pop (for the stuff I like anyway) and physical ownership, why would anyone look at any other source material? I do have some 180g vinyl now though, but mainly so I can do decent TT demos for ones I'm selling.

DAC can make a difference, but whether it's better or worse is in the ears of the beerholder. If you just fancy a change of presentation, how about new speakers? Biggest bang for your buck there!

And whats this about mash tuns? Do you brew?

 

[legrandefromage]

'CD quality'

Allow me a little rant.

CD quality is a 30 year old misnomer. CD's use brick wall filtering that stops everything at around 20 - 21 kHz at 44.1khz. Nothing gets above that. Many albums look crenelated on a 'scope as the mix bounces off this wall. Its an anchor around the industry as everything is still mixed to this out of date 'standard'. Lapsed patents meant a drop in income for Philips and Sony so with some jiggery (SACD) and so on, we are still stuck with it.

'DVD standard' would be better, thousands of DVDs mastered at 48kHz with multi channel mixes, 22khz and over frequency range for us with bat hearing.

I think you get the gist. 48khz has been around donkies along with 96khz sampling rates - it adds headroom, makes live stuff sound better (look up Psychoacoustics) and generally makes music much much better to listen to.