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Re: Phono Preamps

Posted: Sat Sep 03, 2011 11:58 am
by mediatechnology
Hmm. Not sure I know how to run it in half speed.

Re: Phono Preamps

Posted: Sat Sep 03, 2011 12:14 pm
by JR.
I don't either, IIRC some turntables used mains freq as time reference, so might be as simple as making a low power 30 Hz mains... others are DC controlled with some speed control trim, both cases may not be happy over 2:1 range.

Most of my experience with small motor speed control was on cassette machines. We were able to vary simple DC motors over +/- 100%. (back in 70s when we sped up and slowed down cassette players and corrected the pitch back to normal. ).

Since I am unsure how valuable this would be wrt click/pop abatement, (probably not linear with speed change), could easily be too much effort.

Certainly not to be undertaken lightly.


Re: Phono Preamps

Posted: Sat Sep 03, 2011 1:24 pm
by mediatechnology
I have a Techinics SP-15 which uses a PLL and offers 78, 45 and 33-1/3 but no 16-2/3. I could probably hack it with a service manual (I may have one) and add a divider. The VariSpeed doesn't have enough range.

I suppose one disadvantage of the approach is that your transfers take twice as long.

Re: Phono Preamps

Posted: Sun Dec 21, 2014 1:58 pm
by carlmart
Has anyone tried a bit more sophisticated turntables, arms and cartridges than Technics?

Any Thorens or Linn, with better arms and needles will make a lot of a difference in improving the audio from any LP.

Not to speak of even more expensive turntables.

Re: Phono Preamps

Posted: Sun Dec 21, 2014 2:55 pm
by JR.
The technics earned a good reputation as a robust turntable (especially popular for DJ use). Heavy duty cartridges were used with robust styluses that could handle scratching, while audiophiles preferred more delicate cartridges only played in one direction (unless you are searching for demonic messages).

Back in the '80s people would spend many thousands of dollars on esoteric playback systems it was how dentists would impress their neighbors (now they build home theaters instead).

I find it difficult to ponder elevating the playback performance of vinyl when an inexpensive CD mechanism generally smokes even the best vinyl playback available.

If you have time and money burning a hole in your pocket, invest in better loudspeakers. They are still not perfect and your money could actually buy you some better performance. Maybe spend a few dollars on acoustic room treatments.

Of course opinions vary...


[edit] my current turntable is a Garrard (with a top of the line Shure cart I traded the Shure engineering dept some delay line kits for), but honestly I haven't turned it on in this century. [/edit]

Re: Phono Preamps

Posted: Mon Dec 22, 2014 2:52 am
by carlmart
Sorry, but we do differ over this, and it seems that more than a lot.

I'm not a dentist and I never wanted to impress anyone. In fact rarely invited anyone to listen to my home to impress them on my sound.

But I did advice many on how to improve their audio.

As I said I deal with professional audio, applied to film, since my mid '20s, so I did have the experience to use and listen to the best quality quality equipment money could buy. You do not seem to give the importance due to the fact that I could made an immediate comparison between the actual live performance, either of musicians or actors, and the recording you got on the Nagra 4.2, using Beyer DT-48 headphones. Nothing can cheat you there: either the playback sounds or doesn't like the performance. It was the best way to learn and train your ear.

If you find it difficult to elevate vinyl playback performance compare to inexpensive CD players, it's because none of the names you mentioned ever got close to reproduce the quality of the sources, and by that I mean the orchestras or the groups or singers themselves.

I have a friend who manufactures extremely high quality 2-way and 3-way speakers, that cost quite a lot of money and could cost more if they were made in Europe or the USA. And they are among the best money loudspeakers money can buy anywhere.

So he has to have a very good setup to drive the speakers. In my case, when I met him, I had listened to the best professional speaker boxes made at the time, like Tannoy or Altec Lansing.

We modified a lot of CD players to get the high audio quality he got from his turntable setup, which was a Thorens TD150, with Linn arm and several cartridges, with a Luxman preamp and power amp.

When I need to try something new, I take it there, because we both have a trained ear that can't be cheated. If it does cheat and still live with it, it's because LPs are not around anymore, so you have to make it with what it is around.

But I am a member of a DIY audio circle in London, who do try to take the absolutely quality from their equipment, and not only their turntables setup, but their CD and other sources setup which would cost several thousand if commercially available. When they meet, they do comparisons and listenings, and sometimes they go from the original tape recordings or digital recordings, to the actual CDs and LPs.

Of course opinions vary, but not because some people are eccentric or have a lot of money. These people don't.

Audio got more practical when it got digital, but it didn't get necessarily better. A pro music recordist friend of mine in England, who's also an electronics engineer, has to work a lot to get the same audio quality from his digital chain, going high in oversampling and bitrate, to get the quality he gets from his analogue chain. But you can't get tapes anymore, and clients expect you to use digital, because they have been convinced digital is better. That is the sad truth.

So that's why I am looking for a high quality RIAA preamp, to use with my Thorens TD-160, with Linn Basik arm and Grado cartridge. Nothing too fancy or too expensive at the time I bought it. I will use an external DAC at high samplings and bitrates. I should make CDs out of it and higher quality files to put in DVD.

Re: Phono Preamps

Posted: Mon Dec 22, 2014 8:18 am
by mediatechnology
Has anyone tried a bit more sophisticated turntables, arms and cartridges than Technics?
No, we're simpletons here.
For the turntable we simply use what we already have.
Its called "making do" and an excellent way not to die poor.

Re: Phono Preamps

Posted: Mon Dec 22, 2014 10:45 am
by JR.
Sorry I did not mean that as a personal attack, I was making a general statement about markets a few decades ago.

I have designed multiple phono preamps (as well as recording consoles) so I am looking at this from an empirical "what the technology can do" perspective.

Digital media is unquestionably better than vinyl in every measurable metric.

I stand by my observation that loudspeakers are the weakest link (along with the listening space) while in my judgement it is even worse than that. If you attempt to compare playback to live performances, stereo hifi isn't even close. Several decades ago Inventors tries to add realism to playback with additional channels. While a marginal improvement (i designed several surround system delays too) it still is not the same as sitting in the concert hall, or having a live band in your living room as I have several times.

Enjoy your vinyl, you are not alone... Where were you back in the '80s when I was trying to sell my phono preamps?


Re: Phono Preamps

Posted: Mon Dec 22, 2014 2:05 pm
by mediatechnology
For the record (pun intended) my interest in the subject comes from having boxes of LPs of music I can't easily hear.
While there's some nostalgia about pulling a record out of the sleeve, cleaning and playing it I rarely do so.
Having old LPs transferred and stored on a hard drive a few mouse-clicks away, at almost any time anywhere, seems attractive.

The time it takes to transfer, de-click and encode the file however is far greater than the 99 cents Amazon would charge me to buy it.
So some material makes sense to transfer because its not available or sounds better and some doesn't because it can be easily bought and sounds almost as good.
Though the Amazon product is mp3 I tend to be a passive listener moving around the house listening on small monitors.
For me its about enjoying the music as I do something else more than the machinations of building and maintaining the ultimate Hi-Fi machine and being prisoner to it.

The fact is, this thread gets a lot of hits from people looking for flat phono preamps. (Almost as many as the QX5252 landscape lighting IC).
There seems to be a lot of interest in flat transfer, de-click in software before RIAA, then applying RIAA EQ in software.
I've tried it and it does seem to work well despite being non-purist.
Monitoring and auditioning/tuning the de-clicking process on un RIAA-EQ'd material is painful.

What I've explored in addition to the flat preamp is a device that smooths the workflow of recording, de-clicking and auditioning the result.
That's where I'm headed with my project...

On another note I suspect that one of the reasons vinyl can and often sounds better despite it's restrictions is that the material is more carefully processed and un-clipped than the modern loudness war casualties that are pressed onto CD.
That's not the ME's fault, the culprit is more likely the label and "competitive pressure."

Re: Phono Preamps

Posted: Mon Dec 22, 2014 2:44 pm
by JR.
FWIW I had customers of my P-10 kit back in the early '80s tell me they were using them as flat gain stages in front of the stand alone de-clickers sold back then.Then they returned to apply the RIAA after the impulse NR. So not a new concept, but surely made better by digital technology.