MikeC's Audio Craft: An Introduction

Chat room for MikeC's Audio Craft, music & sound reproduction, streaming, audio PC, etc.
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MikeC
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MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 06, 2015 12:50 pm


Linnaeus Tripe
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Re: MikeC's Audio Craft: An Introduction

Post by Linnaeus Tripe » Sun Dec 06, 2015 1:30 pm

Thanks, Mike. That turntable is lovely, but 19kg - wow!
I look forward to the next article.

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Re: MikeC's Audio Craft: An Introduction

Post by LostHighway » Sun Dec 06, 2015 2:11 pm

Very nice work Mike!

For those in community without much background in analogue audio it presents some very difficult engineering problems. On one hand great rigidity is required between the bearing/platter through to the pivot point(s) of the arm and on to the cartridge mount but since records aren't perfectly flat the arm has to be able to move in at least two dimensions while not introducing play at the bearing(s). The entire turntable/tonearm/cartridge assembly has to either not store energy and/or not be easily excited so attempts are made to either attempt to emulate zero mass (more prevalent in English turntables, see Rega skeletal RP8 or RP 10) or infinite mass (more prevalent in US, Australian and German designs - there are several turntables that with their stands weigh over 500lbs/227 Kg).

There are basically three drive systems in common usage:
belt: hopefully self explanatory, flat rubber belts are generally used but Kevlar or silk threads have also been employed
direct drive: the motor is directly coupled to the platter
idler drive: popular in the late '50/60s through early '70s, then very out of fashion, now popular again. Mike's Lenco is an idler, a rubber or composite wheel drives the inside rim of the platter.

PS Although I haven't been in about 15 years I love Singapore's cultural mash-up although I don't like the get-rid-of-anything-more-then-a-decade-old ambiance or the strict state control. In many ways I think Singapore looks more like the near future than just about any other city on the planet.

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Re: MikeC's Audio Craft: An Introduction

Post by Silent but deadly » Sun Dec 06, 2015 3:18 pm

As someone with only a minimal interest in audio (but growing, due to SPCR), I have to say that was a very enjoyable read and I hope there's more to come. The BBBL looks fantastic... sleek but with character. Where as the tonearm looks like something straight from NASA's labs or a piece of Ralph McQuarrie concept art. The juxtaposition between the two elements is really beautiful.
LostHighway wrote: In many ways I think Singapore looks more like the near future than just about any other city on the planet.
Singapore looks like Blade Runner's Los Angeles only with more lights and less dirt. I'd love to visit some day, not least because I love the way Formula 1 cars look under the lights.

As someone with no background of analogue audio, thanks for the added insight.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 06, 2015 5:07 pm

Thanks for the comments, gents, glad to see the piece tickled a few of you. And for that succinct summary of the challenges for a turntable, LostHighway. 8)

The BBBL really looks -- and feels -- even better in person -- something about beeswax on tight grained wood makes it feel so smooth and silky. Lots of comparisons come to mind, mostly involving young skin. :wink:

Singapore as I knew it for those couple of years in my childhood is gone forever. Probably true for most cities in the world if you go back 50 years. I cherish my memories of the place, but I haven't liked it in any revisit going back as far as the early '80s. Way too uptight and pecuniary!

Bangkok is where we went next. It's there that I got into guitars & rock, tape decks, and my first transmission line speakers. Bangkok was grimy chaos in comparison to Singapore, but it was home for upwards of 15 years. I'm still fond of the place and retain many friends there.

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Re: MikeC's Audio Craft: An Introduction

Post by SometimesWarrior » Mon Dec 07, 2015 1:38 am

Thanks for sharing, MikeC--that's a lovely-looking piece of equipment. I've wondered for many years whether I'd get to read some proper articles about your background in audio! I'm eager to read more.

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Re: MikeC's Audio Craft: An Introduction

Post by LostHighway » Mon Dec 07, 2015 6:49 am

MikeC wrote: And for that succinct summary of the challenges for a turntable, LostHighway.
After I posted I wan't particularly happy with my too succinct summary but rather than try to roll out a longer and more complete explanation i thought I'd link to this short video which is only partially about vinyl records. I don't know that it really explains much more but the geek quotient is high:
https://www.youtube.com/watch?v=GuCdsyCWmt8

My apologies for sending people off site, however briefly. I know some forums are extremely touchy about such things and I'm new enough here not to be fully aware of what counts as a major faux pas.

The key is that records are all about retrieving information from very tiny mechanical vibrations so either losing energy/vibration through a mechanically lossy link or adding external vibration/energy (or simply time delaying part of the inherent vibration) creates major headaches. On one hand it is so crude that it is amazing that it works as well as it does but the other hand the technical barriers to get from say 90% "correct retrieval" to 99.5% are formidable and have created a wide range of interesting engineering and materials science solutions. Those interested in looking at some of these should visit the VinylEngine (after thoroughly perusing SPCR, of course). Done right the detail/fidelity/information that can retrieved from this crazy system is amazing.

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Re: MikeC's Audio Craft: An Introduction

Post by CA_Steve » Mon Dec 07, 2015 7:49 am

Very pretty.

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Re: MikeC's Audio Craft: An Introduction

Post by NeilBlanchard » Mon Dec 07, 2015 12:25 pm

Hi Mike,

Looks pretty sweet - the modified Rega arm in particular. I have not heard of the Lenco, nor an idler wheel drive on a serious turntable. Is the motor AC?

I am curious about the platter and the main bearing.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Mon Dec 07, 2015 12:36 pm

NeilBlanchard wrote:Hi Mike,

Looks pretty sweet - the modified Rega arm in particular. I have not heard of the Lenco, nor an idler wheel drive on a serious turntable. Is the motor AC?

I am curious about the platter and the main bearing.
tonearm: Audiomods http://www.audiomods.co.uk/

Lenco: http://www.lencoheaven.net/forum/index.php?topic=13.0
http://www.ptpaudio.com/
http://www.idler-wheel-drive.com/home/

Unlike all other idler wheel drive turntables, the Lenco's idler wheel presses against the underside of the platter, not its rim. This is a pretty significant difference.

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Re: MikeC's Audio Craft: An Introduction

Post by Quinnbeast » Mon Dec 07, 2015 12:39 pm

I don't quite have enough time to digest all of this fully just now, but - wow. That's a work of art Mike. The finish of that 'plywood' is really something & I'll be re-reading this later on. Just out of interest, have you experimented much (or at all) with DIY speaker cabinets? I don't have the workshop (or skillset) for it personally, but it's an idea tumbles around in the back of my little noggin' from time to time.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Mon Dec 07, 2015 1:56 pm

Quinnbeast wrote:I don't quite have enough time to digest all of this fully just now, but - wow. That's a work of art Mike. The finish of that 'plywood' is really something & I'll be re-reading this later on. Just out of interest, have you experimented much (or at all) with DIY speaker cabinets? I don't have the workshop (or skillset) for it personally, but it's an idea tumbles around in the back of my little noggin' from time to time.
Yes. I've built perhaps 30 pairs of speaker systems in total, some of them extremely ambitious and large, some super simple and small. Most not documented or photographed, unfortunately. My building material of choice is Baltic Birch ply. #2 is medite board, but it's a distant second.

I've also got hold of some 3/8" Aerolam -- boards of aluminum honeycomb sandwiched between fiberglass sheets. It is used for paneling, including flooring, on passenger planes. Super strong, stiff, light. I'm planning to bond thin BB ply sheeting on both sides, then cut and use it as baffle boards for speakers and in turntable plinths.

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Re: MikeC's Audio Craft: An Introduction

Post by NeilBlanchard » Tue Dec 08, 2015 6:52 am

MikeC wrote:Unlike all other idler wheel drive turntables, the Lenco's idler wheel presses against the underside of the platter, not its rim. This is a pretty significant difference.
I see that, and I am curious how this is advantageous. A rim drive idler is concentric, and would seem to be lower friction. The Lenco idler wheel seems like it would have some scrub, since it is "turning" all the time.

What is the platter main bearing? Is the platter stock?

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Tue Dec 08, 2015 9:45 am

NeilBlanchard wrote:
MikeC wrote:Unlike all other idler wheel drive turntables, the Lenco's idler wheel presses against the underside of the platter, not its rim. This is a pretty significant difference.
I see that, and I am curious how this is advantageous. A rim drive idler is concentric, and would seem to be lower friction. The Lenco idler wheel seems like it would have some scrub, since it is "turning" all the time.

What is the platter main bearing? Is the platter stock?
"Concentric"...? It is a round wheel with a rubber rim -- same as any idler wheel drive TT. They all have to spin all the time, and they all needed a certain amount of friction against the platter to keep it going.

Lenco motor's vibration is at 90 degree angle to platter rotation, unlike others, which are on same plane. The rim idler drives pull to that side, with resulting imbalance wear on the main bearing over time. And if there's any fluctuation in speed, or even momentary slippage, this causes sideward force in the platter. In the Lenco, there can be no movement along the plane of the spinning LP.

The platter is unmodified except for polishing and spraying another layer of lacquer on the top and rim to protect it -- dynamically balanced, about 8 lbs. Some mix of steel, zinc, etc, non-magnetic. Cast & then machined. Main bearing is a shaft 9mm diameter that rides on a steel ball in an oil-filled 2" deep housing made of... brass? with a steel flange for bolting to the top plate of the turntable. The hole in the center of the platter makes a friction fit with the shaft, which is tapered up to record-hole size. It's a very tight fit.

Not surprisingly, Jean Natais explains the Lenco very well: http://www.idler-wheel-drive.com/scienc ... ve-system/ Well worth a read.

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Re: MikeC's Audio Craft: An Introduction

Post by CA_Steve » Tue Dec 08, 2015 4:25 pm

Hey, the sound's getting low. Better put another log amp in the fireplace. :D

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Re: MikeC's Audio Craft: An Introduction

Post by HammerSandwich » Wed Dec 09, 2015 6:56 pm

Forgot to ask about this earlier...
MikeC wrote:Of course, when I play LPs, now, I run the analog preamp's output into an ADC (a Tascam UH7000), feed it via USB to the PC, which then processes it like any other digital source.
Are you doing RIAA EQ on the PC or digitizing after analog EQ?

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Wed Dec 09, 2015 8:40 pm

HammerSandwich wrote:Are you doing RIAA EQ on the PC or digitizing after analog EQ?
I use a Linn Kairn preamp which has both MM and MC inputs w/ RIAA, of course. It's an excellent preamp. Main preamp with volume at ~70% out to Tascam UH7000, connected to PC via USB. Not the most elegant solution. Have to look into running it straight into the Asus Zen but not sure if the gain will be enough (and residual noise low enough) & how to implement RIAA eq digitally.

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Re: MikeC's Audio Craft: An Introduction

Post by edh » Thu Dec 10, 2015 9:54 am

While I can't say I'd tell the difference with ultra high end audio like this it definitely all looks nice.

Reminds me of an old hifi we have in the family which has a custom wooden enclosure for a mono record deck and a mighty 10W valve amp. Kind of looking for a new home for it right now as it happens!

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Re: MikeC's Audio Craft: An Introduction

Post by LostHighway » Thu Dec 10, 2015 1:58 pm

edh wrote:While I can't say I'd tell the difference with ultra high end audio like this it definitely all looks nice.

Reminds me of an old hifi we have in the family which has a custom wooden enclosure for a mono record deck and a mighty 10W valve amp. Kind of looking for a new home for it right now as it happens!
There are people who either restore old consoles or stuff new components into them, so depending on condition and style ('50s/'60s retro modern tends to be the most sought after right now), you might not have any trouble finding a willing buyer. There are people that have a whole mono system for their mono LPs (and possibly 78s) but that is a much rarer beast.

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Re: MikeC's Audio Craft: An Introduction

Post by NeilBlanchard » Fri Dec 11, 2015 5:43 am

Concentric is maybe the wrong term - the axis of the idler is perpendicular to the platter axis. Typical idler wheels have all the rotational axes parallel.

This thread is bringing back all sorts of memories - I will have to pull out my copies of the HiFi Heretic.

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Re: MikeC's Audio Craft: An Introduction

Post by derekva » Sun Dec 13, 2015 11:24 am

I'm with total agreement with you on the Audiomods tonearm - I built mine in May. I'd been following Jeff's work when it was still just a DIY project and got to see the evolution to the current Series 5 arms. This is one of the best bang-for-your-buck components in audio and will embarrass many pricier tonearms. If you are still auditioning cartridges, may I suggest that when properly weighted at the headshell, a Denon DL-103r works very, very well with the Audiomods.

I am curious as to what you are using for a platter, BTW. Any information on make / price?

Thank you,

-D

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 13, 2015 12:01 pm

derekva wrote:I'm with total agreement with you on the Audiomods tonearm - I built mine in May. I'd been following Jeff's work when it was still just a DIY project and got to see the evolution to the current Series 5 arms. This is one of the best bang-for-your-buck components in audio and will embarrass many pricier tonearms. If you are still auditioning cartridges, may I suggest that when properly weighted at the headshell, a Denon DL-103r works very, very well with the Audiomods.

I am curious as to what you are using for a platter, BTW. Any information on make / price?

Thank you,

-D
Experimenting with cartridges... I might at some point, but the Linn Adikt is working fine for me right now. I'd prefer an elliptical or line-contact stylus, which the Denon 103s don't offer -- wonder why?

By platter, I presume you mean the mat? It is a transfi Resomat -- http://www.trans-fi.com/resomat.htm I quite like it, seems to give a very balanced, detailed sound -- audible better than the rubber mats native to the Lencos. from the maker:
Enter the Reso-Mat. The idea with this mat is to have absolutely no influence on the record. It sits on cones with minimal contact with no clamping. Vibrations from the stylus are free to dissipate in the open air with no reflections. There is nothing to dampen the record either.

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Re: MikeC's Audio Craft: An Introduction

Post by derekva » Sun Dec 13, 2015 1:03 pm

MikeC wrote:
derekva wrote:I'm with total agreement with you on the Audiomods tonearm - I built mine in May. I'd been following Jeff's work when it was still just a DIY project and got to see the evolution to the current Series 5 arms. This is one of the best bang-for-your-buck components in audio and will embarrass many pricier tonearms. If you are still auditioning cartridges, may I suggest that when properly weighted at the headshell, a Denon DL-103r works very, very well with the Audiomods.

I am curious as to what you are using for a platter, BTW. Any information on make / price?

Thank you,

-D
Experimenting with cartridges... I might at some point, but the Linn Adikt is working fine for me right now. I'd prefer an elliptical or line-contact stylus, which the Denon 103s don't offer -- wonder why?

By platter, I presume you mean the mat? It is a transfi Resomat -- http://www.trans-fi.com/resomat.htm I quite like it, seems to give a very balanced, detailed sound -- audible better than the rubber mats native to the Lencos. from the maker:
Enter the Reso-Mat. The idea with this mat is to have absolutely no influence on the record. It sits on cones with minimal contact with no clamping. Vibrations from the stylus are free to dissipate in the open air with no reflections. There is nothing to dampen the record either.
Hmmm...I didn't see that quote before in the article. Thanks for the link (and yes, I meant platter mat).

If you want an elliptical Denon, the Denon DL-301 MKII cartridge is a LOMC with an elliptical tip. It's a pretty different beast from the DL-103R (it's high-compliance rather than low-compliance which means it wants a lighter arm - but if you back off the counterweight and don't add mass to the headshell, it ought to work pretty well with the Audiomods).

The DL-103 line is a descendant of their original broadcast cartridge from the 1960s. The DL-103 is more-or-less identical, while the DL-103R uses better coils, magnets and damping. There is a version of the DL-103 that's as rare as hens' teeth called the DL-103M that uses a hyper-eliptical stylus and boron cantilever. I have two DL-103R cartridges right now (primary and backup). When I finally wear the primary out, I'll get it retipped with a Shibata (since the other bits of cartridge are very well made). The one nice thing about a conical stylus is that your setup doesn't have to be as precise as with a fine-line or elliptical stylus as conical stylii are fairly insensitive to VTA being off - they'll still sound good.

Another to look at might be the Shelter 501 MK III, but that's easily 3x the cost of the Denon. Whatever you decide upon, I'm sure it'll sound fantastic!

-D

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 13, 2015 1:46 pm

Even though I like restoring & building TTs, I just don't listen to LPs enough to make it worthwhile to invest lots of $ in cartridges. I've had Supex 900, Linn Akasa etc in the past, and I'd consider a naked Denon 103R glued to an aluminum L-shaped piece that I think I could make easily enough... but there's lots of other things to play with to improve my system.

Also designing & building a new TT from Thorens 150 parts -- retaining just the motor, belt, main bearing & platter. Baltic Birch + Aerolam + BB sandwich for plinth, motor on separate part of plinth, whole plinth suspended on squash balls or composite elastomer feet. Tonearm pivot & motor on opposite sides. Probably electronic speed control.

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Re: MikeC's Audio Craft: An Introduction

Post by NeilBlanchard » Sun Dec 13, 2015 7:33 pm

I like my Dynavector 10X5 cartridge. I am not up on these anymore, but it is an elliptical stylus.

Works well with my Audible Illusions Modulus 2C - which is my favorite piece of my current stereo. I recently retubed it with excellent 6922's. The challenge with the Modulus is to get robust tubes with ultra-low microphonics. Almost all 6DJ8 tubes, even those from high quality manufacturers can work, without issues. But, when they are quiet - oh the music is amazing.

I am also enamored of the Lineaum tweeter. I have yet to hear them get anything wrong. They have power but are never shrill, and certainly not beamy. Natural and easy, but clear and clean as any I have heard.

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Re: MikeC's Audio Craft: An Introduction

Post by mdrumt » Tue Dec 15, 2015 1:40 pm

Cool article! I myself would love to see more audio articles and reviews! As a recording musician silent PC's and audio do go hand in hand! I am also currently in the process of building a home hifi/htpc setup using a PC as the "source". Perhaps an article with how best build an audiophile pc would be in order? :)

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Tue Dec 15, 2015 4:24 pm

mdrumt wrote:Cool article! I myself would love to see more audio articles and reviews! As a recording musician silent PC's and audio do go hand in hand! I am also currently in the process of building a home hifi/htpc setup using a PC as the "source". Perhaps an article with how best build an audiophile pc would be in order? :)
I've considered that, but you know there are some other pretty well established resources for an audiophile pc.

Like...

http://www.computeraudiophile.com/section/c-p-s-489/

-- Although I have to say the over-the-top obsessive-compulsive concerns about USB power cleanliness & linear PSUs give me a headache. My solutions for those: Use SPDIF, esp optical which has ZERO potential for noise, and choose a PSU rated for the lowest noise/ripple. The "real" audiophiles will claim this is nonsense, that a $350 upgrade to isolate and clean the USB power is a necessity, as is a linear 50% efficient $400 PSU. I differentiate myself by saying I love music & tinkering with gear but I am no audiophile.

I suppose I will have to try a linear PSU and compare it to a good standard ATX switching PSU one day, but it's not a project that is very compelling to me... as I have serious doubts about any audible differences. I still remain open to the idea that I could be wrong here since I haven't really compared.

(PS -- I have no doubt that people who can tell differences between AC cables have hearing acuity an order of magnitude than mine. I'm so glad; I don't have to spend all that $ or obsess over yet something else!)

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Re: MikeC's Audio Craft: An Introduction

Post by cyberspyder » Fri Dec 18, 2015 10:20 pm

Hey Mike, if you ever redo the baltic birch plinth, when laminating the layers, turn each layer perpendicular to each other. This way, you can avoid the dreaded double thickness layer at the glue joint.

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Re: MikeC's Audio Craft: An Introduction

Post by smilingcrow » Sat Dec 19, 2015 9:36 am

MikeC wrote:Also designing & building a new TT from Thorens 150 parts -- retaining just the motor, belt, main bearing & platter.
That name takes me back to my Thorens TD 160 BC if I recall the full name correctly. Sold it when I sold my vinyl collection around 96. I bet some of my close to mint 70s Fusion LPs fetch a pretty penny nowadays and a lot of it was sampled extensively in the interim period.
Don't miss vinyl and interesting to see my 24 year old nephew is now a fan.
Like the project Mike from an aesthetic point.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sat Dec 19, 2015 9:52 am

cyberspyder wrote:Hey Mike, if you ever redo the baltic birch plinth, when laminating the layers, turn each layer perpendicular to each other. This way, you can avoid the dreaded double thickness layer at the glue joint.
"dreaded"?? :?: :!: :lol: I considered this but cutting up the plywood sheet was much simpler & seemingly more efficient not worrying about it, so I didn't. No one has commented on this till now. Everyone just likes the way it looks fine, so.... And I doubt very much that there's any sonic difference.

You'll like what I did with the next one. ;)

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