DL103SA VS. SL1200: How I won the battle and lived happy (for a while)
Hello chaps,
time to spend my 2 cent of the wisdom I reached fighting hard when I had to fit my Denon DL 103 SA to the stock tonearm of my Technics SL 1210 M5G.
Well, now sit down, get a cup of tea or coffee, or a pint of beer, and relax. I'm telling the long story... long.
Introduction
I read of many people simply sticking a DL 103 into their tonearm and then crying the DL 103 is a very bad cartridge. Aware of that, I invested many hours of searching, reading, asking, trying and retrying, during the last 6 months, to be sure to have the best from this piece of Hi-Fi history.
And now I'm sharing with you exactly the whole path of my journey.
Of course what follows is not a new Gospel, but just the whole story of *my* starting point, *my* route, *my* arrival point.
My only wish: I hope this will be useful to someone else, maybe as a new starting point.
I had to keep the theory very simple, so don't complain. But if any of you find something wrong or not completely correct, please let me now, so I can amend it.
Section 1: The Theory
1. Some theory about resonance
Every solid body in nature has its own resonance frequency. So, if a body 'A' is in a quiet state and a body 'B' is vibrating at level of the resonance frequency of 'A', well, 'A' starts vibrating by itself.
The record we are playing outputs a wide range of frequencies, starting from the very low frequencies produced by the wobbling at the vinyl surface, up to the higher ones contained into the musical signal. Because of this, we have to take care about the correct set-up of cartridge+tonearm system, or else our system could start adding unwanted sounds to our music.
The good news is that we can play around to tune the resonance frequency of our cartridge+tonearm system to fit it into a (tight) range of frequencies that will not be disturbed by any "active" signal coming out the vinyl surface or music .
(Complete and scientific infos about resonance here: http://en.wikipedia.org/wiki/Resonance)
Such range of frequencies is: from 8 Hz to 12 Hz
Some people say we can start from 7 Hz, other say we can go up to 15Hz.
Well, the truth is in the meddle, so we stick between 8 and 12.
2. Some theory about Dynamic Compliance
With Dymanic Compliance of a cartridge we talk about the ability, of the cartridge itself, to absorb the very low frequencies produced by a warped or not centered vinyl, without trasferring them to the tonearm. "Dynamic" states that the measure was get with the cartridge playing a record.
A low compliance cartridge *must* match a meddle/high mass tonearm, which has the ability to absorb such low frequencies instead of the cartridge.
All the cartridges of DL 103 series are low compliance and the stock tonearm of SL 1200 is a medium mass. That's way is a good "marriage".
(sorry guys, no good reference about this. If someone has, please let me know)
3. Some math about resonance
First, lets fix this 3 points:
* "Weight" is not the same as "Mass", but...
* SL 1200's tonearm Mass = 12 gr including the stock headshell
* Denon DL 103 dynamic compliance = 5x10-6 cm/dyne @100 Hz
Then some convention:
'W' = Weight
'M' = Mass
'C' = dynamic Compliance at 10 Hz
'FR' = Frequency of Resonance
'BTM' = Bare Tonearm Mass
We cannot directly modify the tonearm mass, but we have the chance of doing it with the cartridge+headshell sub-system.
Anyway, before to start buying (or building) stuff like new headshells, spacers, bolts or whatever, better to predict the resulting FR with some calculations.
There's a simple formula to calculate the FR of a cartridge+tonearm system:
FR = 1000/(6.28 * SQRT( M * C))
where SQRT() = square root
This is the formula Vinylengine uses to calculate the FR with its online calculator.
Easy? well, actually not.
A. "Weight" is not the same as "Mass", but...
Mass is the weight of a moving body. If the SL 1200 tonearm has a Mass=12 gr and the cartridge has a Weight= 9.7 GR, that means that... you couldn't just add cartridge W the tonearm M to have a new, total M.
"But..."
But we'll do anyway, since we cannot do otherwise.
This is an important point. I read around a lot of people fighting about this, but the formula above still produces a useful value, even though is not 100% correct.
(Complete and scientific infos about 'Mass' here: http://en.wikipedia.org/wiki/Mass)
Now lets talk about our items.
B. SL 1200's tonearm Mass = 12 gr including the stock headshell
This is another important point. I read some people believing that the mass of removable headshell tonearm refers to the bare tonearm only. That's no true. Our tonearm with M=12 GR includes the headshell.
C. Denon DL 103 dynamic compliance = 5x10-6 cm/dyne @100 Hz
This is the last and most frequent error around (Vinylengine does it too, even if actually warns you about)
We do need the Compliance value at 10 Hz, not at 100 Hz.
But there is a way out. I learned a very complex formula to translate the 100 Hz down to 10 Hz but we don't need it.
Simply we can multiply the 100 Hz value with the costant 1.8, and we'll get what we need, and this is true for every brand or model of cartridge.
Anyway the right value for this costant, for the DL103SA, is 1.75, but this doesn't actually affects the final result.
Now time is come to apply the above theory.
4.The math practice
To full understand the formula
FR = 1000/(6.28 * SQRT( M * C))
we'll do some real life example.
Our HW with their relevant attributes
1. Stock tonearm, M=12 GR (including headshell)
2. Stock headshell, W=7.5 GR
4. New headshell, W=12 GR
5. Nuts & Bolts, W=2 GR
5. Spare weight, W=4 GR
6. Cartridge, W=10 GR, C= 5@100Hz
Our goal is to calculate the FR of each combination of headshell/cartridge with or without the spare weight
First calculate the C @ 10 Hz: 5 * 1.8 = C = 9
Then calculate the the BTM, subtracting W of the Stock Headshell = 12 - 7.5 = BTM = 4.5 (again, this is not teorically correct, but is still useful)
So:
Assembly 1:
BTM + Stock Headshell + Nuts&Bolts + Cartridge: M = 24
FR = 1000/(6.28 * SQRT( 24 * 9)) = 11 (exactly 10,834)
Assembly 2:
BTM + Stock Headshell + Nuts&Bolts + Cartridge + Spare Weight: M = 28
FR = 1000/(6.28 * SQRT( 28 * 9)) = 10 (exactly 10,03) )
Assembly 3:
BTM + New Headshell + Nuts&Bolts + Cartridge: M = 28,5
FR = 1000/(6.28 * SQRT( 32,5 * 9)) = 10 (exactly 9,942)
Assembly 4:
BTM + New Headshell + Nuts&Bolts + Cartridge + Spare Weight: M = 32,5
FR = 1000/(6.28 * SQRT( 32,5 * 9)) = 9 (exactly 9,310)
We've done.
You can download here my very simple Excel spreadsheet to do some calculations by yourself:
FR_Calculator
Ok, but are these calculations are correct? And more important, are they useful. We discuss about this later.
Section 2: The DIY Practice
1. Staring points
Now is the time to choose which of the above Assembly is the best sounding one.
But first let's think a little:
* All the 4 Assembly outputs a FR falling into the range 8-12 (Assembly 2 & 3 are equivalent).
* Theorycally speaking the lighter Assembly impresses a lower "Momentum" to the tonearm, so should be preferred.(1)
* There is a wide shared opinion around stating the DL 103 needs an high mass toneram to perform at its best.
(1) I'm not bothering you with more theory, but the "momentum" and the "inertia" of the resulting cartridge+tonearm system is an important stuff.
More weight we add at cartridge, more and more we have to add at the tonearm end. And that's no good since the cantilver of the cartridge (the thin rod where the stylus is fixed in) trying to move the tonearm, starts to fold itself.
So:
* Assembly 1 is mathetically the best,
* the 3 should be the suggested one for the DL 103 SA,
* the 2/3 ... could be the right ones choice, philosophically speaking, since they are in the middle :-).
Let's do this way: let's try all of the options we have. Or we'll live forever in doubt (we are hi-fi lovers, and as such we hate doubts)
2. The Headshells
First, my own, straight, plain, honest, opinion about headshells
* I don't believe that the material of the headshell does any difference in sound.
So we are not going to state that an aluminium headshell (tha stock one) is worst than a magnesium headshell.
Other parameters make the difference: the weight, the wires, the quality of bajonet contact, the ability of tuning the azimuth.
I will not talk about the SL 1200 Headshell, since each and everyone of you knows it very well.
I have a vintage Nagaoka MG-704 headshell :
http://www.boxedspace.com/public3/DL...ka_01_Body.JPGHTTP://www.boxedspace.com/public3/DL...a_02_Wires.JPG
HTTP://www.boxedspace.com/public3/DL...Fingerlift.JPG
It's wonderfully well made:
* Magnesium's body
* Cu99.99% Litz wires
* adjustable Azimuth
* thick golden contact at bajonet
It's vintage one and we cannot find it anymore, but the good news is the the Sumiko HS-12 is about the same.
We can get the Sumiko HS-12 Headshell from Analogue Seduction online store:
http://www.analogueseduction.net/pro...adshell_SUM-HS
3. Some DIY: the Spacers
Everybody knows the DL 103 cartridge series have a lower profile than the minimum accepted by VTA regulator of the SL 1200
Infact the DL 103 is 15 mm high, and the SL 1200's VTA start working from a 17 mm. But just believe me, 2 mm more is not enough.
So we need a spacer.
We could buy a spacer, but we don't.
The idea behind this is: we need a very light spacer, because we need the basic Assemblies to be very light, or else we cannot add weight and see what happens
Just grab a piece of acrylic:
HTTP://www.boxedspace.com/public3/DL...01_Acrylic.JPG
The above was as divider of a small container case for screws. It was about 1.6 mm thick, and very easy to work with.
Acrycilc is amagnetic (...of course) and is a good vibrations' absorber.
I made 2 spacer:
HTTP://www.boxedspace.com/public3/DL...ers_02_WIP.JPG
I used a cutter to cut them and a Dremel drill to do the holes. Finally, I used some 300 grit sandpaper to smooth the surfaces.
I used the DL 103 SA as footprint, so the final size of the spacers is 2.3 x 1.6 x 3.4 mm.
To obtain the 3.4 mm height I simply glued togheter 2 piece of acrycilic, with some cyanacrylic glue.
I made 2, one plain and one with a fingerlift
The final weight is very light:
HTTP://www.boxedspace.com/public3/DL...s_03_Plain.JPGHTTP://www.boxedspace.com/public3/DL...ngerlift34.JPG
Actually the spacer with the fingerlift I finally used is 5.5 mm thick:
HTTP://www.boxedspace.com/public3/DL...ngerlift55.JPG
4. Some DIY: the Counter-weight
Now with have to deal with a secondary but still important issue: the tonearm additional counterweight.
All the Assembly are too heavy for the basic, rotative, counterweight only, so:
* for Assembly 1, just use the stock additional counter-weight of 10 GR
* for the Assembly 2/3 we need a counterweight of about 31 - 33 GR
* for the Assembly 4 we need a counterweight of about 36 - 38 GR
Were do we get this additional counterweights? Simple, we just do them by ourself
This is a very easy task, just buy a bolt with 4 mm diameter and 2.5 mm lenght and some big and heavy washers
Optionally you can use a nut to fix the assembly.
I made mine with
* brass bolt & nut
* amagnetic steel big washers
* small nylon washers & heat shrink for vibrations dumping
HTTP://www.boxedspace.com/public3/DL...rWeight_01.JPGHTTP://www.boxedspace.com/public3/DL...rWeight_02.JPG
HTTP://www.boxedspace.com/public3/DL...rWeight_03.JPGHTTP://www.boxedspace.com/public3/DL...rWeight_04.JPG
HTTP://www.boxedspace.com/public3/DL...rWeight_05.JPGHTTP://www.boxedspace.com/public3/DL...rWeight_06.JPG
Important thing to remember is the final weight:
* for the assemblies 2 and 3 it should be around 31 - 33 GR
* for the assembly 4 it should be around 36 - 38 GR
HTTP://www.boxedspace.com/public3/DL...rWeight_07.JPG
In place (not bad, isn't it?):
HTTP://www.boxedspace.com/public3/DL...rWeight_08.JPG
As final thought, I have to say the this solution is not to be considered optimal. If we don't plain to swap very often the cartridge/headshell Assemblies (because we have more cartridges), is better we get a serious counterweight, just like the ones made by Speedy Steve.
http://theartofsound.net/forum/showthread.php?t=6216
5. Bolts & Nuts
"Ommygod, Bolts & Nuts drive me nuts". This was the worst part of the game. Why in the hell Denon doesn't ships longer bolts with the DL 103 ???
Let's do some calculations:
* the Nagaoka Headeshell (and the Sumiko, too) thickness= 2 mm.
* the stock fingerlift thickness= 1.5 mm (Sumiko should be 2 mm)
* the spacer thickness= 3.4 mm
* DL103SA passing holes lenght= 8 mm
* upper washers for bolts= .5 mm (about)
* bolts height: 1,5
Total is 17 mm
So we need a bolts of 18 mm minimum !
After a long time wasted trying to find bolts like that, finally I get here, at Transfiaudio ebay store:
http://shop.ebay.co.uk/transfiaudio/...1&_from=&_ipg=
He offers two kits, one standard and one with lighter bolts. I got both and used the lighter.
Anyway, since my personal need was a spacer of 5.5 mm, I used the 20 mm bolts.
HTTP://www.boxedspace.com/public3/DL...ltsNuts_01.JPG
6. Headshell weight
Well this was the easier.
We have more options:
* using the stock SL1200 headshell weight of 3 GR
* DIY with some metallic
* glueing togheter a couple of pennies or dollarcents or eurocents (1 eurocent W=2.2 GR)
* buying it
We'll fix our weight to the headshell with some blu-tac or double-sided tape.
By my test the optimal headshell weight is 4 or 5 GR. No less, no more.
Once in my life I've been lucky. I have a spacer of 4.2 GR (I quite don't remember were it comes from)
I covered it with some black tape and fixed to the headshell with some double-sided tape:
HTTP://www.boxedspace.com/public3/DL...lWeight_01.JPG
Why I simply didn't use the headshell weight as spacer?
Well, I wanted to deeply understand the differences in sound with and without the additionl 4 GR, without redoing the Assembly each time.
But if you trust my results, you can use the additional cartridge weight as a spacer, it's an optiomal thing.
7. All togheter, now
Let's assemble.
I'm not showing any picture of Assembly 1 & 2, since I didn't take any picture.
-
Her Majesty, the Denon DL 103 SA
HTTP://www.boxedspace.com/public3/DL...DL103SA_01.JPG
The Assembly 3
HTTP://www.boxedspace.com/public3/DL..._Assembly3.JPG
The Assembly 4
HTTP://www.boxedspace.com/public3/DL..._Assembly4.JPG
Section 3: The Sound
1.Comparing the Assemblies
What? load of words about boring work and so little about the funny sound?
Well, that's the way it is. I'm not wasting time telling you a tale you can read everywhere.
* Assembly 1: Stock toneram + Stock Headshell + Cartridge, no headshell weight, Mass = 24, Calculated FR= 11
Let's forget about. Were is the sound? Flat basses, weak meddles e very far trebles. Soundstage is... well is not.
* Assembly 2: Stock toneram + Stock Headshell + Cartridge + Headshell weight, Mass = 28, Calculated FR= 10
Much better. But still this is not the sound I expected from DL103SA.
* Assembly 3: Stock toneram + Nagaoka Headshell + Cartridge, no headshell weight, Mass = 28.5, Calculated FR= 10
I heard this sound before. It's the same of assembly 4. Not exactly, there's a (very very) slight improvement on meddle frequencies and a more clean soundstage. Ah, the Nagaoka has much better wires. That's should be the reason.
* Assembly 4, Stock toneram + Nagaoka Headshell + Cartridge + Headshell weight, Mass = 32.5, Calculated FR= 9
Just one word: W-O-W !!!
(so far, this is best sounding thing I heard in my life)
Section 4: Measures
Finished? No, not yet.
We have still to verify if the calculated FR is correct, since we understood very well one fact:
assembling a cartridge+headshell+tonearm system *IS NOT* a simple mathematical affair.
Too many variables out out of our control:
* we had to sum Mass and Weight
* we had to do lots of roundings
And again: what if we didn't know *at all* the C of the Cartridge or the M of tonearm?
But to measure the FR we need same expensive equipment...
We are lucky, since exists this wonderful tool:
http://www.thecartridgeman.com/hfn_test_record.htm
This record can help us in tuning the Azimuth, the Bias, verify the tracking ability and...
measure the FR, too !!!
So, let's measure the FR of our candidate Assembly 4.
We have two tracks on the record:
* one producing the odd frequencies from 25 to 5 Hz, through lateral oscillations of the groove
* one producing the even frequencies from 16 to 6 Hz, through vertical oscillations of the groove.
Funny thing is that you can see very clearly, with your own eyes, how the cantilever woobles, and at same time hear the distortion of the sound.
The applied VTF was = 2.6 GR
Our Assembly 3 (calculated FR=10):
with the odd track
* start wobbling at 11 Hz
* stop wobbling at 9 Hz
(at 7 hz was completely quiet)
with the even track
* wobbles very bad at 10 Hz
Our Assembly 4 (calculated FR=9):
with the odd track
* wobbles very bad at 9 Hz
with the even track
* wobbles just a little at 10 Hz
What the meaning of the above results?
Well, the meaning is:
Assembly 3 has a FR somewhere between 9 and 11 Hz, with a peak at 10 Hz
Assembly 4 has a FR somewhere between 9 and 10 Hz, with a peak more near 9 Hz
So was the calculation accurate?
Yes, it was, completely,
And, since we learned the FR acts in a range of frequencies, we feel better about some approximations we did in our calculations.
That's all, folks, enjoy ;)
