I'm trying to improve the frequency response of my V15III/SME 3009 S2, and 
remember that Shure or SME had a little equaliser circuit that flattened the 
response at the expense of a couple of dBs of output. Something may have 
been published in HFN and/or Wireless World in the '70s, but my HFNs don't 
go back that far, and I can't find it in my WWs of the era.

I've been searching on-line for the circuit all afternoon, and can't find 
anything. It was simply a capacitor and a resistor or two, but I can't 
remember the configuration or values.

Does anyone have this info please?

Thanks

S.


-- 
http://audiopages.googlepages.com

"Serge Auckland"  wrote in message 
news:jbWdnf5Zls8ZknjVnZ2dneKdnZydnZ2d@bt.com...
> I'm trying to improve the frequency response of my V15III/SME 3009 S2, 
> and remember that Shure or SME had a little equaliser circuit that 
> flattened the response at the expense of a couple of dBs of output. 
> Something may have been published in HFN and/or Wireless World in the 
> '70s, but my HFNs don't go back that far, and I can't find it in my 
> WWs of the era.
>
> I've been searching on-line for the circuit all afternoon, and can't 
> find anything. It was simply a capacitor and a resistor or two, but I 
> can't remember the configuration or values.
>
> Does anyone have this info please?
>
> Thanks
>
> S.
>
>
> -- 
> http://audiopages.googlepages.com


Ah, now this is one I do know about - it applied more or less across the 
Shure range.

Shure cartridges were designed to work into a load of 47K resistance 
(like all others) in parallel with something around 360pF capacitance. 
The pickup arm cables and the interconnect to the amp would account for 
about 120-150pF, which leaves the cartridge underloaded and thus rather 
peaky and bright.

The answer - provided you have the skills to do it - is to make up two 
short phono plug-socket link cables perhaps 3-4in long and fit a 220pF 
capacitor inside one of the connectors in each cable. A small ceramic 
capacitor of that sort of value should be no more than about 4mm square 
and will fit quite easily. Remember capacitors are additive in value 
when they are connected in parallel.

Total cost with components from Maplins would be about £5. There used to 
be manufactured units that did the same thing and cost about £30 
apiece - much the same thing with mains spike protectors which cost 
about £5 to make (retail) and sell for £100++, especially those from 
rip-off Russ. You may have to dig a bit to find the capacitors though.


-- 
Woody

harrogate three at ntlworld dot com

Woody wrote:
> "Serge Auckland"  wrote in message 
> news:jbWdnf5Zls8ZknjVnZ2dneKdnZydnZ2d@bt.com...
>> I'm trying to improve the frequency response of my V15III/SME 3009 S2, 
>> and remember that Shure or SME had a little equaliser circuit that 
>> flattened the response at the expense of a couple of dBs of output. 
>> Something may have been published in HFN and/or Wireless World in the 
>> '70s, but my HFNs don't go back that far, and I can't find it in my 
>> WWs of the era.
>>
>> I've been searching on-line for the circuit all afternoon, and can't 
>> find anything. It was simply a capacitor and a resistor or two, but I 
>> can't remember the configuration or values.
>>
>> Does anyone have this info please?
>>
>> Thanks
>>
>> S.
>>
>>
>> -- 
>> http://audiopages.googlepages.com
> 
> 
> Ah, now this is one I do know about - it applied more or less across the 
> Shure range.
> 
> Shure cartridges were designed to work into a load of 47K resistance 
> (like all others) in parallel with something around 360pF capacitance. 
> The pickup arm cables and the interconnect to the amp would account for 
> about 120-150pF, which leaves the cartridge underloaded and thus rather 
> peaky and bright.
> 

The way the impedances work out, you get more peakiness as the load goes 
up, not down. Adding an extra 200pF to the basic cartridge and wires 
will increase the level at 10kHz by about 2.5dB. This is all about the 
way the capacitance resonates with the inductance of the cartridge.

d

"Don Pearce"  wrote in message 
news:pNudnT_Fq78yr3jVnZ2dnUVZ8v-dnZ2d@posted.plusnet...
> Woody wrote:
>> "Serge Auckland"  wrote in message 
>> news:jbWdnf5Zls8ZknjVnZ2dneKdnZydnZ2d@bt.com...
>>> I'm trying to improve the frequency response of my V15III/SME 3009 
>>> S2, and remember that Shure or SME had a little equaliser circuit 
>>> that flattened the response at the expense of a couple of dBs of 
>>> output. Something may have been published in HFN and/or Wireless 
>>> World in the '70s, but my HFNs don't go back that far, and I can't 
>>> find it in my WWs of the era.
>>>
>>> I've been searching on-line for the circuit all afternoon, and can't 
>>> find anything. It was simply a capacitor and a resistor or two, but 
>>> I can't remember the configuration or values.
>>>
>>> Does anyone have this info please?
>>>
>>> Thanks
>>>
>>> S.
>>>
>>>
>>> -- 
>>> http://audiopages.googlepages.com
>>
>>
>> Ah, now this is one I do know about - it applied more or less across 
>> the Shure range.
>>
>> Shure cartridges were designed to work into a load of 47K resistance 
>> (like all others) in parallel with something around 360pF 
>> capacitance. The pickup arm cables and the interconnect to the amp 
>> would account for about 120-150pF, which leaves the cartridge 
>> underloaded and thus rather peaky and bright.
>>
>
> The way the impedances work out, you get more peakiness as the load 
> goes up, not down. Adding an extra 200pF to the basic cartridge and 
> wires will increase the level at 10kHz by about 2.5dB. This is all 
> about the way the capacitance resonates with the inductance of the 
> cartridge.
>
> d


Try it - it's cheap and simple enough. I used a 75EDII with this process 
and it tamed it well.

Maybe one of those occassions where the theory and practice don't match?


-- 
Woody

harrogate three at ntlworld dot com

"Woody"  wrote in message 
news:TKaFk.2067$Cw7.480@newsfe25.ams2...
>
> Maybe one of those occassions where the theory and practice don't match?
>

Theory and practice always match, if it appears otherwise then you've 
misunderstood the theory or there's some other factors involved that you 
weren't aware of. The use of shunt capacitors acroos the replay heads of 
analogue tape machines to boost the HF response was standard practice, often 
these capacitors were switched according to the speed selected with larger 
capacitor values being used on the lower speeds.

David.

"David Looser"  wrote in message 
news:6kktlcF8ft2aU1@mid.individual.net...
> "Woody"  wrote in message 
> news:TKaFk.2067$Cw7.480@newsfe25.ams2...
>>
>> Maybe one of those occassions where the theory and practice don't match?
>>
>
> Theory and practice always match, if it appears otherwise then you've 
> misunderstood the theory or there's some other factors involved that you 
> weren't aware of. The use of shunt capacitors acroos the replay heads of 
> analogue tape machines to boost the HF response was standard practice, 
> often these capacitors were switched according to the speed selected with 
> larger capacitor values being used on the lower speeds.
>
> David.
>
>
The cartridge is rather dull, not bright, and I know about the recommended 
capacitative load, but that's not what I'm after. In the mid '70s, somebody, 
and I think it was either Shure themselves, or possibly SME, published a 
cartridge equaliser circuit which consisted of one or two resistors and a 
capacitor, may have been two caps, and which had the effect of lifting the 
lower treble suck-out, and the extreme hf droop. It also had the effect of 
dropping the total output by a couple of dB as I recall. It's that circuit 
I'm looking for and sadly can't find.

You can see the frequency response I'm getting
http://audiopages.googlepages.com/V15IIIspectrum27-01-08.png/V15IIIspectrum27-01-08-full;init:.png

My other cartridges, using the same test LP are fine. As an example, my EMT 
cartridge does this:-

http://audiopages.googlepages.com/TSD15HFspectrum27-01-08.png/TSD15HFspectrum27-01-08-full;init:.png

S.

-- 
http://audiopages.googlepages.com

Woody wrote:

> "Serge Auckland"  wrote in message
>
> > I'm trying to improve the frequency response of my V15III/SME 3009 S2,
> > and remember that Shure or SME had a little equaliser circuit that
> > flattened the response at the expense of a couple of dBs of output.
> > Something may have been published in HFN and/or Wireless World in the
> > '70s, but my HFNs don't go back that far, and I can't find it in my
> > WWs of the era.
> >
> > I've been searching on-line for the circuit all afternoon, and can't
> > find anything. It was simply a capacitor and a resistor or two, but I
> > can't remember the configuration or values.
> >
> > Does anyone have this info please?
>
> Ah, now this is one I do know about - it applied more or less across the
> Shure range.
>
> Shure cartridges were designed to work into a load of 47K resistance
> (like all others) in parallel with something around 360pF capacitance.
> The pickup arm cables and the interconnect to the amp would account for
> about 120-150pF, which leaves the cartridge underloaded and thus rather
> peaky and bright.
>
> The answer - provided you have the skills to do it - is to make up two
> short phono plug-socket link cables perhaps 3-4in long and fit a 220pF
> capacitor inside one of the connectors in each cable. A small ceramic
> capacitor of that sort of value should be no more than about 4mm square
> and will fit quite easily. Remember capacitors are additive in value
> when they are connected in parallel.
>
> Total cost with components from Maplins would be about £5. There used to
> be manufactured units that did the same thing and cost about £30
> apiece - much the same thing with mains spike protectors which cost
> about £5 to make (retail) and sell for £100++, especially those from
> rip-off Russ. You may have to dig a bit to find the capacitors though.

Maplin does have capacitors but its website is so completely borked that a
search for 220pf brought up all sorts of values such as anything from 100pF
to 47nF !

One of the worst websites I've ever seen !

Graham

"Don Pearce"
> Woody wrote:
>
>> Shure cartridges were designed to work into a load of 47K resistance 
>> (like all others) in parallel with something around 360pF capacitance. 
>> The pickup arm cables and the interconnect to the amp would account for 
>> about 120-150pF, which leaves the cartridge underloaded and thus rather 
>> peaky and bright.
>>
>
> The way the impedances work out, you get more peakiness as the load goes 
> up, not down.


** Shure V15IIIs definitely sound brighter with less loading capacitance  - 
and or an increase in the load resistance above 47 kohms.


> Adding an extra 200pF to the basic cartridge and wires will increase the 
> level at 10kHz by about 2.5dB.


** Don just plucked that figure out of his bum.

The real number is about 0.5dB  at  8 to 10 kHz.

So barely audible.

What an extra 200pF  * DOES *  do is drop the response at  14 - 17 kHz  by 3 
or 4 dB  -  and  THAT  is what a person with good hearing notices as " 
duller ".


> This is all about the way the capacitance resonates with the inductance of 
> the cartridge.


** For anyone who cares to simulate the situation, a V15III has the 
following :

L  =  550 mH.

R =  1370 ohms

Fo  =  42kHz  ( equates to about 25 pF internal C )



.....   Phil

Serge Auckland wrote:
> 
> "David Looser"  wrote in message 
> news:6kktlcF8ft2aU1@mid.individual.net...
>> "Woody"  wrote in message 
>> news:TKaFk.2067$Cw7.480@newsfe25.ams2...
>>>
>>> Maybe one of those occassions where the theory and practice don't match?
>>>
>>
>> Theory and practice always match, if it appears otherwise then you've 
>> misunderstood the theory or there's some other factors involved that 
>> you weren't aware of. The use of shunt capacitors acroos the replay 
>> heads of analogue tape machines to boost the HF response was standard 
>> practice, often these capacitors were switched according to the speed 
>> selected with larger capacitor values being used on the lower speeds.
>>
>> David.
>>
>>
> The cartridge is rather dull, not bright, and I know about the 
> recommended capacitative load, but that's not what I'm after. In the mid 
> '70s, somebody, and I think it was either Shure themselves, or possibly 
> SME, published a cartridge equaliser circuit which consisted of one or 
> two resistors and a capacitor, may have been two caps, and which had the 
> effect of lifting the lower treble suck-out, and the extreme hf droop. 
> It also had the effect of dropping the total output by a couple of dB as 
> I recall. It's that circuit I'm looking for and sadly can't find.
> 
> You can see the frequency response I'm getting
> http://audiopages.googlepages.com/V15IIIspectrum27-01-08.png/V15IIIspectrum27-01-08-full;init:.png 
> 
> 
> My other cartridges, using the same test LP are fine. As an example, my 
> EMT cartridge does this:-
> 
> http://audiopages.googlepages.com/TSD15HFspectrum27-01-08.png/TSD15HFspectrum27-01-08-full;init:.png 
> 
> 
> S.
> 

Something a little odd there because the Shure appears to have an HF 
droop of more like 10dB, and using just passive components you need to 
lose that much to flatten things out. The response error looks like it 
can be easily corrected with a very slight tweak of a standard treble 
tone control; do you have one on your amplifier?

d

Phil Allison wrote:
> "Don Pearce"
>> Woody wrote:
>>
>>> Shure cartridges were designed to work into a load of 47K resistance 
>>> (like all others) in parallel with something around 360pF capacitance. 
>>> The pickup arm cables and the interconnect to the amp would account for 
>>> about 120-150pF, which leaves the cartridge underloaded and thus rather 
>>> peaky and bright.
>>>
>> The way the impedances work out, you get more peakiness as the load goes 
>> up, not down.
> 
> 
> ** Shure V15IIIs definitely sound brighter with less loading capacitance  - 
> and or an increase in the load resistance above 47 kohms.
> 
> 
>> Adding an extra 200pF to the basic cartridge and wires will increase the 
>> level at 10kHz by about 2.5dB.
> 
> 
> ** Don just plucked that figure out of his bum.
> 
> The real number is about 0.5dB  at  8 to 10 kHz.
> 
> So barely audible.
> 
> What an extra 200pF  * DOES *  do is drop the response at  14 - 17 kHz  by 3 
> or 4 dB  -  and  THAT  is what a person with good hearing notices as " 
> duller ".
> 
> 
>> This is all about the way the capacitance resonates with the inductance of 
>> the cartridge.
> 
> 
> ** For anyone who cares to simulate the situation, a V15III has the 
> following :
> 
> L  =  550 mH.
> 
> R =  1370 ohms
> 
> Fo  =  42kHz  ( equates to about 25 pF internal C )
> 
> 
> 
> .....   Phil
> 
> 
> 
> 
> 
> 

I did the simulation two years ago and the results are still here:

http://81.174.169.10/odds/v15iii/cartridge.html

For some reason this page doesn't work well in IE (saved as HTML from 
Mathcad), but use Firefox and it'll be fine. It shows how peaky the cart 
gets with added capacitance. And of course a 3dB peak at 10kHz is going 
to beat flat extension to 20kHz any day when it comes to sounding bright.

d

In article , Serge Auckland
 wrote:

> The cartridge is rather dull, not bright, and I know about the
> recommended capacitative load, but that's not what I'm after. In the
> mid '70s, somebody, and I think it was either Shure themselves, or
> possibly SME, published a cartridge equaliser circuit which consisted
> of one or two resistors and a capacitor, may have been two caps, and
> which had the effect of lifting the lower treble suck-out, and the
> extreme hf droop. It also had the effect of dropping the total output
> by a couple of dB as I recall. It's that circuit I'm looking for and
> sadly can't find.


My recollection is that Jim Sugden wrote a HFN article on that and gave the
circuit you have in mind. If I get a chance I'll have a look later today
and then report what I can find. I am pretty shure <pun> I have a copy of
the article.  :-)

> You can see the frequency response I'm getting
> http://audiopages.googlepages.com/V15IIIspectrum27-01-08.png/V15IIIspectrum27-01-08-full;init:.png

I would be quite wary of test LPs. I've been comparing some and the
responses they give are all over the place!

Slainte,

Jim

-- 
Change 'noise' to 'jcgl' if you wish to email me.
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html

On 03 Oct, noise@audiomisc.co.uk wrote:
>

> My recollection is that Jim Sugden wrote a HFN article on that and gave
> the circuit you have in mind. If I get a chance I'll have a look later
> today and then report what I can find. I am pretty shure <pun> I have a
> copy of the article.  :-)

Found this quicker that I expected!

HFN April 1968 "Flatten your Head" by Jim Sugden.

The circuit he published uses a shunt of a 330pF and 3k3 in series.

He also used a *series* cap of 0.047microfarads to control the rise at LF,
but said this was optional. Also cautioned that some amps (e.g. his
Radford) didn't like this as the higher LF source impedance led to more
hum.

The above was for the V15/II, not III. I do recall that Shure did sell an
adaptor, but haven't found any details. I assume that most people - inc
myself - were quite happy with just a capacitance shunt with no extras.

FWIW He then reported +/-1dB from 30Hz to 16kHz, which doesn't seem to me
much different to a V15III and a plain cap shunt. However you may find that
fiddling slightly with the values will get flatter response. That said, we
may be in the territory where results will vary from one example to the
next!  :-)

Slainte,

Jim

-- 
Change 'noise' to 'jcgl' if you wish to email me.
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html

Don Pearce wrote:

> Phil Allison wrote:
> > "Don Pearce"
> >> Woody wrote:
> >>
> >>> Shure cartridges were designed to work into a load of 47K resistance
> >>> (like all others) in parallel with something around 360pF capacitance.
> >>> The pickup arm cables and the interconnect to the amp would account for
> >>> about 120-150pF, which leaves the cartridge underloaded and thus rather
> >>> peaky and bright.
> >>>
> >> The way the impedances work out, you get more peakiness as the load goes
> >> up, not down.
> >
> >
> > ** Shure V15IIIs definitely sound brighter with less loading capacitance  -
> > and or an increase in the load resistance above 47 kohms.
> >
> >
> >> Adding an extra 200pF to the basic cartridge and wires will increase the
> >> level at 10kHz by about 2.5dB.
> >
> >
> > ** Don just plucked that figure out of his bum.
> >
> > The real number is about 0.5dB  at  8 to 10 kHz.
> >
> > So barely audible.
> >
> > What an extra 200pF  * DOES *  do is drop the response at  14 - 17 kHz  by 3
> > or 4 dB  -  and  THAT  is what a person with good hearing notices as "
> > duller ".
> >
> >
> >> This is all about the way the capacitance resonates with the inductance of
> >> the cartridge.
> >
> >
> > ** For anyone who cares to simulate the situation, a V15III has the
> > following :
> >
> > L  =  550 mH.
> >
> > R =  1370 ohms
> >
> > Fo  =  42kHz  ( equates to about 25 pF internal C )
>
>
> I did the simulation two years ago and the results are still here:
>
> http://81.174.169.10/odds/v15iii/cartridge.html
>
> For some reason this page doesn't work well in IE (saved as HTML from
> Mathcad), but use Firefox and it'll be fine. It shows how peaky the cart
> gets with added capacitance. And of course a 3dB peak at 10kHz is going
> to beat flat extension to 20kHz any day when it comes to sounding bright.

And some nutcases think CD's crap !

Graham

Jim Lesurf wrote:

> On 03 Oct, noise@audiomisc.co.uk wrote:
> >
> > My recollection is that Jim Sugden wrote a HFN article on that and gave
> > the circuit you have in mind. If I get a chance I'll have a look later
> > today and then report what I can find. I am pretty shure <pun> I have a
> > copy of the article.  :-)
>
> Found this quicker that I expected!
>
> HFN April 1968 "Flatten your Head" by Jim Sugden.
>
> The circuit he published uses a shunt of a 330pF and 3k3 in series.
>
> He also used a *series* cap of 0.047microfarads to control the rise at LF,
> but said this was optional. Also cautioned that some amps (e.g. his
> Radford) didn't like this as the higher LF source impedance led to more
> hum.
>
> The above was for the V15/II, not III. I do recall that Shure did sell an
> adaptor, but haven't found any details. I assume that most people - inc
> myself - were quite happy with just a capacitance shunt with no extras.
>
> FWIW He then reported +/-1dB from 30Hz to 16kHz, which doesn't seem to me
> much different to a V15III and a plain cap shunt. However you may find that
> fiddling slightly with the values will get flatter response. That said, we
> may be in the territory where results will vary from one example to the
> next!  :-)

What joy one no longer has to worry about such things.

I can still recall lining up the tape machines at Sound Developments. And of
course when a new batch of tape came in you had to be very careful.

Does EMI 815 sound familiar to anyone. It was their stock 'standard' tape there
IIRC. They had a couple of Studers and a fair few of Ampexes. I liked the
Ampexes, far more reliable. The MM1100 or was it 1200 ? impressed me
considerably.

Graham

Eeyore wrote:
> 
> Don Pearce wrote:
> 
>> Phil Allison wrote:
>>> "Don Pearce"
>>>> Woody wrote:
>>>>
>>>>> Shure cartridges were designed to work into a load of 47K resistance
>>>>> (like all others) in parallel with something around 360pF capacitance.
>>>>> The pickup arm cables and the interconnect to the amp would account for
>>>>> about 120-150pF, which leaves the cartridge underloaded and thus rather
>>>>> peaky and bright.
>>>>>
>>>> The way the impedances work out, you get more peakiness as the load goes
>>>> up, not down.
>>>
>>> ** Shure V15IIIs definitely sound brighter with less loading capacitance  -
>>> and or an increase in the load resistance above 47 kohms.
>>>
>>>
>>>> Adding an extra 200pF to the basic cartridge and wires will increase the
>>>> level at 10kHz by about 2.5dB.
>>>
>>> ** Don just plucked that figure out of his bum.
>>>
>>> The real number is about 0.5dB  at  8 to 10 kHz.
>>>
>>> So barely audible.
>>>
>>> What an extra 200pF  * DOES *  do is drop the response at  14 - 17 kHz  by 3
>>> or 4 dB  -  and  THAT  is what a person with good hearing notices as "
>>> duller ".
>>>
>>>
>>>> This is all about the way the capacitance resonates with the inductance of
>>>> the cartridge.
>>>
>>> ** For anyone who cares to simulate the situation, a V15III has the
>>> following :
>>>
>>> L  =  550 mH.
>>>
>>> R =  1370 ohms
>>>
>>> Fo  =  42kHz  ( equates to about 25 pF internal C )
>>
>> I did the simulation two years ago and the results are still here:
>>
>> http://81.174.169.10/odds/v15iii/cartridge.html
>>
>> For some reason this page doesn't work well in IE (saved as HTML from
>> Mathcad), but use Firefox and it'll be fine. It shows how peaky the cart
>> gets with added capacitance. And of course a 3dB peak at 10kHz is going
>> to beat flat extension to 20kHz any day when it comes to sounding bright.
> 
> And some nutcases think CD's crap !
> 

Yes, that's a bit harsh - I use the one in the car every so often, when 
there's nothing on the radio. No point ruling them out altogether.

Rob

"Don Pearce"
> Phil Allison wrote:
>>
>>> The way the impedances work out, you get more peakiness as the load goes 
>>> up, not down.
>>
>>
>> ** Shure V15IIIs definitely sound brighter with less loading 
>> apacitance  - and or an increase in the load resistance above 47 kohms.
>>
>>
>>> Adding an extra 200pF to the basic cartridge and wires will increase the 
>>> level at 10kHz by about 2.5dB.
>>
>>
>> ** Don just plucked that figure out of his bum.
>>
>> The real number is about 0.5dB  at  8 to 10 kHz.
>>
>> So barely audible.
>>
>> What an extra 200pF  * DOES *  do is drop the response at  14 - 17 kHz 
>> by 3 or 4 dB  -  and  THAT  is what a person with good hearing notices as 
>> " duller ".
>>
>>
>>> This is all about the way the capacitance resonates with the inductance 
>>> of the cartridge.
>>
>>
>> ** For anyone who cares to simulate the situation, a V15III has the 
>> following :
>>
>> L  =  550 mH R =  1370 ohms Fo  =  42kHz  ( equates to about 25 pF 
>> internal C )
>>
 >
>
> I did the simulation two years ago and the results are still here:
>
> http://81.174.169.10/odds/v15iii/cartridge.html



** I tested using a  ** REAL **   Shure V15III   -   owned one since 1978, 
long out of use now.

No peak around 10kHz is created by adding 200 pF  (or even 400pF ) to 150pF 
with a 47kohms load.

Proves yet again the absolute folly of naive simualtions.

Fools like Jim Leserf and Don the drongo you are world champs at that fake 
art.





.....   Phil

In article ,
   Eeyore  wrote:
> Does EMI 815 sound familiar to anyone.

Yup. Best kept for tying up the roses. ;-)

> It was their stock 'standard' tape there
> IIRC. They had a couple of Studers and a fair few of Ampexes. I liked the
> Ampexes, far more reliable. The MM1100 or was it 1200 ? impressed me
> considerably.

Never had much to do with Ampex audio recorders but loved and hated Studer
in the same breath.

-- 
*Never kick a cow pat on a hot day *

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

In article <MI2dnW72UYpwT3jVRVnyhQA@posted.plusnet>, Don Pearce
 wrote:


> I did the simulation two years ago and the results are still here:

> http://81.174.169.10/odds/v15iii/cartridge.html

> For some reason this page doesn't work well in IE (saved as HTML from
> Mathcad), but use Firefox and it'll be fine. It shows how peaky the cart
> gets with added capacitance. And of course a 3dB peak at 10kHz is going
> to beat flat extension to 20kHz any day when it comes to sounding
> bright.

I'd be interested to know how you did the simulation. In particular, if/how
you included the coupling between the mechanical resonance(s) and
electronic loading.

Slainte,

Jim

-- 
Change 'noise' to 'jcgl' if you wish to email me.
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html

"Serge Auckland"  wrote in
message news:jbWdnf5Zls8ZknjVnZ2dneKdnZydnZ2d@bt.com

> I'm trying to improve the frequency response of my
> V15III/SME 3009 S2, and remember that Shure or SME had a
> little equaliser circuit that flattened the response at
> the expense of a couple of dBs of output. Something may
> have been published in HFN and/or Wireless World in the
> '70s, but my HFNs don't go back that far, and I can't
> find it in my WWs of the era.
> I've been searching on-line for the circuit all
> afternoon, and can't find anything. It was simply a
> capacitor and a resistor or two, but I can't remember the
> configuration or values.

In the day of, I was a V15 fan. I owned a number of V15 III's and IV's, in 
different turntables. I also experimented with using a V15 stylus assembly 
in a M91 cartridge body, which required trimming a little plastic.

As others have noted, the trick is to adjust the capacitive load for 
flattest possible response with the test record of your choice. You can also 
do it by ear, if you have an educated ear.

I built a preamp that had variable capacitors on the input to facilitate 
this adjustment. A number of commercial preamps, including Holman's APT 
preamp also had this feature.

The usual subjective impression is that V15  cartridges are dull sounding 
without proper capacitive loading. This effect may have been somewhat 
reduced in later versions, but it was very strong in the II.

"Arny Krueger"

>
> In the day of, I was a V15 fan. I owned a number of V15 III's and IV's, in 
> different turntables. I also experimented with using a V15 stylus assembly 
> in a M91 cartridge body, which required trimming a little plastic.
>
> As others have noted, the trick is to adjust the capacitive load for 
> flattest possible response with the test record of your choice. You can 
> also do it by ear, if you have an educated ear.
>
> I built a preamp that had variable capacitors on the input to facilitate 
> this adjustment. A number of commercial preamps, including Holman's APT 
> preamp also had this feature.
>
> The usual subjective impression is that V15  cartridges are dull sounding 
> without proper capacitive loading.


** Quite the  REVERSE is true.

Shure V15s sound bright without additional C loading,  beyond that found in 
most RIAA stages.


> This effect may have been somewhat reduced in later versions, but it was 
> very strong in the II.


**  It was very noticeable with V15IIIs also

 -  to anyone with good hearing and speakers with good response to 20kHz.



.....   Phil