Seeking a tutorial thread on matching turntables with amps
- Thread starter bobspets
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tnsilver
Stereo Puppy
AK doesn't have such a thing b/c there is no such thing. Turntables aren't matched with an amp any more than your favorite FM rock station does. Turntables have a built-in or are plugged into a phono stage, which is either an external unit or built into your amp/receiver. In the case of an external phono stage it's plugged into any of the line level inputs of the amp, such as AUX/CD/DAD etc...
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lini
just me...
bp: Depends on what exactly you mean. If you have an integrated amp or receiver with integrated phono stage in mind, one would certainly not want such a low phono input sensitivity, that one could merely access a small fraction of the rated output power in combination with one's phono cartridge(s) - unless the power-amp section would be so overdimensioned for one's loudspeakers, that this small fraction of the rated output power would already easily suffice. And of course one would typically also like the phono input to have suitable load parameters (impedance and capacitance) for one's phono catridge(s) as well as the integrated phono stage and the pre- & power-amp sections to be of adequate quality for the quality of the turntable (or respectively drive/arm/cart combo).
Greetings from Munich!
Manfred / lini
Greetings from Munich!
Manfred / lini
@bobspets , RIAA specs a 47K Ohm input resistor to a mm phono preamp, yet some cartridges could prefer 100K Ohms, while others like 33K Ohms. The standard is 47K Ohms for each channel's input resistor.
Phono stages need 40db of gain for full 20-20KHz frequency range. For 30-15KHz freq. range, gain in the 32+ db range can work well. With the proper phono EQ playback curve, 20Hz is at +20db and 20KHz is at -20db. 0db reference is at 1KHz. This is why/how 40db of gain is the spec. Some outboard phono stages have high output impedance, requiring a high input Resistance in your Line Inputs, like the Aux. In. Other outboard phono stages include a buffer stage, an extra, impedance matching stage. Welcome to your exploration of the world of turntables...
Phono stages need 40db of gain for full 20-20KHz frequency range. For 30-15KHz freq. range, gain in the 32+ db range can work well. With the proper phono EQ playback curve, 20Hz is at +20db and 20KHz is at -20db. 0db reference is at 1KHz. This is why/how 40db of gain is the spec. Some outboard phono stages have high output impedance, requiring a high input Resistance in your Line Inputs, like the Aux. In. Other outboard phono stages include a buffer stage, an extra, impedance matching stage. Welcome to your exploration of the world of turntables...
MCM_Fan
AK Subscriber
When it comes to matching components for vinyl playback, there are two things you need to worry about: matching the cartridge to the tonearm and matching the phono stage to the cartridge. Other than that, a good amp is a good amp regardless of the source.
When matching the cartridge to the tonearm, a heavy tonearm requires a low compliance cartridge and a low mass tonearm requires a high compliance cartridge. Most current tonearms are medium mass and most current cartridges are medium compliance. You actually have to try to get a mismatch with current new products, but it is certainly possible. There are formulas for calculating the resonant frequency of the cartridge/tonearm system, but you need the actual dynamic compliance of the cartridge at 10Hz and the effective mass of the tonearm for those calculations to be accurate. Those specs can be difficult to find. As a rule of thumb, don't put a heavy tracking cartridge (VTF => 3g) on a thin, ultralight straight tonearm and don't put a light tracking cartridge (VTF <= 1.5g) on a heavy broadcast arm. Once you get into vintage cartridges and tonearms, it becomes pretty easy to get a mismatch. When in doubt, do your research. A google search for recommended cartridges for your turntable/tonearm will usually get you pointed in the right direction.
For cartridge/phono stage matching, whether it's the internal phono stage of an integrated amp or a stand alone external phono stage, it's important to match the input impedance and capacitance of the phono stage to the cartridge manufacturer's recommendations. For most current cartridges, these specs are easy to obtain, they will usually say something like 47K ohms and 150 - 300pF. The exact values vary from cart to cart. 47K is pretty standard, especially for current products, and most phono stages are set to that value (or very close) by default. Some phono stages offer other settings, and some don't. Same for input capacitance. Some have a fixed value, others allow multiple settings. It can be difficult to find the input capacitance for many current home theater amplifiers that include a phono stage. That's usually a sign it's higher than it should be and adding a phono input was an afterthought (i.e. it'll probably work, but probably not sound great). In this paragraph, I'm referring specifically to MM/MI/HOMC cartridges. LOMC get a little more complicated, but most beginners don't start out with a LOMC cartridge. If you do, again, google is your friend.
Edit: this post isn't meant to provide all the answers, just a view from 30,000 feet of the basic issues.
When matching the cartridge to the tonearm, a heavy tonearm requires a low compliance cartridge and a low mass tonearm requires a high compliance cartridge. Most current tonearms are medium mass and most current cartridges are medium compliance. You actually have to try to get a mismatch with current new products, but it is certainly possible. There are formulas for calculating the resonant frequency of the cartridge/tonearm system, but you need the actual dynamic compliance of the cartridge at 10Hz and the effective mass of the tonearm for those calculations to be accurate. Those specs can be difficult to find. As a rule of thumb, don't put a heavy tracking cartridge (VTF => 3g) on a thin, ultralight straight tonearm and don't put a light tracking cartridge (VTF <= 1.5g) on a heavy broadcast arm. Once you get into vintage cartridges and tonearms, it becomes pretty easy to get a mismatch. When in doubt, do your research. A google search for recommended cartridges for your turntable/tonearm will usually get you pointed in the right direction.
For cartridge/phono stage matching, whether it's the internal phono stage of an integrated amp or a stand alone external phono stage, it's important to match the input impedance and capacitance of the phono stage to the cartridge manufacturer's recommendations. For most current cartridges, these specs are easy to obtain, they will usually say something like 47K ohms and 150 - 300pF. The exact values vary from cart to cart. 47K is pretty standard, especially for current products, and most phono stages are set to that value (or very close) by default. Some phono stages offer other settings, and some don't. Same for input capacitance. Some have a fixed value, others allow multiple settings. It can be difficult to find the input capacitance for many current home theater amplifiers that include a phono stage. That's usually a sign it's higher than it should be and adding a phono input was an afterthought (i.e. it'll probably work, but probably not sound great). In this paragraph, I'm referring specifically to MM/MI/HOMC cartridges. LOMC get a little more complicated, but most beginners don't start out with a LOMC cartridge. If you do, again, google is your friend.
Edit: this post isn't meant to provide all the answers, just a view from 30,000 feet of the basic issues.
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lini
just me...
Sorry, but that is nonsense - 'cause phono stage gain refers to the neutral point at 1 kHz. That quite a few phono stages (especially integrated ones) are specified for 30 Hz to 15 kHz "only" rather has different reasons and doesn't mean that the response of these phono stages would be limited to that range. Instead, for one thing that 30 Hz to 15 kHz is the most important range, as quite a lot of LPs won't really have actual (in the sense of intended) signal content below and above - and then, even more importantly, the frequency response usually is given for a certain deviation limit (like for example +/- 0.5 dB or +/- 0.25 dB) for the RIAA (re-)equalisation, with a smaller limit indicating a more precise (re-)equalisation. Hence a manufacturer may feel inclined to rather specify the implemented phono stage for 30 Hz to 15 kHz only, in order to boast a smaller deviation limit than what could be specified for the full audible range - even more so, of course, if the phono stage contained for example a non-defeatable subsonic filter, that would cause a larger deviation at 20 Hz.
Greetings from Munich!
Manfred / lini
most amplifiers/receivers that have a built in phono stage will be set up for moving magnet "MM" cartridges. Some will also have an input rated for low output moving coil cartridges "MC".
It's really that simple, but there are exceptions, like high output moving coil that will also work in a MM input, moving Iron "MI" that will also work in the MM input.
Also, there are a few low output moving magnet, but as others have said this all has to do with the cartridge. So if purchasing a turntable with a cartridge already installed its just a matter of knowing which type it is.
