BuzzzFuzzz Posted December 21, 2019 Posted December 21, 2019 8 hours ago, eman said: Yes , there is a standard non phono Preamplifier. Commonly used with a Power amp. Thanks eman. When would one use a standard, non-phono Preamp? I'm leaning towards a direct system, using an intergrated amp that shines without adding extra components. If I went for a power amp, would I be better off with a pre as well? Does a power amp lack features, clarity etc. requiring a pre? I there a concern for any enthusiasts that a system can become too convoluted? Too many components adding flavour to the sound. In my naivety I assume less processing of a signal would be more honest/accurate.
H.E. Pennypacker Posted December 21, 2019 Posted December 21, 2019 (edited) A Pre-amp/power amp combo separates input selection and attenuation (volume control) in one box and the power stage into another box (or boxes). There are many, many reasons for this... seperate (and larger) power supplies, heat dissipation, design freedom... My integrated has a ‘pre out’, so it can run an attenuated signal to a different power amp if I chose, bypassing the power stage that’s inbuilt. The only output of a preamp is RCA or XLR. Edited December 21, 2019 by furtherpale 1
Guest Muon N' Posted December 22, 2019 Posted December 22, 2019 (edited) 3 hours ago, BuzzzFuzzz said: Thanks eman. When would one use a standard, non-phono Preamp? I'm leaning towards a direct system, using an intergrated amp that shines without adding extra components. If I went for a power amp, would I be better off with a pre as well? Does a power amp lack features, clarity etc. requiring a pre? I there a concern for any enthusiasts that a system can become too convoluted? Too many components adding flavour to the sound. In my naivety I assume less processing of a signal would be more honest/accurate. An integrated amp is so called this as it integrates both the pre amplifier and power amplifier. The Pre Amplifier section in most cases applies some amplification and functions such as multiple input connections/selection (can also be passive with no amplification) and sometimes tone controls. The Power Amplifier section is the main amplification section that outputs to the speaker terminals. this is It's only function. So, you can by Integrated amplifiers, or you can buy what is termed separates, where you buy a pre amplifier and a power amplifier and connect the outputs of the Pre Amplifier to the inputs on the power amplifier. A Phono stage can be for Moving Magnet type cartridges, or for both Moving Magnet cartridges and Moving Coil cartridges...switchable between those functions. A Moving Magnet Cartridge has a higher output than a Moving Coil cartridge, so in the case of a Moving Coil cartridge the signal is amplified once by the MC stage of the unit, and then again in the MM stage (Moving Magnet) part to bring the low signal to line level like that of CD or Cassette Tape. The first stage of a MM and MC Phono stage ideals with the lower Moving Coil stage and can use Op Amps or Discrete Circuitry like transistors or Tubes ect' for amplification, or Step Up Transformers for this. The MM stage is one of the previous but not transformers. So you can also have separates here too, where you can buy just a MM Phono stage and add a MC stage whether it uses discrete circuitry ect' or just Step Up Transformers, in front of it if using a MC cartridge. An Integrated Amplifier sometimes also has a Phono Stage integrated into it also, that's when we see it having Phono inputs at the back. This might help but also confuse Edited December 22, 2019 by Muon N'
Guest Muon N' Posted December 22, 2019 Posted December 22, 2019 Just now, furtherpale said: ^that should be pinned somewhere. Could be modified to be a little better and more complete.
H.E. Pennypacker Posted December 22, 2019 Posted December 22, 2019 (edited) 2 minutes ago, Muon N' said: Could be modified to be a little better and more complete. Pretty decent first draft. Could eventually use a signal ‘flow chart’ mirroring the explanation where appropriate. Edited December 22, 2019 by furtherpale
BuzzzFuzzz Posted December 22, 2019 Posted December 22, 2019 (edited) Thanks @furtherpale & @Muon N' Great info making sense to me. Apologies for de-railing slightly. The main reason I have a Phono Preamp/Stage (still not sure how to refer to it), is for gain, as I understand it - more volume (stronger signal). It depends which amp I decide to go with before knowing if a pre would be beneficial. It will be thoroughly researched before the first purchase, pennies saved and at least six months away, and I will most likely hunt speakers first. Right now I'm getting a handle on how many components will come after that. I am considering one monoblock amp for each channel??? But, will hit the other Amp threads for that. Thanks. Ant. Edited December 22, 2019 by BuzzzFuzzz
H.E. Pennypacker Posted December 22, 2019 Posted December 22, 2019 (edited) You will either be getting: - an integrated amp; or - a preamp + power amp The integrated or preamp may have a phono stage inbuilt, or you may have to add one. If you go preamp + power amp, the power amp may be a stereo amp, or 2 x mono amps. Edited December 22, 2019 by furtherpale 1
Guest Muon N' Posted December 22, 2019 Posted December 22, 2019 4 hours ago, BuzzzFuzzz said: Thanks @furtherpale & @Muon N' Great info making sense to me. Apologies for de-railing slightly. The main reason I have a Phono Preamp/Stage (still not sure how to refer to it), is for gain, as I understand it - more volume (stronger signal). It depends which amp I decide to go with before knowing if a pre would be beneficial. It will be thoroughly researched before the first purchase, pennies saved and at least six months away, and I will most likely hunt speakers first. Right now I'm getting a handle on how many components will come after that. I am considering one monoblock amp for each channel??? But, will hit the other Amp threads for that. Thanks. Ant. As mentioned by other posters in this thread, a Phono Stage does two things. 1/ It applies RIAA EQ, https://en.wikipedia.org/wiki/RIAA_equalization 2/ Applies gain to bring the low level of a cartridge up to line level like AUX/CD/Tape ect', so it is at a level acceptable for input into the Pre Amplifiers if separates, or Integrated Amplifier is It's that.
Mark Krause Posted January 1, 2020 Posted January 1, 2020 On 22/12/2019 at 12:10 PM, Muon N' said: So you can also have separates here too, where you can buy just a MM Phono stage and add a MC stage whether it uses discrete circuitry ect' or just Step Up Transformers, in front of it if using a MC cartridge. Has anyone had a good result with a MM phono stage and a stepup transformer?
Guest Muon N' Posted January 1, 2020 Posted January 1, 2020 (edited) 3 hours ago, Mark Krause said: Has anyone had a good result with a MM phono stage and a stepup transformer? For running a low output MC cart? Sure, plenty of folks, but you need to get the transformers that are matched to the cart in a couple of parameters, like impedance and gain, and transformers like many things have different sound signatures. (capacitance is more a concern with MM carts) Edited January 1, 2020 by Muon N' typo
kdoot Posted January 1, 2020 Posted January 1, 2020 On 14/12/2019 at 7:28 AM, andyr said: a. change a MM signal of ~5mV to 500mV (a gain of x100) b. change an MC signal - say, 0.5mV - to 500mV (a gain of x1000). This level of amplification is waaay higher than any power amp or preamp! That gain is not unusually large. Each 10dB is 10x, so 100x is only 20dB and 1000x is 30dB. Most solid state power amps are in the mid to high 20’s and some crack 30dB of gain. What is very different though is the sensitivity. As you say, peaks on the order of 1mV instead of the hundreds or even thousands of mV that a power amp is designed to handle on its inputs.
andyr Posted January 1, 2020 Posted January 1, 2020 (edited) 37 minutes ago, kdoot said: That gain is not unusually large. Each 10dB is 10x, so 100x is only 20dB and 1000x is 30dB. Most solid state power amps are in the mid to high 20’s and some crack 30dB of gain. What is very different though is the sensitivity. As you say, peaks on the order of 1mV instead of the hundreds or even thousands of mV that a power amp is designed to handle on its inputs. Your understanding of voltage gain in terms of dB is different to mine, kd! The standard gain for an MM phono stage is 40dB - this is 100x! (5mv --> 500mV.) The standard gain for an MC phono stage is 60dB - 1000x! (0.5mV --> 500mV.) Andy Edited January 1, 2020 by andyr
kdoot Posted January 1, 2020 Posted January 1, 2020 1 hour ago, andyr said: Your understanding of voltage gain in terms of dB is different to mine, kd! And it turns out... that’s because I only knew half the story! I got some foundational RF training as part of a Wi-Fi course and they never mentioned that their definition of decibel only applies to power, not to amplitude. You are correct. Thanks for prompting me to dig deeper. Wish I liked logarithms more.
almikel Posted January 2, 2020 Posted January 2, 2020 15 hours ago, kdoot said: they never mentioned that their definition of decibel only applies to power, not to voltage amplitude. You are correct. Thanks for prompting me to dig deeper. Wish I liked logarithms more. decibel is just a ratio and is used for many things (power, voltage, sound pressure etc etc) To help me remember whether it's 10 x Log (X1/X2) or 20 x Log(X1/X2), I think about how voltage and power are related ie P=V^2/R in log maths when something is squared (or raised to any power), it comes down the front, so if you start with power gain (dB) = 10 x log (Pout/Pin) and substitute (Pout/Pin) with (Vout/Vin)^2, then the ^2 comes down the front to be Voltage gain (dB) = 2 x 10 x log (Vout/Vin)...that's the way I remember it anyway Mike 2
Frankp01 Posted July 28, 2020 Posted July 28, 2020 Sorry to jump in here late, and change tack a little. I have read that phono preamp (stages) can be left powered on at all times? I know they don't use much power, and can take a little time to "warm up" (some models), but does it do any damage to the amp or does it actually matter at all if it is turned on and off as per usage? I have a Rega Aria.
Quark Posted July 28, 2020 Posted July 28, 2020 17 minutes ago, Frankp01 said: Sorry to jump in here late, and change tack a little. I have read that phono preamp (stages) can be left powered on at all times? I know they don't use much power, and can take a little time to "warm up" (some models), but does it do any damage to the amp or does it actually matter at all if it is turned on and off as per usage? I have a Rega Aria. With my Project phono I've tried powering up from cold vs leaving on - it definitely sounds better left on. Even after 2 hours from power up it's still not quite right. I was a complete cynic on the issue until I tried it. YMMV.
Frankp01 Posted July 28, 2020 Posted July 28, 2020 2 minutes ago, Quark said: With my Project phono I've tried powering up from cold vs leaving on - it definitely sounds better left on. Even after 2 hours from power up it's still not quite right. I was a complete cynic on the issue until I tried it. YMMV. Do they get really warm? This amp is in a floating cabinet and I'd like to leave the door closed.
Quark Posted July 28, 2020 Posted July 28, 2020 1 minute ago, Frankp01 said: Do they get really warm? This amp is in a floating cabinet and I'd like to leave the door closed. My Project doesn't get warm - not sure about your Rega. 1
almikel Posted July 31, 2020 Posted July 31, 2020 (edited) On 28/07/2020 at 12:53 PM, Frankp01 said: Sorry to jump in here late, and change tack a little. I have read that phono preamp (stages) can be left powered on at all times? I know they don't use much power, and can take a little time to "warm up" (some models), but does it do any damage to the amp or does it actually matter at all if it is turned on and off as per usage? I have a Rega Aria. Contentious issue - maybe valve stages need to warm up, maybe semi conductors also - I don't run any valves, and I turn all my gear off when I'm not listening - I've never noticed any change in sound during any initial "warm up" period". On 28/07/2020 at 1:13 PM, Quark said: With my Project phono I've tried powering up from cold vs leaving on - it definitely sounds better left on. Even after 2 hours from power up it's still not quite right. I was a complete cynic on the issue until I tried it. YMMV. @Quark definitely leave it on in that case... ....me being a complete cynic also...I also find the stereo sounds better after 2 hours and several beers... Edited July 31, 2020 by almikel
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