The problem you are up against with a phono section is that the cartridge and tonearm cable have an electrical resonance that can really mess with the front end of a phono section. The resonance can easily overload the input section of the preamp, generating a tick or a pop that sounds for all the world as if its on the LP surface!
The first time I experienced this was about 33 years ago with an employee’s preamp using a Grado cartridge. To be clear, with a MM cartridge that peak can be about 20dB, which with a MM cartridge can be about 5 Volts! Many MM phono sections can’t handle that sort of level, so they make distortion. The thing is, the peak is ultrasonic, so most of the time you can’t hear it (unless you have a tonearm cable that has high capacitance- the higher the capacitance, the lower the frequency of the peak). The distortion is heard as a tick or a pop.
Its far easier to design a phono section using tubes to get a nice high overload margin. With opamps and discreet transistors it can be difficult. So if an opamp is used, its gain must be kept low so it won’t be overloaded. Many designers just don’t think about the implications of this electrical peak, so many inexpensive solid state designs have this problem. It seems that Pass Labs has built good phono sections that have good overload margins- I don’t know if they have one in your price range but its worth a look. 47 Labs makes a very competent phono section that features a current-mode input, and its gotten good reviews. I mention that one becaase it appears that the current mode input has some advantages with reducing the effect of the electrical peak.
If you google ’current mode phono preamp’ you’ll find that 47 Labs is by no means the only manufacturer using current mode inputs. If I were going solid state that kind of phono section is what I would look at first!
The first time I experienced this was about 33 years ago with an employee’s preamp using a Grado cartridge. To be clear, with a MM cartridge that peak can be about 20dB, which with a MM cartridge can be about 5 Volts! Many MM phono sections can’t handle that sort of level, so they make distortion. The thing is, the peak is ultrasonic, so most of the time you can’t hear it (unless you have a tonearm cable that has high capacitance- the higher the capacitance, the lower the frequency of the peak). The distortion is heard as a tick or a pop.
Its far easier to design a phono section using tubes to get a nice high overload margin. With opamps and discreet transistors it can be difficult. So if an opamp is used, its gain must be kept low so it won’t be overloaded. Many designers just don’t think about the implications of this electrical peak, so many inexpensive solid state designs have this problem. It seems that Pass Labs has built good phono sections that have good overload margins- I don’t know if they have one in your price range but its worth a look. 47 Labs makes a very competent phono section that features a current-mode input, and its gotten good reviews. I mention that one becaase it appears that the current mode input has some advantages with reducing the effect of the electrical peak.
If you google ’current mode phono preamp’ you’ll find that 47 Labs is by no means the only manufacturer using current mode inputs. If I were going solid state that kind of phono section is what I would look at first!