Home |
Search |
Today's Posts |
#1
|
|||
|
|||
5mV phono cart to 2.5mV pre-amp -- am I asking for trouble?
Grado Prestige Gold cartridge, the pre-amp is in a Harman Kardon SR900
receiver & is rated at 2.5mV input. I haven't been able to find out if this apparent mismatch is liable to fry something, I'd appreciate any help. I don't think it's likely to fry anything in the preamp. The worst that's likely to happen is that the cartridge's output might overload the preamp and force it (or a later stage) into clipping. This might sound harsh, on the loudest peaks in the signal, but it's unlikely to damage anything. My guess is that the H-K probably has enough overload margin that it'll handle the higher-output cartridge just fine. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#2
|
|||
|
|||
In , on 09/12/04
at 03:38 PM, mescalero said: Grado Prestige Gold cartridge, the pre-amp is in a Harman Kardon SR900 receiver & is rated at 2.5mV input. I haven't been able to find out if this apparent mismatch is liable to fry something, I'd appreciate any help. It's not a problem. The 2.5mV rating means that the receiver will reach full output when a 2.5mV 1000Hz signal is presented to the phono input. The 5.0mV cartridge spec is the cartridge output when playing a specific test record -- which is recorded an "average" level. The 5.0mV is a typical magnetic cartridge spec. Had the cartridge been rated at 2.0mV, you would be turning the volume up a bit (compared to a 5.0mV cartridge playing the same record) for the same speaker output. "Problems" start when the cartridge plays something very loud or crosses a record defect (which can appear as a VERY large signal). Some receivers' phono sections overload at 80mV, others at several hundred mV. Once overloaded, some receivers flounder around a bit while they recover from the insult. Receiver spec sheets don't always give the phono overload point and I don't ever recall seeing one give the overload recovery time. (which would depend somewhat on the nature of the overload) ----------------------------------------------------------- spam: wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15 13 (Barry Mann) [sorry about the puzzle, spammers are ruining my mailbox] ----------------------------------------------------------- |
#3
|
|||
|
|||
"mescalero" wrote in message ... On Sun, 12 Sep 2004 22:30:45 -0000, (Dave Platt) wrote: Grado Prestige Gold cartridge, the pre-amp is in a Harman Kardon SR900 receiver & is rated at 2.5mV input. I haven't been able to find out if this apparent mismatch is liable to fry something, I'd appreciate any help. I don't think it's likely to fry anything in the preamp. The worst that's likely to happen is that the cartridge's output might overload the preamp and force it (or a later stage) into clipping. This might sound harsh, on the loudest peaks in the signal, but it's unlikely to damage anything. My guess is that the H-K probably has enough overload margin that it'll handle the higher-output cartridge just fine. Thanks Dave, I'll give it a try and keep an ear open for clipping. If worse comes to worse I have an Audio-Technica cart that's closer to the H-K's input specs (3.5mV), but it's not as good a cartridge as the Grado and I'm trying to avoid using it. Please!!! Back in the old days, the signal level differences that you are talking about were of almost no concern. The differences between the characteristics between moving magnet and moving coil were of much more concern. The differences between 5mv and 2.5mv are very small, but the difference between a 100pf and 400pf load on a cartridge could often make a very significant sonic difference. Perhaps the biggest concern WRT the cartridge electrical characteristics (assuming moving magnet) would be the capacitive loading. The freq response is often very dependent upon the capacitive loading (or the loading in general.) Some cartridges are more or less dependent upon the specific amount of loading. Other characteristics of concern would be the mechanical characteristics of the cartridge (which affect how the arm should be set-up, or even the choice of arm), and the choice of needle (certain kinds of needles have different advantages with respect to other kinds.) Out of all of the characteristics, given a GOOD preamp design, I'd suggest that the difference of 6dB in voltage level is of almost no concern. John |
#4
|
|||
|
|||
"John Dyson" wrote in message
... "mescalero" wrote in message ... On Sun, 12 Sep 2004 22:30:45 -0000, (Dave Platt) snip Please!!! Back in the old days, the signal level differences that you are talking about were of almost no concern. The differences between the characteristics between moving magnet and moving coil were of much more concern. The differences between 5mv and 2.5mv are very small, but the difference between a 100pf and 400pf load on a cartridge could often make a very significant sonic difference. snip The Grado is supposedly unaffected by cabling capacitance. Mark Z. |
Reply |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Looking for combo tuner CD player WITH phono input | General | |||
Looking for combo tuner CD player WITH phono input | Audio Opinions | |||
WTB: PHONO PREAMP MM/MC; MOVING COIL; PHONO PREAMP OR PRE PREAMP) | Marketplace | |||
Q: phono preamp recommendation please | High End Audio |