Phono pre-amp question

[MacDuff]

I've assembled an analog system using some good vintage gear. Marantz 2275, Pioneer RT-707 reel to reel, NAD 512, JBL L100s and A/D/S L810s and an AR Turntable. A former roomate, 20 years ago, installed a Dynavector Karat 15 moving coil cartridge. When I hooked it up to the 2275, the volume is very low. I can turn it all the way up. The tape, tuner and CD crank, but not the turntable.

I have to assume the pre-amp in the reciever doesn't have a moving coil circuit.

A phono pre-amp seems to make sense, but, with limited inputs, and a CD in the AUX, can I run a phono pre into the phono jacks? How about the Tape 2 in? How will the signal be affected by this input? I could just get a new cartridge, but i really have liked the Dynavector in the past.

What is the best and most reasonable fix for this?

Any ideas? Thanks!

[jbangelfish]

Most, if not all receivers would not have the output for low output MC. I use all separates and don't even have a phono output in my preamp and have to use the AUX. Makes no difference, you either need a step up or separate phono preamp which will allow you to use low output MC. Step up should be your cheapest option and I believe that you should still use your phono output of your receiver although it probably would not matter which circuit you chose.

[markw]

If you go the separate preamp route, you must use a high level (AUX) input. these will put out over a volt and then some. This signal will seriously overdrive a phono input, which works in the millivolt range.

If you use a step up xformer, then you should use your phono input. The signal should be in the range of a MM cartridge now.

[hifitommy]

[QUOTE=.

I have to assume the pre-amp in the reciever doesn't have a moving coil circuit.

How about the Tape 2 in? How will the signal be affected by this input?


Any ideas? Thanks![/QUOTE]

to not use the tape 2 input. that would work just fine for an outboard phono section. which do you have in mind? the clearaudio micro basic would be affordable and bound to sound good.

[jack70]

Your post is a little sketchy in details, however I'll give it a try...

An external "PHONO pre-amp" generally refers to a "normal," magnetic-cartidge pre-amplifier. This is NOT a "moving coil pre-amp", which is generally called a "Pre-pre-amp". They EACH have different input Z, gain, and freq-EQ and are NOT interchangable. You CANNOT use a "normal" outboard pre amp that's designed for a magnetic cartridge(47K) with a moving coil. Moving Coil pre-preamps usually have specific input-Z matching so they match the coil of the cartridge best. A moving coil's Z can vary from 4 to a few hundred ohms. Most magnetic cartridges are 47K.

A few options:
1/ Look at the dynavector (diamond) with a microcope/loup and if it's worn a whole lot, just get yourself an inexpensive Grado (reg cart). Even the cheapest Grados are very good cartridges.

2/ If you do get a moving-coil Pre-pre amp, it'll (generally) be designed to plug into your phono input so it's signal can be stepped up again... but you'd want to read the specs/directions first... it's very possible such a pre-amp (might) have 2 stages of amplification in it already, in which case it would output to your aux (or tape-in) inputs.

[hifitommy]

<An external "PHONO pre-amp" generally refers to a "normal," magnetic-cartidge pre-amplifier. This is NOT a "moving coil pre-amp", which is generally called a "Pre-pre-amp".>

many outboard phono preamps are capable and switchable between mc and mm. a pre-preamp boosts the signal from a mm preamp so the mc can be heard at about the same level as the mm.

i had a terminology disagreement here or at aa with another fellow regarding line stages which are now erroneously called preamps. we ended up having to agree to disagree.

my pre-preamp provides input impedance selections via plug in resistors. i am also borrowing an ortofon transformer which obviates the need for impedance matching. vinyl really is a hobby with experimentation involvement. lotsofun.

[Woochifer]

The 2275 is the receiver that I grew up with and I can tell you that it has a very nice phono stage, but as stated earlier, it is setup for a moving magnet output. You can either go with a phono preamp for a MC cartridge, or use one that can step up a MC output into a line level output. All of the other inputs on the 2275 will handle the line level, but I would not use a turntable on the Tape 2 input simply because you might want to keep it open for an equalizer, tape deck, or other signal processor.

[hifitommy]

if it isnt being used, why not use it for something worthwile. an eq is a waste in most systems because people tend to misuse them anyway. better to buy better speakers than an eq.

ive observed this behavior in friends who should know better. one saw my 5 band metrotec eq and got a 10 band per channel eq and tukrned his response intoa sawtooth and was proud. and this is a guy with a LOT of education and is a civil engineer. go figure.

[Woochifer]

if it isnt being used, why not use it for something worthwile. an eq is a waste in most systems because people tend to misuse them anyway. better to buy better speakers than an eq.

I agree that EQ's are often misused, but considering that the poster already has a reel-to-reel in their system, I would think that at some point they might want to add some other source that can make use of the monitoring function with the Tape 2 position, whether that be a tape deck, or any kind of analog signal processor. The Marantz 2275 has a good phono stage, I'm more partial to using it and leaving other options open.

[Analoguer]

If you can afford them, and you DO like Moving coils, try either the Sumiko Blue Points or the Dynavector 10X series - both will work into a MM input - you will have to crank the volume pot a bit though. Avoid used ones unless there guaranteed low hours: they're both non-user replacement stylus jobs. and last about a year-18months depending on usage.

[Resident Loser]

...as I am late to the party but...an MC step-up transformer is just that: a gain device...it must then be plugged into "phono" inputs or an outboard phono pre-amp(and THEN into a "line level" input) due to the need for the RIAA equalization curve...

If that was covered somewhere...never mind...

And I've realized too late I'm replying to the wrong post, but I'm too lazy to correct the oversight...

jimHJJ(...adios...)