Built in Phono stage question - preamp

[Pablo]

I have a new Marantz PM7000N receiver, as I mentioned in other threads. I find it excellent for my office sound. Really zero complaints.

But I have a question about phono preamps. Not looking to add anything, because the integrated preamp is excellent. Honestly - I mean a phonograph itself is not precision electronics. Marantz did a good job.

So my question. How are people adding a preamp using a the same receiver? Reading about on the web - no gains are claimed so to speak, but some how people do it. How? There are no preamp outputs, no way to bypass the integrated preamp. Can't just drop one in line after the player, seems like it will be overdriven and just add noise. Maybe I'm missing something basic. Hook one up and turn the gain down??

Example reading: https://duckduckgo.com/?q=bypass+phono+stage+Marantz+PM7000N+receiver&t=ffab&ia=web

 

[alarmguy]

If I am reading this right. An external preamp would plug into a "Line In" input on the receiver.

 

[Pablo]

If I am reading this right. An external preamp would plug into a "Line In" input on the receiver.

It could I suppose that would bypass the phono stage preamp. Makes complete sense just a DUH moment on my part. Good preamps have gain settings

 

[Jetronic]

I have a new Marantz PM7000N receiver, as I mentioned in other threads. I find it excellent for my office sound. Really zero complaints.

But I have a question about phono preamps. Not looking to add anything, because the integrated preamp is excellent. Honestly - I mean a phonograph itself is not precision electronics. Marantz did a good job.

So my question. How are people adding a preamp using a the same receiver? Reading about on the web - no gains are claimed so to speak, but some how people do it. How? There are no preamp outputs, no way to bypass the integrated preamp. Can't just drop one in line after the player, seems like it will be overdriven and just add noise. Maybe I'm missing something basic. Hook one up and turn the gain down??

Example reading: https://duckduckgo.com/?q=bypass+phono+stage+Marantz+PM7000N+receiver&t=ffab&ia=web

if you add an external phono pre-amp, you use it with any of the other line inputs, the phono input on the receiver will not be used. So it behaves like a cd-player or tape deck.

Back when I was a kid, phono stages on amps and receivers were noisy, you switched to the phono stage and were greeted by static.

But the one on the Yamaha amp I have now (honestly the whole thing is in another league from the 70s/80s stuff I had) is almost dead silent. I mean, I can hear static if I turn the volume to max and stand close to the speaker. IIRC it's 96dB SNR, considering my best records fail to go much over 50dB it's more than good enough.

So I can see why you don't need an external phono stage. But some people like them because they want to colour the sound they get. After all, the phono stage and the cartridge are 2 peas in a pot, so change either and you might get different sound.

 

[berniedd]

You say you're satisfied with the built-in phono input. Therefore you really don't need another preamp. Well, yes and no. That phono-in jack, the specs say, are for MM (moving magnet) cartridges. There is another type of cartridge, the moving coil (MC). It is said this type delivers better fidelity than the MM type. But the MC type is more expensive than the MM, and perhaps more importantly, it produces a much lower signal output. Using a MM phono-in with a MC cartridge will not produce the desired high fidelity sound output. So, if you want to use a MC cartridge, you'd have to use an external preamp (that connects to your LINE IN input jacks) designed specifically to work with the MC cartridge type. It's a matter of more amplification, RIAA equalization, and correct impedance matching.

 

[Pablo]

You say you're satisfied with the built-in phono input. Therefore you really don't need another preamp. Well, yes and no. That phono-in jack, the specs say, are for MM (moving magnet) cartridges. There is another type of cartridge, the moving coil (MC). It is said this type delivers better fidelity than the MM type. But the MC type is more expensive than the MM, and perhaps more importantly, it produces a much lower signal output. Using a MM phono-in with a MC cartridge will not produce the desired high fidelity sound output. So, if you want to use a MC cartridge, you'd have to use an external preamp (that connects to your LINE IN input jacks) designed specifically to work with the MC cartridge type. It's a matter of more amplification, RIAA equalization, and correct impedance matching.

I doubt with this turntable I would go with a MC cartridge.

 

[mk378]

The integrated preamp is almost always based on an 8-pin dual op amp chip. In a basic receiver it will likely be the very ordinary generic "general purpose" 4558 chip. There are many other choices of low noise / high performance amplifier chips that drop-in replace the 4558. Unsolder the chip and install a socket so you can swap freely. The whole project is only a few dollars.

 

[Pablo]

The integrated preamp is almost always based on an 8-pin dual op amp chip. In a basic receiver it will likely be the very ordinary generic "general purpose" 4558 chip. There are many other choices of low noise / high performance amplifier chips that drop-in replace the 4558. Unsolder the chip and install a socket so you can swap freely. The whole project is only a few dollars.

Check out the schematic for the Marantz PM7000N.

Anyway not soldering on a new receiver

 

[Pablo]

Marantz PM7000N phono stage:

 

[dubber09]

Imho, if you're not doing critical listening with top end headphones or speakers, there is no need to spend time and money on top end equipment in between phono cartridge and sound reproducing device, unless you just want to or want bragging rights.

 

[Pablo]

Imho, if you're not doing critical listening with top end headphones or speakers, there is no need to spend time and money on top end equipment in between phono cartridge and sound reproducing device, unless you just want to or want bragging rights.

Yes. Mainly I am just curious.

 

[ka9mnx]

The output of your phonograph is low impedance and low gain like a "line out". Your receiver has a phono input which takes care of that. No external amp needed. My old tube amp had no line in so the only way to play records was with an external amp/impedance matcher.

 

[Pablo]

The output of your phonograph is low impedance and low gain like a "line out". Your receiver has a phono input which takes care of that. No external amp needed. My old tube amp had no line in so the only way to play records was with an external amp/impedance matcher.

Didn’t read my question

 

[ka9mnx]

Didn’t read my question

Guess I misunderstood your question.

Went to the search you posted. Apparently, people want to bypass the phono input for some odd reason (I didn't read them all the way through). In that case yes, they would need a preamp for the reasons I listed. I wouldn't see any advantage to do that. I would just use the phono input already provided by your receiver. I would guess Marantz would know what they are doing.

 

[Pablo]

Guess I misunderstood your question.

Went to the search you posted. Apparently, people want to bypass the phono input for some odd reason (I didn't read them all the way through). In that case yes, they would need a preamp for the reasons I listed. I wouldn't see any advantage to do that. I would just use the phono input already provided by your receiver. I would guess Marantz would know what they are doing.

Thanks yes I came to the same conclusion

 

[Pablo]

I scored an Ortophon red premounted cartridge for just over $100. That should satisfy my itch to see if I can hear a difference. Haha haha

 

[Pablo]

You say you're satisfied with the built-in phono input. Therefore you really don't need another preamp. Well, yes and no. That phono-in jack, the specs say, are for MM (moving magnet) cartridges. There is another type of cartridge, the moving coil (MC). It is said this type delivers better fidelity than the MM type. But the MC type is more expensive than the MM, and perhaps more importantly, it produces a much lower signal output. Using a MM phono-in with a MC cartridge will not produce the desired high fidelity sound output. So, if you want to use a MC cartridge, you'd have to use an external preamp (that connects to your LINE IN input jacks) designed specifically to work with the MC cartridge type. It's a matter of more amplification, RIAA equalization, and correct impedance matching.

Here is Marantz manual statement as well:

"
This unit is compatible with turntables equipped with a moving magnet (MM) phono cartridge. When you connect this unit to a turntable with a low output moving coil (MC) cartridge, use a commercially available MC head amp or a step-up transformer.
If you set this unit’s input source to “PHONO” and accidentally increase the volume without connecting a turntable, you may hear a humming noise from the speakers."

 

[hank2]

I've been largely out of the audio hifi universe for 25 years. There are, or used to be a number of high output moving coill cartridges. Not as high of an output as a moving magnet but high enough to use with a moving magnet phono stage.

Prevailing opinion used to be, if going to a moving coil cartridge, buy way up. Also have a turntable and other gear that's higher end. There were a number of very highly regarded MM cartridges up the scale a bit. The Sumiko Blue Point was a very popular moving coil cartridge decades ago. I think that was a high output MC. Was $99, now $499. for the budget version.

 

[Hermann]

I scored an Ortophon red premounted cartridge for just over $100. That should satisfy my itch to see if I can hear a difference. Haha haha

Ortofon Red's can be a bit shrill without proper loading and alignment.

 

[sparky123]

The built in phono stage of your Marantz (from what I've read on the forums) sounds pretty good. You would have to spend many hundreds and another interconnect cable if you wanted a different sound and possibly an upgrade in sound quality. I'd kept it as is and not go down that "audiophile" rabbit hole. (BUT...if you're willing to spend $89 buy a Pro-ject Phono Box E and see if it has better synergy in your system.) I have the "blue" Ortofon on my TT w/ this inexpensive Pro-ject Phono Box E. Sounds less analytical than my other Parasound phono pre-amp. All about system matching. One thing I would do if you're using a RCA interconnect, is buy a really good one. Wireworld Equinox (which uses OCC-7N copper) is affordable and does make a difference. BTW, the Marantz looks really nice. You made a good choice going for the Marantz!