How to connect a vintage receiver to a power amp...

Howdy folks, I hope that everyone is doing great. I could use a bit of help, or at most some reassurance. For the sake of audio experimentation and exploration, I've been curious as to how my old Marantz 2270 would sound (particuliarly the phono section) if properly connected to the rest of my system, which includes a McCormack DNA .5 power amp, KEF 104.2 speakers, Morrow IC's, and a Rega RP6. Before I start stuffing holes with cables, I just want to make sure I'm doing it correctly. If this has been covered in another thead, please kindly dirrect me there.

There is a Pre-Out on the back of the Marantz, so I'm assuming I would just connect a pair of RCA's from that directly to my power amp, correct? However, there is some kind of "plug" covering the Pre-Out and Main-in...never messed with either before so I'm not really sure how to approach that. Any help is always appreciated! Thanks.

 

Just remove the jumpers from the Pre Out to Main In, and connect the Pre Out to the power amp. It's as easy as that.

 

Nice.

 

Yep. Make sure the volume control is very low before turning on etc.

 

And always turn the power amp on last, and off first.

 

Ok, awesome. I thought it was pretty simple, but I've never came across stuff with te jumpers so I wanted to make sure.

Do the jumpers just unscrew? I've never really looked at them much. I doubt they have ever been removed.

Also, do I just leave the Main-In uncovered?

 

I think you'll find that the Marantz ones are like big blunt staples and just pull out.

 

They should just be RCA connectors, and pull right out. Unless Marantz installed some sort of anti-tampering safety cover. It's hard to tell without seeing your particular unit.

And yes, just leave the main uncovered.

 

The jumpers should just "pull out".

 

The pre/main bridge is where you would loop in an equalizer or other sound processor. Pre-out outputs the line level signal of whatever source your receiver is currently playing, and the main-in is the input to its actual amplifier. Of course when you don't have an equalizer in the loop, the connection has to be bridged, otherwhise the receiver would remain silent. That's what those jumpers are for. So if you want to use a different amplifier, you route its pre-out to that one instead.

Incidentally you could also use either of the pairs labelled "record", because they also output the line level signal of what the receiver is currently playing. They are meant to be connected to a tape recorder to allow it to record, but you can use it as a source for another amp just the same.

 

So, in my case, you're saying to connect the Pre-Out to my power amp, correct? Do I need to do anything with the Main-In inputs? Can I just leave them open/uncovered? Thanks!

 

Just leave them uncovered. They haven’t seen fresh air in decades and would appreciate it

 

OP,

If you only want to use the phono preamp in the reciever, follow anorak2 suggestion. It should sound better than using the preamp section of the Marantz receiver.

Just connect a pair of ICs from the record RCA jacks from the Marantz to any line level input jacks on your preamp. Set accordingly.

Set the function switch on the Marantz to phono.

Note . No need to pull the pre-out main-in jumpers if you use the tape record RCA jacks. You still should turn the volume control all the way down to minimum on the Marantz receiver though, even though the preamp and amp section will not be used, they still will be active in the receiver.

You probably should be able to use the tuner in the Marantz as well. Just set the function switch to FM or AM.


.

 

Thanks jea, I appreciate it! Out of curiosity, I think I may just have to try it both ways to compare, haha. Thanks for the clarification.

 

Just to clarify, DO NOT connect the tape out to the input of your power amp. If you just want to use the phono and tuner sections of the receiver, then you should connect the tape outs to an available line level input on your preamp. If you want to use the full function of the preamp in the receiver and by-pass or replace your main preamp, then you can connect the preamp outputs of the receiver to the power amp inputs.
-Bill

 

Thanks Bill, always a pleasure to hear from you. I tried it the first way, Pre-Out of the recevier to power amp and things worked fine (I'll post my listening impressions later). I then tried the other method...Record 1 to power amp. First of all, there is no volume/gain knob on my power amp. As soon as I powered up the receiver and then the power amp, I noticed a bit more hum than usual. I dropped the needle and holy #$@!, it was LOUD! Hahaha! I immediately looked to turn the volume knob on the receiver down (thinking I had maybe forgot to do that), but it was completely off. Lesson learned, nothing blew up, so it's all good.

There are no Tape outs on my receiver, only Record 1 and 2, and Play 1 and 2. Are Play 1 and 2 the "Tape outs" you're referring to? I've never used tape equipment, so I'm a little lost.

 

Record 1 and Record 2 are the tape outs. They are not subject to the volume control or other controls. (Play 1 and 2 are the tape ins.)
Going from PRE OUT is the correct way. Make sure the speakers are switched OFF on the receiver.

 

The tape RCA jacks will output Line level of the source set by the source selector switch on the front of the Marantz receiver. The preamp section and volume control for the preamp are not in the tape circuit.

You cannot connect a line level output source directly to the inputs of your power amp. (You cannot vary the volume as you discovered).
You need to connect them to the line level inputs on a preamp, and connect the output of the preamp to the power amp. I guess I just assumed you had a preamp for the power amp.

From my previous post:

 

I'm sorry if that happened because of my advice. I never thought your main amp didn't have a volume dial. Of course it's a given that the "record" output of a receiver is unaffected by its volume setting. Then again I assumed the same for the pre-out, only to learn here that that assumption was also wrong.

 

There's another interesting RCA jack that I'd never heard of before on that receiver, but it will be pretty useless:

"In anticipation of future four channel quadraphonic broadcasting, your model is equipped with an FM QUADRADIAL OUTPUT jack. The signal available at this jack is the unequalized, buffered output of the FM discriminator. Its level, frequency response characteristics, and output impedance are ideal to drive a four channel adaptor. This jack can also be used as a simple "white noise" generator for checking the response characteristics of loudspeakers or amplifiers. For this application, place the receiver in FM mode with the muting off, and tune between FM stations to receive interstation noise."​

 

It was quite a discovery! Hahaha! I do have a preamp that I normally use with my power amp. I was just curious as to how the receiver would sound while using my power amp instead.

 

It's all good man! No worries...nothing exploded. I'm certainly aware all these things now for sure! I have another power amp that does have volume controls, but not the one I had connected. Looks like we're all learning a lot!!!

 

Ok Help ..i have a Marantz 4270 70wpc x2 or 25wpc x4.. I bought a Marantz 250m power amp . 125wpc x 2.. so I disconnected the front left and right speakers and hooked them into the 250m. Then I went from the preout fronts into the left and right of the power amp.. I make sure the reciever is in 2 channel mode..
I turned the volume all the way down on the reciever thinking it would be LOUD..
Amp lights up .meters start to jump..
Now I've got the volume on the reciever turned to the 11 o'clock possition...ITS NO LOUDER (that i can notice) than before hooking up the amp. .GRRRRR.. now it's seems I can turn the volume knob wayyy louder before it starts to distort..
I call my local 80 yr old tech..
He laughs and says that's not how it work !!! I going what the hell..
He says I'll be able to turn it way louder before it starts to distort.. (more head room) is he correct?
I figured going from 70 wpc to 125 wpc would blow my ears at the 12 o'clock possition..
Please teach me before I buy another 250m for the rear channel
Thanks

 

Hey guys - great info here thanks so much for the contributions

I have a Marantz 2240B and just looked - I was going to hook up to a Tube amp and use as a pre-amp - I just looked and I dont have jumpers from the Pre-out to Main-In ??? Make sense to anyone ?

Thanks

 

This brings back some memories. I had a 2270 for over 20 years. Enjoy the music!!