JBL Concert Speakers: power & Connections?

[TLS Guy]

lovinthehd - fire them up is right; but first I am using the cautions of the Audioholics. Today, I powered on the Marantz rcvr, with the volume down; turned to AM and saw the Signal Strength Multipath? meter needle enter the fourth strength bar; but no audio through my headphones. So, I'm looking through the manual now.

That unit has two tape monitor loops. Make sure neither are engaged. The most frequent reason for no sound from those old receivers, is inadvertently engaging a tape monitor loop. If one is engaged you will hear no sound from phones or speakers.
These loops were for off tape monitoring from tape on three head machines during a recording.

 

[lovinthehd]

Yep a tape loop has been a mystery source of no output for a lot of us, just not used to it any more since my last tape machine was ages ago!

 

[kyrvas]

At least part of the electronics are functional. I'd think the headphones would be functional on insertion but you might also make sure there isn't an accumulation of crud in the headphone jack; even lint in a jack can cause issues....when will you try speakers?

PS You were sure to use the headphone rather than dubbing jacks?

lovinthehd - yes, I used the 1/4" Stereophones jack on the right front. Maybe, I need to connect an AM or FM antenna, although there is a ferrite bar antenna on the back which I swung out.

Okay, I'll peer in the phone jack, and try probing for lint. Since there are other inputs like tape, I'll try hooking a tape player up. Regarding the speakers, the JBLs are in storage; I just brought home the rcvr, amp, and cables. Did not try FM selection. I do have two portable Electro-Voice speakers to hook up to the rcvr..

 

[kyrvas]

That unit has two tape monitor loops. Make sure neither are engaged. The most frequent reason for no sound from those old receivers, is inadvertently engaging a tape monitor loop. If one is engaged you will hear no sound from phones or speakers.
These loops were for off tape monitoring from tape on three head machines during a recording.

TLS Guy - the Marantz last setting, out of the box, was on Tape but all the buttons are in out position including Monitor btns.

 

[kyrvas]

That unit has two tape monitor loops. Make sure neither are engaged. The most frequent reason for no sound from those old receivers, is inadvertently engaging a tape monitor loop. If one is engaged you will hear no sound from phones or speakers.
These loops were for off tape monitoring from tape on three head machines during a recording.

Regarding Tape deck, do I just plug it into Switched or Unswitched oulet?

 

[lovinthehd]

Switched would mean it would be powered only when the receiver is on, unswitched would mean live all the time.

 

[-Jim-]

Jim,

His JBL speakers don't have ¼ inch phone jacks. They use Neutrik SpeakOn male connectors for connecting female cable plugs.
Refer to the pics which the OP provided in a previous post. You will also see that he already has the proper SpeakOn female connectors on the cables that he took the pictures of.

My apology, I don't know how I missed that. With those Cables he should be ready to test the JBLs via the 2270.

 

[-Jim-]

lovinthehd - fire them up is right; but first I am using the cautions of the Audioholics. Today, I powered on the Marantz rcvr, with the volume down; turned to AM and saw the Signal Strength Multipath? meter needle enter the fourth strength bar; but no audio through my headphones. So, I'm looking through the manual now.

The Stereophones (Headphone) jack level on the front panel is controlled by the volume knob. Once inserted it should make connection. Once you dialed in an AM station, slowly increase the volume but first make sure none of the Tape Monitor buttons are pressed in. Actually, I'd leave all of the top row of buttons "out" until you get the fundamentals working.

Similarly, when you connect the JBLs as TLS advised, you will need to push the Main SPK button (top right) in before any signal will be directed to the amplifier section. Then slowly increase the volume. These JBLs should be rockin' with the 2270.

 

[kyrvas]

Switched would mean it would be powered only when the receiver is on, unswitched would mean live all the time.

Thanks for that; I can remember having a rcvr in the seventies with a Switched outlet but don't remember if it had an UNswitched one.

Still puzzled why the headphones are not producing sound; have tried another mini to 1/4" adapter and took your advice and cleaned the 1/4" opening but nothing unclean in there. Am now connecting a cassette tape deck and two small speakers; I'm hoping this works. The Marantz rcvr seems like a genuinely solid piece of equipment. Hope that age has not impaired it.

 

[kyrvas]

Well, Audioholics, still no sound output using the Marantz 2270: I have tried headphones with two different adapters (mini to 1/4"), selected AM then FM, with a strong signal in the meter; connected two cassette decks, an Onkyo and a JVC, both showing Peak Meter changes as the tape rolled; even plugged the JVC deck into AUX and set the Selector switch to AUX but still no sound to speakers.
Could it be that these cassette decks do not have preamps to power the speakers?

 

[TLS Guy]

Well, Audioholics, still no sound output using the Marantz 2270: I have tried headphones with two different adapters (mini to 1/4"), selected AM then FM, with a strong signal in the meter; connected two cassette decks, an Onkyo and a JVC, both showing Peak Meter changes as the tape rolled; even plugged the JVC deck into AUX and set the Selector switch to AUX but still no sound to speakers.
Could it be that these cassette decks do not have preamps to power the speakers?

It looks as if that old Marantz does not work. The cassette decks do not power the speakers. The Marantz has preamps and Power amps. Obviously at least the preamp stage of the Marantz does not work.

You will need to power the speakers with another receiver.

 

[-Jim-]

That's unfortunate. As there are pre-out / main in jumpers on the rear, as a last ditch attempt you could (after powering down) remove these jumpers and connect the output of a functioning cassette deck to the main in RCA jacks and try that.

If that doesn't work , you are headed to the repair shop.

 

[TLS Guy]

That's unfortunate. As there are pre-out / main in jumpers on the rear, as a last ditch attempt you could (after powering down) remove these jumpers and connect the output of a functioning cassette deck to the main in RCA jacks and try that.

If that doesn't work , you are headed to the repair shop.

Be careful if you do that. If you take the jumpers out and connect to the amp in, make sure any device you connect has a volume control. All controls on the Marantz will be bypassed including the volume control. So the receiver will be at max power. You need the volume control on any connected device turned right down at the start.

 

[kyrvas]

It looks as if that old Marantz does not work. The cassette decks do not power the speakers. The Marantz has preamps and Power amps. Obviously at least the preamp stage of the Marantz does not work.

You will need to power the speakers with another receiver.

Thanks TLS guy - I was hoping the Marantz was good since the lights came on and the Signal Strength meter responded; then I was hoping that your idea of interconnecting the BGW amp would solve the problem; of course hoping does not get it.

So, my personal rcvr is an old Onkyo that is connected to the usual maze of wires, with difficult access but knowing it works will be a better start point. This afternoon - that's my next step.

 

[kyrvas]

That's unfortunate. As there are pre-out / main in jumpers on the rear, as a last ditch attempt you could (after powering down) remove these jumpers and connect the output of a functioning cassette deck to the main in RCA jacks and try that.

If that doesn't work , you are headed to the repair shop.

Okay -Jim-, that sounds like a good approach. TLS guy gave me a heads up on the jumpers earlier in this thread; I even pulled them when testing the cassette decks but obviously did not know how they worked. Good idea!

 

[kyrvas]

Be careful if you do that. If you take the jumpers out and connect to the amp in, make sure any device you connect has a volume control. All controls on the Marantz will be bypassed including the volume control. So the receiver will be at max power. You need the volume control on any connected device turned right down at the start.

Whoa - good to know; one thought, the small test speakers now hooked up indicate MAX 30 Watts; so, with the volume down on source cassette deck am I still OK to proceed?

 

[-Jim-]

As long as you start from zero gain on the volume control and slowly increase it you should be fine.

 

[TLS Guy]

Whoa - good to know; one thought, the small test speakers now hooked up indicate MAX 30 Watts; so, with the volume down on source cassette deck am I still OK to proceed?

Yes.

 

[kyrvas]

Yes.

Volume control? On the JVC KD-V6 there is an INPUT LEVEL slider which the manual indicates controls the recording input levels; would this equal a volume control if I slid it to its Minimum?

 

[TLS Guy]

Volume control? On the JVC KD-V6 there is an INPUT LEVEL slider which the manual indicates controls the recording input levels; would this equal a volume control if I slid it to its Minimum?

No, that is not a volume control, that is an input control to set the record level and not playback level.

The output level control will act as the volume control.