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Need some help please. The old speakers a set of BOSE Companions worked fine using the front speaker jack. Just tried to setup a set of KRK Rokit5 Studio Monitors on my 7000 using the rear L-R audio jacks. I'm using a set of TRS 1/4 inch to LXR shielded cables for balanced output. I have them plugged into the rear jacks. When the rig is turned on I have a slight buzzing sound. Then when I transmit its sound just like the monitor is on, but it's not. There is feedback from somewhere. What am I missing? Thanks for your help!

Mike W4OCO

What your are missing: you did not read the user manual, combined with the fact that the user manual is confusing and even inaccurate in places, and therefore did not understand that the 1/4" TRS speaker outputs on the back of the radio are NOT balanced line level outputs. They are amplified speaker outputs on the most bizarre and confusing connectorization possible.

Each connector is the output of a bridge-tied 2W amplifier that expects a speaker coil across the tip and ring and nothing on the shield. These should have been provisioned as more traditional speaker connectors, e.g. a terminal strip of some sort. Provisioning this interface on a TRS connector has only been a recipe for trouble.

Sadly, there was a factory decision to not bring left and right line out to the rear panel. That is really what you want. Those signals do exist inside the radio if you ever want to modify things.

In the meantime, your only recourse is to get a 3.5mm stereo to dual RCA cable, plug it into the headphone jack, and use the unbalanced RCA inputs on your speakers.

Scott,

I actually did read the manual and could not find anything
To help me. Then I searched the forum and could not find much information there either. Are the 7000 and the 8000’s
Setup the same as far as the 1/4 inch jacks? It sort of defeats
The purpose of running a set of monitors. Guess I’ll make
Up a set of cables and give it a try. Thanks for your help.

Mike

Hi Mike,

I just reviewed the 7000 manual and it is indeed completely deficient in describing those connectors. The manuals are produced by volunteers for Apache. The 8000 and prior manuals are somewhat more informative, not that helps!

Yes, nothing in the forum yet on this topic, but there is now! That is why the forum is so important, it helps preserve information like this and make it easy to search out. So thank you for posting your problem!

All of the radios, from the ANAN-10 forward, and even the original Hermes board, utilize the same interface, which is based on the TPA0202 stereo amplifier IC. The Orion MkII schematics are available directly from the factory on request, however if you go to the schematics sub-forum here and look at any of the other schematics the audio circuits, comprised of a CODEC IC and a stereo amplifier IC, are identical across all radios.

I use a pair of JBL LSR305's. I thought they would be overkill but instead they turned out to be one of the best investments I've made in the station to date. You'll love those Rokit's when you get them properly hooked up.

73!

Scott

Scott,

I have a friend with an 8000 who is using the rear speaker jacks and it works fine for him. The 8000 manual states that it has a balanced L-R output using TRS connectors so I guess it's different than the 7000. I ordered the Y Connector and cables tonight to hook up to my 7000 the way you suggested. Thanks again for your help!

Mike

Mike W4OCO wrote:I have a friend with an 8000 who is using the rear speaker jacks and it works fine for him. The 8000 manual states that it has a balanced L-R output using TRS connectors so I guess it's different than the 7000.

It is NOT different. The output circuitry and connector wiring on that interface is IDENTICAL across ALL radio models. It is NOT a balanced line level output no matter WHAT the manuals say. Check the schematics. If it is working for your friend he is just getting lucky somehow. I would not want to chance attaching a 2W amplifier output to any line level input.

To further foot stomp this, the 7000 and 8000 both use the Orion MKII SDR board. There are tiny differences in the board revision between the two radios, but, again, ZERO difference in this area.

73,

Scott

Thanks Scott you answered my question that there suppose to be the same on the two rigs. I guess Terry just got lucky. So I guess you could use the Audio our plugs on the back with the plugs wired mono and feed it to the unbalanced input on the speakers. Just curious on how the rear outputs could be used if at all. My plans are just to use the output on the front.

73
Mike

It's not conventional mono. It's not stereo. It's tip to one side of a voice coil, ring to the other side of a voice coil, no connection to shield. Don't ground tip or ring, don't plug in a mono connector, lest you damage the amp.

Not planning on using the back audio connectors! Might modify later when warranty is out to make them usable.

73
Mike

Schematic snippet, for reference:

Hello fellows, Apaches!

I have been playing with 7000dle for over a month and digesting a lot of information from this forum and other venues on how to best setup and operate this radio (is it a radio or a computer?).

Now to my similar case. I have the issue with the connecting speakers, Yaesu SP-9000, on rear jacks (L / R). On SSB TX there is the feedback issue. I cannot use the speakers in this arrangement. Using Yamaha headset plugged in the front port does not have the issue.

I am going to use the front stereo jack as suggested via a proper cable hook up to the Yaesu speaker.

Rafael / NN3RP