The AM Forum

WARNING - Ignorance clearly revealed

What is your recommendation for a speaker to use with a 75A-3 on AM?

I almost bought a ClearSpeech DSP but then thought maybe that is the wrong answer for boatanchor AM listening. I am not an audio wizard (as you can plainly see) so rather lost in the woods.

73
Jack

Hi Jack....I use a Halli R-46 on my A3.
It sounds better than the other speakers that I have but this depends a lot on the speaker cone condition.
My R-46 has the original 10" speaker and the cone is in good shape.
If you find one with a bad speaker they can be reconed easily for cheap.

Dave has a very good suggestion. The Clear Speech will take all of the essence and warmth of AM away and give you telephone quality audio.
The DSP box might be good for SSB and doing digital magic to clear up QRN noises....somewhat.

Any big old stereo speaker is fine.  Unhook the Tweeter, its  Not needed for AM use and only adds Hiss and noise.  I have matching speakers to the rigs where possible.  Lots of times I use the Jensen "vintage" speakers.  By now, most speakers are shot.  You could build a wooden box and put a jensen inside. Then paint/ cover it to match.

http://www.jensentone.com/

any nice speaker on a 75A-3 will be wasted with the stock single ended audio stage -- the audio quality sucks.  You have to tap the audio gain pot wiper and bring that out the back with in a shielded cable and run it into a push pull tube amp driving a speaker.  I tried a number of pickoff points but W3JN was right--the best tap point is the AF pot wiper.  Put a 0.1 uF cap on it and connect the other side of the cap to a phono cable with the shield grounded.  snake it through a back cabinet vent to the input of an audio amp.  try finding one with a built in preamp.  I use an old Heath SE2 or SE3 amp running a pair of 6BQ5s. About 12 w. audio driving a big old stereo speaker.  Pull the audio tube in the 75 A-3 and lay it down in the back.

I have a Behringer 45 watt keyboard amplifier with a nice big speaker. Should work just fine. I hardly ever use it since my Fender KXR100 sounds so much better with my theremin, with a dash of spring reverb.

Philip

The 75A3 audio takes a full rework to sound good as it was designed for the restricted AM of those years. Then into any decent 10-12" speaker. I have the matching speaker on my A3 but Ive tried several others and all are about the same. The Hallicrafters  8" R-42 bass reflex is also very nice.

Most of the time I use decent headphones anyway. Most bands have so much noise and QRM that good PP audio is wasted, I can rattle the windows with the HRO-60, SX-28, SX-42, SP-400X and a few others with PP 6F6 or 6V6's but for what?. The speakers are mostly for show.

Carl

True but a strapping signal is a beautiful thing on p.p. audio and a speaker.  I am getting to where I give two kinds of signal reports:  speaker quality and headphone quality.   ;D

We had a thread on pretty much this topic not too long ago...

My favorite speakers are the equivalent or the actual speakers that you might have found in any typical 50's and early 60's console hi-fi or "stereo". That would be a lightweight paper cone, usually paper surround, and high sensitivity. The key is both the high sensitivity, meaning that it has limited power handling and is designed to run off a low power amplifier.

These older speakers usually have small diameter voice coil which usually means that the driver will run higher in frequency than a large diameter voice coil...

I have used everything from 8" to 15" drivers of this type. They tend to sound warm, clear and rich... like you remember AM radio being! :D

The earlier comment on not using tweeters is good, imo...

The old sealed back Jensen midrange drivers, with a cap in series to block the lows is all that is needed if you want or need a bit of "presence rise" in the speaker. Or a more modern small speaker or midrange will do as well.

If you see old console radios being chucked, grab the speaker boards!

I got some Magnavox "Golden Voice" drivers that are quite nice that way.

The cabinet for these older drivers is not terribly critical... they'll work open baffle.

                     _-_-