AMi K Jukebox sounds muffled

Hi All,

I have an AMi model K juke (mono) with sound that is a little unclear or muffled. It has good volume and bass.

I have recapped the amp and replaced all the tubes. This helped the sound greatly, however I would like it better.

It has an M44C cartridge and a (new) shure needle. I think this may be where the problem originates. I have checked the speakers and the wiring an all appears to be fine.

I also own a mono AMi Continental. The sound is much better from the Continental (and I thought it should be the same or very similar as the amps are the same). The continental has a Stanton N400 cartridge and needle.

Is it worth installing a new cartridge? Which cartridge should I get?

What should I try next?

Hope someone can assist.

Thanks in advance

Gordo.

"Gordo" when you find a marked difference between machines with similar amp/speakers a little detective work is needed.

Have you tried cross-connecting the Continental amp to the K's speakers?

Another test is to connect the pickup cable from one to the other. This may reveal more capacitance in the pickup cable.

I've owned:
H-200
I-200 Mech sel
J-200 (stereo)
Continental 1 (200 sel)
Continental 2 (100 sel)

ALL of which were on the dark side sonically. I used a Pickering DAT (V-15 series) then modded the preamp to reduce the RIAA curve thus adding treble, and finally added an additional high efficiency horn tweeter to the pre Continental machines.

On the Continentals there was no need to add the tweeter but the other mods did help.

Those old Atlas horns in the late 50's machines were, well, laid back to say the least. Add to that the fact that they were padded down in the crossover and you can't expect much high end.

On the I-200 that I still have I changed the whole volume control setup from the original to a more typical cathode follower and dual-tapped pot. this accomplished two things; it got rid of the DC on the volume control (noisy) and allowed an additional place where some tone shaping could be done.

The starting point is to determine where the objectionable differences occur and then we can decide what to do. Personally, while the Pickering tends to be brighter the types of Shure stylus that can deal with that tonearm unmodded will have a thicker cantilever and thus more "sing" due to stylus talk so it will appear brighter than the higher grade styli.

Rob/NYC

Hi Rob,

Thanks for taking the time to respond.

I had not thought of switching the cables, good idea. I was going to swap the amps over but the input cable may eliminate a problem (and easier).

Thanks

I will let you know how I get on.

Regards

Gordo.

Hi Gordo,
Just replacing caps, does not "rebuild" the amp--there are probably some resistors that have drifted--I think I would swap amps first, to see if the poor sound followed an amp, or cart. Ron Rich

Hi Gordo,
Just replacing caps, does not "rebuild" the amp--there are probably some resistors that have drifted--I think I would swap amps first, to see if the poor sound followed an amp, or cart. Ron Rich

I agree with Ron. It's very possible there are some carbon resistors that have shifted in value over the years and are out-of-tolerance.

Hi All,

An update.....

Following your advice I had the amp checked and any (minor) issues fixed. This is difficult in Australia as no Jukebox technicians are available. I found a guitar amp guy who was willing to try.

He found a few things in the amp that required attention.

I swapped the amp with my Continental. It improved the sound a little but not greatly. I then put a new needle into the juke.

Now, with the amp fixed, and a new needle, it sounds great!. I am surprised how good this has worked out. Obviuosly a combination of issues that needed fixing.

Thanks everyone for your assistance and advice.

So, thanks to you all, my Wurly 1700 sounds good and my AMi sounds good. The next challenge is a Seeburg C (which is in transit from the USA).

Thanks again, I would not have gotten this far without your assistance.

Gordo.

Hello Gordo,

I know of at least two companies in Tasmania and a couple more on the mainland.

If you PM me with your contact details and locations in Australia I will find what information I have got.

Regards
Alan

Alan Hood
ami-man
UK