Rowe Ami Jel Base Speaker

Hi Everyone

I am down to just one jukebox now the Jel I parted company with my trusted old Jal

The jel looks better or should I say has seen less action but my old Jal sounded better..

I swapped both the amps from my Jal to my jel to see if it was them but the sound quality was still not as good I even swapped the cart and styli but still the same..
The sounds quality doesn't seem as crisp too much base if you know what I mean.
With my elimination of every thing else I figured it's got to be the speakers?
I think...
So I checked the speakers for damage but they all seem ok
The only thing I could see that was different between the two jukeboxes was that my old Jal had the 12inch Jensen Base speaker where the jel has what appears a unbranded one.
My question is could the base speaker affect the overall sound quality?
I have noticed the base sound is stronger in the jel and does give me a headache after a while..
Any ideas guys or am I barking up the wrong tree

The JEL-JAl was the first jukebox I played as a kid in the sixties, so I have some affinity for it.

When I bought one and rebuilt it in 1988 I was disappointed in the sound quality, particularly the "headache bass"

The problem stems for Rowe's design of a passive acoustical "crossover" for the woofer which places a speaker with a high resonance point of 70-72 Hz in a constricted enclosure.

This same scheme was also used in L-M-N-O.

What I did:
1) Replaced the original tube amp with a Rowe MM-2-3 transistor "100 watt". These have much deeper bass boost which is somewhat below the enclosure resonance point. It did fix the bass issue. I was placing the machine commercially and needed a lot more power anyway.

2) Replaced the Shure 77 pickup with a Pickering-Stanton 500 series. The greatly helps clean up the mids and treble.

3) Modified the transistor preamp for approx 7 db more high end @ 12KHz

4 Replaced the 4X6 "tweeter" with a 2" horn and crossover. I made a filler plate to mount the horn in the same space as the original spk.

This resulted in a good, listenable machine with enough power for my location.
AFAIK; Rowe used Jensen speakers in all of those machines. All were 16 ohm. If there is something else in there I suggest first measuring it's impedance to be sure it is 16. Beyond that you might try either a newer speaker w/a lower resonance point and/or using an actual crossover to reduce the amount of upper bass energy fed to the woofer.

I didn't bother to experiment with many mods to the preamp, which is where the tone is shaped in those machines. What I did try didn't improve things enough.

BTW: On the N and O models I removed the internal bass baffle, cut an additional three 3" inch holes in the front kick plate and placed a metal screen to protect the woofer which was then mounted directly on back of the front face of the machine. Everyone agreed that the bass was 100% better. Rowe went to this more conventional method in following years.

Rob/NYC

Many thanks for the input Rob..
Given me a few things to ponder
Will let you know how I get on

Mark. UK

Hi, Mark, I like you have a love for the Rowe Ami Jal and Jel I have had six of them, and restored three for other people. still have three of them two in the living room along with a Seeburg 201 and a AMI K 200. The other is in my little workshop, not allowed in the house. that's women for you. The jal in my opinion is an excellent sounding jukebox, when set up right. I may be stating the obvious to you here, but the usual case on theses jukeboxes is that the speaker wires have been cut at the pug where they connect to the amp, depending on where they are connected to the speaker terminal strip on the amp can make a big difference to the sound. I have fitted several Rowe Ami jukes with the teac ah 300 seperates amplifier. one of these will give you a very crisp clear sound and reduce the base somewhat. of course keep the valve amp for when you want to sell the box. of course you will loose the mute function but that's neither here or there. also is the oval high frequency speaker working in the front, as this is connected in parallel to the base speaker. I have used the shure m447 DJ cartridge and stylus in all my jals and they certainly improve the sound quality. Harry.

Hi Harry...
Thanks for the update..I have seen some of your jukeboxes on eBay..like the two tone Jal..
The wiring on my Jel is original..not butchered..plus the front speaker works..like you I use the Shure M44-7 cart.
The teac amp is giving me something to think about.is it difficult to sort out the speaker wiring ?
Ps....I have a Jal which needs restoring stashed at work for the last year
Haven't told the Mrs about that one......yet

Regards Mark

HI, Mark, the speaker wiring, is a bit of an oddball, not quite what you would expect, you put all the positive wires from the speakers together, same with negative, (Red Yellow Blue, together ) ( Orange Green White, together), theses connect to the two positive poles on the Teac amplifier speaker connections. one set to each pole, you can split them between the earths and the positive, but sounds crap. fit a three pin socket inside the juke prior to the transformer to give you the 240v for the amp to plug into. I made brackets for the amp to fasten to the back of the jukebox so it is not seen and easy access for volume etc, but not to high, or your phono leads won't reach. also don't forget to unplug your valve amp, not point in burning valves when not in use, also remove the mute plug. You need the Teac Ah 300 it is small and compact, you should get one off ebay for around the £60 mark. And of course you will be able to play cds Ipods etc through your jukebox, but you can't beat vinyl. You must be different to me I like a lot of base, I have come across a lot of sixties Rowe Ami jukes with the speaker wires cut at the plug this was due to problems in the speaker wattage switch. you then reconnect them to the speaker terminal strips in the appropriate locations. I am in need of a JAL or JEL mech cover if you know anyone who has one. I restored a couple of JEL'S for a guy in Bradford last year, The photo's of them are on my Ebay profile. I have another JEL waiting in the wings all repaired and working, just need to decide whether to coca cola it, or to Budweiser it, as I think in their original form were a bit drab. If I can help any way in the future pm me Cheers Harry.

Folks, a general note of caution in using a conventional amplifier in the Rowe machines.

Since the cart is wired out of phase it is understandable that you must place the speaker load across the channels. The potential problem is that this means that a given load draws twice as much power from the amp due to the load being in phase-opposing poles.

If only the center speakers were loaded this way (they are 16 ohms) this effective represent an 8 ohm load. With all speakers connected in parallel and across channels, this now being approx 5.3 ohms load, it is now effectively a little over 2.5 ohms as seen by the amp.

A 2 ohm load is generally OK in professional amps, in consumer stuff it usually represents an overloaded condition.

Hopefully, the amp has internal protection, but its best to watch the levels and bass.

Rob

Hi, Rob, I realize that is the way I have done it, but did it that way for sound quality, the Teac ah 300 amp is a very good quality amp and handles the job great. Had one fitted to a JAL now for over two years, which is used every week on my jukebox Saturday nights. Of course no way would you turn up the volume to far or bye bye speakers, well under half is still a to loud for the next door don't like loud music squad. Harry.

Rob-NYC wrote:Folks, a general note of caution in using a conventional amplifier in the Rowe machines.

Since the cart is wired out of phase

Just to clarify - is the 'phase swap' done in the cartridge itself, the wiring between tonearm and preamp, or in the preamp? I always throught it was done in the pre-amp, but here you make it sound like it's in the cart itself?

Hi, Foxtrotxray, there is no phase swap, Rowe Ami's are wired this way at the cartridge, ie earth bottom, live middle, earth top, and other live to middle. So you could say Rowe Ami had their wire's crossed. Thus the speaker connections are across the two channels to get the better sound quality. the Teac ah300 is very capable of handling this. I have fitted several of these amps to jukeboxes I have sold, because the original amps were shot and the model of jukebox was not worth the cost and time of an amp rebuild. never had anyone come back with a shot amp. And they do sound very good.

djricksha wrote:Hi, Foxtrotray, there is no phase swap, Rowe Ami's are wired this way at the cartridge, ie earth bottom, live middle, earth top, and other live to middle. So you could say Rowe Ami had their wire's crossed. Thus the speaker connections are across the two channels to get the better sound quality. the Teac ah300 is very capable of handling this. I have fitted several of these amps to jukeboxes I have sold, because the original amps were shot and the model of jukebox was not worth the cost and time of an amp rebuild. never had anyone come back with a shot amp. And they do sound very good.

That's really effin' good to know then. I had thought (when I made my new audio cables) that I had flipped a pair of wires, since my phases weren't reversed. But, no, I had just not reversed the wires onto the cartridge.

I'm surprised that those amps (the Teac, and any other one..) could handle that. Impressive!

HI, they were a very good amp in their day close to top of the range. I have got the teac ah500i which I have tried, sounds good but way to powerful for a jukebox. Rowe Ami did a few things back to front like the tone arm on the opposite side to everyone else hence cartridge back to front. And employing some numpty to design their cabinets in the seventies.

Rob,
"numpty"--wasn't that guy a member of the Geppetto Clan ?? Ron Rich

Hi, Ron, close, but not quite, A geppetto knows what he is doing wrong. The numpty doesn't. Harry (The Numpty)

Hi Harry,
You MAY have a point---!
Ron Rich