Beltone AP-12 Dilemma

[bruceisashredder]

Hey guys,

I just picked up an old Beltone AP-12 ('58-'62) amp at my local music store. It had been sitting there for about 6 years on consignment, but nobody was interested. So I finally broke down and bought it. The pots were slightly dirty when I first played it, but when I took it home and cleaned it out real good, it sounds immaculate! Perfect amout of tone and you really get that 60's rock and roll sound. I am still faced with a few problems, however. The tremolo is not working at all, and the 1A fuse is missing. The on/off toggle also does not function. It looks like it had been modified, since the power chord does not look original. I think the on/off switch may have been bypassed for reasons I have no way of knowing. The speaker has likely been replaced since it is not deteriorting, like one from the 60s would be. I suspect that a fuse might be blown, therefore resulting in the tremolo not working (since this amp is fueled by all tubes) I'm just wondering if anyone here remembers these little amps and might have some suggestions on how to get the tremolo back in working order.

Thanks!

 

[Timbresmith1]

No fuse AND no switch?

 

[Timbresmith1]

As far as the trem not working, look for a footswitch jack on the back or bottom of the chassis

 

[W.L.Weller]

How are you powering it on and off? With the plug?

 

[Wally]

Got a tech? As @Timbresmith1 hints, no switch and no fuse equals a dangerous situation.

 

[bruceisashredder]

How are you powering it on and off? With the plug?

View attachment 934189

The amp is always on. You must unplug it to turn it off.

 

[Wally]

The amp is always on. You must unplug it to turn it off.

The lack of a switch and a fuse indicates..imho…that this amp needed a tech long before you found the amp.

 

[W.L.Weller]

Replacing/re-connecting the switch and fuse, and changing the power cord to a grounded one should be done before you plug this amp in again. If you don't know how to do that, take it to someone who does.

For what it's worth, the fuse being blown and the tremolo not working are two unrelated conditions. If the fuse is still connected properly, and it is blown, then the entire amp should not work. Since the amp makes sound when plugged in, then the fuse is not blown, or is not part of the circuit anymore.

If the fuse, like the switch, is no longer part of the power transformer's connection to wall voltage, then it wouldn't matter whether it's blown or missing or made of green cheese.

 

[bruceisashredder]

As far as the trem not working, look for a footswitch jack on the back or bottom of the chassis

Footswitch wasn't included.

Replacing/re-connecting the switch and fuse, and changing the power cord to a grounded one should be done before you plug this amp in again. If you don't know how to do that, take it to someone who does.

For what it's worth, the fuse being blown and the tremolo not working are two unrelated conditions. If the fuse is still connected properly, and it is blown, then the entire amp should not work. Since the amp makes sound when plugged in, then the fuse is not blown, or is not part of the circuit anymore.

If the fuse, like the switch, is no longer part of the power transformer's connection to wall voltage, then it wouldn't matter whether it's blown or missing or made of green cheese.

There is no fuse in this compartment. It is likely that several modifications have been made to this amp. I am not sure if whoever decided to make these modifications meant for the fuse to be left out.

This is the power cable

Also, the fellow who modified this left this tube chart inside the bottom of the amp.

 

[Timbresmith1]

Footswitch wasn't included.

View attachment 934235
There is no fuse in this compartment. It is likely that several modifications have been made to this amp. I am not sure if whoever decided to make these modifications meant for the fuse to be left out.
View attachment 934244
This is the power cable
View attachment 934245
Also, the fellow who modified this left this schematic inside the bottom of the amp. I am not very sure if this is relevant, but it seems to be.

That’s just a tube chart.

We know there’s no footswitch, but if there’s a jack to plug one in, you can make a shorting plug, so you can test the tremolo

 

[Wally]

Footswitch wasn't included.

View attachment 934235
There is no fuse in this compartment. It is likely that several modifications have been made to this amp. I am not sure if whoever decided to make these modifications meant for the fuse to be left out.
View attachment 934244
This is the power cable
View attachment 934245
Also, the fellow who modified this left this schematic inside the bottom of the amp. I am not very sure if this is relevant, but it seems to be.

That is not a schematic. That is a tube chart. The power cable is an ungrounded power cord and for safety should be replaced with a 3-wire grounded AC power cord that is installed by an experienced tech. Whoever bypassed the fuse did NOT a know what they should have been doing. This indicates that whoever did it had very little experience an d therefor no regard for the safety of the amp or anyone who might use the amp.
Again, imho, you need a tech.

 

[Teleguy61]

Please pay attention to Wally and others who say "No switch and no fuse is potentially trouble".

You need to have this checked out by a tech.

 

[Timbresmith1]

Also, let’s see a pic of the whole amp. That covering looks cool!

 

[bruceisashredder]

That is not a schematic. That is a tube chart.

My bad. Still I wonder why they included this.

he power cable is an ungrounded power cord and for safety should be replaced with a 3-wire grounded AC power cord that is installed by an experienced tech.

Yeah. It looks like a chord off a vacuum cleaner or something. I suppose I'll never know why this person decided to modify this amp to begin with. I've never been zapped or anything, but I don't trust that it is hazard-free.

"No switch and no fuse is potentially trouble".

I think these both were wrongfully bypassed, and I've no clue why anyone would want to do that.

Also, let’s see a pic of the whole amp.

 

[Timbresmith1]

They included the chart so you’d know what tubes and where. They don’t last forever. In the olden days, tubes were commonly available at the drug store (along with tube testers). You could take tubes out of your device, test them, and buy replacements.

 

[Timbresmith1]

My bad. Still I wonder why they included this.

Yeah. It looks like a chord off a vacuum cleaner or something. I suppose I'll never know why this person decided to modify this amp to begin with. I've never been zapped or anything, but I don't trust that it is hazard-free.

I think these both were wrongfully bypassed, and I've no clue why anyone would want to do that.

View attachment 934256

Cool!

 

[schmee]

Cool amp!

 

[W.L.Weller]

@bruceisashredder the picture in my post above is a schematic. If it's Greek to you (which I'd assume it is, if you're calling a tube chart a schematic), and you like how the amp sounds, then I'd look for someone near you who has a good reputation for fixing amplifiers. A grounded cord, re-connected/replaced switch (it's possible that the switch was bypassed because it stopped working) and re-connected fuse holder should only be an hour's worth of bench time and maybe $10 for the switch + fuse.

The tech may suggest replacing the electrolytic filter & bypass capacitors, but this amp looks to only have four electrolytic caps. So it shouldn't take too long or cost too much.

 

[24 track]

I have 2 of them and the matching Beltone guitar, great sonding amps that kick hiny I also have the AP14 mine is all original but I did swap the A/C cables

these tiesco made beltones were made for Canada only and never were for sale in the states , there was a model called the chessman ( I believe ) that was released in the states.
Beltone ended up being a hearing aid company, This guitar is a beltone , but the same guitar ( all made by tiesco as well) sold under the name of Carvin, Kawaii, and Beltone, also known as a Hound dog Taylor ( as he used this and a similar model of 4 pick up Tiesco for slide exclusively.), the tube chart in the amp is accurate the AP14 has a different configuration of tubes

these amps breakup at a reasonable level and have a fine tube crunch , I have actually gigged with mine and it has enough juice to drive a 4X12 LOL the tremolo is tube driven

 

[NTC]

Beltone ended up being a hearing aid company,

They wanted to keep serving the same customers...