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Repurposing a broken Rumble 200

#21
No panels needed, cab is closed beneath the amp once it’s removed, crossover is in head, I left the Tweeter disconnected.
Drilled a hole and put in a 1/4” jack.
Got it for 20 bucks, perfect little livingroom amp.

May put in a simple bass remove Cap later , for the Tweeter,sounds fine now without it.
Works fine with a Valeton TAR 20b
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#22
/\/\3phist0 said:
No panels needed, cab is closed beneath the amp once it’s removed, crossover is in head, I left the Tweeter disconnected.
Drilled a hole and put in a 1/4” jack.
Got it for 20 bucks, perfect little livingroom amp.

May put in a simple bass remove Cap later , for the Tweeter,sounds fine now without it.
Works fine with a Valeton TAR 20b
View attachment 7307092View attachment 7307100View attachment 7307102
Click to expand...
Also should mention: does just fine with mt 150 watt Trace Elliott GP7.
 
#23
agedhorse said:
The Rumble is different than the Frontman, that’s why we are discussing the challenge of dealing with the crossover.
Click to expand...
I get that if it's an active crossover, the amp has separate LF and HF outputs and the switch only controls the circuit, then it's a challenge.
But if the amp has a single two-lead output which feeds a passive crossover with an LF output and a HF output feeding the horn tweeter through a simple on-off switch, it shouldn't be a problem, right?
And at the very worst, if the crossover or tweeter doesn't work, if there's a short or something, then it's down to a single 15" driver with no HF horn, but it's still usable, right?
 
#24
Yeah, I really need to open it up and see how many wires lead to the speakers. A friend of mine is guessing that there two wires leading to the woofer, from there to a very simple crossover, to the tweeter, but I haven't checked.
 
#25
@/\/\3phist0 above mentioned that the crossover is in the head, so you'll have four wires from the head to the speakers.
You have three options:
1. Use just the woofer. A 15" cab is nothing to sneeze at.
2. Buy or build a crossover and wire the speakers properly.
3. If the crossover is passive, locate the crossover network on head PCB and cut it off at where the amplifier ends and the crossover begins. Then solder your input wires to the input pads of the crossover.
 
#27
RitterSport said:
If the crossover is in the head, then I'm just going to use the 15 inch speaker.
Click to expand...

Four wires come from the head. Therefore the crossover is in the head, on the main PCB.

In all honesty: the tweeter is not needed, the woofer has plenty of high frequencies. The tweeter is overkill.
Especially when you use drive.
Piezoelectric tweeters are often very harsh (true in this case)

I have vastly more sophisticated amps/ heads to compare it to, and it’s a very serviceable cabinet at low to medium volumes.

A little boxy sounding, I was going to add some poly fill stapled to the sides, or a bit of foam, but it is fine as it is, since I don’t plan on gigging with it.
 
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#28
toughluck said:
I get that if it's an active crossover, the amp has separate LF and HF outputs and the switch only controls the circuit, then it's a challenge.
But if the amp has a single two-lead output which feeds a passive crossover with an LF output and a HF output feeding the horn tweeter through a simple on-off switch, it shouldn't be a problem, right?
And at the very worst, if the crossover or tweeter doesn't work, if there's a short or something, then it's down to a single 15" driver with no HF horn, but it's still usable, right?
Click to expand...
You aren't getting it though, there is a PASSIVE crossover that's located in the amp chassis and there are 4 SPEAKER wires that go to the woofer + tweeter.

THIS is why I posted what I did.
 
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#29
Fair enough, I started writing a reply before I read the reply by @/\/\3phist0 and that the crossover is in the head (and I understand it's on the same PCB).

Assuming the crossover isn't failed and doesn't present a short, it should be safe to saw off the part of the PCB before the crossover, sand the varnish off from the copper leads that were between the amp and the crossover and solder the input jack to that exposed copper, right?
 
#30
toughluck said:
Fair enough, I started writing a reply before I read the reply by @/\/\3phist0 and that the crossover is in the head (and I understand it's on the same PCB).

Assuming the crossover isn't failed and doesn't present a short, it should be safe to saw off the part of the PCB before the crossover, sand the varnish off from the copper leads that were between the amp and the crossover and solder the input jack to that exposed copper, right?
Click to expand...
Oh boy, only the highest quality work, eh?

Sure, in theory that would work but in practice may not be all that practical

What would be better is just repairing the amp and avoid the butcher-kluges.
 
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#35
Just out of curiosity, I had a look at the Service Manual schematics for the Rumble 200 (the Service Manual covers the Rumble 40, 100, 200 and 500).
Available here:
https://www.fmicassets.com/Damroot/Original/10002/Rumble 200 V3 Schematics-Diagrams.pdf

The "crossover" and switch for the Rumble 200's horn consists of a 1uf/250volt film capacitor, an 8.2 ohm 5 watt (10% tolerance) resistor, and a switch in series.

Here is a simplified version of the diagram in the Service Manual:

X-over.png


The resistor; the capacitor; the connection points for the jumper wires from the ICEPower module; and to the horn switch; as well as the output connector to the speaker and horn are all located on the bottom section of the Input/Output board, which is mounted on the back panel:

Crossover location.png


So, if you were careful, it WOULD be possible to "saw off" the bottom section of the Input/Output board that contains the components and redo the proper connections,
BUT, I think that it would be EASIER to just buy the appropriate value resistor and film capacitor and a SPST switch.
Or desolder and re-use the originals.

Connect the four speaker wires from the P106 output connector together so that the speaker and horn are connected in parallel
(RED and WHITE positive wires together, and the two BLACK negative wires together).

Connect the parallel pairs to a 1/4" TS jack mounted on the back of the cab (RED & WHITE wires to TIP, and BLACK & Black wires to sleeve).

Then cut the RED positive wire between the jack and the horn, and splice in the capacitor, resistor, and SPST switch in series.
Mount the switch on the back panel with the jack.

Shouldn't be very difficult.

Now running and hiding from Agedhorse.... :nailbiting:
 
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#37
toughluck said:
Or not saw off anything, but just plug in that WJ201/WJ200 jumper pair to the speaker jack. No soldering needed, the amp board stays in place, even the horn switch works.
Click to expand...
I was assuming that the amp was to be removed completely from the cab.

If the amp IS to be left in place, I would disconnect the AC socket, and ALL of the removeable connectors between the Control, Input/Output, and ICEPower boards, just in case!
 
#38
KenB said:
Just out of curiosity, I had a look at the Service Manual schematics for the Rumble 200 (the Service Manual covers the Rumble 40, 100, 200 and 500).
Available here:
https://www.fmicassets.com/Damroot/Original/10002/Rumble 200 V3 Schematics-Diagrams.pdf

The "crossover" and switch for the Rumble 200's horn consists of a 1uf/250volt film capacitor, an 8.2 ohm 5 watt (10% tolerance) resistor, and a switch in series.

Here is a simplified version of the diagram in the Service Manual:

View attachment 7317654

The resistor; the capacitor; the connection points for the jumper wires from the ICEPower module; and to the horn switch; as well as the output connector to the speaker and horn are all located on the bottom section of the Input/Output board, which is mounted on the back panel:

View attachment 7317669

So, if you were careful, it WOULD be possible to "saw off" the bottom section of the Input/Output board that contains the components and redo the proper connections,
BUT, I think that it would be EASIER to just buy the appropriate value resistor and film capacitor and a SPST switch.
Or desolder and re-use the originals.

Connect the four speaker wires from the P106 output connector together so that the speaker and horn are connected in parallel
(RED and WHITE positive wires together, and the two BLACK negative wires together).

Connect the parallel pairs to a 1/4" TS jack mounted on the back of the cab (RED & WHITE wires to TIP, and BLACK & Black wires to sleeve).

Then cut the RED positive wire between the jack and the horn, and splice in the capacitor, resistor, and SPST switch in series.
Mount the switch on the back panel with the jack.

Shouldn't be very difficult.

Now running and hiding from Agedhorse.... :nailbiting:
Click to expand...
You haven’t seen the butcher jobs that I have…
 
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#39
KenB said:
I was assuming that the amp was to be removed completely from the cab.

If the amp IS to be left in place, I would disconnect the AC socket, and ALL of the removeable connectors between the Control, Input/Output, and ICEPower boards, just in case!
Click to expand...
Absolutely! At the very least, if the power inlet is push in (not screw-in) and removing it would leave a gaping hole, I would cut all wires going to the power inlet and put shrink tubes on the stumps.
Or pour wax into the inlet so nobody gets the stupid idea to plug anything in.
 
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