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Replacing the power amp board with ICEpower

Thumpin6string

Thumpin6string

Supporting Member
Apr 25, 2013
7,054
12,477
Shoals Indiana
#1
I have an older A.M.P. 220 bass head with a blown power amp board. The parts to repair it are no longer available and the ones found online are counterfeit :poop:. Since I like the preamp section in this amp, I thought it would be cool to convert it to a class D. I have access to a couple ICEpower modules. So my question, has anyone here on TB replaced a class A/B power amp with an ICEpower module and if so, how hard was it? I haven't found much info on the wiring of these modules. I have electronic experience and have repaired amps in the past. Just want to see if this is feasible. Looking forward to the insight of my fellow TBers.
 
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#2
It's feasible. ICEpower has all kinds of documentation.
I've taken ICEpower modules out of "DJ" gear for re-use as small amps.
Check electronic forums, like DIYAudio to see how DIYers use the ICEpower modules.

If the head has the pre-amp you like, you can save it this way.

You'll probably save plenty of space in the A.M.P. chassis and can rig up some fan cooling if needed, including a piece of aluminum for passive cooling. Class-D is much more efficient but you do need to dissipate the heat.

It might also be feasible to use the power supply in the ice power for the existing pre-amp.

If your head has a separate pre-amp power supply you could just keep using it. But if it is not separate, you probably want to loose the big transformer if you can use the ICEpower SMPS for the pre-amp.

Double fuse it if you try it as the fuses on the ICEpower are soldered in, and you don't want to be changing them too often.
 
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#3
Someone on here did this with a Mesa Walkabout, years ago. There might have been a dedicated thread for it (I think so), but it might have been posted within one of the other Walkabout threads.
 
#5
Where does the preamp section get its power from? You may need a small DC dual power supply or you may get lucky if the ICE power has an auxiliary power output in the right configuration depending on the model. I tried to do this once with a Carvin BX500 but ran into problems as the preamp section required 3 different voltages and it wasn't worth the effort and expense.
 
#6
seamonkey said:
It's feasible. ICEpower has all kinds of documentation.
I've taken ICEpower modules out of "DJ" gear for re-use as small amps.
Check electronic forums, like DIYAudio to see how DIYers use the ICEpower modules.

If the head has the pre-amp you like, you can save it this way.

You'll probably save plenty of space in the A.M.P. chassis and can rig up some fan cooling if needed, including a piece of aluminum for passive cooling. Class-D is much more efficient but you do need to dissipate the heat.

It might also be feasible to use the power supply in the ice power for the existing pre-amp.

If your head has a separate pre-amp power supply you could just keep using it. But if it is not separate, you probably want to loose the big transformer if you can use the ICEpower SMPS for the pre-amp.

Double fuse it if you try it as the fuses on the ICEpower are soldered in, and you don't want to be changing them too often.
Click to expand...
Thanks for the info. I've searched, but haven't found if there is any power out that can be used to power the preamp or what the plugs on the ICE board go to. They seem to have several multi-pin plugs, but can't find info on them. It would be pretty amazing if I could get this to be a 300 or 500 watt light weight head.
 
#7
Thumpin6string said:
Thanks for the info. I've searched, but haven't found if there is any power out that can be used to power the preamp or what the plugs on the ICE board go to. They seem to have several multi-pin plugs, but can't find info on them. It would be pretty amazing if I could get this to be a 300 or 500 watt light weight head.
Click to expand...

Which model’s datasheet are you looking for, specifically?
 
#9
Thumpin6string said:
Thanks for the info. I've searched, but haven't found if there is any power out that can be used to power the preamp or what the plugs on the ICE board go to. They seem to have several multi-pin plugs, but can't find info on them. It would be pretty amazing if I could get this to be a 300 or 500 watt light weight head.
Click to expand...

I mentioned you should go to an audio electronics forum.
Still a quick internet search finds:
https://www.parts-express.com/pedocs/manuals/icepower-asp-series-manual.pdf

Better yet, sign up here
Homepage - ICEpower
Instrument Amplification - ICEpower
 
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#10
Last edited:
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#11
Thumpin6string said:
I have an older A.M.P. 220 bass head with a blown power amp board. The parts to repair it are no longer available and the ones found online are counterfeit :poop:. Since I like the preamp section in this amp, I thought it would be cool to convert it to a class D. I have access to a couple ICEpower modules. So my question, has anyone here on TB replaced a class A/B power amp with an ICEpower module and if so, how hard was it? I haven't found much info on the wiring of these modules. I have electronic experience and have repaired amps in the past. Just want to see if this is feasible. Looking forward to the insight of my fellow TBers.
Click to expand...

try this guy
Link Removed
 
#12
Keep in mind that a properly designed class D bass amp preamp has had a lot of thought put into the integration of the preamp and amp module. Those modules are quite finicky about the input signal they see and a truly well designed class D amp's preamp will have things like high pass filters and compression that are there specifically to make sure that the class D module and preamp "play nice together". I doubt that the AMP200 preamp has any such considerations. Not to say that it won't work, but that is a pretty cool amp in it's own right, and I would be inclined to recommend leaving it as in and investing in a proper class D amp, if that's what you are looking for.
 
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#13
R Baer said:
Keep in mind that a properly designed class D bass amp preamp has had a lot of thought put into the integration of the preamp and amp module. Those modules are quite finicky about the input signal they see and a truly well designed class D amp's preamp will have things like high pass filters and compression that are there specifically to make sure that the class D module and preamp "play nice together". I doubt that the AMP200 preamp has any such considerations. Not to say that it won't work, but that is a pretty cool amp in it's own right, and I would be inclined to recommend leaving it as in and investing in a proper class D amp, if that's what you are looking for.
Click to expand...
I just would like to keep this amp out of the garbage heap. The preamp works great through every amp I've tried it through. I already have a class D head that suits me well. That is why I came up with the idea. It could be the first Amplified Music Products class D head.
IMG_0335.JPG
 
#14
Passinwind said:
The data sheet for the 300AS1 is here, and calls the entire connector pinout set: ICEpower 300AS1 - ICEpower Shop
Click to expand...
Thanks for that. I've seen similar. I guess some of the pins are confusing. Most power amp boards I've seen have power in, output, preamp in, maybe a power out to the preamp and sometimes a mute. I guess I don't understand all the signal sense pins and the trigger pins. Are these for a specific use and maybe not used in my possible project? The others are self explanatory.
 
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#15
I would be inclined to repair the existing power amp, some techs have access to legacy parts that are either genuine or well thought out substitutes.

What parts failed? Has the power amp been thoroughly AND accurately diagnosed?
 
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#16
Thumpin6string said:
Thanks for that. I've seen similar. I guess some of the pins are confusing. Most power amp boards I've seen have power in, output, preamp in, maybe a power out to the preamp and sometimes a mute. I guess I don't understand all the signal sense pins and the trigger pins. Are these for a specific use and maybe not used in my possible project? The others are self explanatory.
Click to expand...
You are going to need to understand how these all work, there are no shortcuts.
 
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#17
Thumpin6string said:
Thanks for that. I've seen similar. I guess some of the pins are confusing. Most power amp boards I've seen have power in, output, preamp in, maybe a power out to the preamp and sometimes a mute. I guess I don't understand all the signal sense pins and the trigger pins. Are these for a specific use and maybe not used in my possible project? The others are self explanatory.
Click to expand...

Wiring harness: Home

But - you may not be ready for this. :( It does take some knowledge and experience to retrofit and amp into a head.
 
#18
agedhorse said:
I would be inclined to repair the existing power amp, some techs have access to legacy parts that are either genuine or well thought out substitutes.

What parts failed? Has the power amp been thoroughly AND accurately diagnosed?
Click to expand...
A couple of the power transistors are bad. The power transistors that were bought for it were the Ebay Chinese ones. The amp worked great, but the transistors failed within about a minute. Luckily nothing else failed. Currenently, it will power on and the preamp works. I've ran it into the power amp in on several amps and it sounds great. It is the same power amp used in the Eden WT300 and 400 and the Thunderfunk 420.
 

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