Hi all, n00b here. A friend of mine was cleaning out his storage unit and sold these two modules to me for a fairly nominal price...I'm not concerned with how much I paid for them. I was wondering if anybody recognized what amplifier they were originally out of (he said that it was a 5 channel 200W Adcom...nothing comes to mind. edit: under the heatsink, you can see a part number with 1998 as the manufacturing year).
As you can tell from the pictures, they're pretty complete and they've been tested...he said that I all I need to do is supply AC and I'm good to go. The RCA input's on there and I've also included a picture of the "output" part...how do I use these? There's also a four-pin connection on the board with 12V DC/Clip/GND/Protec listed, is it necessary for me to use this information and regardless, how do I go about representing it? Are they all just LED indicators? Lastly, is a proper chassis necessary for grounding/? concerns?
Any help would be great as I figured this would be a nice way to get started on things...I can understand technical concepts fairly well, but I'll probably still be asking a bajillion questions.
As you can tell from the pictures, they're pretty complete and they've been tested...he said that I all I need to do is supply AC and I'm good to go. The RCA input's on there and I've also included a picture of the "output" part...how do I use these? There's also a four-pin connection on the board with 12V DC/Clip/GND/Protec listed, is it necessary for me to use this information and regardless, how do I go about representing it? Are they all just LED indicators? Lastly, is a proper chassis necessary for grounding/? concerns?
Any help would be great as I figured this would be a nice way to get started on things...I can understand technical concepts fairly well, but I'll probably still be asking a bajillion questions.
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I have a GFA-7000, and it uses the same type of construction, and the boards look just like that. But...the manual says the filter caps are 12,000µf 63V, whereas yours are 12,000µf 80V. Since the rail voltages on the amp are 63V, Adcom might have upped ther voltage...or you just have a different amp.
The GFA-7000, 7500, and 7700 all used this type of build.
You need a transformer (the diode bridge is on the module), and connections for input. There is also connections for a clipping LED, and thermal protect.
The GFA-7000, 7500, and 7700 all used this type of build.
You need a transformer (the diode bridge is on the module), and connections for input. There is also connections for a clipping LED, and thermal protect.
Can you tell what ratings the transformers are since they're all monoblock designs? I'm working on all the connectors, but that's no big deal. Lastly, a few fuses...he had said something like an 8A fuse, but I dled the 7700 manual and it lists them as "for 115 volt operation...15 amp 250 Volt".
Hi EvilYoda,
The ADCOM amps with 4-digit part numbers (7500 vs. 555) use MOSFET output devices. So, they typically use dual transformer secondaries, one high-power set for the amp and one low-power set for the higher voltage Gate drive circuitry. By the looks of the power caps and dual rectifiers, this seems to be the case on your modules. I'd recommend buying the $25-$30 manual from ADCOM (or $15 on eBay) and verifying the transformer secondary requirements. It's the safest bet to keep from damaging those nice power modules.
Cheers!
Paul
The ADCOM amps with 4-digit part numbers (7500 vs. 555) use MOSFET output devices. So, they typically use dual transformer secondaries, one high-power set for the amp and one low-power set for the higher voltage Gate drive circuitry. By the looks of the power caps and dual rectifiers, this seems to be the case on your modules. I'd recommend buying the $25-$30 manual from ADCOM (or $15 on eBay) and verifying the transformer secondary requirements. It's the safest bet to keep from damaging those nice power modules.
Cheers!
Paul
Hi EvilYoda,
The people at Adcom are all new to me (they were bought out and moved a while ago). They are a very helpful bunch. I do not believe you will get any free info (not surprising, and completely fair).
They can be reached at http://www.adcom.com/ . Just navigate to the service link and send an email.
I did have occasion to talk to them, they were very helpful. More so than I have experienced with some other companies. I would buy the manual from them.
-Chris
The people at Adcom are all new to me (they were bought out and moved a while ago). They are a very helpful bunch. I do not believe you will get any free info (not surprising, and completely fair).
They can be reached at http://www.adcom.com/ . Just navigate to the service link and send an email.
I did have occasion to talk to them, they were very helpful. More so than I have experienced with some other companies. I would buy the manual from them.
-Chris
Those modules look like 7XXX amplifier modules. They should be pretty good sounding, although I never listened to them.
I tested that series shortly before I left Adcom and they measured very well. I may have even established/wrote the bias proceedure, but it's been a long time & the memory is fuzzy.
No, I don't think they're MOSFETS, they should be plain old BJTs. BTW - This is not a Nelson Pass design, but a Bob Gallien (Gallien-Kruger bass amps) design. C. Victor Campos said Bob was one of the most straightforward & practical engineers he ever met.
Cheers,
I tested that series shortly before I left Adcom and they measured very well. I may have even established/wrote the bias proceedure, but it's been a long time & the memory is fuzzy.
No, I don't think they're MOSFETS, they should be plain old BJTs. BTW - This is not a Nelson Pass design, but a Bob Gallien (Gallien-Kruger bass amps) design. C. Victor Campos said Bob was one of the most straightforward & practical engineers he ever met.
Cheers,
anatech said:
Sooo...that may be the reason why the market was flooded with all the 12kuf 80V Sprauge caps for a while. I bought a box of them when they hit the streets. Too good a price to let pass by,and they are still being flogged by some folk. You know how they (companies) dump stock when changing hands and location... I was happy enough to get the nearly free caps. Not good for the guys who like their warranties to be intact, but hey, I'm not directly involved. Until I bother to go and get that 585. At least I'll hear what an Adcom sounds like, again.
To digress from another thread
p), what brand and model scopemeter would be found of feabay that is of a decent quality?- Status
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