Hi folks. My Spectral DMA-90 amp is blowing woofers, even with proper MIT cabling and Spectral DMC-12 pre. Does anyone work on these things? I've called every Spectral dealer in the country, with little luck, and I'm trying to communicate with Spectral's home base right now, but it's a challenge. Anyone know of a repair person outside of Spectral, that may repair this amp. Any help appreciated.
Spectral Amp DMA-90 circa 1993-Does anyone in the universe work on Spectral gear?
- Thread starter severeear
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Maybe one of your contacts could at least supply a schematic? I would think that would be enough to let an experienced audio tech diagnose the issue. I suspect the design is not really all THAT exotic, though the hint of some sort of sliding bias is a little scary.
I don't think their web site has been updated in many years. They seem to still be in business; are they not responding to phone calls at all?
An quick internet search shows you are not alone, and others have tried for years to get Spectral to respond to them. There are no Spectral dealers in the U.S., just the factory, so if they don't want to support their existing products, you are in for a tough time.
I have a Spectral DMC-12 that I was able to service with some input from prior designer Demian Martin, and then I figured out the rest. Fortunately many of the active devices are still available, but not all. I ended up replacing the power MOSFETs and caps and doing the needed adjustments, and fortunately the metal can transistors and the NPD op amps are good, but I ended up lowering the drive voltage a little because these run pretty warm and I want to eek out as many years as possible.
I've never seen inside a DMA-90 - is yours open so you can post a photo or two?
My avatar at the left is actually the same preamp:
An quick internet search shows you are not alone, and others have tried for years to get Spectral to respond to them. There are no Spectral dealers in the U.S., just the factory, so if they don't want to support their existing products, you are in for a tough time.
I have a Spectral DMC-12 that I was able to service with some input from prior designer Demian Martin, and then I figured out the rest. Fortunately many of the active devices are still available, but not all. I ended up replacing the power MOSFETs and caps and doing the needed adjustments, and fortunately the metal can transistors and the NPD op amps are good, but I ended up lowering the drive voltage a little because these run pretty warm and I want to eek out as many years as possible.
I've never seen inside a DMA-90 - is yours open so you can post a photo or two?
My avatar at the left is actually the same preamp:
Blue Shadow
Waiting for Vintage Gear from this century
Maybe call Overtureav.com (800) 838-1812 to see what they say. It has been a few years since they were a Spectral dealer and might have dropped the brand because of lack of assistance, idk. But as a full service dealer you might be able to find out if there is somewhere to get repairs done or that you need to move on from the brand, something Overture would help their spectral customers do, as needed.
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I also have a DMC-12 and have been looking for information on how to set the bias and DC offset for many years. I believe I figured out how to set the offset but not the bias. Back in the day, I had a DMC-10 and the company provided the necessary information to set bias and offset for that preamp in the user manual. In fact I spoke with Rick Fryer on the phone several times back then about making the DMC-10 adjustments and he was very helpful. But it looks like that was the last generation of Spectral gear that included that sort of info. And for many years the company has clearly not wanted owners (or even dealers) making adjustments or repairing their gear.
Please do post, I'd love to hear about your experience in getting the DMA-90 serviced.
Hi all. As the same thing happened to a friend of mine (the Spectral smoked a pair of precious Altec 416/8B...), I'm interested to see the outcome as well.
(BTW I'm in Italy, it's very unlikely that my friend could use the same service of yours, but as a last resource maybe...)
Guido
(BTW I'm in Italy, it's very unlikely that my friend could use the same service of yours, but as a last resource maybe...)
Guido
I don't know if @severeear will be able to give an update - it's not uncommon for competent repair shops to have months of backlog - but I would like to take this opportunity to say benvenuto to AK!