Mr. Zinda 10 Posted February 1 Posted February 1 Hello to all, I recently had both of my QSC 3500 srues 3 amps act up on me and forced me to start a search for new amps. I was lucky enough to find a Sunfire 300? I'm not exactly sure what the model is but it's a 300wpc amp. It works fine but the light for the joule meter doesn't light and when I took a look into replacing it I found it only has 0.6V at the light contacts and on the board where the wire attach. Disconnecting the bulb didn't change anything and I don't understand the low voltage. Nothing looks obviously burnt and I would never expect a light circuit to go bad, at least I've never seen that before. I am using this amp to power my Electroststic panels in a set of Martin Logan Prodigy's, I have tried it on the woofers but didn't like it as much as a temporary replacement QSC GX5 amp. What Carver amp will work nice on a 2 ohm load running up to 250Hz? I'm used to not hearing any fans and have changed out the GX5 fan and reduced the speed to where it's tolerable. I plan to find another Carver for the woofers and will be looking for a pre. I'm open to anything that will sound good since my speakers will reveal anything good or bad. I'm using an active crossover to separate the sound and I've bypassed the prodigy woofer crossover with great improvement in deep bass.the load is 2 ohms per channel there are 2x10" scanspec woofers in each cabinet. The QSC amps have no problem running them but does Carver have an amp that can do it? One last thing, with the age of most Carver amps how reliable can they be at this point, am I better off looking for something newer or can I depend on a Carver to stay working while playing at moderate levels? I'm busy reading through posts here and I'll check back to see what everyone has to say. I have to be truthful when I was looking for new amps I had no preference but luckily stumbled on the Sunfire for just $225 and took a gamble on it working, that had started me on building a Carver system I have my eye on a PM1201 and a pre. I'm just worried about the age. Ty! 7 1
jmcipale 91 Posted February 1 Posted February 1 Without having access to a service manual, I am not sure if the 0.6V is low or is expected. If you have something as simple as a DMM w/continuity checker and a copy of the schematic, you can trace the signal path. That is the thing I would suggest. Others are far more experienced (I am sure there are a few retired techs who can offer far better advice than myself). Good luck.
Kurt 3,167 Posted February 1 Posted February 1 (edited) Welcome to the Carver Site! I'm not a guru like many of the folks on this site. And, I don't know much about the Sunfire amps. But, I have several Carver amps. I'd think most any Carver amp would be robust under the conditions you mention. But, to your point, some are getting older. I've had my gear updated and upgraded by Nelion (you can find them on this site). My m1.5t mkII's put out nearly 500 WPC now and have all update components. I'd think they could handle your woofers. I use mine on Infinity Kappa speakers that can dip down to 1 Ohm in some circumstances. Never had a bit of trouble. And, under normal to moderately loud listening conditions the m1.5t's barely get warm. Edited February 1 by Kurt
xavionics 2,278 Posted February 1 Posted February 1 Welcome to THE Carver site! You have many options. Depends on what your budget is and what your expectations are. (of course, we would LOVE to see you go full-monte and do a complete Carver/Sunfire setup) 1. Fix the QSC amps and continue as you were. Likely the cheapest in the long run. 2. Either do a refresh on the Sunfire amp or send it to Nelion. https://nelionaudio.com When you get it back, try it out in different configurations and judge for yourself, to see if you will want to dig deeper into the realm of OCCD. 😄 I can't speak to the Sunfire gear, but the Carver gear (and others) I have refreshed and/or rebuilt perform better, after some attention, than they did when they arrived on my bench. 3. Get a second Sunfire amp and have it refreshed, just so you will have a matching pair. (yep, we do that around here.) 4. Get a third Sunfire amp, so you can drive each single ML woofer with its own amp channel. (assuming each woofer is 4 ohms on its own) 5 Begin collecting other Carver, Sunfire, Phase Linear gear. Just 'cuz, well, its there... As for reliability of any of these 40+ year-old amps, anything can fail. Any brand. At any time. My 1988 Carver m1.0t started acting up about 16 years ago. Researching that problem lead me to this site. I rebuilt it myself and performed all the available mods to it. It was used in my main system since then. Or, at least until I gave it to my son for his 30th birthday (with the matching c-1 pre) last spring. Oh, and OCCD = Obsessive Carver Collecting Disorder. There is no cure, only management treatments. Lastly, Going active with the Martin Logans - sweet! That gotta sound good! Now get some good, powerful, musical, accurate electronics to drive the drivers... am I being too enabling? 1
BobTFM35 3,039 Posted February 2 Posted February 2 (edited) Welcome to the Carver Site!! If I'm not buying new I would look for models that have a good service community to take care of the age concerns. Luckily one such vendor, and a site member @Nahash5150 , has the abilities to not only service it and extend the life, but has options to increase the power for some models. His link was given above. I would take a look at the page below to help determine which amps I would be going after, and what kind of upgrades are available for it. Surely the M 1.5t with the mkII upgrade will give you possibly the kind of power what you need. In that description you see mention of the PM1200. That opens up having a place to restore the 1201 you are looking at. Nothing worse than buying an amp that nobody wants to work on. https://nelionaudio.com/index.php?/services.html/carver/carver-amplifiers/ Edited February 2 by BobTFM35 1
Mr. Zinda 10 Posted February 4 Author Posted February 4 On 2/2/2026 at 10:54 AM, BobTFM35 said: Welcome to the Carver Site!! If I'm not buying new I would look for models that have a good service community to take care of the age concerns. Luckily one such vendor, and a site member @Nahash5150 , has the abilities to not only service it and extend the life, but has options to increase the power for some models. His link was given above. I would take a look at the page below to help determine which amps I would be going after, and what kind of upgrades are available for it. Surely the M 1.5t with the mkII upgrade will give you possibly the kind of power what you need. In that description you see mention of the PM1200. That opens up having a place to restore the 1201 you are looking at. Nothing worse than buying an amp that nobody wants to work on. https://nelionaudio.com/index.php?/services.html/carver/carver-amplifiers/ I understand that, when I do get anything serviced I never consider doing anything "extra" to any amps, simply because I understand that you'd need to double the power before you'll get s noticable amount of power increased but I am always interested in things that make it run cooler or quieter. I've been avoiding amps with fans but with the hard load they'll be running (albeit not at concert levels) it reduces the choices available. I do have a few insights into what really happens to older components and I'll bet I won't make any friends when I show my results from removing parts in mass using s torch and scraping parts off boards that are between 50 to 25 years old (I don't bother with any caps made after 2000, they're basically all bad). I have about 20 milk crates (used to be twice that) that have been sitting outside for over 2 years in direct sunlight in AZ and in the rain every day uncovered and I've been bringing in random boards and collecting parts and then testing those parts, I like to keep parts around just in case I see something going (things made after 2000). I've done all the boards with big caps, I would separate them into piles that represent bad (over 10% out of spec), within 10%, within 5%, perfect and slightly above within 20% extra. I would count how many of each manufacturer that I tested and then get a ratio of number of good to unusable. What I found was the ratio even among the most obscure makers was very small. The worst offenders were Elna! They were about ⅓ bad in just about all sizes, really bad in the smaller lower voltage (6v to 25: 47uf to 2200uf). Others were about ⅒ or less, finding them barely out of spec was typical but I've tested brand new caps that were 20% low. The next was Ruby with mostly larger size failures. Then a large swath of unknown makers mostly very common sized. Many brands like Su'con and other off brands tested good but they're mostly smaller sizes in undemanding situations. Years ago even the cheapest junk electronics used Ruby and Nich caps, many VCRs were loaded with them. I had pictures of all the good tested caps but there's so many now that it would take up a huge space to show them in one shot. The amount I tossed was barely anything in comparison. I've been slowly doing this for years. There were a few makers that had nearly every one in the perfect or 5% category one was named HI10 or HI8 (I think) others were Chemcon, Sprague, Wilson, these were mostly the biggest sized to boot! HI10 are all medium sized around 35v 3300uf. I can tell by looking at the cases filled with 400v caps and only a few are Ruby or Nitch, no Elena at all. But heres the one thing I found amazing when I tore apart an old ogan from 1972 and I found no bad parts at all, I removed 6 big cardboard caps and tossed them in the milk crates and they sat for years outside, the leads are rusty on one of them and they all test within 5% or 2%! Cardboard case! I'll have to look to see who made them. So to me there may be a bad cap popping up after many years but the chance is actually quite slim, what I did find was many big ceramic resistors where way out of spec with resistance being 100x spec. So when something does burn out it's not the fault of the cap but more likely a bad resistor or a diode that ends up taking out a cap due to wrong polarization for a brief moment or over voltage for a long time. Caps don't pop from being low on storage they pop because of over voltage or reverse polarity. Being under spec will show up as distortion or noise, of course heat isn't good for a cap but it's not the main cause of failure, high heat is from once again improper voltage going to transistors and rectifiers that will be hot normally but not excessively hot. If the piece performs as it should I would not worry about it until there's a shift in sound on one channel or obvious noise. Then I can see having it serviced but there's always something for sale that can be found for less than a repair and it's much easier to just move on and continue without the need to repair plus there's no guarantee that the repair will last unless the entire board has all new components and has been set up correctly, even then there's no guarantee that the issue won't manifest itself again just due to design. Some things were never meant to last. Trying to squeeze out every last bit of power is not how I do it. I overshoot with my amps so I'm never entering that point where I'm stressing the amp. Always playing in the sweet spot and never even coming close to seeing clipping lights on anything I own. Most people don't think twice about turning an amp up to 10 daily, I would double the watts and stay at 50%. Car stereo has taught me this lesson along with a million other car audio issues like supplying enough voltage and current before even considering building a system that's pulling major power. I've advised many and had few listen when asked about installs, you'd think if someone asks you for advice, they'd just take the advice and try to do it correctly. I find a month later the same person is now asking me about an even more powerful amp when I just explained that the last amp didn't have enough voltage and current, they disagree thinking it was a weak amp, then the 2nd amp burns up and they quit talkng to me and start looking for another amp or maybe running more wires to the amp. Typically that's my first suggestion that has minimal cost but it's still too much work to do things right the first time. Home amps with weak power supplies have the same issues and unless it's addressed it will always be a problem, most don't even consider that fact and just fix the burnt stuff and get it going only to have the same issues repeating over and over until the board traces are bad. That's another issue when fixing amps. Traces are getting thinner and the solder is needing more heat, ruining a trace is very easy and I believe this is part of a plan by manufacturers to stop out of warranty repairs. Removing all parts from a board will have its own set of issues. A complex amp like Carver makes, is a tough fix for anyone even Bob would rather not have to face repairs if avoidable. I'm sure competent repairmen are used to those pitfalls but I can't see a repair bill for less than I paid for the amp working fine and all stock. I have a good stack of back up amps but I'd like to see an all Carver system one time, after using unmatched pieces for so long. I have my eye on an amp pre and a cassette deck for a reasonable price but the seller hadn't replied back after 2 messages in 2 weeks. I still think I might be difficult to find a suitable Caver woofer amp since I tried my 300 x 2 on them and it was not good. Other higher powered amps besides the 600 x2 will have fans, the 600 x 2 amps (signature) are all priced way high but it would be perfect for me, I'll just keep watching sales till I find one or can get a trade going since I have piles of speakers that I'll never use. Theres a Carver Sunfire 200w x2 locally but it's priced high right now and that wouldn't solve my problem 2
Yamacarver 838 Posted February 4 Posted February 4 16 hours ago, Mr. Zinda said: I understand that you'd need to double the power before you'll get s noticable amount of power increased You can more than double the power (130% increase) on this model: https://nelionaudio.com/index.php?/services.html/carver/carver-amplifiers/carver-m-10t-mkii-opt002-restore-and-upgrade-r3/ It's pretty popular around here. It could be my favorite but I haven't heard them all yet. Interesting write up on capacitor testing.
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