Looking for advice on replacing my amps

M

Mr. zinda

New Around These Parts
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Jan 8, 2026
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I've been using some tired but very good performing amps that are starting to show signs of age. Made in 1985 QSC 3500 series 3, convection cooled and they're stable into a near dead short, put out gobs of watts and sound great but heat has entered one channel and the other channel quit turning on . The working one now needs a new switch, I probably have one but it's getting old.

The speakers are difficult loads, Martin Logan Prodigy, they'll dip to 1.6Ω at different frequencies especially up at 20KHz. I'm actively crossing them using 2 amps with great results. i have a pile of other amps, 5x BGW 150's which are 2x 75w @ 4 ohms and stable to 2 ohms but 50w is not enough to push the panels without running them at near max output and they are older than the QSC.

The problem is I won't put up with any fan noise and I need to be able to run them at 1.6Ω without the usual issues. Since I'm in AZ the heat in the summer doesn't help with AC blasting and im used to indoor temps being kinda high anyway but would rather try to keep the heat down. My QSC ran hot as hell while idle and I finally got it down but then have other issues.

So I've been looking at a few Carver amps one is a 2x 200w another is 2x 300 and the other is the 2400 which is rated @ 750wpc. Is there anything I need to be careful of or look for when looking at carver amps?

I picked up a QSV GX3 a few nights ago for $100 and it came with a fiberglass case so it was a steal and it's serving as my woofer amp for now.
The fan was way loud and I put a 60Ω resistor on it and it's quiet. I want to get something more home stereo-ish that has XLR cable inputs and having a built in crossover that can run up to 250Hz would help but not needed. Only one amp would need the crossover.

I'm also going to bass a new pre on the amps I end up with but that's not important now.

I saw posts on carved stuff here and that's how I found this site. Most other sites have little helpful info on those amps, just a few saying good or others saying no good for various reasons.

I'm thinking they'll probably be best if they've been recapped already and work but is it required? I've found that caps made prior to 2000 seem to have long lives, I have bins full of caps I've removed from various scrap electronics made in the 1970s that all test perfect even after spending years outside in direct sunlight band rain. So I'm a hard sell on the cap failure rate on vintage gear.

Since I know little about Carver stuff I need to know if there are track records of failure and if parts are still available? Also what is considered good prices on them? I have seen prices all over the place and nobody is saying recent recap. I have been trying to get ahold of a seller with a 2x 300 for $250 but it's been weeks and I contacted them within hours of posting and it's still posted after 6 messages I gave up. Then they tell me theirs a possible butef coming this weekend and they'll let me know if it's still available. I'm kinda pissed because this happens so much.

The 2x 200 priced $500 seems steep the 2400 is priced $800 and I've seen them priced all over the place.

What's recommended by someone who's familiar with carver and typical prices now? Or what is recommended for the speakers I have. I've used commercial amps like QSC just because it's easy to find them at decent prices and they're worth free, if there is a problem, tossing it in the trash is not a huge deal since I'd only be out $100. I'd hate to spend $500 and have an issue that requires unobtainable parts.

I've checked out a bunch of digital amps class D and H but I still can't see them being a viable replacement because I don't believe their specs and they aren't made for 1.6Ω loads. They are mostly fan less but I don't trust they sound good no matter what Amir says since his tests don't cover the areas that matter to me. Just because an amp is quiet doesn't make it the best in the world when it can't run my speakers and can barely put out any sound after 15KHz and can't supply bass below 20Hz.

I guess I just disagree with what makes a good amp. I don't think he has any carver tested to compare with their Chinese D amps they all worship on that site. The QSC GX3 is an H class and it's fine for bass for now.

It has a 2Ω rating unlike the newer Chinese amps and it has some resale value if I want to get rid of it. I would never buy a used Chinese amp and most people recommend running them in mono so that's just more risk and heat and cost ends up close to what 2 good carvers would cost and carver has resale value as well.

Any advice is wrlcome.ty.
 
I came here 8 years ago from "the other" sites. I do not fool around "over there" much any longer. I came trying to find information too. I had found and bought a Bob Carver design Phase Linear PL 400 that I was scared to continue using with my speakers because it was 40+ years old and never had any work done on it far as I could tell. There are a hell of a lot of really old, great amps out there that have no DC protection. How does 60V-100V DC sound ran directly to your woofers? Does not make as much sound as smoke and I did not want to stand over it like it was a tube amp to keep from worrying myself frantic about burning my house down! I half ass listened to what these folks had to say. I could have done things differently but I thought I knew a pretty good bit about amps, resistors, transistors, caps and all that type stuff. I had ran 100's of amplifiers. I wasted a hell of a lot of time and money trying to buy, restore, buy again, refurb all these things. I kept hearing about this WOPL amplifier... White Oak .... Na, I got too many amplifiers to go buying parts and trying to figure out how to build one basically from an old Phase Linear case, transformer and a set of meters. I stayed around long enough to learn. I am now in the process of selling ALL of my other amplifiers. Krell, Sherwood, Adcom, Dynaco tubes, Hafler, Kenwood, Conrad Johnson tubes, Carver amplifiers of all sorts and models, Fisher tubes, B&K's on and on. Once I finally owned and listened to the WOPL amplifier it was over. Now, the same company offers all new parts for an all new made in USA amplifier. The White Oak Model One. Its incredible. After I get building this PL 400 Series II, then my PL 700 and a PL 700b I just picked up I do believe that is whats next. A Model One. Then, done. Good to see you here! You are about to be amazed!!!
 
If you want a "beast at 2 ohms" look at older Crown amps . . . they are rated to 2, and thier ratings are very generous.

Myself, I have two Phase Linear 400' Series 2 amps that I have recapped, done all the service bulletins on, and made the changes to avoid DC lockup problems, as well as adding the same DC protect board used in the WOPL. To me (at least on a clean S2), the price of a full "rip and replace" just isn't worth it, and I find it hard to imagine that much difference between a "reworked to like new" PL400S2 and one with White Oak cards in it . . . same power supply, same output devices and topology (mine are full comp already), and White Oak alludes to thier cards being largely Carver's design anyhow, and only about $100 for the rework (as well as less time - iirc, only 6 or 8 caps in a S2). If the cards were trashed, or the amps completely blown up, it would be an option, but not for a working amp *for me*.

In any case, the PL stuff is only rated to 4 ohms (no matter whose cards are in it) so likely not an option for you anyhow.

I'd seriously look at Crowns . . . https://www.365electric.com/Home-Audio/amplifiers/26828.html
 
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WOPL'S WILL DO 2 OHMS...Takes some air moving over the heatsinks to keep it cool, but they'll do it.
The only Martin Logans I've spent any time with was the Summits. Pretty wild dips on that one too. The guy tried some underpowered Yamaha and Marantz.
The day those ML's woke the fuck up was when an SAE A1001 was hooked up to em.....that system.was mesmerizing....after a certain SPL the ML's would give that SAE all it could handle.
 
laatsch55 said:
WOPL'S WILL DO 2 OHMS...Takes some air moving over the heatsinks to keep it cool, but they'll do it.
The only Martin Logans I've spent any time with was the Summits. Pretty wild dips on that one too. The guy tried some underpowered Yamaha and Marantz.
The day those ML's woke the fuck up was when an SAE A1001 was hooked up to em.....that system.was mesmerizing....after a certain SPL the ML's would give that SAE all it could handle.
Click to expand...
Then why not a stock PL? Same power supply, same finals . . . ? ? ? IE, same available current and power ? ? ?
 
I didn't say they wouldn't Tim. But I have had a reasonable amount of time seeing the WOPL's pushing some difficult loads...
 
I thought the PL published specs say they don't . . . (but admit, I haven't checked), but then there is always the difference between "not spec'ed to" and "won't".

Also, more modern output devices handle more current as well, but I have no memory of seeing an output device change being needed to WOPL . . .
 
Just because a guy can do it doesn't mean he should. Im sure the lawyers and bean counters were apoplectic about endorsing the 4 ohm capability. Can you imagine the warranty work on a bunch of 2 ohm load runners? Being rated for two ohms is entirely different than doing 2 ohms. Just gotta keep em cool.....
 
I really do wonder if the old PL909's would have tolerated it, and they likely didn't want to change the specs and have the model stay the same. That, and how many 2 ohm loads were there in the late 70's in the home market?
 
A set of AR 9's supposedly dips down below 2 ohms at times .
Will tax many amps .
Crown 300's are the amp of choice for many owners.
My restored SX 1250 sounds good with my set but struggles at higher volume levels .
 
In the mid 1970's I bought a brand new Amcron (Crown) DC300A and IC150. My speakers then were double Advents wired in parallel.

The band I played with used to jam in my basement and that's where my stereo system was set up. An incident happened not too long after I first got the Amcron/Crown pair.

Sometimes, when the band took breaks, if there was a particular song on a record that one of the band members suggested we learn, that song got played and evaluated.

One on of those occasions, just after the needle dropped, there was an unbelievably loud sound. So loud that no one in the room could tell where it came from. It continued for a few seconds and then - total silence. There was no music from the speakers but there was smoke drifting through the grille cloth. Stepping towards the speakers, that distinct burnt electronics smell was in the air.

When I removed the drivers the next day, what I saw a startled me - all four woofers had no tinsel wires. Like vaporized, totally missing. Plus the insulation inside the cabinets had scorch marks where the insulation was partially melted.

Needless to say, I returned the Amcron/Crown amp and pre-amp to the dealer, who in turn sent them to the distributor under warranty. Turnaround time was maybe two weeks and both were returned The distributor however, refused to tell the dealer what it was that failed that they fixed. The distributor also refused to cover the cost of replacing all four woofers and all four tweeters of my Advent speakers. All eight drivers were destroyed.

I refused to accept the DC300A and IC150 and the dealer didn't blame me. They were taken back into stock, I got something else and resolved to never even consider owning either a DC300A or IC150 ever again.
 
I've worked on/withn DC300's and my Phase Linears. The schematics for the two are remarkably similar . . .

And I have heard very, very, few DC300 horror stories . . . . That amp was one of the pillars in the birth of live sound.

(I currently have three D75's (same vintage) in use as headphone amps, and miscellaneous small systems as well.)
 
I have owned one Crown amp. Brand new out of box one channel was bad. Sent it back and got me money back. I would run a Crown amp and never would think twice about it. I ain't scared of them. I think they are probably one of the better amplifiers. But why when I can have a Phase Linear WOPL or Model One White Oak?
PL amp VS Crown amp.
With a Phase Linear amp I get:
Friends, people I can trust implicitly. A community of absolutely fine folks here at Phoenix that help me any way they can. Its more about community. Its about helping everyone.
A bad ass looking vintage amp. Or a brand new Made In The USA amp.
That may not mean as much to some as it does me. I like Made In USA!
I like spending my money here any time I can.
Any color I want as long as its silver or black! And if I talk to Perry I might even be able to swing a Green one!
Huge swinging VU meters, Bad ass LED meters or, no meters at all.
Pretty much any color LED's for the meters!
It not so damn heavy like all the other near 100lb monsters like the Krell, PS Audio, Sherwood.
It does not heat up the room. (Not saying it will not heat up yours though, all depends on what ya got and how you play it)
Audiophile quality sound. I actually did not think amps really sound any different. I am 60 years old. I have heard 1000's.
The WOPL amplifiers do sound best to me. This is what I have been trying to find in an amplifier well. all my life.
One SAE amplifier I had came close. My friend has it now. However, he heard my WOPL PL 700 Series II I got from Lee and the day after put in an order for a WOPL with Lee. My other audio friend a trained musician now has saliva for an amplifier. Yep. hes salivating all over his amplifiers wanting a WOPL so badly.
Parts and more parts. Full amplifier even, ground up if I want. All in current production and backed with a solid warranty.
Modern. Like brand new or even brand new if I like. Very reasonable, affordable parts. I like knowing that.
I can DIY the amp I want OR I can have one of these guys like Lee build it up for me.
DC Protection. Dons board makes my speakers and I really, really happy! We both agree, No to DC!
I am not worrying all the time when the amp I am running is going to burn my speakers up or burn down my house.
Sorry, I am ADD as hell. I built my speakers up by hand. Modding them part by part as I could afford better. They may not be high end Audiophile speakers like Martin Logans but to me they are worth even more than that.
Overall the price is better. I can buy a shitload of amplifiers and swap em in and out like I did for years, restoring them down to the last filter cap. Adding shit, modding them over and over and still not have the sound I was looking for so yeah, the overall price is thousands less.
Bragging rights. As soon as you fire up one of these WOPL amplifiers you immediately know... You got for real bragging rights now.
History. I love the vintage look and feel. I love all the documentation.
Availability. You can actually still find em. Cores and such. Just bought a PL 700b off Reverb the other day. It ain't as easy as it used to be but shit, They are there.
Shipping. No need worry about that. When I got mine it arrived in a Cabbage Case. Nothing short of a nuclear blast could have damaged it. And if that had happened then shit, I would not be worrying over an amplifier.
I am pretty sure there are other fine points I have missed or overlooked. Anyone of course feel free to add.

Crown. A fine amplifier I am sure I would worry about all the time.
Prices all over the place. From what I see finding really nice ones might be hard at a decent price.
Basically, none of the above quality's.
Why try to write any more.
 
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J!m said:
You can weld with a Crown. Older QSC amps too. The staple of the road for a few decades…

But filling an arena is not ideal for filling your living space. Instruments should sound “right” and I’m picky in that regard…
Click to expand...

Crest was another outstanding unit before Peavy got their hands on them as well. (Never much cared for QSC).

Solid as a rock, and fully modular making field maintenance a breeze. A full channel changeout is sub 10 minutes . . .

A guy from Audio Analysts told me that part of the sales pitch was the sales guy holding one in the air and dropping it on a concrete floor, and they always worked. I own 12, and I can see why . . .
 
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