• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Carver Crimson 275 Measurements

OP
paulbottlehead

paulbottlehead

Active Member
Audio Company
Joined
Dec 22, 2021
Messages
209
Likes
843
How is the ratio of power output transformers to power supply transformer stuff? Does the power supply transformer heat up in these units and does it have a thermal fuse?
I have no idea! Everything is covered up and that's not something I measured. That is not the easiest thing to measure with a PT tucked under a shroud.
 

Cougar

Member
Joined
Nov 26, 2021
Messages
88
Likes
22
Just as another data point, I did measure one of these a few years back:
Yaqin-MC-10T-50261.JPG

The thing made 42W at 32Hz with decent THD, that was a pleasant surprise!
Did you open this one upas well to look inside? There was some buzz a few years back on the net about these amps having issues as well and possible issues with OPT's too as well as the Music Angel 845 amp. I was going to get one of these until I saw those posts, changed my mind about them. Went for the VTA-120 after I found out about that amp from a buddy.
 

TriodeLuvr

Member
Joined
Dec 23, 2021
Messages
46
Likes
87
Location
Central Texas
I would never buy an amplifier with potted/shrouded transformers unless it was a highly reputable legacy brand like Mac or Luxman. Even then, what's to keep a previous owner from gutting the containers if a transformer fails and replacing the originals with underrated Edcors or Hammonds? These are the most expensive and most important components in the entire amplifier. it's easy to cheat when the buyer can't even see what he's getting.

Jack
 

audioholic63

Member
Joined
Jun 29, 2019
Messages
72
Likes
95
I almost pulled the trigger on some of these ET speakers, but I was worried about my VTA-120 being able to push them. I hear they are one of the best sounding speakers .
I love mine. Bought as LFT8a new and then field upgraded with the "b" tweeter when that came out. I run them from a pair of Cary SLM-100 monoblocs. Each is 4xKT-88/6550/EL-34 with 113wpc, currently running EL-34. They have been modded with the Triode/UL switches. In triode at 1/2 the rated power they still drive the LFT8b just fine. I expect your VTA-120 would be up to the task. Despite 83db rated sensitivity they are a very stable 8 ohm load so a friendly load. I too run them full range with subs crossed in at 40Hz with just a little gain. In a smaller room I might have dispensed with the subs.
 

Cougar

Member
Joined
Nov 26, 2021
Messages
88
Likes
22
I love mine. Bought as LFT8a new and then field upgraded with the "b" tweeter when that came out. I run them from a pair of Cary SLM-100 monoblocs. Each is 4xKT-88/6550/EL-34 with 113wpc, currently running EL-34. They have been modded with the Triode/UL switches. In triode at 1/2 the rated power they still drive the LFT8b just fine. I expect your VTA-120 would be up to the task. Despite 83db rated sensitivity they are a very stable 8 ohm load so a friendly load. I too run them full range with subs crossed in at 40Hz with just a little gain. In a smaller room I might have dispensed with the subs.

The deal breaker me was after a few emails with Bruce T. I asked if there was a small sweet spot and the answer was yes. So that did it for me, I have some Carver Amazings that are really nice sounding but have a small sweet spot as well. So I didn't want another speaker like that.

I'm looking into maybe a Cary or Rouge high power intergrate amp or may look into what Conrad Johnson is offering now for my last amp.

The ET LFT8b's are a really good deal too! Enjoy!
 
OP
paulbottlehead

paulbottlehead

Active Member
Audio Company
Joined
Dec 22, 2021
Messages
209
Likes
843
Did you open this one upas well to look inside? There was some buzz a few years back on the net about these amps having issues as well and possible issues with OPT's too as well as the Music Angel 845 amp. I was going to get one of these until I saw those posts, changed my mind about them. Went for the VTA-120 after I found out about that amp from a buddy.
That was not a very fun amp to open up, as I remember it having a bunch of plastic standoffs for the main PC board that screw down to the bottom plate, and I think there were 3-4 different types of screws that all went through the bottom panel. I wanted to take the covers off to see what was up, but that ended up being quite a process, so I had to settle for taking output measurements instead.
 

audioholic63

Member
Joined
Jun 29, 2019
Messages
72
Likes
95
The deal breaker me was after a few emails with Bruce T. I asked if there was a small sweet spot and the answer was yes. So that did it for me, I have some Carver Amazings that are really nice sounding but have a small sweet spot as well. So I didn't want another speaker like that.

I'm looking into maybe a Cary or Rouge high power intergrate amp or may look into what Conrad Johnson is offering now for my last amp.

The ET LFT8b's are a really good deal too! Enjoy!
I don't find the sweet spot to be all that small. Much better than various ML ESL hybrids I had heard. I think Bruce tends to be overly cautious with some of his advice (like stating 75wpc minimum when there are other factors that really determine how much power you need).
 

Cougar

Member
Joined
Nov 26, 2021
Messages
88
Likes
22
That was not a very fun amp to open up, as I remember it having a bunch of plastic standoffs for the main PC board that screw down to the bottom plate, and I think there were 3-4 different types of screws that all went through the bottom panel. I wanted to take the covers off to see what was up, but that ended up being quite a process, so I had to settle for taking output measurements instead.
I had read it was a pain to work on and to get to some pcbs or parts inside.
 

Cougar

Member
Joined
Nov 26, 2021
Messages
88
Likes
22
Not to high jack this thread, but upon looking up on some of the Carver claims I found a post on another forum that has some explaination for the DC Restorer circuit. I'm just curious if any of the experienced Tube Guys here have used this or know if it actually works as said? Is there any other Audio Tube amp using this currently?

Here's what I came across.

 
Last edited:

egellings

Major Contributor
Joined
Feb 6, 2020
Messages
4,004
Likes
3,244
I can see the fuses blowing. When the iron in those walnut OPTs saturates, the primary inductance just about disappears, dropping the impedance and allowing fuse blowing currents to flow in the primary windings.
 

Cougar

Member
Joined
Nov 26, 2021
Messages
88
Likes
22
Has anyone here seen the videos over on Youtube of the Carver Crimson 275 schematics? The guy from Real World Audio is going through them explaining how the circuits works. I see that the Plates on those KT120's have 685VDC on them, quite a bit! He explains the reason why you can have smaller OPTs in that design. I'm not an Engineer so I would be really interested in what some of the guys here have to say about it. There are 2 parts. One on the Circuit and the other on the Power supply.
 
Last edited:

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,745
Likes
20,757
Location
Canada
Has anyone here seen the videos over on Youtube of the Carver Crimson 275 schematics? The guy from Real World Audio is going through them explaining how thcircuits works. I see that the Plates on those KT120's have 685VDC on them, quite a bit! He explains the reason why you can have smaller OPTs in that design. I'm not an Engineer so I would be really interested in what some of the guys here have to say about it. There are 2 parts. One on the Circuit and the other on the Power supply.
Can you provide a link?
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,745
Likes
20,757
Location
Canada
@Cougar I watched Part 1 and some of Part 2 and then I skimmed and scanned Part 2. He lost me at saying the output power doesn't matter it is the voltage and power supply that matters. They are both mutually tied together and the same thing could be said about a solid state amp. If an amp puts out wattage that is the power output. It either does or it doesn't. No magic. He is also very subjective about some stuff.
 

Zackthedog

Member
Joined
Nov 16, 2019
Messages
85
Likes
121
Has anyone here seen the videos over on Youtube of the Carver Crimson 275 schematics? The guy from Real World Audio is going through them explaining how the circuits works. I see that the Plates on those KT120's have 685VDC on them, quite a bit! He explains the reason why you can have smaller OPTs in that design. I'm not an Engineer so I would be really interested in what some of the guys here have to say about it. There are 2 parts. One on the Circuit and the other on the Power supply.
Well, he's got *some* of it right. Current feedback and voltage feedback--yes, we know that. It is most decidedly NOT a Williamson topology. It's a Mullard topology.

The reason the amp uses tiny OPT's is to reduce the weight while employing some tricks to make those OPT's behave well enough to produce some peak power in the mid-band. NONE of this changes the fact that the amplifier, as advertised, is grossly overrated in terms of power response as related to bandwidth and distortion.
 
Last edited:

mhardy6647

Grand Contributor
Joined
Dec 12, 2019
Messages
11,213
Likes
24,172
They are both mutually tied together and the same thing could be said about a solid state amp. If an amp puts out wattage that is the power output. It either does or it doesn't. No magic. He is also very subjective about some stuff.

I concur (FWIW) -- and the mode of coupling the power amplification output devices to the load in the case of the 275 (or most vacuum tube amplifiers) is... rather different than the way it's done in most ss amplifiers, of course! ;)

518KQKvUtxL._AC_SS450_.jpg



There is magic in hifi, I'd opine, but it results from implementation of E, I, and P and L, C, and R. :)
 
Top Bottom