Peeking inside a Carver Crimson 275 Tube Amplifier

@corelli, 

Sure, I'll give it a try--remember, these are my ears, my room and my gear. 

First off, I love what PrimaLuna does and stands for.  I had a wonderful experience with them.  I love what Kevin Deal does.  He's a good guy with tons of knowledge.  I think he's a tremendously positive businessman and a lover of all things hifi. The PrimaLuna is a fantastic build and sounding amp.  The remotes are to die for.  (Speaking of which, my remote had issues and they ultimately gave me a new one ($250) for free even though I was well past warranty expiration. 

I really loved the PL when it powered more modern loudspeaker designs--KEF LS50s, PSB Imagine T3s and T2s, Dynaudio, Golden Ear, hmmm...what else, oh, B&W.  I'm sure over the years I heard others.  Never a bad match with any stuff I had or heard it with.    

Disclaimer--I have not heard the PL EVO range. 

The PL I had was the Dialogue HP.  That thing could seemingly power anything!  It was built like a tank.  The construction is super.  It is really gold standard on point-to-point, layout, clean build, etc.  I wouldn't want to service one or go back in one, as there is little room in the bigger models' chassis.  I felt like a surgeon in there.   

Pros to PL

• Build quality; good to great parts quality.
  
• Power
• Ease of use/maintenance 

• Tube rolling paradise
  
• Can drive and sound good with most stuff on the market (so long as it's not paired with something crazy)
  
• Dealer and customer service are IMPECCABLE.  They are like Manley Labs--you're almost family.
• Pleasant sound that doesn't offend.

Cons

• It weighs a ton (at least the HP I had).  Moving a 60lb amp is no fun. 
• Aesthetics.  I never cared for how it looked (this is entirely subjective).  The casework is awesome, but wasn't my cup of tea. It looks clunky to me. Others like it. Who cares? It's my silly view. 
• Not the last word on detail, air, sweetness, and so on.  I think it's the equivalent of going to a really nice restaurant that has continental fare--you can find something you'll like and it will generally please everyone and offend no one. 

In my system, the PL sounded BIG (I have efficient speakers), bold, pleasant, and generally musical.  Imaging was good. Bass was large. However, compared to the 275, the sound was thicker, denser.  The 275 is sweeter, substantially more holographic, clearer, more delineated without being hyper detailed or analytical.  I've never really understood how to use the PRAT description but I suppose it would fit.  The 275 boogies.  It swings.  It's sweeter, creamier, but has more air too.  

I just go for what I hear and what wins in my personal shootouts.  Maybe this will help--- I built a highly upgraded Elekit 300B amp (see Herb Reichert's reviews on it--it's pretty amazing).  When I had the PL, I would go back and forth between the PL and the 300B.  The 300B gave me water like clarity and rich detail.  But, as Ralph of Atmasphere correctly taught me on these forums, the 300B has little distortion at very very low wattage--once you start getting up to like 30% of its power, it starts distorting substantial.  The PL gave me balls and bombast--also a killer remote, tons of inputs, and tube rolling fun. 

When I got the 275, I ultimately stopped using the PL.  And, here's what was surprising to me--I used the 300 B a bit less. Why? I asked.  I think the answer is the 275 has a healthy dose of clarity, sweetness and space with holographic images.

Note--I'm not saying the 275 is better than the 300B, but I use the 275 way more. 

When I started messing around with the PL, I was never really able to tweak it to make it sound like what I thought was missing or what I was after.  Again it was a great sounding amp.  With the 275, I thought it fit my taste better for long term.  So I sold the PL.  Someone out there has a PL with VCap CuTFs on the two gain tubes.  :)

I think the 275 is about 75-80% stock of where the amp could be, but I'd defer to Mr. Carver for sure.  

Our esteemed member JJSS bought one and tried it about the time I got mine.  He has some killer gear, and great ears/experience.  He liked it much but felt there was just a bit of sheen or haze on top--I think he said he might be nit picking though.  I agreed. 

So I cracked it open.  My jaw hit the ground when I saw these.  https://www.suntan.com.hk/Plastic-Film-Capacitors/TS02.html.  Not because I think you have to have boutique or hi end parts to sound good, but because the amp sounded pretty darn great with inexpensive caps that I think are below good quality WIMA, AMtrans, and so on.  So I though, King Bob Carver's circuit and know how was squeezing everything out of those mediocre-at-best caps.  How would it sound with legitimate caps?  By the way, the physical size of the original caps in the 275 is almost laughable.  The .22uFs on the signal/phase section are no bigger than my pinky finger nail--actually smaller. 

I'm inclined to tweak via a cap, resistor, or tube before going after a $1K power cord or interconnects--just me.  I have decent cables, but none costs more than $200, maybe $300.  

Finally, keep in mind that I'm running Klipsch Cornwall IVs. I just don't know how this amp would sound with modern, less efficient designs.  I would expect it would sound great. Who knows!?  It's got balls. 

Also, Bob is a genius.  The PL would heat my room. The 275 weighs 18lbs or so, I can lift it with one hand, and it never puts out noticeable heat.  I think Mr. Carver admitted he lifted and tweaked the DC restorer circuit from 1950s television design.  It idles those big KT120s at 9 watts or something insane. It's not a gimmick. It works, saves energy, less heat, and your tubes last longer.  

Oh, one more thing-- the user gets to set the bias (sooooo easy--do not be bashful) on the 275.  I run mine around 70, which produces a big soundstage and images.  

Thanks guys!  Yes, I don't get the negativity out there.  When I'm on guitar forums, it's soooo rare to hear someone tell another their view is stupid or they don't know what they're doing, etc.  In guitar world, for instance, techs set the gold standard on how strings should be wound and say do not wind them more than 2-3 turns max (or something)--YET they admit guys like BBKing wound the living crap out of his strings and no one ever said, Hey BB sounds like his intonation is off and he's constantly re-tuning.  There is more than one way to skin a cat. :)

Check out the pic in my virtual system (last one) of the original caps.  You'll see I used a Phillips screw driver head from my impact driver to show the scale.  It's shocking. https://systems.audiogon.com/systems/9364

@jbhiller

attempts at morning humor aside, a few points back to you

1 - went through your system pics... just love your room, the guitars hanging... that is a sweet place to be for sure, i can feel the positive vibes just seeing the photos... 👍👍👍

2 - also want to commend you on your spirit of positivity, enthusiasm and passion, and your willingness to tinker to learn and potentially improve already very good gear, ’make it all it can be’ - i don’t trust myself with a soldering iron to save my life, but i am so glad a fellow dedicated enthusiast like you is willing to climb the learning curve and share findings -- for all its faults and garbage, this is the a-gon forum at its very best...

3 - the carver amp is brilliantly conceived, bob carver has more than a little spark of genius, but clearly the crimson amp is built to a price point to make it commercially successful and sell at good volumes, so i can imagine some of the internal components can stand upgrading if the owner seeks a higher level of absolute performance, and is willing to pay for it ... that is no knock on carver (quite the contrary), it takes talent, serious talent to make affordable stuff sound so great, it requires knowing where spending $ makes a real difference, and where $ can be intelligently saved

4 - i know e j sarmento at w4s fairly well, he is a smart, very nice guy, a fellow enthusiast, and he of course builds these units for carver and frank m... i would think he would be very open to trying to incorporate potential mods commercially, but bear in mind he is the contract manufacturer -- bob c and frank m own the brand, and thus the right to ok development changes - no harm in reaching out to them though...

jb, i really look forward to hearing your further observations on how your lightly modded 275 is improved as it has more playing time, and i will likely follow your lead on passive component upgrades... it is a killer app amp at its modest price point in stock form, and the thought of making it even better is exciting!

@jbhiller   Thanks much for such a detailed and thoughtful response.  Also enjoyed your comparison to the Elekit.  Your impressions of the PL seemed to parallel mine but you used yours with far more speakers than did I. 

I love elegant solutions--and the 275 surely leans in that direction compared to the PL.  Your caps are only going to sound better in time and I hope this amp is long term keeper for you!

Thanks again.

jjss,  thank you Sir.  You are always doing good on these forums.  I for one have learned much from you.  I also like how you are open minded.  For example, I saw you picked up a Devialet integrated.  I like that you are not diametrically opposed to something just because you typically like lots of tubes.  

I did reach out to Frank.  I keep in touch with him a bit here and there.  I'm going to have lunch with him soon.  He lives in Chicagoland, like me.   I want to be careful not to give them too many opinions--lest they think I'm a charlatan or a know it all.  I do, however, think they could expand their product line.  There's a BIG gap between the $2800 275 and the $10k 350 monos.  

There are pics and a press release out there concerning a slick integrated they might be bringing to market.  

@corelli, I'm happy that my words helped at all.  

The PL is such a great product.  I'd add a big caveat:  Perhaps the PL is just too warm, big and dark for my system.  With the exception of my CD transport (which I rarely even use) I have nary a transistor in my system.  In other words, the PL might be a great fit for folks who have no other tubes in their system.  I'm not sure. 

I've been running the system 12 hours on and then 12 hours off.  The caps are opening up a bit more in the midrange and bass.  The high treble sounds about the same to me.  

I'm hoping the Clarity Caps and the VCap CuTFs mate well. So far so good.  

Quite honestly, I wish I could buy the 275 in a kit form where they sell me the chassis, transformers (power and output), and then I source the rest.  I say this because I cannot help but wonder what $50 of premium resistors and the very few small electrolytic capacitors would do.  

In fact, I'd love it if I could buy a new PCB from Wyred4Sound and mod it up completely, and then compare it to a stock model in A/B.

I'm about 70 hours into the VCaps and ClarityCaps.  

Everything sounds wonderful.  

An update on the differences between the stock Suntan brand caps and the new VCap CuTF and ClarityCaps---

With the stock caps, I had a massive soundstage; nicely holographic.  

With the new caps, the soundstage is just as big but the things going on are more focused without losing that holographic nature.  There's an added composure to the sound.  Things were little less organized before, but that was quite pleasurable given the overall picture.  Now, however, I feel as though I didn't give up the size of the picture while detail and definition increased.  Very cool. 

One thing about the size of the soundstage did increase; that is the depth of the performance.  It was good before. I heard depth on many recordings that made me smile. Now, I'm just hearing more of it, across more recordings.

I'll stop the reviews and updates now as things are settling in nicely.  All the best to those who chimed in!

I am Frank Malitz, owner of the Bob Carver Company. I should be addressing capacitor and resistor questions. But, I would like to respond to phantom. here’s what he said about my company:
"I used to own the Black Beauty, It ran very difficult speakers and can handle difficult loads, Unfortunately Bob carver setup Distributors globally and got everyone to buy and market the amps for some time and then dropped all the distributors within an instant. Nice Amps but the people running the company have no idea."
1) the Black beauty was made many years ago and has nothing whatsoever to do with Glass Audio Inc. doing business as the Bob Carver Company.
2) Bob and I started the Bob Carver Company on January 1, 2016. I took over ownership January 1, 2020. Bob remains as my chief designer and certainly one of my best friends; we speak weekly. EJ is my only partner and builds it all by hand in CA.
3) I have only expanded into Thailand, New Zealand and Australia. I have not set up distributors globally because we have never been able to meet the demand and still cannot to this day. All purchasers of my product will be forced to wait between two weeks and six weeks depending on the model although two of our three approved Internet resellers stock large quantities which makes it easier on us all. Phantom, I have never dumped a distributor. Let me explain what a distributor is: we have no distributors in the United States. We only sell through retailers. We do not sell directly to the public. In the world of audio, a distributor will stock inventory in a warehouse in larger quantities than a retailer. That distributor would sell to the local retailers in his country who are too small to buy directly from the manufacturer--a common scenario.
4) the only time that Bob set up distributors globally was for the Carver brand and they fired him 35 years ago so phantom is a little bit behind the times. Even Sunfire, which Bob opened after being fired by the Carver Company, did not have global distribution.
5) Bob is still honoring the warranty on in-warranty tube units that he sold before January 2016. When he bought the Carver name back, he covered all the warranties out of his pocket. It is not legally our responsibility to back up those units but we always help anyone with a problem as best we can. This is easy because there are no failures. We have no service department. I can remember one 350 failure and about four 275s with buzzing transformers due to a mistake made by our supplier in not following Bob’s design. This is over a 15 year period representing hundreds of units sold. Our warranty is 40 times longer on the tubes than McIntosh or Audio Research, on our point to point units and 20 times longer on our PCB models and ten times longer that Prima Luna who are smart people! We’ve sent out eight tubes in ten years. In my 55 years in the industry, I have never handled any product with this low a failure rate (In all honesty, I don’t recall a defective Bel Canto).
6) I do not think it’s appropriate for phantom to claim that I have no idea what I’m doing. Most people would be offended. If this response is too wordy and defensive, I hope you can understand. I spent my life in this industry trying to bring good sound to everybody at every price level, hosting trainings at 8:00pm in the middle of nowhere. Yet, according to phantom I have failed.

Here’s a list of companies I’ve established, designed for or represented: (from my profile):

Onkyo USA

Integra (part of Onkyo USA)

Yamaha (twice)

SME

Grace

Supex

Denon

DCM

a/d/s/

Meitner

Museatex

VPI

Thorens

Trinnov

Pro-ject

REL

Counterpoint

Vector Research

Kenwood

Audio Alchemy (twice)

Acoustic Research (second launch)

Dahlquist (second launch)

Apogee (second launch)

Sonus Faber

Totem Acoustic (three times)

Triad Loudspeakers (three times)

Golden Tube

Tandberg (second launch)

Electrocompaniet

Cambridge Audio

Earthquake Sound

ADA

Artison

Harmon International (incl JBL, Infinity, etc)

ELAC

Sunfire

Carver

Sennheiser

Focal

Klipsch

M&K

AudioControl

Nordost

Monster Cable

Arcam

and at my age, I can guarantee I’ve left some out!

Consultation Experience:

Denon (tone arms and cartridges)

Stax (designed their first close back headphone)

Ortofon (phono cartridges)

BES (loudspeakers and marketing)

Thiel (product and marketing)

Acoustic Research (product and marketing)

Signet (electret headphones)

MXR (third octave equalization)

I’ve enjoyed every minute of it. Coolest job in the world! Almost.

Sometimes, when I visit a forum, at the close of business, which is a rare occurrence because I own three companies and I’m 75 years old, I see a note like phantom’s and I wonder why I’m participating in this until the wee hours of the morning. But, the positive responses make it all worthwhile. I know some of you folks and you hopefully know I’m on the level. Come see me at the shows. I’m delighted to help anyone on any hifi topic and my phone number is published right on my website! I’m here for you seven days a week. 

@fmalitz a lovely note Sir, and quite the nice recounting of a career full of high end engagements;-).

JB i would echo @jjss49  kind and accurate words. Cool room and groove, cool system…. Keep on trucking and soldering !

@fmalitz, Hope all is well with you!  Your curriculum vitae is impressive indeed!  Thanks for dropping by these humble parts.  

I trust you know, from my correspondence and previous phone call or two, that I respect everything you, EJ, and Bob have done and are doing.  

All the best!  

@tomic601,thank you Sir!  I really enjoy learning, listening, tweaking and the journey.  It is a passion and a hobby after all. 

I have a great Bob Carver system.  My Magnepan 1.6 QR have bypassed factory crossovers.  They are bi-amped by a pair of Carver 350 monoblocks (woofers) and one Carver 275 (tweeters) using a Marchand vacuum tube electronic crossover.  The preamp is a Vacuum Tube Audio SP14 by Roy Mottard.  (The monoblocks are early iterations of the 350 series and have red, “Crimson,” chassis, but are definitely 350 watts per channel.)

so jbh - would you please write a short post with specifics as to your passive components mod (sorry to make you repeat this), so that i can pass the info to my tech to replicate your successful minor surgery to the unit?

i have my parts connexion account locked and loaded to order the caps etc etc!!

thanks in advance!  🙏

@jjss49, 

Sure thing.  

1. Output Coupling Caps:  

Four (4) .68uF 630v ClarityCap CMR
Four (4) .1uF 630v ClarityCap CMR

Available at PartsConnexion.

2.  2 Caps on Pre/Gain Tubes.  Note, I don't have a schematic so I'm taking my best guess as to what caps ore on the signal input side of things. 

Available at VCap. 

Two (2) .22uF V-Cap CuTF 300v (matched to at least 5% or lower)

3.  Resistors 

Two (2) 36k ohm (36kR) 5watt. Kiwame
Two (2) 39k ohm (39kR) 5 watt Kiwame

Available at PartsConnexion. 

***********

Some notes:  

If I did this again, I might use VCap ODAMs throughout.  They are so amazing.  ClarityCaps are very good to excellent too and I adore their sound as well.  ODAMs can sound better than even the VCap CuTF to me. 

Your tech is probably better and smarter than I.  But, those two sets of 36k and 39k resistors right in the middle of the board are placed counterintuively.  They do not seem to be symmetrically placed to the circuit.  Even though I took photos in case I needed to see the original layout, I still installed one channel's 36k and 39k resistors incorrectly--I swapped them.  Well, that channel was super faint as an extra 3k ohm of resistance (I had a 39k where a 36k should go) made the output too low.  Takeaway--be sure to follow exactly how they are in there to begin with.  It's easy to do one side/channel and mirror it on the other, which is incorrect.  You won't blow anything up, but it won't work right and you'll know it.  

Here's a photo from my virtual system for your tech. https://systems.audiogon.com/systems/9364#&gid=1&pid=7

PS--There's no need to duplicate exactly what I did.  Any decent cap will be an upgrade over the cheap, generic caps that were in there.  

There's a couple of giant Dale dark grey/black resistors on the input side of things.  I suppose you could look at Mills, Ohmite, etc. 

many thanks jb... info and your points all noted  👍🏻👍🏻👍🏻

@fmalitz Frank thank you for this response.. however I’d like for you to respond to why the 275 does not even come close to its specs? Why does an amp spec’d for 75 watts per channel only put out 17 wpc? Why are the transformer covers very large fake covers over very small transformers that are only capable of 15-18 wpc?

I almost bought a 275. I am glad I did not, seeing how I know from experience that my speakers need at minimum 75 to 100wpc. Can you imagine how angry I would have been finding out it can only put out 17 wpc?

 

I visit Audiogon often but hardly ever post.. I was moved to post this question. I’d like an honest answer.

The 275 is under scrutiny on at least four other audio forums as we speak. Interestingly on one, the negative comments are largely removed. I’m happy here we can have a warranted inquiry without censorship. I’m not sure why the forum mods are protecting truth on this other audio forum.. but the real measurements and specs are all over the internet like wild fire. Multiple sources sharing the same failures to meet published spec in epic proportion.

As a previous fan and owner of Carver products I’m anxious to hear the other side. My confidence has waned and I’m becoming bias with facts that will be tough to refute or explain.

The 275 is a disappointment. Why would you modify it and not just sell it?

@funky54,  I'm curious to read the fire from other cites/posts.  Can you put up some links?  

 

fiesta75,  Can you tell us why you believe the 275 is a disappointment?  Did you/do you own one?  What experience do you have with the amp?  What is it about the amp that let you down?  

 

I have no comment on the unit's power output in watts.  I have 102dB sensitive speakers so I don't need much juice.  

Let it rip folks!  Transparency is a great policy.  

Frank, looks like you have some things to answer!

I read the Audiosciencereview site testing and forum posts on this amp.  A couple of thoughts. 

Folks, especially those who tested it, seem very confident that the amp cannot make spec output, uses Edcor PT and/or OPTs, and is a fraud.  

The original testers of the amp on ASR admit they didn't have units with a serial number on them.  Other posters provided pics from Bob Carver's amp camp, a la Nelson Pass type of thing, where you could build one using Edcors as shown in photos.  

The piling on continues for 13 pages.  Will ASR test a genuine model with serial number?  They promise it's coming and things drop off from there.  Let's see. 

Lest I forget, I own this amp and feel it beat out (in my system) a Primaluna HP integrated weighing 55lbs.  I personally never cared for Bob's marketing. But sound wise, I think this thing sounds great.  

Be careful out there.  As Benjamin Disraeli said, "There are lies, damn lies, and statistics!" 

I'm not sure where this will end up on ASR or any site. I do, however, question how valid, comprehensive or meaningful some of this criticism is on the amp.  

I don't think I care enough to crack my amp open again to look at the transformers.

Keep it coming!

PS. I've heard some of the DAC stuff they love on ASR because "it measures so perfectly."  I tried two of them.  They sounded good--not great, not musical.  Kind of like a stereo in a luxury car.  I also wonder how a Fender Bassman would measure.  I bet gobs of distortion.  Thank goodness ASR doesn't supply bands with amps. :)

 

A little birdie told me that the amps subject of ASR's testing were, in fact, $600 kit amps--differing in quality from actual units sold with serial numbers. 

It doesn't come as a surprise that folks over at ASR believe they've uncovered a fraud.  However, surprise element aside, isn't it ironic that those touting science so heavily in high end audio likely didn't do their testing scientifically? 

For the love of all things sacred....If you're going to test things "scientifically" can you  at least (a) buy the unit from a licensed dealer; (b) note the serial number(s);  (c) make sure you know what you are talking about before posting alleged scientific conclusions.  

What's sad to me is that after reading all 13 pages of the ASR forum thread on their uncovering of "fraud", the confidence in their opinions never budges--even after a reputable dealer chimed in to clear some things up.  

For the love of all things sacred....If you’re going to test things "scientifically" can you at least (a) buy the unit from a licensed dealer; (b) note the serial number(s); (c) make sure you know what you are talking about before posting alleged scientific conclusions.

What’s sad to me is that after reading all 13 pages of the ASR forum thread on their uncovering of "fraud", the confidence in their opinions never budges--even after a reputable dealer chimed in to clear some things up.

Sad (And regrettable)? Yes.

Surprising? No.

I’ve visited that site in the past and was very disappointed with the content quality. They can’t even be thorough enough to be sure they have a true representative Carver amplifier. Yet can natter incessantly about conclusions. Real scientific method being practiced over there. I think not.

Charles

Carver’s own specs: 19 lbs for a Crimson 275 rated @ 2x 75 Watts?? That’s ridiculously lightweight, for a tube amp. That puts it in the class of a console-pull EL84 amp pushing ~ 15 Watts a side. No amount of Bob Carver "magic tech" talk can make that go away from my mind. The higher-end Carver monos also weigh only 44 lbs a side and claim 350 Watts! That’s very concerningly over-light, for the tube powers involved. The Rogue Audio Atlas weighs 55 lbs, actually hits its rated 100 Watts x2, and costs roughly the same as a Crimson 275. The Rogue Apollos weigh 100 lbs per side, spec 250 Watts, and cost similar to the Carver monos. Hell, I have a pair of Heathkit W5 that EACH weigh over 20 lbs. These are 25 Watts/ch KIT amps from freaking 1959. Their manual publishes detailed power response curves under load, and they literally kick the crap out of what ASR measured for the modern-year Carver Crimson 275! They sound really sweet, too.

Perhaps the proper production models contain the appropriately sized transformers AND a magic Bob Carver gravity-cancelling device?

Kinda silly.. doesn’t take an engineer to look up the transformer part number and see it’s only rated for 15 watts. . Doesn’t take an engineer to measure output at only 15 to 17 watts per channel.. pick on science nerds all you want. 
 

Why does the manual say the transformers are made from fictional steel from Greek mythology or Wolverine’s claws… no kidding right out of the manual. FROM CARVER, there it’s verified.

Two points, 

If you're going to test a component,  ensure you have the authentic model.

At the end of the day the sound quality is the most important parameter for an audio component. It's being purchased to reproduce music, so presumably you care how it sounds, No?

Charles 

I agree listening enjoyment is most important to our hobby. I’m no fan of ASR - they put listening dead last. But outright false claims by manufacturers can also damage the hobby. And I don’t see how these particular amps come close to hitting their power specifications, unless they can break the laws of physics or have a hidden plate amp under those transformer covers. I’m not a stickler for 1% THD being the "clipping" cutoff for power measurement, but it shouldn’t be pushed much more than a few %.

Sure, I’m biased - I had a Sunfire Sig II amp a while ago and hated its sound. Too many aspects of Carver, and these tube amps, set off my BS alarms. Aren’t the tube fuses on these amps even advertised as a tube HEALING feature somewhere? LOL

These amps might well sound good, but it’s looking more and more like they should have been spec’d at a much, MUCH lower power. Now where’s the value? Plenty of low power vintage amps that sound wonderful. EL84, 6L6, and EL34 tubes are hard to make sound bad.

yep, sonics matter..but so does ability to drive a speaker… so no speaker, no music. The specs are useful in assessing current and future suitability to drive various speakers….

Having said that, i am guessing the Music Reference RM-10 , also a lightweight gives the Carver a run for the sonic money…..Modjeski like Carver a genius…

@mulveling

These amps might well sound good, but it’s looking more and more like they should have been spec’d at a much, MUCH lower power. Now where’s the value? Plenty of low power vintage amps that sound wonderful. EL84, 6L6, and EL34 tubes are hard to make sound bad.

I’m not disagreeing with you, perhaps the specs are inflated and I do not support that. The OP and others posting here say it’s a very good sounding amplifier, to me that means something. ASR seems to care little (If any) about how a product sounds. What do you hear? That’s the essential question.

We’ll let’s talk about what I would hear. The manufacturer of my speakers says 100 watts are to be seen as an absolute minimum and it’s highly recommended to be ran on 200 Watts. It’s easy to hear noticeable differences going from 100 and then 200 W with my speakers. So having been a carver fan and owning twin C-500’s vertically bi-amped, I toyed with buying 275s. Can you imagine how incredibly angry I would have been? He, the manufacturer, Mr. Carver, is saying his amps put out 75 watts… it’s not true.. but he’s not even close. He puts out something like 17 W. You’re telling me I should be just OK with that because it might sound nice on some efficient speakers? 17 is not 75. And hiding the fact by putting teeny weenie little tiny transformers under big gigantic covers is just fraudulent.

Funky54, I think you are making a big assumption, which may be true or it may not be true.  That assumption is that ASR's testing was accurate and that it actually had a Crimson 275.  

The models ASR tested did not have serial numbers.  The build quality from pictures is not consumer grade or fit for resale.  

Did you know Wyred4Sound makes these amps for the Carver Corporation?  They must be in on the scam too. 

Look, if the Company made material misrepresentations then that is terrible. But don't you, or the numerous folks piling on the ASR forum recognize how absurd this would be?  It would be one thing to miss your specs by a bit.  Here, if ASR is correct then the Crimson 275 only makes 22% of its specified output.  

The Crimson 275 drove Kef Blades at Axpona a few years back with pleasant results.  Maybe they just love 17 watts of power to get them to sing.  I suppose that's possible.  I once had LS50s linked to a 300b SET and they sounded pretty good.  

I did drive Wharfedale Linton Heritage speakers with the Crimson too.  They are reportedly 90dB efficient and 6 ohm nominal impedance.  Had gobs of power for those loudspeakers. Maybe 17 watts is all you need.  

I used to play around with vintage tube amps. Lovely sounding amps, in the range of 20 - 35 Watts. With 90dB speakers, an honest 20 Watts is plenty to drive them quite loud for LOTS of music. It'll even sound very pleasing, too - good to the last Watt, so to speak. In an intimate setting, with a controlled playlist (lots of Krall etc) you may never want for power. The could even play dynamically compressed rock recordings very loud (and they weighed more than the Carver, btw). But it would run out of power in a hurry once you started cranking more dynamic material. 

Modern push/pull amps with KT120 are SUPPOSED to give you all the power and overhead you need, at meaningfully low distortion levels, with a good dose of the tube sound if not the full boat E84/6L6/EL34 "sweetness".

Modjeski like Carver a genius…

 

Yes, they both are! Good points Tomic 

Kinda silly.. doesn’t take an engineer to look up the transformer part number and see it’s only rated for 15 watts. . Doesn’t take an engineer to measure output at only 15 to 17 watts per channel.. pick on science nerds all you want. 

Well, it doesn't take an engineer to throw out all of ASR's testing and your conclusions because the amps in question are not shown to be actual amps built by Wyred4Sound for the Carver Corporation.  The logic above and at ASR is dime store at best.  But, hey, if it turns out Carver puts a 15w OPT from Edcor in its amps and they cannot actually come close to spec, then yes that's a problem. 

It's clear folks are assuming what they seek to prove.  I'm not an engineer--I'm a lawyer.  Such conclusions would never make it into the record from a law perspective (which is a way lower threshold than scientific method).  Think about that.   Hey, this vacuum cleaner is defective Judge and killed my wife.  My expert says its wiring was faulty.  Judge:  But you cannot say the vacuum actually came of the manufacturer's line.  You can't cite to a bona fide serial number on the vacuum. 

I will say, however, Frank Malik should step up and explain this away (if he can) as folks are coming with pitchforks for his brand. 

Sure that’s cool, now all Carver has to do is explain how 19 lbs of tube amp from his factory breaks the laws of physics to drive an honest 75 Watts per side 😂

It will definitely involve "magic transformers". I guess they didn't have the magic ones on hand for Carver fest 😥

Yes, let's see how it plays out.  I may even open mine up to take a look.  It's tough to get into the transformer covers as you have to remove the circuit boards completely, which is a PIA!  

The amp does sound great.  I had it side by side with a Primaluna HP Integrated and it sounded better to me.  I was quite familiar with the Primaluna too.  

Before all this controversy, I posted (above) about how some of the parts quality was great and other parts were cheap stuff that I wouldn't put into anything.  

@mulveling you are correct in that some moderate to low power amps sound awesome and that's what matters.  I also agree that if the Carver Corporation made material misrepresentations about the amplfier's capabilities that would not be acceptable. 

Frank Malik (owner of Carver Corp) said he will provide responses to some of the questions raised in the forums about the amp.  And so we wait....

A little birdie told me that the amps subject of ASR’s testing were, in fact, $600 kit amps--differing in quality from actual units sold with serial numbers.

@jbhiller Do you have any evidence to support this claim?

I’ve been in the industry for about 47 years. @mulveling has an excellent point, one which I’ve also found troubling. I’m a big fan of the Harmon Kardon Citation 2 which is a stereo 60W/channel amplifier. It weighs about 3 times more. But its made of the same materials. We make a 60 watt monoblock amp that lacks the weight of an output transformer and it weighs about 25 pounds while employing an aluminum chassis.

IMO something doesn’t add up. Put plainly, prior to the Carver amp, no stereo or monoblock tube amps capable of 75 watts that weighed so little were ever made! Since this spec comes from the Carver website: https://www.bobcarvercorp.com/copy-of-crimson-raven-features-spec

I’m inclined to think one of two things. (Using Occam’s Razor...); one explanation is that the weight is a typo. The other explanation, the weight is correct, requires too many other things (some quite wild) such that the answer is for too complex to be correct.

The problem here is that a 19 pound amp would also very coincidentally be about the same weight as a tube amp capable of about 17 watts per channel. I don’t like it when coincidences like that pop up- it makes me think something is fishy.

You are in a position to shed some light on this, and apparently possess the required skills to do what needs to be done, as evidenced by the work you talked about prior on this thread.

I’ve become quite curious and am holding all explanations in abeyance. Could you weigh your amplifier and relay to us that value? Could you remove the output transformer cover and show us what the output transformer looks like? If the ASR review is not of the same amp they are doing a disservice IMO.

@atmasphere 

the amp weighs 19.4 lbs by my scale, with no ac cord attached, tubes in place

here is the asr thread, ralph, it is long, jim clark responds on pg 6, and the conversation ensues from there, with photos from carverfest where kits were distributed

https://www.audiosciencereview.com/forum/index.php?threads/carver-crimson-275-measurements.29271/

doesn't explain the magic of a 20 lb amp making 75 wpc, but there is the info

Ralph!  Always great to hear from you. I've learned much from you over the years and, from what I can tell from due diligence, you have yet to steer me wrong. 

As far as the little birdie, I contacted Frank Malitz by email letting him know folks were really hitting him and the company hard with questions (some very viable and meritorious) and accusations (some legal, etc.).  For full disclaimer, I do not work for Frank, Bob Carver, or have any affiliation with any of them. Yet I do know Frank "virtually" so to speak. I'm just as curious as anyone on this subject. 

Mine weighs 21 lbs, likely from the numerous caps I put in that dwarf the original Suntan el cheapo caps.  

I do have efficient speakers so I'm not a good gauge of how powerful it is.  It does sound great. 

Ralph, it may be time for me to buy your S30!  It seems like it would be a match in heaven for Cornwall IVs. 

Oh, Ralph, I'll think about opening it up again.  I'd have to remove all the guts to get to the trannies.  Not something I'm keen on doing, but I could....

Rather than take it apart it’s not that difficult to test power, distortion and bandwidth… maybe it makes 75 wpc at 1-2 kHz w 5% THD

like most 300 b amps ( this is a joke… calm down )

phase error tells about bandwidth 

But…  my 40 wpc 1961 MC240 w 6L6 has some of the highest bandwidth transformer Mac ever made and it weighs a beefy 50 lbs , my Roger Modjeski ( RIP ) RM.9 puts out 100 wpc at 62#, so I remain highly doubtful of the Crimson claim…

Jim

call me Deacon Blues

Another explanation is they subcontracted the writing of the spec sheet to Raven ????

Jim

Keeping me laughing and having fun tomic601!  Thank you!

Frank Malik (owner of Carver Corp) said he will provide responses to some of the questions raised in the forums about the amp. And so we wait

I hope he follows through and clearly explains the method for how the amplifier rated a 75 watt output. People deserve the facts.

Charles

I agree Charles1Dad!

@fmalitz , we are waiting with bated breath!

Hello everyone,

In our three labs, we all get around 75 watts @ 1% or less, 90 @ 2%, etc. 

From Jordon Gerber, ex-partner, degreed physicist and co-founder: The units are about 75 to 90 watts depending on the measurement technique. . I kept a record of every unit. The power drops at low frequencies but given the way they slam with Kef Blade IIs, the innovative towers from SpeakerLab, and Wilsons is impressive.

 From Edward Suver (our WA tech support, QC and manufacturing supervisor (we have production and QC supervisors in CA as well): That's a crazy review.  The amps actually put out 90w or so at 1k into 8ohms, one channel, with .6% distortion. Every one if them made on my watch was tested and confirmed to work. Maybe 2 or 3 in 100 put out maybe 80 to 85w at that distortion, don't know why though. They put out clean 90W down to 80Hz, and distort more as it goes down, due to the lack of steel in the output transformers. When Bob initially tested it, the crazy thing is that nobody minded it. Reviews confirm that. The frequency response is flat, it just gets distorted at lower frequencies, probably leading to "punchy" bass. And Bob argues that most have subwoofers and won't be using them below 80. For the output impedance, Bob wanted 1.7 ohm, and they usually measured 1.5 to 1.6. Never 2.5 or some BS.

From Speakerlab owner: "We've solidified our booth plan and will be premiering our Super SevenT-c's (the symmetrical tower version of our Super Sevens) powered by Bob Carver Crimson 350 monoblocks, and our Point2's powered by the new Bob Carver 275 Stereo amp. Source will be a Wolf Audio server run through a Mytek Brooklyn DAC, all wired with Kimber Kable Ascent and Base cables. Come see us next week at RMAF, room 2018!"

From Joe Parvey, owner, Wolf Audio Systems: "We almost always partner with Frank at shows. Their 350s and 275s outperform anything close in price. We sell them at our retail location.".

From Ken Kessler (the dean of British reviewers): "Wonderful; bought one for myself and I'm not selling it."

From Geoff Poor of Glenn Poor's AV--the largest BAT dealer in the world and the largest Wilson dealer in the Midwest. Geoff has consulted and worked with some of the most respected names in audio - Niro Nakamichi, Yamaha, MRC, Sony, & more - and in 1992, he was one of the founders of Dunlavy Audio Labs. In the spring of 1995, he left Dunlavy to become a partner at Balanced Audio Technology - a company he helped launch at the 1995 CES.: "

"Since we began showing his ALS (Amazing Line Source) loudspeaker system and his incredible 350 watt all-tube Raven mono-block amplifiers, the interest in Bob and his products has exploded. Both the ALS system ($18,500 with powered subwoofer) and the Raven mono-blocks ($9500/pair) represent incredible values - especially since they're built here in the United States. Another factor in their great value is the fact they are virtually bullet proof! It's so cool to be able to sell a high power, all tube system that is totally reliable.  To this date, we have experienced 100% reliability, and, based on Bob's design, the tube life expectancy is so long that the tubes and the mono-blocks are actually warrantied for 15 years!    

What if Bob could make a less powerful, and even more affordable, stereo version of the mono's?  Well, guess what?  He has, and we now have his new Crimson 275 playing in the same room as the Raven mono-blocks.  

The Crimson 275 is beautiful - looking and sounding - and is selling for only $2,750!  Using the same Tung-Sol KT-120 power tubes as the Raven mono's,  the same tube-saving "DC Restorer" circuit (that prolongs tube life by decades), the 75 watt/channel Crimson 275 is a genuine breath of fresh air in a world where most American-made electronics are simply too expensive for most of us.  The new stereo Crimson 275 is warrantied (tubes and all) for 5 years! It seems too good to be true, but it's not.  The Bob Carver Crimson 275 is a great amp!  And that's the truth!"

I'm hoping Bob will reply but he's pretty disappointed that no one from the blog called to discuss this. First time I've seen him angry. They seem to be $600 carver 37-watt Carverfest kits made by Jordon. He made 65 kits but we never manufactured them for sale to the public.

Remember we guarantee it will sound better than what you have or you get a full refund (subject to dealer policies on time frame, etc) and we've never had one returned. We've also never been able to keep up with demand. We may need a second warehouse! I'm meeting with Bob to discuss this on Thursday (two days from now).

Frank Malitz VP/Co-Founder

The Bob Carver Co.

847-668-4519