No one will tear it apart. It will be measured to see if it meets advertised specs. Those who like the amp why wouldn't you still like it? Still interesting to see how it does on the bench.
Peeking inside a Carver Crimson 275 Tube Amplifier
So, I just had to pop the hood on the Carver Crimson 275 tube amplifier. I was so curious as to how this little guy weighs so little and sounds so lovely.
Does the sound quality of this amp bear a relationship to the fact that there’s not too much going on in the unit? There are very few caps--from what this humble hobbyist can tell--in the signal chain. And, none of these caps are even what many would consider decent quality--i.e. they aren’t WIMA level, just generic. This amplifier beat out a PrimaLuna Dialogue HP (in my room/to my ears...much love for what PrimaLuna does). When I explored the innards of the PrimaLuna, it was cramped, busy and had so much going on--a way more complicated design.
Is it possible that Bob Carver, who many regard as a wily electronics expert, is able to truly tweak the sound by adding a resistor here or there, etc.? Surely all designers are doing this, but is he just really adroit at this? I wonder this because while some parts quality is very good to excellent, I was shocked to see the Suntan caps. They might be cheaper than some of the Dale resistors in the unit. I should note that Carver reportedly designed this amp and others similar with Tim de Paravicini--no slouch indeed!
I have described the sound of this amp as delicious. It’s that musical and good. But, as our esteemed member jjss [ @jjss ] pointed out in his review, he wondered if the sound quality could be improved further still. He detected a tiny amount of sheen here and there [I cannot recall his exact words.] even though he loved it like I do.
I may extract the two .22uF caps that look to be dealing with signal related to the 12at7 gain tubes and do a quick listening test.
- The layout is simple and clean looking. Unlike the larger monoblocks (that cost $10k), this model uses a PCB.
- The DC restorer circuit is nicely off to one side and out of the way. It doesn’t look all that complicated but I’m no electrical engineer. Why don’t more designers use this feature? It allows the power tubes to idle around 9.75w. Amazingly efficient.
- The amp has very good planned out ventilation and spacing. No parts are on top of each other.
- Most of the parts quality is good. There’s a host of Dale resistors, what look like Takmans, nice RCA jacks, heavy teflon hookup wire, and so on.
- Some of the parts quality is questionable. There’s some cheap Suntan (Hong Kong mfr.) film caps coupled to the power tubes and some no name caps linked to the gain signal tubes. I was not happy to see those, but I very much understand building stuff to a price point.
Does the sound quality of this amp bear a relationship to the fact that there’s not too much going on in the unit? There are very few caps--from what this humble hobbyist can tell--in the signal chain. And, none of these caps are even what many would consider decent quality--i.e. they aren’t WIMA level, just generic. This amplifier beat out a PrimaLuna Dialogue HP (in my room/to my ears...much love for what PrimaLuna does). When I explored the innards of the PrimaLuna, it was cramped, busy and had so much going on--a way more complicated design.
Is it possible that Bob Carver, who many regard as a wily electronics expert, is able to truly tweak the sound by adding a resistor here or there, etc.? Surely all designers are doing this, but is he just really adroit at this? I wonder this because while some parts quality is very good to excellent, I was shocked to see the Suntan caps. They might be cheaper than some of the Dale resistors in the unit. I should note that Carver reportedly designed this amp and others similar with Tim de Paravicini--no slouch indeed!
I have described the sound of this amp as delicious. It’s that musical and good. But, as our esteemed member jjss [ @jjss ] pointed out in his review, he wondered if the sound quality could be improved further still. He detected a tiny amount of sheen here and there [I cannot recall his exact words.] even though he loved it like I do.
I may extract the two .22uF caps that look to be dealing with signal related to the 12at7 gain tubes and do a quick listening test.
- ...
- 234 posts total
Please note: this post is not related to testing but improving the amp. Bob's response on the Carver forum identified R53 and R26 as doing the following: "Note that one end of the resistor is connected to amplifier ground, the other to the negative binding post. Now just imagine what would happen if you connected the some test equipment to the negative binding post that turned out to be grounded to the amplifier ground. That resistor is important. It senses current going to the speakers and provides a signal into the feedback network that, among other things, reduces distortion in the amp." As these are important resistors, I may swap them out and put in .1 ohm 5w Mills resistors, which are $4 each. Why? Because I'm nuts. :) |
I’m bothered by the view point that we should just gloss over the big covers over little 15w trannies or it making less than 25% of what its advertised to make because a few can still enjoy it with super efficient speakers in little rooms. So their false advertising and sneaky use of big fake covers should excuse its non performance for those who may buy this amp and have it totally not work for them because of the misrepresented specs.
What about the guy in a 30 x 40 room with 3 ohm speakers rated at 84 sensitivity? Think he feels this amp is “sweet sounding”? There is just no excuse for it.
I have no doubt that it isn’t a wonderful 15 or 17 watt amp.. thats not the issue. The issue is All the other people who spend their hard earned cash only to receive something thats a lie and not help them or worse harm their current equipment.
Maybe Bob can remarket it as the Crimson -120 since its missing 120 watts? or how about the Crimson 2-60. I suppose the Crimson 215 or 217 could work. |
Who is glossing over anything? Responses on this thread have been virtually unanimous in condemning the misrepresentation of amplifier output power? Even those who own/like the amplifier have been openly critical. Charles |
+1 Charles1dad. @funky54 , you are correct in that misrepresentations are unacceptable. If someone is buying a 75w push pull tube amp for 84dB speakers with nominal impedance of 3 ohms I doubt they would ever look at this thing. But the Company did market it as going into 4 ohms at 75w. I'm just not sure how this thing could test out near 75w with that 15w Edcor OPT in mine from MusicDirect. I have my doubts. But Bob has pulled rabbits out of the hat before and it indeed sounds good. I have only 3 audiophile friends within an hour's drive. They all have sensitive speakers. Does anyone with less efficient speakers live in Chicagoland and want to have me bring the amp by for a listening test? You could bring speakers here too, yet that's more work than lifting this light amp. :) I'd be curious to hear it with more demanding loads.
|
- 234 posts total